AudioTrackList: addtrack event - Web APIs
the addtrack event is fired when a track is added to an audiotracklist.
... bubbles no cancelable no interface trackevent event handler property onaddtrack examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.audiotracks.addeventlistener('addtrack', (event) => { console.log(`audio track: ${event.track.label} added`); }); using the onaddtrack event handler property: const videoelement = document.queryselector('video'); videoelement.audiotracks.onaddtrack = (event) => { console.log(`audio track: ${event.track.label} added`); }; specifications specification status html living standardthe definition of 'addtrack' in that specification.

AudioTrackList: removetrack event - Web APIs
the removetrack event is fired when a track is removed from an audiotracklist.
... bubbles no cancelable no interface trackevent event handler property onremovetrack examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.audiotracks.addeventlistener('removetrack', (event) => { console.log(`audio track: ${event.track.label} removed`); }); using the onremovetrack event handler property: const videoelement = document.queryselector('video'); videoelement.audiotracks.onremovetrack = (event) => { console.log(`audio track: ${event.track.label} removed`); }; specifications specification status html living standardthe definition of 'removetrack' in that specification.

TextTrackList: addtrack event - Web APIs
the addtrack event is fired when a track is added to a texttracklist.
... bubbles no cancelable no interface trackevent event handler property onaddtrack examples using addeventlistener(): const mediaelement = document.queryselector('video, audio'); mediaelement.texttracks.addeventlistener('addtrack', (event) => { console.log(`text track: ${event.track.label} added`); }); using the onaddtrack event handler property: const mediaelement = document.queryselector('video, audio'); mediaelement.texttracks.onaddtrack = (event) => { console.log(`text track: ${event.track.label} added`); }; specifications specification status html living standardthe definition of 'addtrack' in that specification.

TextTrackList: removeTrack event - Web APIs
the removetrack event is fired when a track is removed from a texttracklist.
... bubbles no cancelable no interface trackevent event handler property onremovetrack examples using addeventlistener(): const mediaelement = document.queryselector('video, audio'); mediaelement.texttracks.addeventlistener('removetrack', (event) => { console.log(`text track: ${event.track.label} removed`); }); using the onremovetrack event handler property: const mediaelement = document.queryselector('video, audio'); mediaelement.texttracks.onremovetrack = (event) => { console.log(`text track: ${event.track.label} removed`); }; specifications specification status html living standardthe definition of 'removetrack' in that specification.

TrackDefaultList.TrackDefaultList() - Web APIs
the trackdefaultlist() constructor of the trackdefaultlist interface constructs and returns a new trackdefaultlist object.
... syntax var trackdefaultlist = new trackdefaultlist(trackdefaults); parameters trackdefaults a sequence (array) of trackdefault objects.

VideoTrackList: addtrack event - Web APIs
the addtrack event is fired when a track is added to a videotracklist.
... bubbles no cancelable no interface trackevent event handler property onaddtrack examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.videotracks.addeventlistener('addtrack', (event) => { console.log(`video track: ${event.track.label} added`); }); using the onaddtrack event handler property: const videoelement = document.queryselector('video'); videoelement.videotracks.onaddtrack = (event) => { console.log(`video track: ${event.track.label} added`); }; specifications specification status html living standardthe definition of 'addtrack' in that specification.

VideoTrackList: removetrack event - Web APIs
the removetrack event is fired when a track is removed from a videotracklist.
... bubbles no cancelable no interface trackevent event handler property onremovetrack examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.videotracks.addeventlistener('removetrack', (event) => { console.log(`video track: ${event.track.label} removed`); }); using the onremovetrack event handler property: const videoelement = document.queryselector('video'); videoelement.videotracks.onremovetrack = (event) => { console.log(`video track: ${event.track.label} removed`); }; specifications specification status html living standardthe definition of 'removetrack' in that specification.

Storage access policy: Block cookies from trackers
firefox includes a new storage access policy that blocks cookies and other site data from third-party tracking resources.
...this policy protects against cross-site tracking while minimizing the site breakage associated with traditional cookie blocking.
...firefox nightly may also contain experimental features that we don't yet plan to ship to release users; experimental features will not be included in this documentation, but may nevertheless impact the functionality of domains classified as trackers.
...And 55 more matches

RTCPeerConnection.addTrack() - Web APIs
the rtcpeerconnection method addtrack() adds a new media track to the set of tracks which will be transmitted to the other peer.
... note: adding a track to a connection triggers renegotiation by firing a negotiationneeded event.
... syntax rtpsender = rtcpeerconnection.addtrack(track, stream...); parameters track a mediastreamtrack object representing the media track to add to the peer connection.
...And 29 more matches

MediaStreamTrack - Web APIs
the mediastreamtrack interface represents a single media track within a stream; typically, these are audio or video tracks, but other track types may exist as well.
... properties in addition to the properties listed below, mediastreamtrack has constrainable properties which can be set using applyconstraints() and accessed using getconstraints() and getsettings().
... mediastreamtrack.contenthint a string that may be used by the web application to provide a hint as to what type of content the track contains to guide how it should be treated by api consumers.
...And 27 more matches

TextTrack.mode - Web APIs
the texttrack interface's mode property is a string specifying and controlling the text track's mode: disabled, hidden, or showing.
... syntax var mode = texttrack.mode; texttrack.mode = "disabled" | "hidden" | "showing"; value a domstring which indicates the track's current mode.
... the text track mode is one of the values listed below, under text track mode constants.
...And 21 more matches

MediaTrackSettings - Web APIs
the mediatracksettings dictionary is used to return the current values configured for each of a mediastreamtrack's settings.
... these values will adhere as closely as possible to any constraints previously described using a mediatrackconstraints object and set using applyconstraints(), and will adhere to the default constraints for any properties whose constraints haven't been changed, or whose customized constraints couldn't be matched.
...for example, because rtp doesn't provide some of these values during negotiation of a webrtc connection, a track associated with a rtcpeerconnection will not include certain values, such as facingmode or groupid.
...And 20 more matches

AudioTrack - Web APIs
the audiotrack interface represents a single audio track from one of the html media elements, <audio> or <video>.
... the most common use for accessing an audiotrack object is to toggle its enabled property in order to mute and unmute the track.
... properties enabled a boolean value which controls whether or not the audio track's sound is enabled.
...And 18 more matches

HTMLTrackElement - Web APIs
the htmltrackelement interface represents an html <track> element within the dom.
... this element can be used as a child of either <audio> or <video> to specify a text track containing information such as closed captions or subtitles.
...aco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">htmlelement</text></a><polyline points="491,25 501,20 501,30 491,25" stroke="#d4dde4" fill="none"/><line x1="501" y1="25" x2="509" y2="25" stroke="#d4dde4"/><line x1="509" y1="25" x2="509" y2="90" stroke="#d4dde4"/><line x1="509" y1="90" x2="492" y2="90" stroke="#d4dde4"/><a xlink:href="/docs/web/api/htmltrackelement" target="_top"><rect x="331" y="65" width="160" height="50" fill="#f4f7f8" stroke="#d4dde4" stroke-width="2px" /><text x="411" y="94" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">htmltrackelement</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} properties inherits p...
...And 18 more matches

AudioTrackList - Web APIs
the audiotracklist interface is used to represent a list of the audio tracks contained within a given html media element, with each track represented by a separate audiotrack object in the list.
... retrieve an instance of this object with htmlmediaelement.audiotracks.
... the individual tracks can be accessed using array syntax.
...And 17 more matches

VideoTrackList - Web APIs
the videotracklist interface is used to represent a list of the video tracks contained within a <video> element, with each track represented by a separate videotrack object in the list.
... retrieve an instance of this object with htmlmediaelement.videotracks.
... the individual tracks can be accessed using array syntax or functions such as foreach() for example.
...And 17 more matches

RTCRtpSender.replaceTrack() - Web APIs
the rtcrtpsender method replacetrack() replaces the track currently being used as the sender's source with a new mediastreamtrack.
... the new track must be of the same media kind (audio, video, etc) and switching the track should not require negotiation.
... among the use cases for replacetrack() is the common need to switch between the rear- and front-facing cameras on a phone.
...And 16 more matches

RTCTrackEvent - Web APIs
the webrtc api interface rtctrackevent represents the track event, which is sent when a new mediastreamtrack is added to an rtcrtpreceiver which is part of the rtcpeerconnection.
... the target is the rtcpeerconnection object to which the track is being added.
... this event is sent by the webrtc layer to the web site or application, so you will not typically need to instantiate an rtctrackevent yourself.
...And 16 more matches

TextTrack - Web APIs
the texttrack interface—part of the api for handling webvtt (text tracks on media presentations)—describes and controls the text track associated with a particular <track> element.
... texttrack.activecues read only a texttrackcuelist object listing the currently active set of text track cues.
... track cues are active if the current playback position of the media is between the cues' start and end times.
...And 15 more matches

TextTrackList - Web APIs
the texttracklist interface is used to represent a list of the text tracks defined by the <track> element, with each track represented by a separate texttrack object in the list.
... retrieve an instance of this object with htmlmediaelement.texttracks.
... the individual tracks can be accessed using array syntax or functions such as foreach() for example.
...And 15 more matches

VideoTrack - Web APIs
the videotrack interface represents a single video track from a <video> element.
... the most common use for accessing a videotrack object is to toggle its selected property in order to make it the active video track for its <video> element.
... properties selected a boolean value which controls whether or not the video track is active.
...And 14 more matches

AudioTrack.kind - Web APIs
the kind property contains a string indicating the category of audio contained in the audiotrack.
... the kind can be used to determine the scenarios in which specific tracks should be enabled or disabled.
... see audio track kind strings for a list of the kinds available for audio tracks.
...And 12 more matches

HTMLMedia​Element​.textTracks - Web APIs
the read-only texttracks property on htmlmediaelement objects returns a texttracklist object listing all of the texttrack objects representing the media element's text tracks, in the same order as in the list of text tracks.
... you can detect when tracks are added to and removed from an <audio> or <video> element using the addtrack and removetrack events.
...instead, they're sent to the track list object of the htmlmediaelement that corresponds to the type of track that was added to the element the returned list is live; that is, as tracks are added to and removed from the media element, the list's contents change dynamically.
...And 12 more matches

Tracking Protection
what is tracking protection?
... firefox desktop and firefox for android include built-in tracking protection.
... in private browsing windows (tabs, in firefox for android), firefox will block content loaded from domains that track users across sites.
...And 11 more matches

VideoTrack.kind - Web APIs
the kind property contains a string indicating the category of video contained in the videotrack.
... the kind can be used to determine the scenarios in which specific tracks should be enabled or disabled.
... see video track kind strings for a list of the kinds available for video tracks.
...And 11 more matches

AudioTrack.enabled - Web APIs
the audiotrack property enabled specifies whether or not the described audio track is currently enabled for use.
... if the track is disabled by setting enabled to false, the track is muted and does not produce audio.
... syntax isaudioenabled = audiotrack.enabled; audiotrack.enabled = true | false; value the enabled property is a boolean whose value is true if the track is enabled; enabled tracks produce audio while the media is playing.
...And 10 more matches

MediaStreamTrack.enabled - Web APIs
the enabled property on the mediastreamtrack interface is a boolean value which is true if the track is allowed to render the source stream or false if it is not.
... this can be used to intentionally mute a track.
... when enabled, a track's data is output from the source to the destination; otherwise, empty frames are output.
...And 10 more matches

MediaTrackConstraints - Web APIs
the mediatrackconstraints dictionary is used to describe a set of capabilities and the value or values each can take on.
... a constraints dictionary is passed into applyconstraints() to allow a script to establish a set of exact (required) values or ranges and/or preferred values or ranges of values for the track, and the most recently-requested set of custom constraints can be retrieved by calling getconstraints().
...for example, because rtp doesn't provide some of these values during negotiation of a webrtc connection, a track associated with a rtcpeerconnection will not include certain values, such as facingmode or groupid.
...And 10 more matches

TrackEvent - Web APIs
the trackevent interface, which is part of the html dom specification, is used for events which represent changes to a set of available tracks on an html media element; these events are addtrack and removetrack.
... it's important not to confuse trackevent with the rtctrackevent interface, which is used for tracks which are part of an rtcpeerconnection.
... events based on trackevent are always sent to one of the media track list types: events involving video tracks are always sent to the videotracklist found in htmlmediaelement.videotracks events involving audio tracks are always sent to the audiotracklist specified in htmlmediaelement.audiotracks events affecting text tracks are sent to the texttracklist object indicated by htmlmediaelement.texttracks.
...And 10 more matches

Spaces and reference spaces: Spatial tracking in WebXR - Web APIs
to accomplish this, software needs the ability to not only track the locations, orientation, and movements of objects in the virtual world, but the user's location, orientation, and movement as well.
... but webxr goes beyond that by adding the ability to track the location, orientation, and motion of the input devices which generate data used to determine the position and movement of individual parts of the viewer's body (with appropriate equipment).
... in this guide, we'll explore how webxr uses spaces and, more specifically, reference spaces, to track the positions, orientations, and movements of objects and of the user's body in the virtual world.
...And 10 more matches

HTMLMediaElement.audioTracks - Web APIs
the read-only audiotracks property on htmlmediaelement objects returns an audiotracklist object listing all of the audiotrack objects representing the media element's audio tracks.
... the returned list is live; that is, as tracks are added to and removed from the media element, the list's contents change dynamically.
... once you have a reference to the list, you can monitor it for changes to detect when new audio tracks are added or existing ones removed.
...And 8 more matches

TextTrackCue - Web APIs
texttrackcue is an abstract class which is used as the basis for the various derived cue types, such as vttcue; you will instead work with those derived types.
... these cues represent a string of text that is presented for some duration of time during the performance of a texttrack.
... texttrackcue.track read only the texttrack that this cue belongs to, or null if it doesn't belong to any.
...And 8 more matches

MediaStreamTrack.stop() - Web APIs
the mediastreamtrack.stop() method stops the track.
... syntax track.stop() description calling stop() tells the user agent that the track's source—whatever that source may be, including files, network streams, or a local camera or microphone—is no longer needed by the mediastreamtrack.
... since multiple tracks may use the same source (for example, if two tabs are using the device's microphone), the source itself isn't necessarily immediately stopped.
...And 7 more matches

MediaStream.getAudioTracks() - Web APIs
the getaudiotracks() method of the mediastream interface returns a sequence that represents all the mediastreamtrack objects in this stream's track set where mediastreamtrack.kind is audio.
... syntax var mediastreamtracks = mediastream.getaudiotracks() parameters none.
... return value an array of mediastreamtrack objects, one for each audio track contained in the stream.
...And 6 more matches

MediaStream.getVideoTracks() - Web APIs
the getvideotracks() method of the mediastream interface returns a sequence of mediastreamtrack objects representing the video tracks in this stream.
... syntax var mediastreamtracks[] = mediastream.getvideotracks(); parameters none.
... return value an array of mediastreamtrack objects, one for each video track contained in the media stream.
...And 6 more matches

Web Video Text Tracks Format (WebVTT) - Web APIs
web video text tracks format (webvtt) is a format for displaying timed text tracks (such as subtitles or captions) using the <track> element.
...there is also a small api available to represent and manage these tracks and the data needed to perform the playback of the text at the correct times.
... we can then have one or more lines that start with a hyphen (-), each containing part of the text track to be shown.
...And 6 more matches

AudioTrack.label - Web APIs
the read-only audiotrack property label returns a string specifying the audio track's human-readable label, if one is available; otherwise, it returns an empty string.
... syntax var audiotracklabel = audiotrack.label; value a domstring specifying the track's human-readable label, if one is available in the track metadata.
... for example, a track whose kind is "commentary" might have a label such as "commentary with director mark markmarkimark and star donna donnalidon".
...And 5 more matches

AudioTrackList.length - Web APIs
the read-only audiotracklist property length returns the number of entries in the audiotracklist, each of which is an audiotrack representing one audio track in the media element.
... a value of 0 indicates that there are no audio tracks in the media.
... syntax var trackcount = audiotracklist.length; value a number indicating how many audio tracks are included in the audiotracklist.
...And 5 more matches

HTMLMediaElement.videoTracks - Web APIs
the read-only videotracks property on htmlmediaelement objects returns a videotracklist object listing all of the videotrack objects representing the media element's video tracks.
... the returned list is live; that is, as tracks are added to and removed from the media element, the list's contents change dynamically.
... once you have a reference to the list, you can monitor it for changes to detect when new video tracks are added or existing ones removed.
...And 5 more matches

MediaStream.onaddtrack - Web APIs
the mediastream.onaddtrack property is an eventhandler which specifies a function to be called when the addtrack event occurs on a mediastream instance.
... this happens when a new track of any kind is added to the media stream.
... this event is fired when the browser adds a track to the stream (such as when a rtcpeerconnection is renegotiated or a stream being captured using htmlmediaelement.capturestream() gets a new set of tracks because the media element being captured loaded a new source.
...And 5 more matches

MediaStream.onremovetrack - Web APIs
the mediastream.onremovetrack property is an eventhandler which specifies a function to be called when the removetrack event occurs on a mediastream instance.
... this happens when a track of any kind is removed from the media stream.
... this event is fired when the browser removes a track from the stream (such as when a rtcpeerconnection is renegotiated or a stream being captured using htmlmediaelement.capturestream() gets a new set of tracks because the media element being captured loaded a new source.
...And 5 more matches

MediaStreamTrack: mute event - Web APIs
the mute event is sent to a mediastreamtrack when the track's source is temporarily unable to provide media data.
... when the track is once again able to produce media output, an unmute event is sent.
... during the time between the mute event and the unmute event, the value of the track's muted property is true.
...And 5 more matches

MediaStreamTrackAudioSourceNode() - Web APIs
the web audio api's mediastreamtrackaudiosourcenode() constructor creates and returns a new mediastreamtrackaudiosourcenode object whose audio is taken from the mediastreamtrack specified in the given options object.
... another way to create a mediastreamtrackaudiosourcenode is to call theaudiocontext.createmediastreamtracksource() method, specifying the mediastreamtrack from which you want to obtain audio.
... syntax audiotracknode = new mediastreamtrackaudiosourcenode(context, options); parameters context an audiocontext representing the audio context you want the node to be associated with.
...And 5 more matches

MediaTrackSettings.deviceId - Web APIs
the mediatracksettings dictionary's deviceid property is a domstring which uniquely identifies the source for the corresponding mediastreamtrack for the origin corresponding to the browsing session.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.deviceid property you provided when calling either getusermedia().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.deviceid as returned by a call to mediadevices.getsupportedconstraints().
...And 5 more matches

RTCTrackEvent() - Web APIs
the rtctrackevent() constructor creates and returns a new rtctrackevent object, configured to describe the track which has been added to the rtcpeerconnection.
... in general, you won't need to use this constructor, as rtctrackevent objects are created by webrtc and delivered to your rtcpeerconnector's ontrack event handler as appropriate.
... syntax trackevent = new rtctrackevent(eventinfo); parameters eventinfo an object based on the rtctrackeventinit dictionary, providing information about the track which has been added to the rtcpeerconnection.
...And 5 more matches

TrackDefault - Web APIs
the trackdefault interface provides a sourcebuffer with kind, label, and language information for tracks that do not contain this information in the initialization segments of a media chunk.
... a trackdefault object is provided to a sourcebuffer object by setting its sourcebuffer.trackdefaults property.
... constructor trackdefault() constructs and returns a new trackdefault object.
...And 5 more matches

AudioTrack.language - Web APIs
the read-only audiotrack property language returns a string identifying the language used in the audio track.
... for tracks that include multiple languages (such as a movie in english in which a few lines are spoken in other languages), this should be the video's primary language.
... syntax var audiotracklanguage = audiotrack.language; value a domstring specifying the bcp 47 (rfc 5646) format language tag of the primary language used in the audio track, or an empty string ("") if the language is not specified or known, or if the track doesn't contain speech.
...And 4 more matches

AudioTrackList.onchange - Web APIs
the audiotracklist property onchange is an event handler which is called when the change event occurs, indicating that one or more of the audiotracks in the audiotracklist have been enabled or disabled.
...to determine the new state of media's tracks, you'll have to look at their audiotrack.enabled flags.
... syntax audiotracklist.onchange = eventhandler; value set onchange to a function that should be called whenever tracks are enabled or disabled on the media element.
...And 4 more matches

MediaStreamTrack.muted - Web APIs
the muted read-only property of the mediastreamtrack interface returns a boolean value indicating whether or not the track is currently unable to provide media output.
... to implement a way for users to mute and unmute a track, use the enabled property.
... when a track is disabled by setting enabled to false, it generates only empty frames (audio frames in which every sample is 0, or video frames in which every pixel is black).
...And 4 more matches

MediaStreamTrackAudioSourceNode - Web APIs
the mediastreamtrackaudiosourcenode interface is a type of audionode which represents a source of audio data taken from a specific mediastreamtrack obtained through the webrtc or media capture and streams apis.
... a mediastreamtrackaudiosourcenode has no inputs and exactly one output, and is created using the audiocontext.createmediastreamtracksource() method.
... this interface is similar to mediastreamaudiosourcenode, except it lets you specifically state the track to use, rather than assuming the first audio track on a stream.
...And 4 more matches

MediaStreamTrackEvent() - Web APIs
the mediastreamtrackevent() constructor returns a newly created mediastreamtrackevent object, which represents an event announcing that a mediastreamtrack has been added to or removed from a mediastream.
... syntax var trackevent = new mediastreamtrackevent(type, {track: amediastreamtrack}); parameters the mediastreamtrackevent() constructor also inherits arguments from event().
... type a domstring representing the name of the type of the mediastreamtrackevent.
...And 4 more matches

MediaTrackConstraints.cursor - Web APIs
the mediatrackconstraints dictionary's cursor property is a constraindomstring describing the requested or mandatory constraints placed upon the value of the cursor constrainable property, which is used to specify whether or not the cursor should be included in the captured video.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.cursor as returned by a call to mediadevices.getsupportedconstraints().
... syntax var constraintsobject = { cursor: constraint }; constraintsobject.cursor = constraint; value a constraindomstring which specifies whether or not the mouse cursor should be rendered into the video track in the mediastream returned by the call to getdisplaymedia().
...And 4 more matches

MediaTrackSettings.displaySurface - Web APIs
the mediatracksettings dictionary's displaysurface property indicates the type of display surface being captured.
... syntax displaysurface = mediatracksettings.displaysurface; value the value of displaysurface is a string that comes from the displaycapturesurfacetype enumerated type, and is one of the following: application the stream's video track contains all of the windows belonging to the application chosen by the user.
... the windows are aggragated into a single video track, with any empty space filled with a backdrop; that backdrop is selected by the user agent.
...And 4 more matches

MediaTrackSettings.groupId - Web APIs
the mediatracksettings dictionary's groupid property is a browsing-session unique domstring which identifies the group of devices which includes the source for the mediastreamtrack.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.groupid property you provided when calling either getusermedia().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.groupid as returned by a call to mediadevices.getsupportedconstraints().
...And 4 more matches

RTCPeerConnection.ontrack - Web APIs
the rtcpeerconnection property ontrack is an eventhandler which specifies a function to be called when the track event occurs, indicating that a track has been added to the rtcpeerconnection.
... the function receives as input the event object, of type rtctrackevent; this event is sent when a new incoming mediastreamtrack has been created and associated with an rtcrtpreceiver object which has been added to the set of receivers on connection.
... syntax rtcpeerconnection.ontrack = eventhandler; value set ontrack to be a function you provide that accepts as input a rtctrackevent object describing the new track and how it's being used.
...And 4 more matches

RTCPeerConnection: track event - Web APIs
the track event is sent to the ontrack event handler on rtcpeerconnections after a new track has been added to an rtcrtpreceiver which is part of the connection.
... bubbles yes cancelable no interface rtctrackevent event handler property ontrack by the time this event is delivered, the new track has been fully added to the peer connection.
... see track event types in rtctrackevent for details.
...And 4 more matches

TextTrackList.length - Web APIs
the read-only texttracklist property length returns the number of entries in the texttracklist, each of which is a texttrack representing one track in the media element.
... a value of 0 indicates that there are no text tracks in the media.
... syntax var trackcount = texttracklist.length; value a number indicating how many text tracks are included in the texttracklist.
...And 4 more matches

VideoTrack.label - Web APIs
the read-only videotrack property label returns a string specifying the video track's human-readable label, if one is available; otherwise, it returns an empty string.
... syntax var videotracklabel = videotrack.label; value a domstring specifying the track's human-readable label, if one is available in the track metadata.
... for example, a track whose kind is "sign" might have a label such as "a sign-language interpretation.".
...And 4 more matches

VideoTrackList.length - Web APIs
the read-only videotracklist property length returns the number of entries in the videotracklist, each of which is a videotrack representing one video track in the media element.
... a value of 0 indicates that there are no video tracks in the media.
... syntax var trackcount = videotracklist.length; value a number indicating how many video tracks are included in the videotracklist.
...And 4 more matches

Grid Tracks - MDN Web Docs Glossary: Definitions of Web-related terms
a grid track is the space between two grid lines.
...tracks are also created in the implicit grid by positioning a grid item outside of the tracks created in the explicit grid.
... the image below shows the first row track on a grid.
...And 3 more matches

AudioContext.createMediaStreamTrackSource() - Web APIs
the createmediastreamtracksource() method of the audiocontext interface creates and returns a mediastreamtrackaudiosourcenode which represents an audio source whose data comes from the specified mediastreamtrack.
... this differs from createmediastreamsource(), which creates a mediastreamaudiosourcenode whose audio comes from the audio track in a specified mediastream whose id is first, lexicographically (alphabetically).
... syntax var audioctx = new audiocontext(); var track = audioctx.createmediastreamtracksource(track); parameters track the mediastreamtrack to use as the source of all audio data for the new node.
...And 3 more matches

AudioTrack.id - Web APIs
the id property contains a string which uniquely identifies the track represented by the audiotrack.
... this id can be used with the audiotracklist.gettrackbyid() method to locate a specific track within the media associated with a media element.
... the track id can also be used as the fragment of a url that loads the specific track (if the media supports media fragments).
...And 3 more matches

CanvasCaptureMediaStreamTrack - Web APIs
the canvascapturemediastreamtrack interface represents the video track contained in a mediastream being generated from a <canvas> following a call to htmlcanvaselement.capturestream().
... properties this interface inherits the properties of its parent, mediastreamtrack.
... canvascapturemediastreamtrack.canvas read only returns the htmlcanvaselement object whose surface is captured in real-time.
...And 3 more matches

HTMLTrackElement: cuechange event - Web APIs
the cuechange event fires when a texttrack has changed the currently displaying cues.
... the event is fired at both the texttrack and at the htmltrackelement in which it's being presented, if any.
... bubbles no cancelable no interface event event handler oncuechange examples on the texttrack you can set up a listener for the cuechange event on a texttrack using the addeventlistener() method: track.addeventlistener('cuechange', function () { let cues = track.activecues; // array of current cues }); or you can just set the oncuechange event handler property: track.oncuechange = function () { let cues = track.activecues; // array of current cues } on the track element the underlying texttrack, indicated by the track property, receives a cuechange event every time the currently-presented cue is changed.
...And 3 more matches

MediaStream.getTrackById() - Web APIs
the mediastream.gettrackbyid() method returns a mediastreamtrack object representing the track with the specified id string.
... if there is no track with the specified id, this method returns null.
... syntax var track = mediastream.gettrackbyid(id); parameters id a domstring which identifies the track to be returned.
...And 3 more matches

MediaStreamTrack: unmute event - Web APIs
the unmute event is sent to a mediastreamtrack when the track's source is once again able to provide media data after a period of not being able to do so.
... bubbles no cancelable no interface event event handler property onunmute note: the condition that most people think of as "muted" (that is, a user-controllable way to silence a track) is actually managed using the mediastreamtrack.enabled property, for which there are no events.
... examples in this example, event handlers are established for the mute and unmute events in order to detect when the media is not flowing from the source for the mediastreamtrack stored in the variable musictrack.
...And 3 more matches

MediaStreamTrackEvent - Web APIs
the mediastreamtrackevent interface represents events which indicate that a mediastream has had tracks added to or removed from the stream through calls to media stream api methods.
..."50" fill="#fff" stroke="#d4dde4" stroke-width="2px" /><text x="38.5" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">event</text></a><polyline points="76,25 86,20 86,30 76,25" stroke="#d4dde4" fill="none"/><line x1="86" y1="25" x2="116" y2="25" stroke="#d4dde4"/><a xlink:href="/docs/web/api/mediastreamtrackevent" target="_top"><rect x="116" y="1" width="210" height="50" fill="#f4f7f8" stroke="#d4dde4" stroke-width="2px" /><text x="221" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">mediastreamtrackevent</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} the events based on ...
...this interface are addtrack and removetrack properties also inherits properties from its parent interface, event.
...And 3 more matches

MediaTrackConstraints.deviceId - Web APIs
the mediatrackconstraints dictionary's deviceid property is a constraindomstring describing the requested or mandatory constraints placed upon the value of the deviceid constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.deviceid as returned by a call to mediadevices.getsupportedconstraints().
... because rtp doesn't include this information, tracks associated with a webrtc rtcpeerconnection will never include this property.
...And 3 more matches

MediaTrackSettings.echoCancellation - Web APIs
the mediatracksettings dictionary's echocancellation property is a boolean value whose value indicates whether or not echo cancellation is enabled on an audio track.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.echocancellation property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
...for example, it might apply a filter that negates the sound being produced on the speakers from being included in the input track generated from the microphone.
...And 3 more matches

TextTrack: cuechange event - Web APIs
the cuechange event fires when a texttrack has changed the currently displaying cues.
... the event is fired at both the texttrack and at the htmltrackelement in which it's being presented, if any.
... bubbles no cancelable no interface event event handler property globaleventhandlers.oncuechange examples on the texttrack you can set up a listener for the cuechange event on a texttrack using the addeventlistener() method: track.addeventlistener('cuechange', function () { let cues = track.activecues; // array of current cues }); or you can just set the oncuechange event handler property: track.oncuechange = function () { let cues = track.activecues; // array of current cues } on the track element the underlying texttrack, indicated by the track property, receives a cuechange event every time the currently-presented cue is changed.
...And 3 more matches

getTrackById() - Web APIs
the texttracklist method gettrackbyid() returns the first texttrack object from the track list whose id matches the specified string.
... this lets you find a specified track if you know its id string.
... syntax var thetrack = texttracklist.gettrackbyid(id); paramters id a domstring indicating the id of the track to locate within the track list.
...And 3 more matches

TrackEvent() - Web APIs
the trackevent() constructor creates and returns a new trackevent object describing an event which occurred on a list of tracks (audiotracklist, videotracklist, or texttracklist).
... syntax trackevent = new trackevent(type, eventinfo); parameters type the type of track event which is described by the object: "addtrack" or "removetrack".
... eventinfo optional an optional dictionary providing additional information configuring the new event; it can contain the following fields in any combination: track optional the track to which the event refers; this is null by default, but should be set to a videotrack, audiotrack, or texttrack as appropriate given the type of track.
...And 3 more matches

getTrackById - Web APIs
the videotracklist method gettrackbyid() returns the first videotrack object from the track list whose id matches the specified string.
... this lets you find a specified track if you know its id string.
... syntax var thetrack = videotracklist.gettrackbyid(id); paramters id a domstring indicating the id of the track to locate within the track list.
...And 3 more matches

VideoTrackList.onchange - Web APIs
the videotracklist property onchange is an event handler which is called when the change event occurs, indicating that a videotrack in the videotracklist has been made active.
...to determine the new state of media's tracks, you'll have to look at their videotrack.selected flags.
... syntax videotracklist.onchange = eventhandler; value set onchange to a function that should be called whenever a track is made active.
...And 3 more matches

::-ms-track - Archive of obsolete content
the ::-ms-track css pseudo-element is a microsoft extension that represents the track of a slider control.
... applying the color property within the ::-ms-track selector affects the tick marks inside the track area.
... it is possible to use the ::-ms-ticks-after, ::-ms-ticks-before, and ::-ms-track pseudo-elements together.
...And 2 more matches

MediaStream.addTrack() - Web APIs
the mediastream.addtrack() method adds a new track to the stream.
... the track is specified as a parameter of type mediastreamtrack.
... if the specified track is already in the stream's track set, this method has no effect.
...And 2 more matches

MediaStream.getTracks() - Web APIs
the gettracks() method of the mediastream interface returns a sequence that represents all the mediastreamtrack objects in this stream's track set, regardless of mediastreamtrack.kind.
... syntax var mediastreamtracks = mediastream.gettracks() parameters none.
... return value an array of mediastreamtrack objects.
...And 2 more matches

MediaStreamTrack.applyConstraints() - Web APIs
the applyconstraints() method of the mediastreamtrack interface applies a set of constraints to the track; these constraints let the web site or app establish ideal values and acceptable ranges of values for the constrainable properties of the track, such as frame rate, dimensions, echo cancelation, and so forth.
... syntax const appliedpromise = track.applyconstraints([constraints]) parameters constraints optional a mediatrackconstraints object listing the constraints to apply to the track's constrainable properties; any existing constraints are replaced with the new values specified, and any constrainable properties not included are restored to their default constraints.
...the object may contain an advanced property containing an array of additional mediatrackconstrants objects, which are treated as exact requires.
...And 2 more matches

MediaStreamTrack.kind - Web APIs
the mediastreamtrack.kind read-only property returns a domstring set to "audio" if the track is an audio track and to "video", if it is a video track.
... it doesn't change if the track is deassociated from its source.
... syntax const type = track.kind value the possible values are a domstring with on of the following values: "audio": the track is an audio track.
...And 2 more matches

MediaStreamTrack.onended - Web APIs
the mediastreamtrack.onended event handler is used to specify a function which serves as an eventhandler to be called when the ended event occurs on the track.
... this event occurs when the track will no longer provide data to the stream for any reason, including the end of the media input being reached, the user revoking needed permissions, the source device being removed, or the remote peer ending a connection.
... syntax mediastreamtrack.onended = function; value a function to serve as an eventhandler for the ended event.
...And 2 more matches

MediaStreamTrack.onunmute - Web APIs
mediastreamtrack's onunmute event handler is called when the unmute event is received.
... such an event is sent when the track is again able to send data.
... when the onunmute event handler is called, the track's muted flag is false.
...And 2 more matches

MediaTrackConstraints.displaySurface - Web APIs
the mediatrackconstraints dictionary's displaysurface property is a constraindomstring describing the requested or mandatory constraints placed upon the value of the displaysurface constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.displaysurface as returned by a call to mediadevices.getsupportedconstraints().
... usage notes you can check the setting selected by the user agent after the display media has been created by getdisplaymedia() by calling getsettings() on the display media's video mediastreamtrack, then checking the value of the returned mediatracksettings object's displaysurface object.
...And 2 more matches

MediaTrackConstraints.groupId - Web APIs
the mediatrackconstraints dictionary's groupid property is a constraindomstring describing the requested or mandatory constraints placed upon the value of the groupid constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.groupid as returned by a call to mediadevices.getsupportedconstraints().
... however, the value of the groupid is determined by the source of the track's content, and there's no particular format mandated by the specification (although some kind of guid is recommended).
...And 2 more matches

MediaTrackConstraints.logicalSurface - Web APIs
the mediatrackconstraints dictionary's logicalsurface property is a constraindomstring describing the requested or mandatory constraints placed upon the value of the logicalsurface constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.logicalsurface as returned by a call to mediadevices.getsupportedconstraints().
... usage notes you can check the setting selected by the user agent after the display media has been created by getdisplaymedia() by calling getsettings() on the display media's video mediastreamtrack, then checking the value of the returned mediatracksettings object's logicalsurface object.
...And 2 more matches

MediaTrackSettings.aspectRatio - Web APIs
the mediatracksettings dictionary's aspectratio property is a double-precision floating-point number indicating the aspect ratio of the mediastreamtrack as currently configured.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.aspectratio property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.aspectratio as returned by a call to mediadevices.getsupportedconstraints().
...And 2 more matches

MediaTrackSettings.facingMode - Web APIs
the mediatracksettings dictionary's facingmode property is a domstring indicating the direction in which the camera producing the video track represented by the mediastreamtrack is currently facing.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.facingmode property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.facingmode as returned by a call to mediadevices.getsupportedconstraints().
...And 2 more matches

MediaTrackSettings.latency - Web APIs
the mediatracksettings dictionary's latency property is a double-precision floating-point number indicating the estimated latency (specified in seconds) of the mediastreamtrack as currently configured.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.latency property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.latency as returned by a call to mediadevices.getsupportedconstraints().
...And 2 more matches

MediaTrackSettings.sampleSize - Web APIs
the mediatracksettings dictionary's samplesize property is an integer indicating the linear sample size (in bits per sample) the mediastreamtrack is currently configured for.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.samplesize property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.samplesize as returned by a call to mediadevices.getsupportedconstraints().
...And 2 more matches

MediaTrackSupportedConstraints.frameRate - Web APIs
the mediatracksupportedconstraints dictionary's framerate property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the framerate constraint.
... the framerate constraint can be used to establish acceptable upper and lower bounds on the video frame rate for a new video track, or to specify an exact frame rate that must be provided for the request to succeed.
... checking the value of this property lets you determine if the user agent allows constraining the video track configuration by frame rate.
...And 2 more matches

RTCPeerConnection.removeTrack() - Web APIs
the rtcpeerconnection.removetrack() method tells the local end of the connection to stop sending media from the specified track, without actually removing the corresponding rtcrtpsender from the list of senders as reported by rtcpeerconnection.getsenders().
... if the track is already stopped, or is not in the connection's senders list, this method has no effect.
... syntax pc.removetrack(sender); parameters mediatrack a rtcrtpsender specifying the sender to remove from the connection.
...And 2 more matches

RTCTrackEvent.transceiver - Web APIs
the webrtc api interface rtctrackevent's read-only transceiver property indicates the rtcrtptransceiver affiliated with the event's track.
... the transceiver pairs the track's receiver with an rtcrtpsender.
... syntax var rtptransceiver = trackevent.transceiver; value the rtcrtptransceiver which pairs the receiver with a sender and other properties which establish a single bidirectional srtp stream for use by the track associated with the rtctrackevent.
...And 2 more matches

RTCTrackEventInit.transceiver - Web APIs
the rtctrackeventinit dictionary's transceiver property specifies the rtcrtptransceiver associated with the track event.
... the transceiver pairs the track's receiver with an rtcrtpsender to allow bidirectional communication.
... syntax var trackeventinit = { receiver: rtpreceiver, track: mediastreamtrack, streams: [videostream], transceiver: rtptransceiver }; var rtptransceiver = trackeventinit.transceiver; value the rtcrtptransceiver which pairs the receiver with a sender and other properties which establish a single bidirectional srtp stream for use by the track associated with the rtctrackevent.
...And 2 more matches

RTCTrackEventInit - Web APIs
the webrtc api's rtctrackeventinit dictionary is used to provide information describing an rtctrackevent when instantiating a new track event using new rtctrackevent().
... properties rtctrackeventinit inherits properties from the eventinit dictionary, and also includes the following properties: receiver the rtcrtpreceiver which is being used to receive the track's media.
... streams optional an array of mediastream objects representing each of the streams that comprise the event's corresponding track.
...And 2 more matches

TrackDefaultList - Web APIs
the trackdefaultlist interface represents a simple container list for multiple trackdefault objects.
... the trackdefaultlist associated with a particular sourcebuffer can be retrieved using the sourcebuffer.trackdefaults property.
... constructor trackdefaultlist() constructs and returns a new trackdefaultlist object.
...And 2 more matches

VideoTrack.id - Web APIs
the id property contains a string which uniquely identifies the track represented by the videotrack.
... this id can be used with the videotracklist.gettrackbyid() method to locate a specific track within the media associated with a media element.
... the track id can also be used as the fragment of a url that loads the specific track (if the media supports media fragments).
...And 2 more matches

Videotrack.language - Web APIs
the read-only videotrack property language returns a string identifying the language used in the video track.
... for tracks that include multiple languages (such as a movie in english in which a few lines are spoken in other languages), this should be the video's primary language.
... syntax var videotracklanguage = videotrack.language; value a domstring specifying the bcp 47 (rfc 5646) format language tag of the primary language used in the video track, or an empty string ("") if the language is not specified or known, or if the track doesn't contain speech.
...And 2 more matches

HTMLTrackElement.src - Web APIs
the htmltrackelement.src property reflects the value of the <track> element's src attribute, which indicates the url of the text track's data.
... syntax var texttrackurl = htmltrackelement.src; value a domstring object containing the url of the text track data.
... example // coming soon specifications specification status comment html living standardthe definition of 'htmltrackelement.src' in that specification.
... living standard no change from html5 html5the definition of 'htmltrackelement.src' in that specification.

MediaStreamTrack: ended event - Web APIs
the ended event of the mediastreamtrack interface is fired when playback or streaming has stopped because the end of the media was reached or because no further data is available.
... bubbles no cancelable no interface event event handler property mediastreamtrack.onended usage notes ended events fire when the media stream track's source permanently stops sending data on the stream.
... examples this example sets up an event handler for the ended event, which changes an on-screen icon to indicate that the track is no longer active.
... track.addeventlistener('ended', () => { let statuselem = document.getelementbyid("status-icon"); statuselem.src = "/images/stopped-icon.png"; }) you can also set up the event handler using the mediastreamtrack.onended property: track.onended = function() { let statuselem = document.getelementbyid("status-icon"); statuselem.src = "/images/stopped-icon.png"; } specifications specification status comment media capture and streamsthe definition of 'ended' in that specification.

MediaStreamTrack.getConstraints() - Web APIs
the getconstraints() method of the mediastreamtrack interface returns a mediatrackconstraints object containing the set of constraints most recently established for the track using a prior call to applyconstraints().
... syntax const constraints = track.getconstraints() return value a mediatrackconstraints object which indicates the constrainable properties the web site or app most recently set using applyconstraints().
... example this example obtains the current constraints for a track, sets the facingmode, and applies the updated constraints.
... function switchcameras(track, camera) { const constraints = track.getconstraints(); constraints.facingmode = camera; track.applyconstraints(constraints); } specifications specification status comment media capture and streamsthe definition of 'getconstraints()' in that specification.

MediaStreamTrack.onmute - Web APIs
mediastreamtrack's onmute event handler is called when the mute event is received.
... such an event is sent when the track is temporarily not able to send data.
... syntax track.onmute = mutehandler; value a function to serve as an eventhandler for the mute event.
... mytrack.onmute = function(evt) { playstateicon.innerhtml = "&#1f507;"; }; specifications specification status comment media capture and streamsthe definition of 'mediastreamtrack.onmute' in that specification.

MediaStreamTrack.readyState - Web APIs
the mediastreamtrack.readystate read-only property returns an enumerated value giving the status of the track.
... syntax const state = track.readystate value it takes one of the following values: "live" which indicates that an input is connected and does its best-effort in providing real-time data.
... in that case, the output of data can be switched on or off using the mediastreamtrack.enabled property.
... specifications specification status comment media capture and streamsthe definition of 'mediastreamtrack.readystate' in that specification.

MediaStreamTrackAudioSourceOptions - Web APIs
the mediastreamtrackaudiosourceoptions dictionary is used when specifying options to the mediastreamtrackaudiosourcenode() constructor.
... it isn't needed when using the audiocontext.createmediastreamtracksource() method.
... properties mediastreamtrack the mediastreamtrack from which to take audio data for this node's output.
... specifications specification status comment web audio apithe definition of 'mediastreamtrackaudiosourceoptions' in that specification.

MediaTrackConstraints.facingMode - Web APIs
the mediatrackconstraints dictionary's facingmode property is a constraindomstring describing the requested or mandatory constraints placed upon the value of the facingmode constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.facingmode as returned by a call to mediadevices.getsupportedconstraints().
... because rtp doesn't include this information, tracks associated with a webrtc rtcpeerconnection will never include this property.
... syntax var constraintsobject = { facingmode: constraint }; constraintsobject.facingmode = constraint; value an object based on constraindomstring specifying one or more acceptable, ideal, and/or exact (mandatory) facing modes are acceptable for a video track.

MediaTrackConstraints.latency - Web APIs
the mediatrackconstraints dictionary's latency property is a constraindouble describing the requested or mandatory constraints placed upon the value of the latency constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.latency as returned by a call to mediadevices.getsupportedconstraints().
... because rtp doesn't include this information, tracks associated with a webrtc rtcpeerconnection will never include this property.
... syntax var constraintsobject = { latency: constraint }; constraintsobject.latency = constraint; value a constraindouble describing the acceptable or required value(s) for an audio track's latency, with values specified in seconds.

MediaTrackSettings.autoGainControl - Web APIs
the mediatracksettings dictionary's autogaincontrol property is a boolean value whose value indicates whether or not automatic gain control (agc) is enabled on an audio track.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.autogaincontrol property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.autogaincontrol as returned by a call to mediadevices.getsupportedconstraints().
... syntax var autogaincontrol = mediatracksettings.autogaincontrol; value a boolean value which is true if the track has automatic gain control enabled or false if agc is disabled.

MediaTrackSettings.channelCount - Web APIs
the mediatracksettings dictionary's channelcount property is an integer indicating how many audio channel the mediastreamtrack is currently configured to have.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.channelcount property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.channelcount as returned by a call to mediadevices.getsupportedconstraints().
... syntax var channelcount = mediatracksettings.channelcount; value an integer value indicating the number of audio channels on the track.

MediaTrackSettings.frameRate - Web APIs
the mediatracksettings dictionary's framerate property is a double-precision floating-point number indicating the frame rate, in frames per second, of the mediastreamtrack as currently configured.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.framerate property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.framerate as returned by a call to mediadevices.getsupportedconstraints().
... syntax var framerate = mediatracksettings.framerate; value a double-precision floating-point number indicating the current configuration of the track's frame rate, in frames per second.

MediaTrackSettings.height - Web APIs
the mediatracksettings dictionary's height property is an integer indicating the number of pixels tall mediastreamtrack is currently configured to be.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.height property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.height as returned by a call to mediadevices.getsupportedconstraints().
... syntax var height = mediatracksettings.height; value an integer value indicating the height, in pixels, of the video track as currently configured.

MediaTrackSettings.noiseSuppression - Web APIs
the mediatracksettings dictionary's noisesuppression property is a boolean value whose value indicates whether or not noise suppression technology is enabled on an audio track.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.noisesuppression property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.noisesuppression as returned by a call to mediadevices.getsupportedconstraints().
... syntax var noisesuppression = mediatracksettings.noisesuppression; value a boolean value which is true if the input track has noise suppression enabled or false if agc is disabled.

MediaTrackSettings.sampleRate - Web APIs
the mediatracksettings dictionary's samplerate property is an integer indicating how many audio samples per second the mediastreamtrack is currently configured for.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.samplerate property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.samplerate as returned by a call to mediadevices.getsupportedconstraints().
... syntax var samplerate = mediatracksettings.samplerate; value an integer value indicating how many samples each second of audio data includes.

MediaTrackSettings.volume - Web APIs
the mediatracksettings dictionary's volume property is a double-precision floating-point number indicating the volume of the mediastreamtrack as currently configured, as a value from 0.0 (silence) to 1.0 (maximum supported volume for the device).
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.volume property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.volume as returned by a call to mediadevices.getsupportedconstraints().
... syntax var volume = mediatracksettings.volume; value a double-precision floating-point number indicating the volume, from 0.0 to 1.0, of the audio track as currently configured.

MediaTrackSettings.width - Web APIs
the mediatracksettings dictionary's width property is an integer indicating the number of pixels wide mediastreamtrack is currently configured to be.
... this lets you determine what value was selected to comply with your specified constraints for this property's value as described in the mediatrackconstraints.width property you provided when calling either getusermedia() or mediastreamtrack.applyconstraints().
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.width as returned by a call to mediadevices.getsupportedconstraints().
... syntax var width = mediatracksettings.width; value an integer value indicating the width, in pixels, of the video track as currently configured.

MediaTrackSupportedConstraints - Web APIs
the mediatracksupportedconstraints dictionary establishes the list of constrainable properties recognized by the user agent or browser in its implementation of the mediastreamtrack object.
... an object conforming to mediatracksupportedconstraints is returned by mediadevices.getsupportedconstraints().
... an actual constraint set is described using an object based on the mediatrackconstraints dictionary.
... properties specific to shared screen tracks for tracks containing video sources from the user's screen contents, the following additional properties are may be included in addition to those available for video tracks.

RTCRtpReceiver.track - Web APIs
the track read-only property of the rtcrtpreceiver interface returns the mediastreamtrack associated with the current rtcrtpreceiver instance.
... syntax var mediastreamtrack = rtcrtpreceiver.track value a mediastreamtrack instance.
... specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'track' in that specification.
... desktopmobilechromeedgefirefoxinternet exploreroperasafariandroid webviewchrome for androidfirefox for androidopera for androidsafari on iossamsung internettrackchrome full support 59edge full support 12firefox full support yesie no support noopera full support 46safari full support yeswebv...

RTCRtpSender.track - Web APIs
the track read-only property of the rtcrtpsender interface returns the mediastreamtrack which is being handled by the rtcrtpsender.
... syntax var mediastreamtrack = rtcrtpsender.track value a mediastreamtrack object representing the media associated with the rtcrtpsender.
... if no track is associated with the sender, this value is null, in which case the sender transmits nothing.
... specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'track' in that specification.

RTCRtpStreamStats.trackId - Web APIs
the rtcrtpstreamstats dictionary's trackid property is a string which uniquely identifies the rtcmediastreamtrackstats object which contains the track statistics for the mediastreamtrack for which statistics are provided in this object.
... syntax var trackid = rtcrtpstreamstats.trackid; value a domstring which uniquely identifies the rtcmediastreamtrackstats object that provides statistics for the track for which statistics are being collected by this rtcstatsreport.
... note: this value is not the same as the value of mediastramtrack.id.
... specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcrtpstreamstats.trackid' in that specification.

TextTrackList.onchange - Web APIs
the texttracklist property onchange is an event handler which is called when the change event occurs, indicating that a change has occurred on a texttrack in the videotracklist.
... syntax texttracklist.onchange = eventhandler; example this snippet establishes a handler for the change event that looks at each of the tracks in the list, calling a function to update the state of a user interface control that indicates the current state of the track.
... var tracklist = document.queryselector("video, audio").texttracks; tracklist.onchange = function(event) { ....
... /* do something */ }; specifications specification status comment html living standardthe definition of 'texttracklist: onchange' in that specification.

VideoTrack.selected - Web APIs
the videotrack property selected controls whether or not a particular video track is active.
... syntax isvideoselected = videotrack.selected; videotrack.selected = true | false; value the selected property is a boolean whose value is true if the track is active.
... only a single video track can be active at any given time, so setting this property to true for one track while another track is active will make that other track inactive.
... specifications specification status comment html living standardthe definition of 'videotrack: selected' in that specification.

-ms-scrollbar-track-color - Archive of obsolete content
the -ms-scrollbar-track-color css property is a microsoft extension that specifies the color of the track element of a scrollbar.
... initial valuescrollbarapplies toall elementsinheritedyescomputed valueas specifiedanimation typediscrete syntax values <color> the color of the track element.
...)where <alpha-value> = <number> | <percentage><hue> = <number> | <angle> examples this example uses -ms-scrollbar-track-color, -ms-scrollbar-face-color, and -ms-scrollbar-arrow-color to create two <div> elements with different scroll bar color schemes.

Blocked: Storage access requests from trackers
message firefox: cookieblockedtracker=request to access cookies or storage on “x” was blocked because it came from a tracker and content blocking is enabled.
... a request to access cookies or storage was blocked because the browser identified it as coming from a tracker and content blocking is enabled.
... the permission can be changed or removed by: going to preferences > content blocking and either adding an exception with the manage exceptions… button choosing the custom content blocking and unchecking the tracker checkbox if the blocked resource doesn't need authentication, you can fix the warning message by adding a crossorigin="anonymous" attribute to the relevant element.

AudioTrack.sourceBuffer - Web APIs
the read-only audiotrack property sourcebuffer returns the sourcebuffer that created the track, or null if the track was not created by a sourcebuffer or the sourcebuffer has been removed from the mediasource.sourcebuffers attribute of its parent media source.
... syntax var sourcebuffer = audiotrack.sourcebuffer; value a sourcebuffer or null.
... specifications specification status comment media source extensionsthe definition of 'audiotrack: sourcebuffer' in that specification.

AudioTrackList: change event - Web APIs
the change event is fired when an audio track is enabled or disabled, for example by changing the track's enabled property.
... bubbles no cancelable no interface event event handler property onchange examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.audiotracks.addeventlistener('change', (event) => { console.log(`'${event.type}' event fired`); }); // changing the value of `enabled` will trigger the `change` event const toggletrackbutton = document.queryselector('.toggle-track'); toggletrackbutton.addeventlistener('click', () => { const track = videoelement.audiotracks[0]; track.enabled = !track.enabled; }); using the onchange event handler property: const videoelement = document.queryselector('video'); videoelement.audiotracks.onchange = (event) => { console.log(`'${event.type}' event fired`); ...
...}; // changing the value of `enabled` will trigger the `change` event const toggletrackbutton = document.queryselector('.toggle-track'); toggletrackbutton.addeventlistener('click', () => { const track = videoelement.audiotracks[0]; track.enabled = !track.enabled; }); specifications specification status html living standardthe definition of 'change' in that specification.

ImageCapture.track - Web APIs
the track read-only property of the imagecapture interface returns a reference to the mediastreamtrack passed to the imagecapture() constructor.
... syntax const mediastreamtrack = imagecaptureobj.track value a mediastreamtrack object.
... specifications specification status comment mediastream image capturethe definition of 'track' in that specification.

MediaStreamTrack.clone() - Web APIs
the clone() method of the mediastreamtrack interface creates a duplicate of the mediastreamtrack.
... this new mediastreamtrack object is identical except for its unique id.
... syntax const newtrack = track.clone() return value a new mediastreamtrack instance which is identical to the one clone() was called, except for its new unique id.

MediaStreamTrack.getCapabilities() - Web APIs
the getcapabilities() method of the mediastreamtrack interface returns a mediatrackcapabilities object which specifies the values or range of values which each constrainable property, based upon the platform and user agent.
... once you know what the browser's capabilities are, your script can use applyconstraints() to ask for the track to be configured to match ideal or acceptable settings.
... syntax const capabilities = track.getcapabilities() return value a mediatrackcapabilities object which specifies the value or range of values which are supported for each of the user agent's supported constrainable properties.

MediaStreamTrack.getSettings() - Web APIs
the getsettings() method of the mediastreamtrack interface returns a mediatracksettings object containing the current values of each of the constrainable properties for the current mediastreamtrack.
... syntax const settings = track.getsettings() returns a mediatracksettings object describing the current configuration of the track's constrainable properties.
...to instead fetch the most-recently established constraints for the track's properties, as specified by the site's code, use getconstraints().

MediaStreamTrack.label - Web APIs
the mediastreamtrack.label read-only property returns a domstring containing a user agent-assigned label that identifies the track source, as in "internal microphone".
...when the track is deassociated from its source, the label is not changed.
... syntax const label = track.label specifications specification status comment media capture and streamsthe definition of 'mediastreamtrack.label' in that specification.

MediaStreamTrack.onoverconstrained - Web APIs
the mediastreamtrack.onoverconstrained event handler is a property called when the overconstrained event is received.
... such an event is sent when the track is again able to send data.
... syntax track.onoverconstrained = function; values function is the name of a user-defined function, without the () suffix or any parameters, or an anonymous function declaration, such as function(event) {...}.

MediaStreamTrack.remote - Web APIs
the mediastreamtrack.remote read-only property allows javascript to know whether a webrtc mediastreamtrack is from a remote source or a local one.
... it returns a boolean with a value of true if the track is sourced remotely (that is, sourced by an rtcpeerconnection), or false if it is sourced locally.
... syntax var bool ​= track.remote; ...

MediaTrackConstraints.aspectRatio - Web APIs
the mediatrackconstraints dictionary's aspectratio property is a constraindouble describing the requested or mandatory constraints placed upon the value of the aspectratio constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.aspectratio as returned by a call to mediadevices.getsupportedconstraints().
... syntax var constraintsobject = { aspectratio: constraint }; constraintsobject.aspectratio = constraint; value a constraindouble describing the acceptable or required value(s) for a video track's aspect ratio.

MediaTrackConstraints.echoCancellation - Web APIs
the mediatrackconstraints dictionary's echocancellation property is a constrainboolean describing the requested or mandatory constraints placed upon the value of the echocancellation constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.echocancellation as returned by a call to mediadevices.getsupportedconstraints().
... because rtp doesn't include this information, tracks associated with a webrtc rtcpeerconnection will never include this property.

MediaTrackConstraints.frameRate - Web APIs
the mediatrackconstraints dictionary's framerate property is a constraindouble describing the requested or mandatory constraints placed upon the value of the framerate constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.framerate as returned by a call to mediadevices.getsupportedconstraints().
... syntax var constraintsobject = { framerate: constraint }; constraintsobject.framerate = constraint; value a constraindouble describing the acceptable or required value(s) for a video track's frame rate, in frames per second.

MediaTrackControls.volume - Web APIs
the mediatrackconstraints dictionary's volume property is a constraindouble describing the requested or mandatory constraints placed upon the value of the volume constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.volume as returned by a call to mediadevices.getsupportedconstraints().
... syntax var constraintsobject = { volume: constraint }; constraintsobject.volume = constraint; value a constraindouble describing the acceptable or required value(s) for an audio track's volume, on a linear scale where 0.0 means silence and 1.0 is the highest supported volume.

MediaTrackSettings.cursor - Web APIs
the mediatracksettings dictionary's cursor property indicates whether or not the cursor should be captured as part of the video track included in the mediastream returned by getdisplaymedia().
... syntax cursorsetting = mediatracksettings.cursor; value the value of cursor comes from the cursorcaptureconstraint enumerated string type, and may have one of the following values: always the mouse should always be visible in the video content of the {domxref("mediastream"), unless the mouse has moved outside the area of the content.
... specifications specification status comment screen capturethe definition of 'mediatracksettings.cursor' in that specification.

MediaTrackSettings.logicalSurface - Web APIs
the mediatracksettings dictionary's logicalsurface property indicates whether or not the display area being captured is a logical surface.
... syntax islogicalsurface = mediatracksettings.logicalsurface; value a boolean value which is true if the video track in the stream of captured video is taken from a logical display surface.
... specifications specification status comment screen capturethe definition of 'mediatracksettings.logicalsurface' in that specification.

MediaTrackSupportedConstraints.noiseSuppression - Web APIs
the mediatracksupportedconstraints dictionary's noisesuppression property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the noisesuppression constraint.
... the noisesuppression constraint indicates whether or not the browser offers the ability to automatically control the gain (volume) on media tracks; this obviously is contingent on whether or not the individual device supports automatic gain control as well.
... syntax noisesuppressionsupported = supportedconstraintsdictionary.noisesuppression; value this property is present in the dictionary (and its value is always true) if the user agent supports the noisesuppression constraint (and therefore supports noise suppression on audio tracks).

RTCInboundRtpStreamStats.trackId - Web APIs
the trackid property of the rtcinboundrtpstreamstats dictionary indicates the id of the rtcreceiveraudiotrackattachmentstats or rtcreceivervideotrackattachmentstats object representing the mediastreamtrack which is receiving the incoming media.
... syntax var trackstatsid = rtcinboundrtpstreamstats.trackid; value a domstring containing the id of the rtcreceiveraudiotrackattachmentstats or rtcreceivervideotrackattachmentstats object representing the track which is receiving the media from this rtp session.
... specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcinboundrtpstreamstats.trackid' in that specification.

RTCOutboundRtpStreamStats.trackId - Web APIs
the trackid property of the rtcoutboundrtpstreamstats dictionary indicates the id of the rtcsenderaudiotrackattachmentstats or rtcsendervideotrackattachmentstats object representing the mediastreamtrack which is being sent on this stream.
... syntax var trackstatsid = rtcoutboundrtpstreamstats.trackid; value a domstring containing the id of the rtcsenderaudiotrackattachmentstats or rtcsendervideotrackattachmentstats object representing the track which is the source of the media being sent on this stream.
... specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcoutboundrtpstreamstats.trackid' in that specification.

RTCTrackEvent.receiver - Web APIs
the read-only receiver property of the rtctrackevent interface indicates the rtcrtpreceiver which is used to receive data containing media for the track to which the event refers.
... syntax var rtpreceiver = trackevent.receiver; value the rtcrtptransceiver which pairs the receiver with a sender and other properties which establish a single bidirectional srtp stream for use by the track associated with the rtctrackevent.
... specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtctrackevent.receiver' in that specification.

RTCTrackEvent.streams - Web APIs
the webrtc api interface rtctrackevent's read-only streams property specifies an array of mediastream objects, one for each of the streams that comprise the track being added to the rtcpeerconnection.
... syntax var streams = trackevent.streams; value an array of mediastream objects, one for each stream that make up the new track.
... specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtctrackevent.streams' in that specification.

RTCTrackEventInit.receiver - Web APIs
the rtctrackeventinit dictionary's receiver property specifies the rtcrtpreceiver associated with the event.
... syntax var trackeventinit = { receiver: rtpreceiver, track: mediastreamtrack, streams: [videostream], transceiver: rtptransceiver }; var rtpreceiver = trackeventinit.receiver; value the rtcrtptransceiver which pairs the receiver with a sender and other properties which establish a single bidirectional srtp stream for use by the track associated with the rtctrackevent.
... specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtctrackeventinit.receiver' in that specification.

RTCTrackEventInit.streams - Web APIs
the rtctrackeventinit dictionary's optional streams property provides an array containing a mediastream object for each of the streams associated with the event's track.
... syntax var trackeventinit = { receiver: rtpreceiver, track: mediastreamtrack, streams: [videostream], transceiver: rtptransceiver }; var streamlist = trackeventinit.streams; value an array of mediastream objects, one for each stream which make up the track.
... specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtctrackeventinit.streams' in that specification.

SourceBuffer.audioTracks - Web APIs
the audiotracks read-only property of the sourcebuffer interface returns a list of the audio tracks currently contained inside the sourcebuffer.
... syntax var myaudiotracks = sourcebuffer.audiotracks; value an audiotracklist object.
... example tbd specifications specification status comment media source extensionsthe definition of 'audiotracks' in that specification.

SourceBuffer.textTracks - Web APIs
the texttracks read-only property of the sourcebuffer interface returns a list of the text tracks currently contained inside the sourcebuffer.
... syntax var mytexttracks = sourcebuffer.texttracks; value an texttracklist object.
... example tbd specifications specification status comment media source extensionsthe definition of 'texttracks' in that specification.

SourceBuffer.videoTracks - Web APIs
the videotracks read-only property of the sourcebuffer interface returns a list of the video tracks currently contained inside the sourcebuffer.
... syntax var myvideotracks = sourcebuffer.videotracks; value an videotracklist object.
... example tbd specifications specification status comment media source extensionsthe definition of 'videotracks' in that specification.

VideoTrack.sourceBuffer - Web APIs
the read-only videotrack property sourcebuffer returns the sourcebuffer that created the track, or null if the track was not created by a sourcebuffer or the sourcebuffer has been removed from the mediasource.sourcebuffers attribute of its parent media source.
... syntax var sourcebuffer = videotrack.sourcebuffer; value a sourcebuffer or null.
... specifications specification status comment media source extensionsthe definition of 'videotrack: sourcebuffer' in that specification.

VideoTrackList: change event - Web APIs
the change event is fired when a video track is made active or inactive, for example by changing the track's selected property.
... bubbles no cancelable no interface event event handler property onchange examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.videotracks.addeventlistener('change', (event) => { console.log(`'${event.type}' event fired`); }); // changing the value of `selected` will trigger the `change` event const toggletrackbutton = document.queryselector('.toggle-track'); toggletrackbutton.addeventlistener('click', () => { const track = videoelement.videotracks[0]; track.selected = !track.selected; }); using the onchange event handler property: const videoelement = document.queryselector('video'); videoelement.videotracks.onchange = (event) => { console.log(`'${event.type}' event fired`...
...); }; // changing the value of `selected` will trigger the `change` event const toggletrackbutton = document.queryselector('.toggle-track'); toggletrackbutton.addeventlistener('click', () => { const track = videoelement.videotracks[0]; track.selected = !track.selected; }); specifications specification status html living standardthe definition of 'change' in that specification.

VideoTrackList.selectedIndex - Web APIs
the read-only videotracklist property selectedindex returns the index of the currently selected track, if any, or -1 otherwise.
... syntax var index = videotracklist.selectedindex; value a number indicating the index of the currently selected track, if any, or -1 otherwise.
... specifications specification status comment html living standardthe definition of 'videotracklist: selectedindex' in that specification.

::-moz-range-track - CSS: Cascading Style Sheets
the ::-moz-range-track css pseudo-element is a mozilla extension that represents the track (i.e., groove) in which the indicator slides in an <input> of type="range".
... note: using ::-moz-range-track with anything but an <input type="range"> doesn't match anything and has no effect.
... syntax ::-moz-range-track examples html <input type="range" min="0" max="100" step="5" value="50"/> css input[type=range]::-moz-range-track { background-color: green; } result a progress bar using this style might look something like this: specifications not part of any standard.

Feature-Policy: xr-spatial-tracking - HTTP
the http feature-policy header xr-spatial-tracking directive controls whether the current document is allowed to use the webxr device api.
... this policy controls whether navigator.xr.requestsession() can return xrsession that requires spatial tracking and whether user agent can indicate support for sessions supporting spatial tracking via navigator.xr.issessionsupported() and devicechange event on navigator.xr object.
... syntax feature-policy: xr-spatial-tracking <allowlist>; <allowlist> an allowlist is a list of origins that takes one or more of the following values, separated by spaces: *: the feature will be allowed in this document, and all nested browsing contexts (iframes) regardless of their origin.

CanvasCaptureMediaStreamTrack.canvas - Web APIs
the canvascapturemediastreamtrack canvas read-only property returns the htmlcanvaselement from which frames are being captured.
... // obtain the canvas associated with the stream var canvas = stream.canvas; specifications specification status comment media capture from dom elementsthe definition of 'canvascapturemediastreamtrack.canvas' in that specification.

CanvasCaptureMediaStreamTrack.requestFrame() - Web APIs
the canvascapturemediastreamtrack method requestframe() requests that a frame be captured from the canvas and sent to the stream.
... example // find the canvas element to capture var canvaselt = document.getelementsbytagname("canvas")[0]; // get the stream var stream = canvaselt.capturestream(25); // 25 fps // send the current state of the canvas as a frame to the stream stream.getvideotracks()[0].requestframe(); specifications specification status comment media capture from dom elementsthe definition of 'canvascapturemediastream.requestframe()' in that specification.

MediaStream: addtrack event - Web APIs
the addtrack event is fired when a new mediastreamtrack object has been added to a mediastream.
... bubbles no cancelable no interface mediastreamtrackevent event handler property onaddtrack examples using addeventlistener(): let stream = new mediastream(); stream.addeventlistener('addtrack', (event) => { console.log(`new ${event.track.kind} track added`); }); using the onaddtrack event handler property: let stream = new mediastream(); stream.onaddtrack = (event) => { console.log(`new ${event.track.kind} track added`); }; specifications specification status media capture and streamsthe definition of 'addtrack' in that specification.

MediaStream: removetrack event - Web APIs
the removetrack event is fired when a new mediastreamtrack object has been removed from a mediastream.
... bubbles no cancelable no interface mediastreamtrackevent event handler property onremovetrack examples using addeventlistener(): let stream = new mediastream(); stream.addeventlistener('removetrack', (event) => { console.log(`${event.track.kind} track removed`); }); using the onremovetrack event handler property: let stream = new mediastream(); stream.onremovetrack = (event) => { console.log(`${event.track.kind} track removed`); }; specifications specification status media capture and streamsthe definition of 'removetrack' in that specification.

MediaStreamTrack.id - Web APIs
the mediastreamtrack.id read-only property returns a domstring containing a unique identifier (guid) for the track, which is generated by the user agent.
... syntax const id = track.id specifications specification status comment media capture and streamsthe definition of 'mediastreamtrack.id' in that specification.

MediaTrackConstraints.autoGainControl - Web APIs
the mediatrackconstraints dictionary's autogaincontrol property is a constrainboolean describing the requested or mandatory constraints placed upon the value of the autogaincontrol constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.autogaincontrol as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackConstraints.channelCount - Web APIs
the mediatrackconstraints dictionary's channelcount property is a constrainlong describing the requested or mandatory constraints placed upon the value of the channelcount constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.channelcount as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackConstraints.height - Web APIs
the mediatrackconstraints dictionary's height property is a constrainlong describing the requested or mandatory constraints placed upon the value of the height constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.height as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackConstraints.noiseSuppression - Web APIs
the mediatrackconstraints dictionary's noisesuppression property is a constrainboolean describing the requested or mandatory constraints placed upon the value of the noisesuppression constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.noisesuppression as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackConstraints.sampleRate - Web APIs
the mediatrackconstraints dictionary's samplerate property is a constrainlong describing the requested or mandatory constraints placed upon the value of the samplerate constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.samplerate as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackConstraints.sampleSize - Web APIs
the mediatrackconstraints dictionary's samplesize property is a constrainlong describing the requested or mandatory constraints placed upon the value of the samplesize constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.samplesize as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackConstraints.width - Web APIs
the mediatrackconstraints dictionary's width property is a constrainlong describing the requested or mandatory constraints placed upon the value of the width constrainable property.
... if needed, you can determine whether or not this constraint is supported by checking the value of mediatracksupportedconstraints.width as returned by a call to mediadevices.getsupportedconstraints().

MediaTrackSupportedConstraints.autoGainControl - Web APIs
the mediatracksupportedconstraints dictionary's autogaincontrol property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the autogaincontrol constraint.
... the autogaincontrol constraint indicates whether or not the browser offers the ability to automatically control the gain (volume) on media tracks; this obviously is contingent on whether or not the individual device supports automatic gain control as well; it's typically a feature provided by microphones.

MediaTrackSupportedConstraints.cursor - Web APIs
the mediatracksupportedconstraints dictionary's cursor property indicates whether or not the cursor constraint is supported by the user agent and the device on which the content is being used.
...urface: "browser" }, audio: false; }; if (supportedconstraints.cursor) { displaymediaoptions.video.cursor = "always"; } try { videoelem.srcobject = await navigator.mediadevices.getdisplaymedia(displaymediaoptions); } catch(err) { /* handle the error */ } } specifications specification status comment screen capturethe definition of 'mediatracksupportedconstraints.cursor' in that specification.

MediaTrackSupportedConstraints.displaySurface - Web APIs
the mediatracksupportedconstraints dictionary's displaysurface property indicates whether or not the displaysurface constraint is supported by the user agent and the device on which the content is being used.
... }, audio: false; }; if (supportedconstraints.displaysurface) { displaymediaoptions.video.displaysurface = "monitor"; } try { videoelem.srcobject = await navigator.mediadevices.getdisplaymedia(displaymediaoptions); } catch(err) { /* handle the error */ } } specifications specification status comment screen capturethe definition of 'mediatracksupportedconstraints.displaysurface' in that specification.

MediaTrackSupportedConstraints.logicalSurface - Web APIs
the mediatracksupportedconstraints dictionary's logicalsurface property indicates whether or not the logicalsurface constraint is supported by the user agent and the device on which the content is being used.
... }, audio: false; }; if (supportedconstraints.logicalsurface) { displaymediaoptions.video.logicalsurface = "monitor"; } try { videoelem.srcobject = await navigator.mediadevices.getdisplaymedia(displaymediaoptions); } catch(err) { /* handle the error */ } } specifications specification status comment screen capturethe definition of 'mediatracksupportedconstraints.logicalsurface' in that specification.

Navigator.doNotTrack - Web APIs
the navigator.donottrack property returns the user's do not track setting, which indicates whether the user is requesting web sites and advertisers to not track them.
... example console.log(navigator.donottrack); // prints "1" if dnt is enabled; "0" if the user opted-in for tracking; otherwise this is "unspecified" specifications specification status comment tracking preference expression (dnt)the definition of 'navigator.donottrack' in that specification.

SourceBuffer.trackDefaults - Web APIs
the trackdefaults property of the sourcebuffer interface specifies the default values to use if kind, label, and/or language information is not available in the initialization segment of the media to be appended to the sourcebuffer.
... syntax var mytrackdefaults = sourcebuffer.trackdefaults; sourcebuffer.trackdefaults = mytrackdefaultlist; value a trackdefaultlist object.

TextTrackList: change event - Web APIs
the change event is fired when a text track is made active or inactive, or a texttracklist is otherwise changed.
... bubbles no cancelable no interface event event handler property onchange examples using addeventlistener(): const mediaelement = document.queryselectorall('video, audio')[0]; mediaelement.texttracks.addeventlistener('change', (event) => { console.log(`'${event.type}' event fired`); }); using the onchange event handler property: const mediaelement = document.queryselector('video, audio'); mediaelement.texttracks.onchange = (event) => { console.log(`'${event.type}' event fired`); }; specifications specification status html living standardthe definition of 'change' in that specification.

TrackDefault.kinds - Web APIs
the kinds read-only property of the trackdefault interface returns default kinds for an associated sourcebuffer to use when an initialization segment does not contain label information for a new track.
... syntax var mykinds = trackdefault.kinds; value an array of domstrings.

TrackDefault.label - Web APIs
the label read-only property of the trackdefault interface returns the default label for an associated sourcebuffer to use when an initialization segment does not contain label information for a new track.
... syntax var mylabel = trackdefault.label; value a domstring.

TrackDefault.language - Web APIs
the language read-only property of the trackdefault interface returns a default language for an associated sourcebuffer to use when an initialization segment does not contain language information for a new track.
... syntax var mylanguage = trackdefault.language; value a domstring.

TrackDefault.type - Web APIs
the type read-only property of the trackdefault interface returns the type of track that this sourcebuffer's media segment data relates to (i.e.
... audio, video, or text track.) syntax var mytype = trackdefault.type; value a domstring — one of audio, video or text.

TrackDefaultList.length - Web APIs
the length read-only property of the trackdefaultlist interface returns the number of trackdefault objects in the list.
... syntax var mylistlength = trackdefaultlist.length; value an unsigned long number.

::-webkit-slider-runnable-track - CSS: Cascading Style Sheets
the ::-webkit-slider-runnable-track css pseudo-element represents the "track" (the groove in which the indicator slides) of an <input type="range">.
... syntax ::-webkit-slider-runnable-track specifications not part of any standard.

MediaTrackSupportedConstraints.aspectRatio - Web APIs
the mediatracksupportedconstraints dictionary's aspectratio property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the aspectratio constraint.

MediaTrackSupportedConstraints.channelCount - Web APIs
the mediatracksupportedconstraints dictionary's channelcount property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the channelcount constraint.

MediaTrackSupportedConstraints.deviceId - Web APIs
the mediatracksupportedconstraints dictionary's deviceid property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the deviceid constraint.

MediaTrackSupportedConstraints.echoCancellation - Web APIs
the mediatracksupportedconstraints dictionary's echocancellation property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the echocancellation constraint.

MediaTrackSupportedConstraints.facingMode - Web APIs
the mediatracksupportedconstraints dictionary's facingmode property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the facingmode constraint.

MediaTrackSupportedConstraints.groupId - Web APIs
the mediatracksupportedconstraints dictionary's groupid property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the groupid constraint.

MediaTrackSupportedConstraints.height - Web APIs
the mediatracksupportedconstraints dictionary's height property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the height constraint.

MediaTrackSupportedConstraints.latency - Web APIs
the mediatracksupportedconstraints dictionary's latency property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the latency constraint.

MediaTrackSupportedConstraints.sampleRate - Web APIs
the mediatracksupportedconstraints dictionary's samplerate property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the samplerate constraint.

MediaTrackSupportedConstraints.sampleSize - Web APIs
the mediatracksupportedconstraints dictionary's samplesize property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the samplesize constraint.

MediaTrackSupportedConstraints.volume - Web APIs
the mediatracksupportedconstraints dictionary's volume property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the volume constraint.

MediaTrackSupportedConstraints.width - Web APIs
the mediatracksupportedconstraints dictionary's width property is a read-only boolean value which is present (and set to true) in the object returned by mediadevices.getsupportedconstraints() if and only if the user agent supports the width constraint.

Index - Web APIs
129 audiocontext.createmediastreamsource() api, audio, audiocontext, audionode, media, mediastream, mediastreamtrack, method, reference, web, web audio, web audio api, createmediastreamsource for more details about media stream audio source nodes, check out the mediastreamaudiosourcenode reference page.
... 130 audiocontext.createmediastreamtracksource() api, audio, audiocontext, mediastreamtrack, mediastreamtrackaudiosource, method, node, reference, web audio api, createmediastreamtracksource, sound, source, track a mediastreamtrackaudiosourcenode object which acts as a source for audio data found in the specified audio track.
... 186 audiotrack audio, audiotrack, html, html dom, interface, media, reference, track the audiotrack interface represents a single audio track from one of the html media elements, <audio> or <video>.
...And 297 more matches

Capabilities, constraints, and settings - Web APIs
the constraint exerciser lets you experiment with the results of different constraint sets being applied to the audio and video tracks coming from the computer's a/v input devices (such as its webcam and microphone).
... overview the process works like this (using mediastreamtrack as an example): if needed, call mediadevices.getsupportedconstraints() to get the list of supported constraints, which tells you what constrainable properties the browser knows about.
... once the script knows whether the property or properties it wishes to use are supported, it can then check the capabilities of the api and its implementation by examining the object returned by the track's getcapabilities() method; this object lists each supported constraint and the values or range of values which are supported.
...And 46 more matches

Basic Concepts of grid layout - CSS: Cascading Style Sheets
css grid layout has the following features: fixed and flexible track sizes you can create a grid with fixed track sizes – using pixels for example.
... creation of additional tracks to hold content you can define an explicit grid with grid layout.
... if we want to start making this more grid-like we need to add column tracks.
...And 37 more matches

Using DTMF with WebRTC - Web APIs
sending dtmf on an rtcpeerconnection a given rtcpeerconnection can have multiple media tracks sent or received on it.
... when you wish to transmit dtmf signals, you first need to decide which track to send them on, since dtmf is sent as a series of out-of-band payloads on the rtcrtpsender responsible for transmitting that track's data to the other peer.
... once the track is selected, you can obtain from its rtcrtpsender the rtcdtmfsender object you'll use for sending dtmf.
...And 23 more matches

Audio for Web games - Game development
the htmlmediaelement interface comes with lots of properties to help determine whether a track is in a state to be playable.
... one way you can make your music soundtrack more dynamic is by splitting it up into component loops or tracks.
...once you have the various tracks that make up your piece you can bring tracks in and out as appropriate.
...And 18 more matches

Realizing common layouts using CSS Grid Layout - CSS: Cascading Style Sheets
i have not defined any column or row tracks but this layout dictates a single column, and rows will be created as needed for each of the items in the implicit grid.
...the header spans over two column tracks, as does the nav.
... in the third row track we have the sidebar alongside the content.
...And 18 more matches

JavaScript Client API - Archive of obsolete content
tracker entity that tracks changes to data.
... each engine has a corresponding tracker which listens for changes to data or events it is interested in.
...this involves writing types that extend the store, tracker, and record types as well.
...And 17 more matches

Grids - Learn web development
you can use any length unit, or percentages to create these column tracks.
... change your track listing to the following definition, creating three 1fr tracks.
... .container { display: grid; grid-template-columns: 1fr 1fr 1fr; } you should now see that you have flexible tracks.
...And 17 more matches

MediaStream - Web APIs
a stream consists of several tracks such as video or audio tracks.
... each track is specified as an instance of mediastreamtrack.you can obtain a mediastream object either by using the constructor or by calling mediadevices.getusermedia().
...you can create an empty stream, a stream which is based upon an existing stream, or a stream that contains a specified list of tracks (specified as an array of mediastreamtrack objects).
...And 17 more matches

Signaling and video calling - Web APIs
starting a call when the user clicks on a username they want to call, the invite() function is invoked as the event handler for that click event: var mediaconstraints = { audio: true, // we want an audio track video: true // ...and we want a video track }; function invite(evt) { if (mypeerconnection) { alert("you can't start a call because you already have one open!"); } else { var clickedusername = evt.target.textcontent; if (clickedusername === myusername) { alert("i'm afraid i can't let you talk to yourself.
... that would be weird."); return; } targetusername = clickedusername; createpeerconnection(); navigator.mediadevices.getusermedia(mediaconstraints) .then(function(localstream) { document.getelementbyid("local_video").srcobject = localstream; localstream.gettracks().foreach(track => mypeerconnection.addtrack(track, localstream)); }) .catch(handlegetusermediaerror); } } this begins with a basic sanity check: is the user already connected?
... we then iterate over the tracks in the stream, calling addtrack() to add each track to the rtcpeerconnection.
...And 17 more matches

grid-template-rows - CSS: Cascading Style Sheets
the grid-template-rows css property defines the line names and track sizing functions of the grid rows.
... syntax /* keyword value */ grid-template-rows: none; /* <track-list> values */ grid-template-rows: 100px 1fr; grid-template-rows: [linename] 100px; grid-template-rows: [linename1] 100px [linename2 linename3]; grid-template-rows: minmax(100px, 1fr); grid-template-rows: fit-content(40%); grid-template-rows: repeat(3, 200px); grid-template-rows: subgrid; /* <auto-track-list> values */ grid-template-rows: 200px repeat(auto-fill, 100px) 300px; grid-template-rows: minmax(100px, max-content) repeat(auto-fill, 200px) 20%; grid-template-rows: [linename1...
... repeat(auto-fit, [linename3 linename4] 300px) 100px; grid-template-rows: [linename1 linename2] 100px repeat(auto-fit, [linename1] 300px) [linename3]; /* global values */ grid-template-rows: inherit; grid-template-rows: initial; grid-template-rows: unset; this property may be specified as: either the keyword value none or a <track-list> value or an <auto-track-list> value.
...And 17 more matches

Video and audio content - Learn web development
they define a structure in which the audio and/or video tracks that make up the media are stored, along with metadata describing the media, what codecs are used to encode its channels, and so forth.
... a webm file containing a movie which has a main video track and one alternate angle track, plus audio for both english and spanish, in addition to audio for an english commentary track can be conceptualized as shown in the diagram below.
... also included are text tracks containing closed captions for the feature film, spanish subtitles for the film, and english captions for the commentary.
...And 16 more matches

grid-template-columns - CSS: Cascading Style Sheets
the grid-template-columns css property defines the line names and track sizing functions of the grid columns.
... syntax /* keyword value */ grid-template-columns: none; /* <track-list> values */ grid-template-columns: 100px 1fr; grid-template-columns: [linename] 100px; grid-template-columns: [linename1] 100px [linename2 linename3]; grid-template-columns: minmax(100px, 1fr); grid-template-columns: fit-content(40%); grid-template-columns: repeat(3, 200px); grid-template-columns: subgrid; /* <auto-track-list> values */ grid-template-columns: 200px repeat(auto-fill, 100px) 300px; grid-template-columns: minmax(100px, max-content) repeat(auto-fill, 200px) 20%; ...
...if the size of the grid container depends on the size of its tracks, then the percentage must be treated as auto.
...And 16 more matches

Adding captions and subtitles to HTML5 video - Developer guides
this article will take the same player and show how to add captions and subtitles to it, using the webvtt format and the <track> element.
... for this article we will refer to the text tracks displayed as subtitles, as their content is aimed at hearing people who have difficulty understanding the language of the film, rather than deaf or hard-of-hearing people.
... the <track> element html5 allows us to specify subtitles for a video using the <track> element.
...And 15 more matches

Subgrid - CSS: Cascading Style Sheets
these grids however are independent of the parent grid and of each other, meaning that they do not take their track sizing from the parent grid.
... if you set the value subgrid on grid-template-columns, grid-template-rows or both, instead of creating a new track listing the nested grid uses the tracks defined on the parent.
... for example, if you use grid-template-columns: subgrid and the nested grid spans three column tracks of the parent, the nested grid will have three column tracks of the same size as the parent grid.
...And 14 more matches

repeat() - CSS: Cascading Style Sheets
the repeat() css function represents a repeated fragment of the track list, allowing a large number of columns or rows that exhibit a recurring pattern to be written in a more compact form.
... /* <track-repeat> values */ repeat(4, 1fr) repeat(4, [col-start] 250px [col-end]) repeat(4, [col-start] 60% [col-end]) repeat(4, [col-start] 1fr [col-end]) repeat(4, [col-start] min-content [col-end]) repeat(4, [col-start] max-content [col-end]) repeat(4, [col-start] auto [col-end]) repeat(4, [col-start] minmax(100px, 1fr) [col-end]) repeat(4, [col-start] fit-content(200px) [col-end]) repeat(4, 10px [col-start] 30% [col-middle] auto [col-end]) repeat(4, [col-start] min-content [col-middle] max-content [col-end]) /* <auto-repeat> values */ repeat(auto-fill, 250px) repeat(auto-fit, 250px) repeat(auto-fill, [col-start] 250px [col-end]) repeat(auto-fit, [col-start] 250px [col-end]) repeat(auto-fil...
... <percentage> a non-negative percentage relative to the inline size of the grid container in column grid tracks, and the block size of the grid container in row grid tracks.
...And 14 more matches

Index - Archive of obsolete content
searches, lookups, package tracking, and even word definitions can all be retrieved from user-customized bookmarks.
...the extension will access tinderbox, mozilla.org's webtool for tracking source code status, to get the status of the code.
...for this we have to first create four icons, one for each tinderbox state (none, success, test failed, and busted), then create a set of css rules that displays the icon corresponding to the current tinderbox state: 398 tinderbox add-ons, extensions tinderbox is a web tool for tracking the status of the mozilla source code.
...And 11 more matches

RTCPeerConnection - Web APIs
such an event is sent when a mediastream is removed from this connection.onsignalingstatechangethe onsignalingstatechange event handler property of the rtcpeerconnection interface specifies a function to be called when the signalingstatechange event occurs on an rtcpeerconnection interface.ontrack the rtcpeerconnection property ontrack is an eventhandler which specifies a function to be called when the track event occurs, indicating that a track has been added to the rtcpeerconnection.methodsalso inherits methods from: eventtargetaddicecandidate()when a web site or app using rtcpeerconnection receives a new ice candidate from the remote peer over its signaling channel, it delivers the new...
...instead of using this obsolete method, you should instead use addtrack() once for each track you wish to send to the remote peer.addtrack()the rtcpeerconnection method addtrack() adds a new media track to the set of tracks which will be transmitted to the other peer.close() the rtcpeerconnection.close() method closes the current peer connection.createanswer() the createanswer() method on the rtcpeerconnection interface creates an sdp answer to an offer received from a remote peer during the offer/answer negotiation of a webrtc connection.
...each rtp receiver manages the reception and decoding of data for a mediastreamtrack on an rtcpeerconnectiongetsenders()the rtcpeerconnection method getsenders() returns an array of rtcrtpsender objects, each of which represents the rtp sender responsible for transmitting one track's data.getstats()the rtcpeerconnection method getstats() returns a promise which resolves with data providing statistics about either the overall connection or about the specified mediastreamtrack.gets...
...And 11 more matches

Inputs and input sources - Web APIs
this may involve the user simply tapping on a spot on the screen, tracking their eyes, or the use of a joystick or motion-sensing controller to move a cursor.
... motion-sensing controllers, which use accelerometers, magnetometers, and other sensors for motion tracking and targeting and may additionally include any number of buttons, joysticks, thumbpads, touchpads, force sensors, and so on to provide additional input sources for both targeting and selection.
... spatially-tracked articulated hands, such as haptic gloves can provide both targeting and squeeze actions, as well as selection if outfitted with buttons or other sources of selection actions.
...And 10 more matches

Using the Web Audio API - Web APIs
we'll briefly look at some concepts, then study a simple boombox example that allows us to load an audio track, play and pause it, and change its volume and stereo panning.
...if you simply want to control playback of an audio track, the <audio> media element provides a better, quicker solution than the web audio api.
...let's begin with a simple method — as we have a boombox, we most likely want to play a full song track.
...And 10 more matches

Relationship of grid layout to other layout methods - CSS: Cascading Style Sheets
this time we have three 1fr column tracks.
...it is possible to create tracks that respond to the size of the content, however, they will also change the entire track.
... <div class="box2">two</div> <div class="box3">three</div> </div> .wrapper { display: grid; grid-template-columns: repeat(3,1fr); align-items: end; grid-auto-rows: 200px; } .box1 { align-self: stretch; } .box2 { align-self: start; } the fr unit and flex-basis we have already seen how the fr unit works to assign a proportion of available space in the grid container to our grid tracks.
...And 10 more matches

<audio>: The Embed Audio element - HTML: Hypertext Markup Language
note: sites that automatically play audio (or videos with an audio track) can be an unpleasant experience for users, so should be avoided when possible.
... detecting addition and removal of tracks you can detect when tracks are added to and removed from an <audio> element using the addtrack and removetrack events.
...instead, they're sent to the track list object within the <audio> element's htmlmediaelement that corresponds to the type of track that was added to the element: htmlmediaelement.audiotracks an audiotracklist containing all of the media element's audio tracks.
...And 10 more matches

Geometry and reference spaces in WebXR - Web APIs
the article spatial tracking in webxr builds upon the information provided here to cover how the physical position and orientation of the user's head, as well as potentially other parts of their body such as the hands, are mapped into the digital world, as well as how the relative positions of both physical and virtual objects are tracked as they move around, so that the scene can be properly rendered and composited.
...each space has its own native origin, which is tracked by the xr device's tracking system.
... to be useful for spatial tracking and scene geometry, though, you need to be able to correlate the xr device's perceived position with the space's coordinate system.
...And 9 more matches

XRReferenceSpace - Web APIs
the webxr device api's xrreferencespace interface describes the coordinate system for a specific tracked entity or object within the virtual world using a specified tracking behavior.
... the tracking behavior is defined by the selected reference space type.
... it expands upon the base class, xrspace, by adding support for several different tracking behaviors as well as to request a new reference space which describes the offset transform between the tracked object and another location in the world.
...And 9 more matches

Implementing a Microsoft Active Accessibility (MSAA) Server - Accessibility
third party assistive technology, such as screen readers, screen magnifiers and voice input software, want to track what's happening inside mozilla.
...using this information, a screen reader will speak out loud important changes to the document or ui, and allow the user to track where they navigate.
...there's a very good chance they won't ask for more than the states marked [important]: state_unavailable [important] state_selected [important] state_focused [important] state_pressed state_checked [important] state_mixed state_readonly [important] state_hottracked state_default [important] state_expanded [important] state_collapsed [important] state_busy [important] state_floating state_marqueed state_animated state_invisible state_offscreen [important] state_sizeable state_moveable state_selfvoicing state_focusable [important] state_selectable [important] state_linked [important] state_trave...
...And 9 more matches

Auto-placement in CSS Grid Layout - CSS: Cascading Style Sheets
</div> <div>five</div> </div> .wrapper { display: grid; grid-template-columns: repeat(3, 1fr); grid-gap: 10px; grid-auto-rows: minmax(100px, auto); } you can also pass in a track listing, this will repeat.
... the following track listing will create an initial implicit row track as 100 pixels and a second as 200px.
...when it fills up a column it will move onto the next explicit column, or create a new column track in the implicit grid.
...And 9 more matches

grid-auto-columns - CSS: Cascading Style Sheets
the grid-auto-columns css property specifies the size of an implicitly-created grid column track or pattern of tracks.
... if a grid item is positioned into a column that is not explicitly sized by grid-template-columns, implicit grid tracks are created to hold it.
... grid-auto-columns: 33.3%; /* <flex> values */ grid-auto-columns: 0.5fr; grid-auto-columns: 3fr; /* minmax() values */ grid-auto-columns: minmax(100px, auto); grid-auto-columns: minmax(max-content, 2fr); grid-auto-columns: minmax(20%, 80vmax); /* fit-content() values */ grid-auto-columns: fit-content(400px); grid-auto-columns: fit-content(5cm); grid-auto-columns: fit-content(20%); /* multiple track-size values */ grid-auto-columns: min-content max-content auto; grid-auto-columns: 100px 150px 390px; grid-auto-columns: 10% 33.3%; grid-auto-columns: 0.5fr 3fr 1fr; grid-auto-columns: minmax(100px, auto) minmax(max-content, 2fr) minmax(20%, 80vmax); grid-auto-columns: 100px minmax(100px, auto) 10% 0.5fr fit-content(400px); /* global values */ grid-auto-columns: inherit; grid-auto-columns: initi...
...And 9 more matches

Tk - HTTP
the tk response header indicates the tracking status that applied to the corresponding request.
... (dynamic) tk: g (gateway or multiple parties) tk: n (not tracking) tk: t (tracking) tk: c (tracking with consent) tk: p (potential consent) tk: d (disregarding dnt) tk: u (updated) directives !
...the origin server is currently testing its communication of tracking status.
...And 9 more matches

Box alignment in CSS Grid Layout - CSS: Cascading Style Sheets
we are able to align the content inside grid areas, and the grid tracks themselves on these two axes.
...a a ."; } .item1 { grid-area: a; align-self: center; justify-self: center; } <div class="wrapper"> <div class="item1">item 1</div> </div> aligning the grid tracks on the block axis if you have a situation where your grid tracks use an area that is smaller than the grid container, then you can align the grid tracks themselves, inside that container.
... once again, this operates on the block and inline axes, with align-content aligning tracks on the block axis, and justify-content performing alignment on the inline axis.
...And 8 more matches

grid-auto-rows - CSS: Cascading Style Sheets
the grid-auto-rows css property specifies the size of an implicitly-created grid row track or pattern of tracks.
... if a grid item is positioned into a row that is not explicitly sized by grid-template-rows, implicit grid tracks are created to hold it.
...id-auto-rows: auto; /* <length> values */ grid-auto-rows: 100px; grid-auto-rows: 20cm; grid-auto-rows: 50vmax; /* <percentage> values */ grid-auto-rows: 10%; grid-auto-rows: 33.3%; /* <flex> values */ grid-auto-rows: 0.5fr; grid-auto-rows: 3fr; /* minmax() values */ grid-auto-rows: minmax(100px, auto); grid-auto-rows: minmax(max-content, 2fr); grid-auto-rows: minmax(20%, 80vmax); /* multiple track-size values */ grid-auto-rows: min-content max-content auto; grid-auto-rows: 100px 150px 390px; grid-auto-rows: 10% 33.3%; grid-auto-rows: 0.5fr 3fr 1fr; grid-auto-rows: minmax(100px, auto) minmax(max-content, 2fr) minmax(20%, 80vmax); grid-auto-rows: 100px minmax(100px, auto) 10% 0.5fr fit-content(400px); /* global values */ grid-auto-rows: inherit; grid-auto-rows: initial; grid-auto-rows: unse...
...And 8 more matches

<video>: The Video Embed element - HTML: Hypertext Markup Language
note: sites that automatically play audio (or videos with an audio track) can be an unpleasant experience for users, so should be avoided when possible.
... to show subtitles/captions along with your video, you can use some javascript along with the <track> element and the webvtt format.
... detecting track addition and removal you can detect when tracks are added to and removed from a <video> element using the addtrack and removetrack events.
...And 8 more matches

Index - MDN Web Docs Glossary: Definitions of Web-related terms
62 call stack call stack, codingscripting, glossary, javascript a call stack is a mechanism for an interpreter (like the javascript interpreter in a web browser) to keep track of its place in a script that calls multiple functions — what function is currently being run and what functions are called from within that function, etc.
... 183 grid column css, codingscripting a grid column is a vertical track in a css grid layout, and is the space between two vertical grid lines.
... 184 grid lines css grids grid lines are created when you define tracks in the explicit grid using css grid layout.
...And 7 more matches

Accessible multimedia - Learn web development
video text tracks to make video accessible for deaf, blind, or even other groups of users (such as those on low bandwidth, or who don't understand the language the video is recorded in), you need to include text tracks along with your video content.
... note: text tracks are also useful for potentially any user, not just those with disabilities.
...ht not want to disturb others if they are in a quiet place (like a library.) this is not a new concept — television services have had closed captioning available for quite a long time: whereas many countries offer english films with subtitles written in their own native languages, and different language subtitles are often available on dvds, for example there are different types of text track with different purposes.
...And 7 more matches

Ember interactivity: Events, classes and state - Learn web development
along the way, we'll look at using events in ember, creating component classes to contain javascript code to control interactive features, and setting up a service to keep track of the data state of our app.
... objective: to learn how to create component classes and use events to control interactivity, and keep track of app state using a service.
...for example, the @tracked decorator (see slightly later on) runs code it is applied to, but additionally tracks it and automatically updates the app when values change.
...And 7 more matches

DisplayMediaStreamConstraints.audio - Web APIs
the displaymediastreamconstraints dictionary's audio property is used to specify whether or not to request that the mediastream containing screen display contents also include an audio track.
... this value may simply be a boolean, where true indicates that an audio track should be included an false (the default) indicates that no audio should be included in the stream.
... more precise control over the audio data may be exercised by instead providing a mediatrackconstraints object, which is used to process the audio prior to adding it to the stream.
...And 7 more matches

MediaStreamAudioSourceNode - Web APIs
this media could be from a microphone (through getusermedia()) or from a remote peer on a webrtc call (using the rtcpeerconnection's audio tracks).
... the mediastreamaudiosourcenode takes the audio from the first mediastreamtrack whose kind attribute's value is audio.
... see track ordering for more information about the order of tracks.
...And 7 more matches

MediaStream Image Capture API - Web APIs
do this by calling mediastream.getvideotracks().
... this returns an array of mediastreamtrack objects.
... the code below assumes that the first item in the mediastreamtrack array is the one to use.
...And 7 more matches

NavigationPreloadManager - Web APIs
androidfirefox for androidopera for androidsafari on iossamsung internetnavigationpreloadmanager experimentalchrome full support 62edge full support 18firefox no support nonotes no support nonotes notes implementation tracked in bug 1290958ie ?
... webview android full support 62chrome android full support 62firefox android no support nonotes no support nonotes notes implementation tracked in bug 1290958opera android full support 46safari ios ?
... samsung internet android full support 8.0disable experimentalchrome full support 62edge full support 18firefox no support nonotes no support nonotes notes implementation tracked in bug 1290958ie ?
...And 7 more matches

RTCRtpSender - Web APIs
the rtcrtpsender interface provides the ability to control and obtain details about how a particular mediastreamtrack is encoded and sent to a remote peer.
... with it, you can configure the encoding used for the corresponding track, get information about the device's media capabilities, and so forth.
...if null, the track and/or the connection doesn't support dtmf.
...And 7 more matches

Introduction to the Real-time Transport Protocol (RTP) - Web APIs
these correspond to the following three types of transport supported by rtcpeerconnection: rtcrtpsender rtcrtpsenders handle the encoding and transmission of mediastreamtrack data to a remote peer.
... rtcrtpreceiver rtcrtpreceivers provide the ability to inspect and obtain information about incoming mediastreamtrack data.
... async function enablehold(audiostream) { try { await audiotransceiver.sender.replacetrack(audiostream.getaudiotracks()[0]); audiotransceiver.receiver.track.enabled = false; audiotransceiver.direction = "sendonly"; } catch(err) { /* handle the error */ } } the three lines of code within the try block perform the following steps: replace their outgoing audio track with a mediastreamtrack containing hold music.
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Establishing a connection: The WebRTC perfect negotiation pattern - Web APIs
async function start() { try { const stream = await navigator.mediadevices.getusermedia(constraints); for (const track of stream.gettracks()) { pc.addtrack(track, stream); } selfvideo.srcobject = stream; } catch(err) { console.error(err); } } this isn't appreciably different from older webrtc connection establishment code.
...the resulting media tracks are then added to the rtcpeerconnection by passing them into addtrack().
... handling incoming tracks we next need to set up a handler for track events to handle inbound video and audio tracks that have been negotiatied to be received by this peer connection.
...And 7 more matches

Layout using named grid lines - CSS: Cascading Style Sheets
in previous guides we’ve looked at placing items by the lines created by defining grid tracks and also how to place items using named template areas.
...line naming is incredibly useful, but some of the more baffling looking grid syntax comes from this combination of names and track sizes.
... multiple lines with the same name with repeat() if you want to give all of the lines in your grid a unique name then you will need to write out the track definition long-hand rather than using the repeat syntax, as you need to add the name in square brackets while defining the tracks.
...And 7 more matches

Line-based placement with CSS Grid - CSS: Cascading Style Sheets
a basic example as a very simple example we can take a grid with 3 column tracks and 3 row tracks.
...i would like the first item to start on the far left of the grid and span a single column track.
... addressing each item individually we can place all four items spanning row and column tracks.
...And 7 more matches

minmax() - CSS: Cascading Style Sheets
syntax /* <inflexible-breadth>, <track-breadth> values */ minmax(200px, 1fr) minmax(400px, 50%) minmax(30%, 300px) minmax(100px, max-content) minmax(min-content, 400px) minmax(max-content, auto) minmax(auto, 300px) minmax(min-content, auto) /* <fixed-breadth>, <track-breadth> values */ minmax(200px, 1fr) minmax(30%, 300px) minmax(400px, 50%) minmax(50%, min-content) minmax(300px, max-content) minmax(200px, auto) /* <inflexible-bread...
...as a maximum, a <flex> value sets the flex factor of a grid track; it is invalid as a minimum.
... <percentage> a non-negative percentage relative to the inline size of the grid container in column grid tracks, and the block size of the grid container in row grid tracks.
...And 7 more matches

Codecs used by WebRTC - Web media technologies
to communicate, the two devices need to be able to agree upon a mutually-understood codec for each track so they can successfully communicate and present the shared media.
... containerless media webrtc uses bare mediastreamtrack objects for each track being shared from one peer to another, without a container or even a mediastream associated with the tracks.
... which codecs can be within those tracks is not mandated by the webrtc specification.
...And 7 more matches

DisplayMediaStreamConstraints.video - Web APIs
the displaymediastreamconstraints dictionary's video property is used to configure the video track in the stream returned by getdisplaymedia().
...since a video track must always be included, a value of false results in a typeerror exception being thrown.
... more precise control over the format of the returned video track may be exercised by instead providing a mediatrackconstraints object, which is used to process the video data after obtaining it from the device but prior to adding it to the stream.
...And 6 more matches

MediaStreamConstraints.video - Web APIs
the mediastreamconstraints dictionary's video property is used to indicate what kind of video track, if any, should be included in the mediastream returned by a call to getusermedia().
... syntax var videoconstraints = true | false | mediatrackconstraints; value the value of the video property can be specified as either of two types: boolean if a boolean value is specified, it simply indicates whether or not a video track should be included in the returned stream; if it's true, a video track is included; if no video source is available or if permission is not given to use the video source, the call to getusermedia() will fail.
... if false, no video track is included.
...And 6 more matches

RTCRtpSender.setStreams() - Web APIs
the rtcrtpsender method setstreams() associates the sender's track with the specified mediastream or array of mediastream objects.
... syntax rtcrtpsender.setstreams(mediastream); rtcrtpsender.setstreams([mediastream...]); parameters mediastream or [mediastream...] optional an mediastream object—or an array of multiple mediastream objects—identifying the streams to which the rtcrtpsender's track belongs.
... if this parameter isn't specified, no new streams will be associated with the track.
...And 6 more matches

Screen Capture API - Web APIs
mediatrackconstraints mediatrackconstraints.cursor a constraindomstring indicating whether or not the cursor should be included in the captured display surface's stream, and if it should always be visible or if it should only be visible while the mouse is in motion.
... mediatrackconstraints.displaysurface a constraindomstring indicating what type of display surface is to be captured.
... mediatrackconstraints.logicalsurface indicates whether or not the video in the stream represents a logical display surface (that is, one which may not be entirely visible onscreen, or may be completely offscreen).
...And 6 more matches

Media container formats (file types) - Web media technologies
instead, it streams the encoded audio and video tracks directly from one peer to another using mediastreamtrack objects to represent each track.
...for example, an ogg file with only an opus audio track is sometimes referred to as an opus file, and might even have the extension .opus.
...a good example of this is the mp3 audio file, which is in fact an mpeg-1 container with a single audio track encoded using mpeg-1 audio layer iii encoding.
...And 6 more matches

ImageCapture - Web APIs
it provides an interface for capturing images from a photographic device referenced through a valid mediastreamtrack.
... constructor imagecapture() creates a new imagecapture object which can be used to capture still frames (photos) from a given mediastreamtrack which represents a video stream.
... properties imagecapture.track read only returns a reference to the mediastreamtrack passed to the constructor.
...And 5 more matches

MediaStreamConstraints.audio - Web APIs
the mediastreamconstraints dictionary's audio property is used to indicate what kind of audio track, if any, should be included in the mediastream returned by a call to getusermedia().
... syntax var audioconstraints = true | false | mediatrackconstraints; value the value of the audio property can be specified as either of two types: boolean if a boolean value is specified, it simply indicates whether or not an audio track should be included in the returned stream; if it's true, an audio track is included; if no audio source is available or if permission is not given to use the audio source, the call to getusermedia() will fail.
... if false, no audio track is included.
...And 5 more matches

Media Capture and Streams API (Media Stream) - Web APIs
it provides the interfaces and methods for working with the streams and their constituent tracks, the constraints associated with data formats, the success and error callbacks when using the data asynchronously, and the events that are fired during the process.
... a mediastream consists of zero or more mediastreamtrack objects, representing various audio or video tracks.
... each mediastreamtrack may have one or more channels.
...And 5 more matches

RTCConfiguration.bundlePolicy - Web APIs
if the remote peer isn't bundle-aware, the ice agent chooses one audio track and one video track and those two tracks are each assigned to the corresponding rtcdtlstransport.
... all other tracks are ignored by the connection.
... max-compat the ice agent intially creates one rtcdtlstransport for each media track and a separate one for the rtcdatachannel, if one is created.
...And 5 more matches

RTCRtpStreamStats - Web APIs
kind a domstring whose value is "audio" if the associated mediastreamtrack is audio-only or "video" if the track contains video.
... this value will match that of the media type indicated by rtccodecstats.codec, as well as the track's kind property.
... trackid a domstring which uniquely identifies the rtcmediastreamtrackstats object representing the associated mediastreamtrack.
...And 5 more matches

WebRTC API - Web APIs
media streams can consist of any number of tracks of media information; tracks, which are represented by objects based on the mediastreamtrack interface, may contain one of a number of types of media data, including audio, video, and text (such as subtitles or even chapter names).
... most streams consist of at least one audio track and likely also a video track, and can be used to send and receive both live media or stored media information (such as a streamed movie).
... rtcstatsreport provides information detailing statistics for a connection or for an individual track on the connection; the report can be obtained by calling rtcpeerconnection.getstats().
...And 5 more matches

XRReferenceSpace: reset event - Web APIs
this is common when the user calibrates or recalibrates an xr device, or if the device automatically changes its origin after losing tracking of the user, then re-gaining it.
... the tracking system has temporarily lost the user, then regained them, but not until after they had moved enough to leave the immediate vicinity of the last-known position.
... the webxr infrastructure or hardware drivers detected that the device had temporarily lost tracking, causing the hardware and software to be out of sync on position and orientation.
...And 5 more matches

Linear-gradient Generator - CSS: Cascading Style Sheets
= 'hsl' + a + hsl + v + ')'; return value; }; color.prototype.getcolor = function getcolor() { if (this.a | 0 === 1) return this.gethexa(); return this.getrgba(); }; /*=======================================================================*/ /*=======================================================================*/ /*========== capture mouse movement ==========*/ var setmousetracking = function setmousetracking(elem, callback) { elem.addeventlistener('mousedown', function(e) { callback(e); document.addeventlistener('mousemove', callback); }); document.addeventlistener('mouseup', function(e) { document.removeeventlistener('mousemove', callback); }); }; /*====================*/ // color picker class /*====================*/ function colorpicker(node)...
...ting the color-picker /*************************************************************************/ colorpicker.prototype.createpickingarea = function createpickingarea() { var area = document.createelement('div'); var picker = document.createelement('div'); area.classname = 'picking-area'; picker.classname = 'picker'; this.picking_area = area; this.color_picker = picker; setmousetracking(area, this.updatecolor.bind(this)); area.appendchild(picker); this.node.appendchild(area); }; colorpicker.prototype.createhuearea = function createhuearea() { var area = document.createelement('div'); var picker = document.createelement('div'); area.classname = 'hue'; picker.classname ='slider-picker'; this.hue_area = area; this.hue_picker = picker; setmousetracking(are...
...a, this.updatehueslider.bind(this)); area.appendchild(picker); this.node.appendchild(area); }; colorpicker.prototype.createalphaarea = function createalphaarea() { var mask = document.createelement('div'); var picker = document.createelement('div'); mask.classname = 'alpha'; picker.classname = 'slider-picker'; this.alpha_mask = mask; this.alpha_picker = picker; setmousetracking(mask, this.updatealphaslider.bind(this)); mask.appendchild(picker); this.node.appendchild(mask); }; colorpicker.prototype.createpreviewbox = function createpreviewbox(e) { var preview_box = document.createelement('div'); var preview_color = document.createelement('div'); preview_box.classname = 'preview'; preview_color.classname = 'preview-color'; this.preview_color = preview_c...
...And 5 more matches

CSS - Archive of obsolete content
lbar-highlight-color css property is a microsoft extension that specifies the color of the slider tray, the top and left edges of the scroll box, and the scroll arrows of a scroll bar.-ms-scrollbar-shadow-colorthe -ms-scrollbar-shadow-color css property is a microsoft extension that specifies the color of the bottom and right edges of the scroll box and scroll arrows of a scroll bar.-ms-scrollbar-track-colorthe -ms-scrollbar-track-color css property is a microsoft extension that specifies the color of the track element of a scrollbar.-ms-text-autospacethe -ms-text-autospace css property is a microsoft extension that specifies the autospacing and narrow space width adjustment of text.-ms-touch-selectthe -ms-touch-select css property is a microsoft extension that toggles the gripper visual elemen...
...typically it is a triangle that points downward.::-ms-fillthe ::-ms-fill css pseudo-element is a microsoft extension that represents a progress bar displayed by <progress>.::-ms-fill-lowerthe ::-ms-fill-lower css pseudo-element represents the lower portion of the track of a slider control; that is, the portion corresponding to values less than the value currently selected by the thumb.
... a slider control is one possible representation of <input type="range">.::-ms-fill-upperthe ::-ms-fill-upper css pseudo-element is a microsoft extension that represents the upper portion of the track of a slider control; that is, the portion corresponding to values greater than the value currently selected by the thumb.
...And 4 more matches

Debugger.Memory - Firefox Developer Tools
allocation site tracking the javascript engine marks each new object with the call stack at which it was allocated, if: the object is allocated in the scope of a global object that is a debuggee of some debugger instancedbg; and dbg.memory.trackingallocationsites is set to true.
... allocation logging ifdbg is a debugger instance, and dbg.memory.trackingallocationsites is set to true, then the javascript engine logs each object allocated bydbg’s debuggee code.
... accessor properties of the debugger.memory.prototype object ifdbg is a debugger instance, then <i>dbg</i>.memory is a debugger.memory instance, which inherits the following accessor properties from its prototype: trackingallocationsites a boolean value indicating whether this debugger.memory instance is capturing the javascript execution stack when each object is allocated.
...And 4 more matches

Timing element visibility with the Intersection Observer API - Web APIs
in this article, we'll build a mock blog which has a number of ads interspersed among the contents of the page, then use the intersection observer api to track how much time each ad is visible to the user.
... there's a good reason why the notion of tracking visibility of ads is being used in this example.
... nextarticleid each article is given a unique id number; this variable tracks the next id to use, starting with 1.
...And 4 more matches

MediaStream() - Web APIs
the mediastream() constructor returns a newly-created mediastream, which serves as a collection of media tracks, each represented by a mediastreamtrack object.
... if any parameters are given, the specified tracks are added to the new stream.
... otherwise, the stream has no tracks.
...And 4 more matches

XRSession: selectend event - Web APIs
primary actions include things like users pressing triggers or buttons, tapping a touchpad, speaking a command, or performing a recognizable gesture when using a video tracking system or handheld controller with an accelerometer.
... after checking to ensure that the received event is a tracked-pointer event (the only kind we handle here), the target ray's pose is obtained using getpose().
... if the target ray pose was fetched successfully, the code then uses the value of event property type to route control to an appropriate function to handle the event which arrived: for selectstart events, a mybegintracking() function is called with the target ray pose's matrix.
...And 4 more matches

XRSession: selectstart event - Web APIs
primary actions include things like users pressing triggers or buttons, tapping a touchpad, speaking a command, or performing a recognizable gesture when using a video tracking system or handheld controller with an accelerometer.
... after checking to ensure that the received event is a tracked-pointer event (the only kind we handle here), the target ray's pose is obtained using getpose().
... if the target ray pose was fetched successfully, the code then uses the value of event property type to route control to an appropriate function to handle the event which arrived: for selectstart events, a mybegintracking() function is called with the target ray pose's matrix.
...And 4 more matches

XRSession: squeezeend event - Web APIs
primary squeeze actions include things like users pressing triggers or buttons, tapping a touchpad, speaking a command, or performing a recognizable gesture when using a video tracking system or handheld controller with an accelerometer.
... after checking to ensure that the received event is a tracked-pointer event (the only kind we handle here), the target ray's pose is obtained using getpose().
... if the target ray pose was fetched successfully, the code then uses the value of event property type to route control to an appropriate function to handle the event which arrived: for squeezestart events, a mybegintracking() function is called with the target ray pose's matrix.
...And 4 more matches

Web APIs
analysernode animation animationeffect animationevent animationplaybackevent animationtimeline arraybufferview attr audiobuffer audiobuffersourcenode audioconfiguration audiocontext audiocontextlatencycategory audiocontextoptions audiodestinationnode audiolistener audionode audionodeoptions audioparam audioparamdescriptor audioparammap audioprocessingevent audioscheduledsourcenode audiotrack audiotracklist audioworklet audioworkletglobalscope audioworkletnode audioworkletnodeoptions audioworkletprocessor authenticatorassertionresponse authenticatorattestationresponse authenticatorresponse b baseaudiocontext basiccardrequest basiccardresponse batterymanager beforeinstallpromptevent beforeunloadevent biquadfilternode blob blobbuilder blobevent bluetooth bluetoothadvertisin...
...oduct cssmathsum cssmathvalue cssmediarule cssnamespacerule cssnumericvalue cssomstring csspagerule csspositionvalue cssprimitivevalue csspseudoelement cssrule cssrulelist cssstyledeclaration cssstylerule cssstylesheet cssstylevalue csssupportsrule cssunitvalue cssunparsedvalue cssvalue cssvaluelist cssvariablereferencevalue cache cachestorage canvascapturemediastreamtrack canvasgradient canvasimagesource canvaspattern canvasrenderingcontext2d caretposition channelmergernode channelsplitternode characterdata childnode client clients clipboard clipboardevent clipboarditem closeevent comment compositionevent constantsourcenode constrainboolean constraindomstring constraindouble constrainulong contentindex contentindexevent convolvernode countqueuingstrate...
... htmlpictureelement htmlpreelement htmlprogresselement htmlquoteelement htmlscriptelement htmlselectelement htmlshadowelement htmlslotelement htmlsourceelement htmlspanelement htmlstyleelement htmltablecaptionelement htmltablecellelement htmltablecolelement htmltableelement htmltablerowelement htmltablesectionelement htmltemplateelement htmltextareaelement htmltimeelement htmltitleelement htmltrackelement htmlulistelement htmlunknownelement htmlvideoelement hashchangeevent headers history hkdfparams hmacimportparams hmackeygenparams i idbcursor idbcursorsync idbcursorwithvalue idbdatabase idbdatabaseexception idbdatabasesync idbenvironment idbenvironmentsync idbfactory idbfactorysync idbindex idbindexsync idbkeyrange idblocaleawarekeyrange idbmutablefile idbobje...
...And 4 more matches

grid-template - CSS: Cascading Style Sheets
<string> <track-size>?
...]+ [ / <explicit-track-list> ]?
... sets grid-template-areas to the strings listed, grid-template-rows to the track sizes following each string (filling in auto for any missing sizes), and splicing in the named lines defined before/after each size, and grid-template-columns to the track listing specified after the slash (or none, if not specified).
...And 4 more matches

HTTP Index - HTTP
45 http cookies advertising, browser, cookies, cookies article, guide, http, history, javascript, privacy, protocols, server, storage, web development, data, request, tracking an http cookie (web cookie, browser cookie) is a small piece of data that a server sends to the user's web browser.
... 112 dnt dnt, http, reference, header the dnt (do not track) request header indicates the user's tracking preference.
... 151 feature-policy: xr this feature policy directive was at one point defined as xr (but implemented only in chrome as vr), use xr-spatial-tracking instead.
...And 4 more matches

Introduction to web APIs - Learn web development
for example, the web audio api provides javascript constructs for manipulating audio in the browser — taking an audio track, altering its volume, applying effects to it, etc.
... audio and video apis like htmlmediaelement, the web audio api, and webrtc allow you to do really interesting things with multimedia such as creating custom ui controls for playing audio and video, displaying text tracks like captions and subtitles along with your videos, grabbing video from your web camera to be manipulated via a canvas (see above) or displayed on someone else's computer in a web conference, or adding effects to audio tracks (such as gain, distortion, panning, etc).
...next, we include a <button> that we'll use to play and stop the music, and an <input> element of type range, which we'll use to adjust the volume of the track while it's playing.
...And 3 more matches

Gecko info for Windows accessibility vendors
microsoft active accessibility (msaa) an api devised by microsoft so that accessibility aids can track what's going on inside the user interface of any software package that supports it.
...events such as focus changes must be tracked through msaa events, rather than dom events.
...if it is a role_application, role_dialog or role_alert then stay in focus tracking mode -- there is no need to parse the document.
...And 3 more matches

Localizing with Koala
for example: c:\users\stas> cd c:\mozilla\l10n\locale\x-testing c:\mozilla\l10n\locale\x-testing> rmdir 3.6 c:\mozilla\l10n\locale\x-testing> hg clone http://bitbucket.org/mozillal10n/x-testing 3.6 otherwise, it's a good idea to create your local repository in order to be able to track changes you make to the localization files.
...this will allow you to track changes, export them to remote repositories (first on bitbucket, later on hg.mozilla.org) and revert files to earlier versions in case of errors.
...browser\chrome\browser\searchbar.dtd the question marks ("?") in front of the file names indicate that the files are not tracked by mercurial in this repository (yet).
...And 3 more matches

Tutorial: Show Allocations Per Call Path - Firefox Developer Tools
window.demotrackallocations = function() { dbg = new debugger; // this makes hacking on the demo *much* more // pleasant.
... var w = gbrowser.selectedbrowser.contentwindow; console.log("tracking allocations in page: " + w.location.href); // make that window a debuggee of our debugger.
... dbg.adddebuggee(w.wrappedjsobject); // enable allocation tracking in dbg's debuggees.
...And 3 more matches

DisplayMediaStreamConstraints - Web APIs
the displaymediastreamconstraints dictionary is used to specify whether or not to include video and/or audio tracks in the mediastream to be returned by getdisplaymedia(), as well as what type of processing must be applied to the tracks.
... processing information is specified using mediatrackconstraints objects providing options which are applied to the track after the media data is received but before it is made available on the mediastream.
... properties audio a boolean or mediatrackconstraints value; if a boolean, this value simply indicates whether or not to include an audio track in the mediastream returned by getdisplaymedia().
...And 3 more matches

MediaStreamConstraints - Web APIs
the mediastreamconstraints dictionary is used when calling getusermedia() to specify what kinds of tracks should be included in the returned mediastream, and, optionally, to establish constraints for those tracks' settings.
... track constraints audio either a boolean (which indicates whether or not an audio track is requested) or a mediatrackconstraints object providing the constraints which must be met by the audio track included in the returned mediastream.
... if constraints are specified, an audio track is inherently requested.
...And 3 more matches

Using the Screen Capture API - Web APIs
there are three new constraints added to mediatrackconstraints (as well as to mediatracksupportedconstraints and mediatracksettings) for configuring a screen capture stream: cursor indicates whether or not to capture the mouse cursor, and if so, whether to do so all the time or only while the mouse is in motion.
...this could be refined further by specifying additional information for each of audio and video: const gdmoptions = { video: { cursor: "always" }, audio: { echocancellation: true, noisesuppression: true, samplerate: 44100 } } in this example the cursor will always be visible in the capture, and the audio track should ideally have noise suppression and echo cancellation features enabled, as well as an ideal audio sample rate of 44.1khz.
... capturing audio is always optional, and even when web content requests a stream with both audio and video, the returned mediastream may still have only one video track, with no audio.
...And 3 more matches

WebRTC Statistics API - Web APIs
rtcicecandidatestats rtcstats media-source statistics about the media produced by the mediastreamtrack attached to an rtp sender.
... the dictionary this key maps to depends on the track's kind.
...this has been obsoleted since the transition to webrtc being track-based rather than stream-based.
...And 3 more matches

Using bounded reference spaces - Web APIs
introduction a bounded reference space is one which represents an xr environment in which the user is able to move around physically in the real world while being tracked by the xr hardware, with their movements being then transposed into the simulation.
... the boundaries established by the bounded reference space, then, represent the edges of the safely passable, tracked space in the user's real world environment that are available for their movement while in the simulation.
... the requirements, then, for a bounded reference space are: xr hardware that can track the user's movement in the real world, such as a camera-based system.
...And 3 more matches

Viewpoints and viewers: Simulating cameras in WebXR - Web APIs
the cameras may be fixed in place, but they may also be set up to move around as well, tracking the movement of the performers, dollying in and out to achieve emotional impact, and so forth.
...for example: const transform = createperspectivematrix(viewport, 130, 1, 100); const translatevec = vec3.fromvalues(-trackdistance, -cranedistance, pushdistance); mat4.translate(transform, transform, translatevec); this starts with the perspective matrix representing a 130° vertical field of view, then applies a translation that moves the camera in a manner that includes track, crane, and push movements.
...in classic filmmaking, this is typically done with the camera mounted on a track or on a moving vehicle.
...And 3 more matches

WebXR Device API - Web APIs
webxr-compatible devices include fully-immersive 3d headsets with motion and orientation tracking, eyeglasses which overlay graphics atop the real world scene passing through the frames, and handheld mobile phones which augment reality by capturing the world with a camera and augment that scene with computer-generated imagery.
... xrframe while presenting an xr session, the state of all tracked objects which make up the session are represented by an xrframe.
...events which communicate tracking states will also use xrframe to contain that information.
...And 3 more matches

XRPermissionDescriptor.optionalFeatures - Web APIs
xrboundedreferencespace local a tracking space whose native origin is located near the viewer's position at the time the session was created.
...the user isn't expected to move much if at all beyond their starting position, and tracking is optimized for this use case.
... for devices with six degrees of freedom (6dof) tracking, the local reference space tries to keep the origin stable relative to the environment.
...And 3 more matches

XRPermissionDescriptor.requiredFeatures - Web APIs
xrboundedreferencespace local a tracking space whose native origin is located near the viewer's position at the time the session was created.
...the user isn't expected to move much if at all beyond their starting position, and tracking is optimized for this use case.
... for devices with six degrees of freedom (6dof) tracking, the local reference space tries to keep the origin stable relative to the environment.
...And 3 more matches

XRPermissionStatus.granted - Web APIs
xrboundedreferencespace local a tracking space whose native origin is located near the viewer's position at the time the session was created.
...the user isn't expected to move much if at all beyond their starting position, and tracking is optimized for this use case.
... for devices with six degrees of freedom (6dof) tracking, the local reference space tries to keep the origin stable relative to the environment.
...And 3 more matches

XRReferenceSpaceType - Web APIs
xrboundedreferencespace local a tracking space whose native origin is located near the viewer's position at the time the session was created.
...the user isn't expected to move much if at all beyond their starting position, and tracking is optimized for this use case.
... for devices with six degrees of freedom (6dof) tracking, the local reference space tries to keep the origin stable relative to the environment.
...And 3 more matches

XRSession.requestReferenceSpace() - Web APIs
xrboundedreferencespace local a tracking space whose native origin is located near the viewer's position at the time the session was created.
...the user isn't expected to move much if at all beyond their starting position, and tracking is optimized for this use case.
... for devices with six degrees of freedom (6dof) tracking, the local reference space tries to keep the origin stable relative to the environment.
...And 3 more matches

XRSession: squeezestart event - Web APIs
after checking to ensure that the received event is a tracked-pointer event (the only kind we handle here), the target ray's pose is obtained using getpose().
... if the target ray pose was fetched successfully, the code then uses the value of event property type to route control to an appropriate function to handle the event which arrived: for squeezestart events, a mybegintracking() function is called with the target ray pose's matrix.
... the mybegintracking() function would presumably start the presentation of the object-dragging process, using the transform to perform a hit test, determining which object to pick up.
...And 3 more matches

XRTargetRayMode - Web APIs
targeting may be done by looking at the target using a gaze-tracking system, pointing at the target with a hand controller, glove, or motion-tracking system, or by tapping or clicking on the target using a finger on a screen or with a mouse.
... values gaze the user is using a gaze-tracking system (or gaze input) which detects the direction in which the user is looking.
... tracked-pointer targeting is being performed using a handheld device or hand-tracking system which the user points in the direction of the target.
...And 3 more matches

Box-shadow generator - CSS: Cascading Style Sheets
true : false; this.topic = topic; this.node = node; var pointer = document.createelement('div'); pointer.classname = 'ui-slider-pointer'; node.appendchild(pointer); this.pointer = pointer; setmousetracking(node, updateslider.bind(this)); sliders[topic] = this; setvalue(topic, this.value); } var setbuttoncomponent = function setbuttoncomponent(node) { var type = node.getattribute('data-type'); var topic = node.getattribute('data-topic'); if (type === "sub") { node.textcontent = '-'; node.addeventlistener("click", function() { decrement(topic); }); } if (type === "ad...
... if (value > slider.max || value < slider.min) return; var delta = slider.max - slider.min; var width = slider.node.clientwidth; var offset = slider.pointer.clientwidth; var pos = (value - slider.min) * width / delta; slider.value = value; slider.pointer.style.left = pos - offset / 2 + "px"; slider.node.setattribute('data-value', value); notify.call(slider); } var setmousetracking = function setmousetracking(elem, callback) { elem.addeventlistener("mousedown", function(e) { callback(e); document.addeventlistener("mousemove", callback); }); document.addeventlistener("mouseup", function(e) { document.removeeventlistener("mousemove", callback); }); } var subscribe = function subscribe(topic, callback) { if (subscribers[topic] === undefined) subscr...
...snan(value) === false && value >= 0 && value <= 1) color.a = value.tofixed(2); updateui(); } var inputchangehexa = function inputchangehexa(topic) { var selector = "[data-action='set-hexa-" + topic + "']"; var node = document.queryselector("#colorpicker " + selector); var value = node.value; color.sethexa(value); color.updatehsv(); updateui(); } var setmousetracking = function setmousetracking(elem, callback) { elem.addeventlistener("mousedown", function(e) { callback(e); document.addeventlistener("mousemove", callback); }); document.addeventlistener("mouseup", function(e) { document.removeeventlistener("mousemove", callback); }); } /* * observer */ var setcolor = function setcolor(obj) { if(obj instanceof color !
...And 3 more matches

Grid template areas - CSS: Cascading Style Sheets
note that for the wide layout i keep my nine column track grid, i redefine where items are placed using grid-template-areas.
... our grid is a two-column track grid, with the column for the image sized at 1fr and the text 3fr.
...a single column track of 1fr would then take up the rest of the space.
...And 3 more matches

Card - CSS: Cascading Style Sheets
recipe download this example choices made the card is laid out using css grid layout despite being a single dimensional layout, as it enables the use of content sizing for the grid tracks.
... when setting up the single column grid i use the following: .card { display: grid; grid-template-rows: max-content 200px 1fr; } the heading track is set to max-content, which prevents it from stretching.
... i have decided that i want my image to live within a track that is 200 pixels tall.
...And 3 more matches

scrollbar-color - CSS: Cascading Style Sheets
the scrollbar-color css property sets the color of the scrollbar track and thumb.
... the track refers to the background of the scrollbar, which is generally fixed regardless of the scrolling position.
... the thumb refers to the moving part of the scrollbar, which usually floats on top of the track.
...And 3 more matches

Autoplay guide for media and Web Audio APIs - Web media technologies
automatically starting the playback of audio (or videos with audio tracks) immediately upon page load can be an unwelcome surprise to users.
... autoplay blocking is not applied to <video> elements when the source media does not have an audio track, or if the audio track is muted.
... media with an active audio track are considered to be audible, and autoplay blocking applies to them.
...And 3 more matches

Enhanced Extension Installation - Archive of obsolete content
}; tracking install locations since there are only two locations, the installed location of an extension is expressed throughout the code using a boolean value, often referred to as isprofile - true if the item is installed in the profile directory's extensions folder.
... tracking item type item type is tracked for the most part by containment in one or other of the two containers.
... the extension manager loads the xml/rdf datasources (this is allowable and necessary because a major change has happened) and gets a list of all items that need to be installed (tracked using a tobeinstalled flag on the item in the datasource).
...And 2 more matches

Building accessible custom components in XUL - Archive of obsolete content
when you click a spreadsheet cell, assistive technologies track the focus change and know which cell has received focus.
...inspect32 confirms that assistive technologies track the focus as we navigate within the spreadsheet.
... <caption>focus is tracked properly during keyboard navigation</caption> further reading document object model events adding editing capabilities download stage-5.zip install stage-5.xpi we now have a fully accessible xul spreadsheet, correctly focusable, correctly keyboard-navigable, and correctly exposed to assistive technologies.
...And 2 more matches

mozbrowsersecuritychange
non-standard this feature is non-standard and is not on a standards track.
... trackingstate a domstring representing the current loading state of tracking content.
... possible values are: loaded_tracking_content: indicates that the tracking content has been loaded.
...And 2 more matches

Key Values - Web APIs
vk_media_stop (0xb2) appcommand_media_stop gdk_key_audiostop (0x1008ff15) qt::key_mediastop (0x01000081) keycode_media_stop (86) "mediatracknext" [1] seeks to the next media or program track.
... vk_media_next_track (0xb0) appcommand_media_nexttrack gdk_key_audionext (0x1008ff17) qt::key_medianext (0x01000083) keycode_media_next (87) "mediatrackprevious" [1] seeks to the previous media or program track.
... vk_media_prev_track (0xb1) appcommand_media_previoustrack gdk_key_audioprev (0x1008ff16) qt::key_mediaprevious (0x01000082) keycode_media_previous (88) [1] internet explorer, edge, and firefox (36 and earlier) use "medianexttrack" and "mediaprevioustrack" instead of "mediatracknext" and "mediatrackprevious".
...And 2 more matches

LocalMediaStream - Web APIs
see stopping a video stream in mediastreamtrack to learn how.
...however, control over playback of media has been moved to the individual mediastreamtrack objects, so this is no longer necessary.
... instead, media is stopped by calling mediastreamtrack.stop() on each track that needs to be stopped.
...And 2 more matches

MediaDevices.getUserMedia() - Web APIs
the mediadevices.getusermedia() method prompts the user for permission to use a media input which produces a mediastream with tracks containing the requested types of media.
... that stream can include, for example, a video track (produced by either a hardware or virtual video source such as a camera, video recording device, screen sharing service, and so forth), an audio track (similarly, produced by a physical or virtual audio source like a microphone, a/d converter, or the like), and possibly other track types.
...if the browser cannot find all media tracks with the specified types that meet the constraints given, then the returned promise is rejected with notfounderror.
...And 2 more matches

MediaStreamAudioSourceNode.mediaStream - Web APIs
the mediastreamaudiosourcenode interface's read-only mediastream property indicates the mediastream that contains the audio track from which the node is receiving audio.
... syntax audiosourcestream = mediastreamaudiosourcenode.mediastream; value a mediastream representing the stream which contains the mediastreamtrack serving as the source of audio for the node.
... the user agent uses the first audio track it finds on the specified stream as the audio source for this node.
...And 2 more matches

Media Source API - Web APIs
media source extensions concepts and usage playing video and audio has been available in web applications without plugins for a few years now, but the basic features offered have really only been useful for playing single whole tracks.
...mse allows us to replace the usual single track src value fed to media elements with a reference to a mediasource object, which is a container for information like the ready state of the media for being played, and references to multiple sourcebuffer objects that represent the different chunks of media that make up the entire stream.
... trackdefault provides a sourcebuffer with kind, label, and language information for tracks that do not contain this information in the initialization segments of a media chunk.
...And 2 more matches

RTCPeerConnection.getSenders() - Web APIs
the rtcpeerconnection method getsenders() returns an array of rtcrtpsender objects, each of which represents the rtp sender responsible for transmitting one track's data.
... a sender object provides methods and properties for examining and controlling the encoding and transmission of the track's data.
... syntax var senders = rtcpeerconnection.getsenders(); return value an array of rtcrtpsender objects, one for each track on the connection.
...And 2 more matches

RTCRtpSender.setParameters() - Web APIs
the setparameters() method of the rtcrtpsender interface applies changes the configuration of sender's track, which is the mediastreamtrack for which the rtcrtpsender is responsible.
... in other words, setparameters() updates the configuration of the rtp transmission as well as the encoding configuration for a specific media track on the webrtc connection.
... syntax var promise = rtcrtpsender.setparameters(parameters) parameters parameters an object conforming with the rtcrtpsendparameters dictionary, specifying options for the rtcrtpsender; these include potential codecs that could be use for encoding the sender's track.
...And 2 more matches

Storage Access API - Web APIs
prompting heuristics currently vary across the two implementers of the storage access api — safari shows prompts for all embedded tracking content that has not previously received storage access, while firefox only prompts users after a tracking origin has requested storage access on more than a threshold number of sites.
...design properties unique to firefox are summarized here: if the embedded origin tracker.example has already obtained first-party storage access on the top-level origin foo.example, and the user visits a page from foo.example embedding a page from tracker.example again in less than 30 days, the embedded origin will have storage access immediately when loading.
... if a page from top-level origin foo.example embeds more than one <iframe> from tracker.example, and one of those <iframe>s uses the storage access api in order to obtain storage access successfully, all other iframes from tracker.example on foo.example top-level origins will immediately gain storage access as well, without needing to call requeststorageaccess() separately.
...And 2 more matches

Touch events - Web APIs
to provide quality support for touch-based user interfaces, touch events offer the ability to interpret finger (or stylus) activity on touch screens or trackpads.
...this may be a screen or trackpad.
... example this example tracks multiple touchpoints at a time, allowing the user to draw in a <canvas> with more than one finger at a time.
...And 2 more matches

XRInputSource.targetRayMode - Web APIs
the possible values are: gaze the user is using a gaze-tracking system (or gaze input) which detects the direction in which the user is looking.
... tracked-pointer targeting is being performed using a handheld device or hand-tracking system which the user points in the direction of the target.
... for each such input, this example looks for inputs whose targetraymode is tracked-pointer, indicating that the input is in fact intended to represent a targeting device rather than a gazing device, screen tap, or mouse click.
...And 2 more matches

XRInputSource.targetRaySpace - Web APIs
its native origin tracks the position of the origin point of the target ray, and its orientation indicates the orientation of the controller device itself.
... the target ray space reported by tracked pointer inputs (targetraymode of tracked-pointer) is actually based upon the true spatial position and orientation of the input device.
... for each such input, this example looks for inputs whose targetraymode is tracked-pointer, indicating that the input is in fact intended to represent a targeting device rather than a gazing device, screen tap, or mouse click.
...And 2 more matches

XRSession: squeeze event - Web APIs
examples of comon kinds of primary action are users pressing triggers or buttons, tapping a touchpad, speaking a command, or performing a recognizable gesture when using a video tracking system or handheld controller with an accelerometer.
...the handler fetches the pose representing the target ray for tracked-pointer inputs and sends the pose's transform to a function called myhandlesqueezewithray().
... this code treats the squeeze as an instantaneous action that doesn't involve tracking an ongoing activity.
...And 2 more matches

ARIA Test Cases - Accessibility
when the button is pressed, the menu should be tracked like any other menu.
...menus are tracked, closing menus also results in correct focus tracking.
...menus and focus are properly tracked upon activation.
...And 2 more matches

CSS grids, logical values, and writing modes - CSS: Cascading Style Sheets
the grid in my next example has three columns and two row tracks.
... this means there are three tracks running down the block axis.
...it then moves onto the next line, creating a new row track, and fills in more items: * {box-sizing: border-box;} .wrapper { border: 2px solid #f76707; border-radius: 5px; background-color: #fff4e6; } .wrapper > div { border: 2px solid #ffa94d; border-radius: 5px; background-color: #ffd8a8; padding: 1em; color: #d9480f; } .wrapper { display: grid; grid-template-columns: repeat(3, 100px); grid-template-rows: repeat(2, 100px); grid-gap: 10px; } <div class="wrapper"> <div class="item1">item 1</div> <div class="item2">item 2</div> <div class="item3">item 3</div> <div class="item4">item 4</div> ...
...And 2 more matches

Recipe: Media objects - CSS: Cascading Style Sheets
another reason to use grid layout is in order that i can use fit-content() for the track sizing of the image.
... by using fit-content with a maximum size of 200 pixels, when we have a small image such as the icon, the track only gets as large as the size of that image — the max-content size.
... if the image is larger, the track stops growing at 200 pixels and as the image has a max-width of 100% applied, it scales down so that it continues to fit inside the column.
...And 2 more matches

WebKit CSS extensions - CSS: Cascading Style Sheets
bkit-text-combine -webkit-text-decoration-skip -webkit-text-decorations-in-effect -webkit-text-fill-color -webkit-text-security -webkit-text-stroke-color -webkit-text-stroke-width -webkit-text-stroke -webkit-text-zoom -webkit-transform-origin-x -webkit-transform-origin-y -webkit-transform-origin-z u -webkit-user-drag -webkit-user-modify * a few are on the standards, unprefixed track ** new syntax has been standardized.
... webkit-prefixed properties on the standards track -webkit-appearance -webkit-font-size-delta -webkit-mask-composite -webkit-mask-position-x -webkit-mask-position-y -webkit-mask-repeat-x -webkit-mask-repeat-y formerly proprietary properties that are now standard note: to maximize the compatibility of your css, you should use the unprefixed standard properties instead of the prefixed ones listed below.
...form-style -webkit-transition -webkit-transition-delay -webkit-transition-duration -webkit-transition-property -webkit-transition-timing-function u-w -webkit-user-select -epub-word-break -epub-writing-mode supported in non-webkit browsers without a prefix, but not standard the following properties are supported in at least one browser without a prefix, but are not on the standards track.
...And 2 more matches

HTML attribute reference - HTML: Hypertext Markup Language
default <track> indicates that the track should be enabled unless the user's preferences indicate something different.
... kind <track> specifies the kind of text track.
... label <optgroup>, <option>, <track> specifies a user-readable title of the element.
...And 2 more matches

Using HTTP cookies - HTTP
cookies are mainly used for three purposes: session management logins, shopping carts, game scores, or anything else the server should remember personalization user preferences, themes, and other settings tracking recording and analyzing user behavior cookies were once used for general client-side storage.
... tracking and privacy third-party cookies a cookie is associated with a domain.
...these are mainly used for advertising and tracking across the web.
...And 2 more matches

DNT - HTTP
the dnt (do not track) request header indicates the user's tracking preference.
... header type request header forbidden header name yes syntax dnt: 0 dnt: 1 dnt: null directives 0 the user prefers to allow tracking on the target site.
... 1 the user prefers not to be tracked on the target site.
...And 2 more matches

JavaScript Debugger Service - Archive of obsolete content
in firefox versions prior to gecko 33 (firefox 33 / thunderbird 33 / seamonkey 2.30), the javascript debugger service (or simply jsd) used to be an xpcom component that allows the tracking of javascript while it was being executed in the browser.
...see the tracking bug bug 800200 for more details.
...l-known why debughook sometimes fails to trigger jsd.debughook = { onexecute: function(frame, type, rv) { stacktrace = ""; for (var f = frame; f; f = f.callingframe) { stacktrace += f.script.filename + "@" + f.line + "@" + f.functionname + "\n"; } dump(stacktrace); return components.interfaces.jsdiexecutionhook.return_continue; } }; filters jsd also allows the use of filters to track which scripts should trigger the hooks.
... jsd.clearfilters(); // clear the list of filters // we exclude the scripts with the following filenames from being tracked jsd.appendfilter(createfilter("*/firefox/components/*")); jsd.appendfilter(createfilter("*/firefox/modules/*")); jsd.appendfilter(createfilter("xstringbundle")); jsd.appendfilter(createfilter("chrome://*")); jsd.appendfilter(createfilter("x-jsd:ppbuffer*")); jsd.appendfilter(createfilter("xpcsafejsobjectwrapper.cpp")); jsd.appendfilter(createfilter("file://*")); note that appendfilter adds th...

Archived Mozilla and build documentation - Archive of obsolete content
searches, lookups, package tracking, and even word definitions can all be retrieved from user-customized bookmarks.
...the extension will access tinderbox, mozilla.org's webtool for tracking source code status, to get the status of the code.
...the space manager is responsible for keeping track of where space is taken up and where it is available.
... tamarin the download manager schema the download manager uses an sqlite table to keep track of downloads in progress as well as queued and past downloads.

Mozilla XForms Specials - Archive of obsolete content
(limitation tracked in bug 280368) mixing repeat and table or ul it is not possible to mix repeats with either table or ul.
...(limitation tracked in bug 313111)pseudo element support there is no support for the pseudo elements (::value, ::repeat-item, and ::repeat-index ).
...(limitation tracked in bug 271724) optional parameters in xpath functions optional parameters in xpath functions are not supported, you will have to specify all parameters when calling a function.
...instead of using digest('abc', 'sha-1') explicitly use the third parameter (the results are equal): digest('abc', 'sha-1', 'base64') (limitation tracked in bug 477857) extensions enumerating instances the standardized nsixformsmodelelement does not allow one to enumerate over all possible instances, but only to retrieve instances by their name.

Grid Lines - MDN Web Docs Glossary: Definitions of Web-related terms
grid lines are created when you define tracks in the explicit grid using css grid layout.
... in the following example there is a grid with three column tracks and two row tracks.
... lines are also created in the implicit grid when implicit tracks are created to hold content positioned outside of the explicit grid, however these lines cannot be addressed by a number.
...} <div class="wrapper"> <div class="item">item</div> </div> .wrapper { display: grid; grid-template-columns: repeat(3, 1fr); grid-template-rows: 100px 100px; } .item { grid-column-start: 1; grid-column-end: 3; grid-row-start: 1; grid-row-end: 3; } naming lines the lines created in the explicit grid can be named, by adding the name in square brackets before or after the track sizing information.

Gutters - MDN Web Docs Glossary: Definitions of Web-related terms
gutters or alleys are spacing between content tracks.
... in the example below we have a three-column and two-row track grid, with 20-pixel gaps between column tracks and 20px-gaps between row tracks.
...und-color: #fff8f8; padding: 1em; color: #d9480f; } .wrapper { display: grid; grid-template-columns: repeat(3,1.2fr); grid-auto-rows: 45%; grid-column-gap: 20px; grid-row-gap: 20px; } <div class="wrapper"> <div>one</div> <div>two</div> <div>three</div> <div>four</div> <div>five</div> </div> in terms of grid sizing, gaps act as if they were a regular grid track however nothing can be placed into the gap.
... the grid-gap properties are not the only thing that can cause tracks to space out.

Index - Learn web development
3 accessible multimedia accessibility, article, audio, beginner, codingscripting, html, images, javascript, learn, multimedia, video, captions, subtitles, text tracks this chapter has provided a summary of accessibility concerns for multimedia content, along with some practical solutions.
...you should also appreciate that objects are very useful as structures for storing related data and functionality — if you tried to keep track of all the properties and methods in our person object as separate variables and functions, it would be inefficient and frustrating, and we'd run the risk of clashing with other variables and functions that have the same names.
...as a recap, there are two distinct problems we've been discussing here: 250 video and audio content article, audio, beginner, guide, html, video, captions, subtitles, track and that's a wrap; we hope you had fun playing with video and audio in web pages!
...we can now add todo items to our app, and the state of the data is tracked using our service.

Experimental features in Firefox
nightly 64 no developer edition 64 no beta 64 no release 64 no preference name media.setsinkid.enabled htmlmediaelement properties: audiotracks and videotracks enabling this feature adds the htmlmediaelement.audiotracks and htmlmediaelement.videotracks properties to all html media elements.
... however, because firefox doesn't currently suport multiple audio and video tracks, the most common use cases for these properties don't work, so they're both disabled by default.
... nightly 33 no developer edition 33 no beta 33 no release 33 no preference name media.track.enabled dom document property: autoplaypolicy the document property autoplaypolicy returns a string indicating how the browser handles requests to automatically play media (either using the autoplay property on a media element or by attempting to trigger playback from javascript code.
...there currently is no real plan to ship this on desktop, but you can track the state of that just in case it changes in bug 1551302.

Index
170 storage access policy: block cookies from trackers privacy, storage access policy, tracking protection firefox includes a new storage access policy that blocks cookies and other site data from third-party tracking resources.
...the new policy protects against cross-site tracking while minimizing the site breakage associated with traditional cookie blocking.
... 171 tracking protection privacy, private browsing, blocking, tracking starting in version 42, firefox desktop and firefox for android include built-in tracking protection.
... in private browsing windows (tabs, in firefox for android), firefox will block content loaded from domains that track users across sites.

Shell global objects
setpromiserejectiontrackercallback() sets the callback to be invoked whenever a promise rejection is unhandled or a previously-unhandled rejection becomes handled.
... trackedopts(fun) returns an object describing the tracked optimizations of fun, if any.
... enabletrackallocations() start capturing the js stack at every allocation.
... disabletrackallocations() stop capturing the js stack at every allocation.

nsIJumpListBuilder
the system tracks removed items between commits.
...to prevent repeatedly adding entires users have removed, applications are encouraged to track removed items internally.
...applications that use recent or frequent lists should keep document use tracking up to date by calling the shaddtorecentdocs shell api.
...applications that use recent or frequent lists should keep document use tracking up to date by calling the shaddtorecentdocs shell api.

nsIMsgWindow
transactionmanager nsitransactionmanager this is used to track undo/redo transactions.
... openfolder nsimsgfolder this is used to track the folder currently open in the ui.
... rootdocshell nsidocshell this is used to track the chrome window's nsidocshell object.
... mailcharacterset acstring this is used to track the character set of the currently displayed message.

BaseAudioContext.decodeAudioData() - Web APIs
this is the preferred method of creating an audio source for web audio api from an audio track.
... older callback syntax in this example, the getdata() function uses xhr to load an audio track, setting the responsetype of the request to arraybuffer so that it returns an array buffer as its response that we then store in the audiodata variable .
... the buttons in the example simply run getdata() to load the track and start it playing, and stop it playing, respectively.
... note: you can run the example live (or view the source.) // define variables var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var source; var pre = document.queryselector('pre'); var myscript = document.queryselector('script'); var play = document.queryselector('.play'); var stop = document.queryselector('.stop'); // use xhr to load an audio track, and // decodeaudiodata to decode it and stick it in a buffer.

HTMLMediaElement - Web APIs
htmlmediaelement.audiotracks a audiotracklist that lists the audiotrack objects contained in the element.
... htmlmediaelement.texttracks read only returns the list of texttrack objects contained in the element.
... htmlmediaelement.videotracks read only returns the list of videotrack objects contained in the element.
... htmlmediaelement.addtexttrack() adds a text track (such as a track for subtitles) to a media element.

ImageCapture() constructor - Web APIs
syntax const imagecapture = new imagecapture(videotrack) parameters videotrack a mediastreamtrack from which the still images will be taken.
... return value a new imagecapture object which can be used to capture still frames from the specified video track.
... example the following example shows how to use a call to mediadevices.getusermedia() to retrieve the mediastreamtrack needed by the imagecapture() constructor.
... navigator.mediadevices.getusermedia({video: true}) .then(mediastream => { document.queryselector('video').srcobject = mediastream const track = mediastream.getvideotracks()[0]; imagecapture = new imagecapture(track); }) .catch(error => console.log(error)); specifications specification status comment mediastream image capturethe definition of 'imagecapture' in that specification.

MediaDevices.getDisplayMedia() - Web APIs
since getdisplaymedia() requires a video track, the returned stream will have one even if no video track is expressly requested by the constraints object.
... return value a promise that resolves to a mediastream containing a video track whose contents come from a user-selected screen area, as well as an optional audio track.
... note: browser support for audio tracks varies, both in terms of whether or not they're supported at all by the media recorder and in terms of the which audio source or sourcoes are supported.
...the stream is then returned to the caller for use, perhaps for adding to a webrtc call using rtcpeerconnection.addtrack() to add the video track from the stream.

MediaRecorder.start() - Web APIs
invalidmodificationerror the number of tracks on the stream being recorded has changed.
... you can't add or remove tracks while recording media.
... notsupportederror the media stream you're attempting to record is inactive, or one or more of the stream's tracks is in a format that can't be recorded using the current configuration.
... this also happens when a mediastreamtrack within the stream is marked as isolated due to the peeridentity constraint on the source stream.

RTCPeerConnection.addStream() - Web APIs
instead of using this obsolete method, you should instead use addtrack() once for each track you wish to send to the remote peer.
... navigator.mediadevices.getusermedia({video:true, audio:true}, function(stream) { var pc = new rtcpeerconnection(); pc.addstream(stream); }); migrating to addtrack() compatibility allowing, you should update your code to instead use the addtrack() method: navigator.getusermedia({video:true, audio:true}, function(stream) { var pc = new rtcpeerconnection(); stream.gettracks().foreach(function(track) { pc.addtrack(track, stream); }); }); the newer addtrack() api avoids confusion over whether later changes to the track-makeup of a stream affects a ...
...you can write web compatible code using feature detection instead: // add a track to a stream and the peer connection said stream was added to: stream.addtrack(track); if (pc.addtrack) { pc.addtrack(track, stream); } else { // if you have code listening for negotiationneeded events: settimeout(() => pc.dispatchevent(new event('negotiationneeded'))); } // remove a track from a stream and the peer connection said stream was added to: stream.removetrack(track); if (pc.removetrack) { pc.removetrack(pc.g...
...etsenders().find(sender => sender.track == track)); } else { // if you have code listening for negotiationneeded events: settimeout(() => pc.dispatchevent(new event('negotiationneeded'))); } specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtcpeerconnection.addstream()' in that specification.

RTCPeerConnection: addstream event - Web APIs
you should instead watch for the track event, which is sent for each media track added to the rtcpeerconnection.
... examples this example looks to determine if the user's browser supports the track event.
... if it does, a track event listener is set up; otherwise, an addstream event listener is set up.
... if (pc.addtrack !== undefined) { pc.ontrack = ev => { ev.streams.foreach(stream => doaddstream(stream)); } } else { pc.onaddstream = ev => { doaddstream(ev.stream); } } this calls a function doaddstream() once for each stream being added to the rtcpeerconnection, regardless of whether the browser sends addstream or track.

RTCPeerConnection.getStats() - Web APIs
the rtcpeerconnection method getstats() returns a promise which resolves with data providing statistics about either the overall connection or about the specified mediastreamtrack.
... syntax promise = rtcpeerconnection.getstats(selector) parameters selector optional a mediastreamtrack for which to gather statistics.
... exceptions this method does not throw exceptions; instead, it rejects the returned promise with one of the following errors: invalidaccesserror there is no rtcrtpsender or rtcrtpreceiver whose track matches the specified selector, or selector matches more than one sender or receiver.
... promise = rtcpeerconnection.getstats(selector, successcallback, failurecallback) parameters selector optional a mediastreamtrack for which to gather statistics.

SourceBuffer - Web APIs
sourcebuffer.audiotracks read only a list of the audio tracks currently contained inside the sourcebuffer.
... sourcebuffer.texttracks read only a list of the text tracks currently contained inside the sourcebuffer.
... sourcebuffer.trackdefaults specifies the default values to use if kind, label, and/or language information is not available in the initialization segment of the media to be appended to the sourcebuffer.
... sourcebuffer.videotracks read only a list of the video tracks currently contained inside the sourcebuffer.

VTTCue - Web APIs
the vttcue interface—part of the api for handling webvtt (text tracks on media presentations)—describes and controls the text track associated with a particular <track> element.
... properties this interface also inherits properties from texttrackcue.
... example html <video controls src="https://udn.realityripple.com/samples/c6/f8a3489533.webm"></video> css video { width: 320px; height: 180px; } javascript let video = document.queryselector('video'); video.addeventlistener('loadedmetadata', () => { const track = video.addtexttrack("captions", "简体中文subtitles", "zh_cn"); track.mode = "showing"; const cuecn = new vttcue(0, 2.500, '字幕会在0至2.5秒间显示'); track.addcue(cuecn); const cueen = new vttcue(2.6, 4, 'subtitles will display between 2.6 and 4 seconds'); track.addcue(cueen); }); result chrome: please open in jsfiddle to view the live sample.
... specifications specification status comment webvtt: the web video text tracks format candidate recommendation ...

Web Audio API - Web APIs
if multiple audio tracks are present on the stream, the track whose id comes first lexicographically (alphabetically) is used.
... mediastreamtrackaudiosourcenode a node of type mediastreamtrackaudiosourcenode represents an audio source whose data comes from a mediastreamtrack.
... when creating the node using the createmediastreamtracksource() method to create the node, you specify which track to use.
... mediastreamaudiodestinationnode the mediastreamaudiodestinationnode interface represents an audio destination consisting of a webrtc mediastream with a single audiomediastreamtrack, which can be used in a similar way to a mediastream obtained from getusermedia().

XRInputSource.gripSpace - Web APIs
the read-only xrinputsource property gripspace returns an xrspace whose native origin tracks the pose used to render virtual objects so they appear to be held in (or part of) the user's hand.
...gripspace is null if the input source is inherently untrackable.
... for example, only inputs whose targetraymode is tracked-pointer provide a gripspace.
...the native origin of the grip space is located at the centroid—the center of mass—of the user's fist, tracking the position of the user's hand.

Keyboard-navigable JavaScript widgets - Accessibility
use onfocus to track the current focus don't assume that all focus changes will come via key and mouse events: assistive technologies such as screen readers can set the focus to any focusable element.
... track focus using onfocus and onblur instead.
...if you want to track the focus status, you can use the document.activeelement to get the active element.
... technique 2: aria-activedescendant this technique involves binding a single event handler to the container widget and using the aria-activedescendant to track a "virtual" focus.

Mouse gesture events - Developer guides
non-standard this feature is non-standard and is not on a standards track.
...these are special movements that can be made with a mouse or trackpad and can be interpreted to perform specific tasks.
...types of gesture events mozswipegesture the mozswipegesture event is sent when the user uses three fingers to "swipe" the trackpad.
...mozrotategesturestart the mozrotategesturestart event is sent when the user begins performing a rotate gesture, by placing two fingers on the trackpad and rotating them around the center of the trackpad.

Web audio codec guide - Web media technologies
pulse code modulation (pcm) of voice frequencies rtp / webrtc g.722 7 khz audio coding within 64 kbps (for telephony/voip) rtp / webrtc mp3 mpeg-1 audio layer iii mp4, adts, mpeg1, 3gp opus opus webm, mp4, ogg vorbis vorbis webm, ogg [1] when mpeg-1 audio layer iii codec data is stored in an mpeg file, and there is no video track on the file, the file is typically referred to as an mp3 file, even though it's still an mpeg format file.
...this can be particularly important for classical music, theatrical soundtracks, and for background music during gameplay.
...these files are mpeg-1 files that contain an audio layer iii track.
... voice recording and playback usually needs to be low-latency in order to synchronize with video tracks, or in order to avoid cross-talk or other problems.

The "codecs" parameter in common media types - Web media technologies
however, many media types—especially those that support video tracks—can benefit from the ability to more precisely describe the format of the data within them.
...this information may include things like the profile of the video codec, the type used for the audio tracks, and so forth.
... audio/ogg; codecs=vorbis an ogg file containing a vorbis audio track.
...both video and audio tracks can be described using the codecs parameter with the following mime types: base mime types supporting the iso bmff codecs parameter mime type description audio/3gpp 3gp audio (rfc 3839: mime type registrations for 3rd generation partnership project (3gp) multimedia files) video/3gpp 3gp video (rfc 3839: mime type registrations for 3rd generation partners...

Intercepting Page Loads - Archive of obsolete content
it means you have to keep track of tabs being opened and closed, in order to add and remove your listener.
... here's a code sample that keeps track of your progress listeners for all tabs: init : function() { gbrowser.browsers.foreach(function (browser) { this._toggleprogresslistener(browser.webprogress, true); }, this); gbrowser.tabcontainer.addeventlistener("tabopen", this, false); gbrowser.tabcontainer.addeventlistener("tabclose", this, false); }, uninit : function() { gbrowser.browsers.foreach(function (browser) { this ._toggleprogresslistener(browser.webprogress, false); }, this); gbrowser.tabcontainer.removeeventlistener("tabopen", this, false); gbrowser.tabcontainer.removeeventlistener("tabclose", this, false); }, handleevent : function(aevent) { let tab = aevent.target; let webprogress = gbrowser.getbrowserfortab(tab).webprogress; this._toggleprogresslistene...
...we register and unregister the progress listeners for the first tab manually, and then add tab open and close event listeners so we can keep track of the rest of the listeners for all the tabs.

Search Extension Tutorial (Draft) - Archive of obsolete content
cu.import("resource://gre/modules/services.jsm"); // keep track of whether this is the first run.
...cu.import("resource://gre/modules/services.jsm"); // the details of the engine to add const engine_details = { name: "example engine", iconurl: "data:image/png;base64,...", alias: "example-engine", description: "an example search engine", method: "get", // the http request method url: "https://www.example.com/?q=_searchterms_" }; // keep track of whether this is the first run.
...const engine_url = "chrome://example-engine/content/search.xml"; // keep track of whether this is the first run.

Tree View Details - Archive of obsolete content
this is a fairly tricky process as it involves keeping track of which items have children and also which rows are open and closed.
...the view is required to keep track of this.
...remember that a custom view must keep track of which items are visible itself.

Introduction to Public-Key Cryptography - Archive of obsolete content
with this arrangement, the user must supply a new password for each server, and the administrator must keep track of the name and password for each user, typically on separate servers.
...users have difficulty keeping track of different passwords, tend to choose poor ones, and tend to write them down in obvious places.
... administrators must keep track of a separate password database on each server and deal with potential security problems related to the fact that passwords are sent over the network routinely and frequently.

Anatomy of a video game - Game development
* * mygame.lastrender keeps track of the last provided requestanimationframe timestamp.
... * mygame.lasttick keeps track of the last update time.
... // note: as we mention in summary, you should keep track of how large numticks is.

Grid - MDN Web Docs Glossary: Definitions of Web-related terms
if you place content outside of this explicit grid, or if you are relying on auto-placement and the grid algorithm needs to create additional row or column tracks to hold grid items, then extra tracks will be created in the implicit grid.
... the implicit grid is the grid created automatically due to content being added outside of the tracks defined.
...the third row on the grid is an implicit grid row track, formed due to their being more than the six items which fill the explicit tracks.

Responsive design - Learn web development
css grid in css grid layout the fr unit allows the distribution of available space across grid tracks.
... the next example creates a grid container with three tracks sized at 1fr.
... this will create three column tracks, each taking one part of the available space in the container.

Framework main features - Learn web development
this component should be responsible for tracking its own count state, and could be written like this: function counterbutton() { const [count] = usestate(0); return ( <button>clicked {count} times</button> ); } usestate() is a react hook which, given an initial data value, will keep track of that value as it is updated.
... the code will be initially rendered like so in the browser: <button>clicked 0 times</button> the usestate() call keeps track of the count value in a robust way across the app, without you needing to write code to do that yourself.
...all of them track the current rendered version of your browser's dom, and each makes slightly different decisions about how the dom should change as components in your application re-render.

Componentizing our React app - Learn web development
in order to track the names of tasks we want to complete, we should ensure that each <todo /> component renders a unique name.
... unique keys now that react is rendering our tasks out of an array, it has to keep track of which one is which in order to render them properly.
... react tries to do its own guesswork to keep track of things, but we can help it out by passing a key prop to our <todo /> components.

Componentizing our Svelte app - Learn web development
however, when your application grows larger and more complex it can easily get difficult to keep track of all your bound values.
... handling the events we'll need one variable to track whether we are in editing mode and another to store the name of the task being updated.
... add the following variable definitions at the bottom of the <script> section of the todo component: let editing = false // track editing mode let name = todo.name // hold the name of the todo being edited we have to decide what events our todo component will emit: we could emit different events for the status toggle and editing of the name.

Application Translation with Mercurial
progress tracking tool to track which strings and files already have been translated and later also to see which new strings have already been tested in the product as being a good translation for the functionality behind the translated strings and that the translated texts fit into the available, the translation progress should be tracked.
... tracking the translation progress if you translate more than a few strings, you usually want to keep track of what has already been translated (and later if the text has been tested in the product as fitting into the available area and suiting the functionality it describes).
... start tracking changes you make against the localization repository by telling it that with the qnew subcommand to save these changes as patch in a mercurial queue.

What every Mozilla translator should know
l10n stands for localization = l + another 10 letters + n mailing lists and other resources there are several mailing lists to keep the track of what's going on, which are available as newsgroups, as well, both on news.mozilla.org and google groups: the main l10n list also available as mozilla.dev.l10n, .l10n in short.
... to keep the track of what's going on, it's also a good idea to read the planet mozilla l10n when you have a problem use the above mailing lists the person in charge of the mozilla l10n is axel hecht (l10n at mozilla.com), pike on irc another interesting way of getting help is the irc channel #l10n at irc.mozilla.org useful tools the l10n dashboard pontoon narro translate toolkit koala 0.1 mozillatr...
... bugzilla, the bug-tracking system you do need an account in bugzilla you should configure the account to watch the following addresses: firefoxl10n@hotmail.com calendar-l10n@mozilla.bugs (specific for calendar related bugs) this way you will receive mail for bugs affecting many or even all locales.

Are We Slim Yet
the are we slim yet project (commonly known as awsy) for several years tracked memory usage across builds on the (now defunct) website areweslimyet.com.
...the results are posted to perfherder where we can track regressions automatically.
... as new processes are added to firefox we want to make sure their memory usage is also tracked by awsy.

DMD
in this mode, dmd tracks the contents of the heap, including which heap blocks have been reported by memory reporters.
...in this mode, dmd tracks the current contents of the heap.
...in this mode, dmd tracks both the past and current contents of the heap.

AsyncTestUtils extended framework
this class not only holds references to the syntheticmessage instances, but it also tracks what folders they were injected into as well as what folders you move them to.
...keep in mind that the class is not magic and will lose track of the message headers if you manipulate them without referencing the message set.
... messagemodifier.js: slightly misnamed, this provides the syntheticmessageset abstraction that is a set abstraction for syntheticmessages that also tracks what folders they got injected into and provides code to directly manipulate or aid other code that wants to directly manipulate them.

Web Replay
this is done in code associated with the non-deterministic components, such as during gc or ion compilation, to help track down behaviors that should go unrecorded.
... keeping track of the exact point where an interrupt occurred would require quite a bit of recording overhead, and it doesn't seem worth it to try to do this.
... recording and replaying executions using these buffers will require new techniques like treating all accesses on the buffers as atomic (probably unacceptable overhead) or performing all accesses on the buffer on a single core and keeping track of context switches.

Component Internals
xpcom registry manifests xpcom uses special files called manifests to track and persist information about the components to the local system.
... there are two types of manifests that xpcom uses to track components: component manifests when xpcom first starts up, it looks for the component manifest, which is a file that lists all registered components, and stores details on exactly what each component can do.
... the smart pointer class, nscomptr, for example, which makes reference counting less tedious and error-prone, is not actually frozen, and neither is nsdebug, a class for aiding in tracking down bugs, nor is nsmemory, a class to ensure that everyone uses the same heap, generic factory, and module.

nsIDocShell
layouthistorystate nsilayouthistorystate loadedtransindex long keeps track of the previous shtransaction index and the current shtransaction index at the time that the doc shell begins to load.
... previoustransindex long keeps track of the previous shtransaction index and the current shtransaction index at the time that the doc shell begins to load.
... restoringdocument boolean track whether we're currently restoring a document presentation.

Migrating from Firebug - Firefox Developer Tools
it is currently missing the preview for html, xml and svg, though, which is tracked in bug 1247392 and bug 1262796, but when you click on the url of the request you switch to the network monitor, which has a preview tab.
...only the live preview of changes is currently missing, which is tracked in bug 1067318 and bug 815464.
...a few property values are not auto-completed yet, which is tracked in bug 1337918.

Examine and edit CSS - Firefox Developer Tools
click that icon to display the grid overlaid on the page, including grid lines and tracks.
...ts the rule view displays the following pseudo-elements, if they are applied to the selected element: ::after ::backdrop ::before ::first-letter ::first-line ::selection :-moz-color-swatch :-moz-number-spin-box :-moz-number-spin-down :-moz-number-spin-up :-moz-number-text :-moz-number-wrapper :-moz-placeholder :-moz-progress-bar :-moz-range-progress :-moz-range-thumb :-moz-range-track :-moz-selection if the selected element has pseudo-elements applied to it, they are displayed before the selected element but hidden by a disclosure triangle: clicking the triangle displays them: viewing common pseudo-classes there's a button to the right of the filter box: click the button to see checkboxes that you can use to enable the :hover, :active and :focus, :focus-within and ...
... track changes when you are editing the rules in the rules view, you can see the changes you have made in the changes pane.

CSS Grid Inspector: Examine grid layouts - Firefox Developer Tools
clicking the icon toggles the display of a grid overlay on the page, which appears over the element, laid out like a grid to show the position of its grid lines and tracks: the overlay is still shown when you select other elements, so you can edit related css properties and see how the grid is affected.
... extend lines infinitely: by default, grid lines/tracks are only shown inside the element with display: grid set on it; when toggling this option on, the grid lines extend to the edge of the viewport along each axis.
... extend lines infinitely by default, the grid lines/tracks are only shown inside the element with display: grid set on it.

Background Tasks API - Web APIs
currenttasknumber is used to track how many tasks have been processed so far.
... statusrefreshscheduled is used to track whether or not we've already scheduled an update of the status display box for the upcoming frame, so that we only do it once per frame the shim to function even if idle callbacks aren't supported.
... we increment currenttasknumber to track how many tasks we've executed.

CacheStorage - Web APIs
use cachestorage.match() to check if a given request is a key in any of the cache objects that the cachestorage object tracks.
... methods cachestorage.match() checks if a given request is a key in any of the cache objects that the cachestorage object tracks, and returns a promise that resolves to that match.
... cachestorage.keys() returns a promise that will resolve with an array containing strings corresponding to all of the named cache objects tracked by the cachestorage.

Force Touch events - Web APIs
non-standard this feature is non-standard and is not on a standards track.
... force touch events are a proprietary, apple-specific feature which makes possible (where supported by the input hardware) new interactions based on how hard the user clicks or presses down on the touchscreen or trackpad.
... event properties the following property is known to be available on the webkitmouseforcewillbegin, mousedown, webkitmouseforcechanged, webkitmouseforcedown, webkitmouseforceup, mousemove, and mouseup event objects: mouseevent.webkitforce read only the amount of pressure currently being applied to the trackpad/touchscreen constants these constants are useful for determining the relative intensity of the pressure indicated by mouseevent.webkitforce: mouseevent.webkit_force_at_mouse_down read only minimum force necessary for a normal click mouseevent.webkit_force_at_force_mouse_down read only minimum force necessary for a force click specifications not part of any specification.

HTMLCanvasElement.captureStream() - Web APIs
the htmlcanvaselement capturestream() method returns a mediastream which includes a canvascapturemediastreamtrack containing a real-time video capture of the canvas's contents.
...if not set, a new frame will be captured each time the canvas changes; if set to 0, frames will not be captured automatically; instead, they will only be captured when the returned track's requestframe() method is called.
... return value a reference to a mediastream object, which has a single canvascapturemediastreamtrack in it.

Using IndexedDB - Web APIs
if you're doing lots of database operations, then tracking the transaction rather than individual requests can certainly aid your sanity.
...as a workaround for this normal shutdown notification, you might track your transactions and add a beforeunload event to warn the user if any transactions have not yet completed at the time of unloading.
...); compat.empty(); compat.append('<ul id="compat-list"></ul>'); compat_envs.foreach(function(val, idx, array) { $('#compat-list').append('<li>' + val[0] + ': ' + val[1] + '</li>'); }); const db_name = 'mdn-demo-indexeddb-epublications'; const db_version = 1; // use a long long for this value (don't use a float) const db_store_name = 'publications'; var db; // used to keep track of which view is displayed to avoid uselessly reloading it var current_view_pub_key; function opendb() { console.log("opendb ..."); var req = indexeddb.open(db_name, db_version); req.onsuccess = function (evt) { // equal to: db = req.result; db = this.result; console.log("opendb done"); }; req.onerror = function (evt) { console.error("opendb:", evt...

KeyboardEvent: code values - Web APIs
"" 0x007d "intlyen" "intlyen" 0x007e "numpadcomma" "" 0x007f "unidentified" "" 0xe000 ～ 0xe007 "unidentified" "" 0xe008 "unidentified" "undo" 0xe009 "unidentified" "" 0xe00a "" "paste" 0xe00b ～ 0xe00f "" "" 0xe010 "mediatrackprevious" "mediatrackprevious" 0xe011 ～ 0xe016 "" "" 0xe017 "unidentified" "cut" 0xe018 "unidentified" "copy" 0xe019 "mediatracknext" "mediatracknext" 0xe01a, 0xe01b "unidentified" "" 0xe01c "numpadenter" "numpadenter" 0xe01d "controlright" "controlright" ...
...�� 0x00a2 "unidentified" "" 0x00a3 "launchmail" "" 0x00a4 "browserfavorites" "" 0x00a5 "unidentified" "" 0x00a6 "browserback" "browserback" 0x00a7 "browserforward" "browserforward" 0x00a8 "unidentified" "" 0x00a9 "eject" "" 0x00aa "unidentified" "" 0x00ab "mediatracknext" "" 0x00ac "mediaplaypause" "" 0x00ad "mediatrackprevious" "" 0x00ae "mediastop" "" 0x00af ～ 0x00b2 "unidentified" "" 0x00b3 "launchmediaplayer" "" 0x00b4 "browserhome" "" 0x00b5 "browserrefresh" "browserrefresh" 0x00b6 ～ 0x00ba "unidentified" "" 0x00bb ...
... 0x008f "wakeup" 0x0090 "launchapp1" 0x0091 ～ 0x009b "unidentified" 0x009c "browserfavorites" 0x009d "unidentified" 0x009e "browserback" 0x009f "browserforward" 0x00a0 "unidentified" 0x00a1 "eject" 0x00a2 "unidentified" 0x00a3 "mediatracknext" 0x00a4 "mediaplaypause" 0x00a5 "mediatrackprevious" 0x00a6 "mediastop" 0x00a7 ～ 0x00ac "unidentified" 0x00ad "browserrefresh" 0x00ae ～ 0x00b6 "unidentified" 0x00b7 "f13" 0x00b8 "f14" 0x00b9 "f15" 0x00ba "f16" 0x00bb "f17" 0x00bc "f18" ...

MediaDevices - Web APIs
getsupportedconstraints() returns an object conforming to mediatracksupportedconstraints indicating which constrainable properties are supported on the mediastreamtrack interface.
... getusermedia() with the user's permission through a prompt, turns on a camera and/or a microphone on the system and provides a mediastream containing a video track and/or an audio track with the input.
...var video = document.queryselector('video'); var constraints = window.constraints = { audio: false, video: true }; var errorelement = document.queryselector('#errormsg'); navigator.mediadevices.getusermedia(constraints) .then(function(stream) { var videotracks = stream.getvideotracks(); console.log('got stream with constraints:', constraints); console.log('using video device: ' + videotracks[0].label); stream.onremovetrack = function() { console.log('stream ended'); }; window.stream = stream; // make variable available to browser console video.srcobject = stream; }) .catch(function(error) { if (error.name === 'constraintnotsatisfiederror') { errormsg('the resol...

MediaSession.setActionHandler() - Web APIs
it will be one of play, pause, seekbackward, seekforward, seekto, skipad,previoustrack, or nexttrack.
...the following strings identify the currently available types of media session action: nexttrack advances playback to the next track.
... previoustrack moves back to the previous track.

Media Session action types - Web APIs
to support an action on a media session, such as seeking, pausing, or changing tracks, you need to call the mediasession interface's setactionhandler() method to establish a handler for that action.
...the following strings identify the currently available types of media session action: nexttrack advances playback to the next track.
... previoustrack moves back to the previous track.

Using Pointer Events - Web APIs
this may be a trackpad, a touch screen, or even a virtual mapping of a user's desk surface (or mousepad) with the physical screen.
... tracking new touches we'll keep track of the touches in-progress.
...the result is that we stop tracking that touch point.

RTCConfiguration - Web APIs
if the remote endpoint is bundle-aware, all media tracks and data channels are bundled onto a single transport at the completion of negotiation, regardless of policy used, and any superfluous transports that were created initially are closed at that point.
... "max-compat" the ice agent initially creates one rtcdtlstransport per media track and a separate one for data channels.
...if the remote endpoint is not bundle-aware, then only a single track will be negotiated and the rest ignored.

RTCPeerConnection.addTransceiver() - Web APIs
syntax rtptransceiver = rtcpeerconnection.addtransceiver(trackorkind, init); parameters trackorkind a mediastreamtrack to associate with the transceiver, or a domstring which is used as the kind of the receiver's track, and by extension of the rtcrtpreceiver itself.
... streams optional a list of mediastream objects to add to the transceiver'srtcrtpreceiver; when the remote peer's rtcpeerconnection's track event occurs, these are the streams that will be specified by that event.
... exceptions typeerror a string was specified as trackorkind which is not valid.

RTCRtpEncodingParameters.maxBitrate - Web APIs
the rtcrtpencodingparameters dictionary's maxbitrate property specifies the maximum number of bits per second to allow a track encoded with this encoding to use.
... syntax rtpencodingparameters.maxbitrate = maxbitspersecond; rtpencodingparameters = { maxbitrate: maxbitspersecond }; maxbitspersecond = rtpencodingparameters.maxbitrate; value an unsigned long integer value specifying the maximum bandwidth this encoding is permitted to use for a track of media it encodes in terms of bits per second.
... other parameters may further reduce the bandwidth used by the track; for example, maxframerate will, if set low enough, constrain the bandwidth as well.

RTCRtpReceiver - Web APIs
the rtcrtpreceiver interface of the webrtc api manages the reception and decoding of data for a mediastreamtrack on an rtcpeerconnection.
... properties rtcrtpreceiver.track read only returns the mediastreamtrack associated with the current rtcrtpreceiver instance.
... rtcrtpreceiver.transport read only returns the rtcdtlstransport instance over which the media for the receiver's track is received.

RTCRtpSendParameters.encodings - Web APIs
the rtcrtpsendparameters dictionary's encodings property is an rtcrtpencodingparameters object providing configuration settings for the encoder being used for the rtcrtpsender's track.
... syntax sendparameters.encodings = encodingparameterlist; encodingparameterlist = sendparameters.encodings; value an array of objects conforming to the rtcrtpencodingparameters dictionary, each of which contains properties which provide settings and parameters that describe and configure a single codec that could be used to encode the track.
... scaleresolutiondownby only used for senders whose track's kind is video, this is a double-precision floating-point value specifying a factor by which to scale down the video during encoding.

Streams API concepts - Web APIs
an internal queue keeps track of the chunks that have not yet been read (see the internal queues and queuing strategies section below).
... an internal queue keeps track of the chunks that have been written to the stream but not yet been processed by the underlying sink.
... internal queues and queuing strategies as mentioned earlier, the chunks in a stream that have not yet been processed and finished with are kept track of by an internal queue.

VTTCue() - Web APIs
syntax vttcue = new vttcue(starttime, endtime, text); parameters starttime this is a double representing the initial text track cue start time.
... endtime this is a double representing the ending time for this text track cue.
...var cue = new vttcue(2, 3, 'cool text to be displayed'); specifications specification status comment webvtt: the web video text tracks formatthe definition of 'vttcue()' in that specification.

Rendering and the WebXR frame animation callback - Web APIs
the xrframe doesn't directly keep track of the positions or orientations of the objects in your world.
...these input sources may include devices such as hand controllers, optical tracking systems, acclerometers and magnetometers, and other devices of that nature.
... the third and final type of input is the traditional non-xr input device such as keyboards, mice, trackpads, touch screens, and non-xr gamepads and joysticks.

Starting up and shutting down a WebXR session - Web APIs
first among these is that use of immersive-vr mode—which entirely replaces the user's view of the world—requires that the xr-spatial-tracking feature policy be in place.
... detecting reference space resets occasionally, discontinuities or jumps in the native origin may occur while tracking the user's position in the world.
... the most common scenarios in which this happens are when the user requests a recalibration of their xr device or when a hiccup or glitch occurs in the flow of tracking data received from the xr hardware.

WindowOrWorkerGlobalScope.setTimeout() - Web APIs
throttling of tracking timeout scripts since firefox 55, tracking scripts (e.g.
... google analytics, any script url that firefox recognises as a tracking script through its tp lists) have been subject to further throttling.
... the prefs that control this behaviour are: dom.min_tracking_timeout_value: 4 dom.min_tracking_background_timeout_value: 10000 dom.timeout.tracking_throttling_delay: 30000 late timeouts in addition to "clamping", the timeout can also fire later when the page (or the os/browser itself) is busy with other tasks.

XRPose.emulatedPosition - Web APIs
usage notes there are two basic categories of xr tracking systems.
... a basic xr headset provides three degrees of freedom (3dof), tracking the pitch, yaw, and roll of the user's head.
... contrariwise, xr devices which can also track movement forward and backward as well as laterally—six degree of freedom (6dof) devices—don't require any information from other sources to determine the user's position, so the value of emulatedposition is false.

XRSession: select event - Web APIs
examples of comon kinds of primary action are users pressing triggers or buttons, tapping a touchpad, speaking a command, or performing a recognizable gesture when using a video tracking system or handheld controller with an accelerometer.
...the handler fetches the pose representing the target ray for tracked-pointer inputs and sends the pose's transform to a function called myhandleselectwithray().
... xrsession.addeventlistener("select", event => { if (event.inputsource.targetraymode == "tracked-pointer") { let targetraypose = event.frame.getpose(event.inputsource.targetrayspace, myrefspace); if (targetraypose) { myhandleselectwithray(targetraypose.transform); } } }); you can of course also set up a handler for select events by setting the xrsession object's onselect event handler property to a function that handles the event: xrsession.onselect = event => { if (event.inputsource.targetraymode == "tracked-pointer") { let targetraypose = event.frame.getpose(event.inputsource.targetrayspace, myrefspace); if (targetraypose) { myhandleselectwithray(targetraypose.transform); } } }; specif...

Perceivable - Accessibility
see text alternatives for static caption options, and audio transcripts, video text tracks, and other multimedia content for other alternatives.
... see video text tracks for html5 video captions, and other multimedia content for other technologies.
... understanding non-text contrast 1.4.12 text spacing (aa) added in 2.1 no loss of content or functionality occurs when the following styles are applied: line height (line spacing) to at least 1.5 times the font size spacing following paragraphs to at least 2 times the font size letter spacing (tracking) to at least 0.12 times the font size word spacing to at least 0.16 times the font size understanding text spacing 1.4.13 content on hover or focus (aa) added in 2.1 while additional content may appear and disappear in coordination with hover and keyboard focus, this success criterion specifies three conditions that must be met: dismissable (can be ...

::-webkit-scrollbar - CSS: Cascading Style Sheets
::-webkit-scrollbar-track — the track (progress bar) of the scrollbar.
... ::-webkit-scrollbar-track-piece — the part of the track (progress bar) not covered by the handle.
..., .mostly-customized-scrollbar { display: block; width: 10em; overflow: auto; height: 2em; } .invisible-scrollbar::-webkit-scrollbar { display: none; } /* demonstrate a "mostly customized" scrollbar * (won't be visible otherwise if width/height is specified) */ .mostly-customized-scrollbar::-webkit-scrollbar { width: 5px; height: 8px; background-color: #aaa; /* or add it to the track */ } /* add a thumb */ .mostly-customized-scrollbar::-webkit-scrollbar-thumb { background: #000; } <div class="visible-scrollbar"> etiam sagittis sem sed lacus laoreet, eu fermentum eros auctor.

Border-radius generator - CSS: Cascading Style Sheets
= 0; i < size; i++) new checkbox(elem[i]); } return { init : init, setvalue : setvalue, subscribe : subscribe, unsubscribe : unsubscribe } })(); window.addeventlistener("load", function() { borderradius.init(); }); var borderradius = (function borderradius() { function getelembyid(id) { return document.getelementbyid(id); } /** * shadow dragging */ var previewmousetracking = (function drag() { var active = false; var lastx = 0; var lasty = 0; var subscribers = []; var init = function init(id) { var elem = getelembyid(id); elem.addeventlistener('mousedown', dragstart, false); document.addeventlistener('mouseup', dragend, false); } var dragstart = function dragstart(e) { if (e.button !== 0) return; active = true; lastx = e.cl...
...e handle-top-left' if (x === 'right' && y == 'top') handle.classname = 'handle handle-top-right'; if (x === 'right' && y == 'bottom') handle.classname = 'handle handle-bottom-right'; if (x === 'left' && y == 'bottom') handle.classname = 'handle handle-bottom-left'; handle.addeventlistener("mousedown", function(e) { active = true; this.radius.style.display = 'block'; previewmousetracking.subscribe(this.updatecontainer.bind(this)); }.bind(this)); document.addeventlistener("mouseup", function(e) { this.radius.style.display = 'none'; if (active === true) previewmousetracking.unsubscribe(this.updatecontainer.bind(this)); }.bind(this)); inputslidermanager.subscribe(this.topic + '-w', this.setwidth.bind(this)); inputslidermanager.subscribe(this.topic + '-h', th...
... updateuiwidth); inputslidermanager.subscribe("height", updateuiheight); inputslidermanager.setvalue("width", subject.clientwidth); inputslidermanager.setvalue("height", subject.clientheight); } return { init : init, updateoutput : updateoutput } })(); /** * init tool */ var init = function init() { buttonmanager.init(); inputslidermanager.init(); previewmousetracking.init("preview"); tool.init(); } return { init : init } })(); ...

Box alignment in grid layout - CSS: Cascading Style Sheets
basic example in this example using grid layout, there is extra space in the grid container after laying out the fixed width tracks on the inline (main) axis.
... content alignment justify-content align-content place-content these properties deal with aligning the tracks of the grid when there is extra space to distribute.
... this scenario will occur if the tracks that you have defined total less than the total width of the grid container.

Color picker tool - CSS: Cascading Style Sheets
= 'hsl' + a + hsl + v + ')'; return value; }; color.prototype.getcolor = function getcolor() { if (this.a | 0 === 1) return this.gethexa(); return this.getrgba(); }; /*=======================================================================*/ /*=======================================================================*/ /*========== capture mouse movement ==========*/ var setmousetracking = function setmousetracking(elem, callback) { elem.addeventlistener('mousedown', function(e) { callback(e); document.addeventlistener('mousemove', callback); }); document.addeventlistener('mouseup', function(e) { document.removeeventlistener('mousemove', callback); }); }; /*====================*/ // color picker class /*====================*/ function colorpicker(node)...
...ting the color-picker /*************************************************************************/ colorpicker.prototype.createpickingarea = function createpickingarea() { var area = document.createelement('div'); var picker = document.createelement('div'); area.classname = 'picking-area'; picker.classname = 'picker'; this.picking_area = area; this.color_picker = picker; setmousetracking(area, this.updatecolor.bind(this)); area.appendchild(picker); this.node.appendchild(area); }; colorpicker.prototype.createhuearea = function createhuearea() { var area = document.createelement('div'); var picker = document.createelement('div'); area.classname = 'hue'; picker.classname ='slider-picker'; this.hue_area = area; this.hue_picker = picker; setmousetracking(are...
...; colorpicker.prototype.createalphaarea = function createalphaarea() { var area = document.createelement('div'); var mask = document.createelement('div'); var picker = document.createelement('div'); area.classname = 'alpha'; mask.classname = 'alpha-mask'; picker.classname = 'slider-picker'; this.alpha_area = area; this.alpha_mask = mask; this.alpha_picker = picker; setmousetracking(area, this.updatealphaslider.bind(this)); area.appendchild(mask); mask.appendchild(picker); this.node.appendchild(area); }; colorpicker.prototype.createpreviewbox = function createpreviewbox(e) { var preview_box = document.createelement('div'); var preview_color = document.createelement('div'); preview_box.classname = 'preview'; preview_color.classname = 'preview-color'; ...

Microsoft CSS extensions - CSS: Cascading Style Sheets
microsoft-only properties (avoid using on websites) note: these properties will only work in microsoft applications, and are not on a standards track.
... -ms-flow-from -ms-flow-into -ms-high-contrast-adjust -ms-hyphenate-limit-chars -ms-hyphenate-limit-lines -ms-hyphenate-limit-zone -ms-ime-align -ms-overflow-style -ms-scrollbar-3dlight-color -ms-scrollbar-arrow-color -ms-scrollbar-base-color -ms-scrollbar-darkshadow-color -ms-scrollbar-face-color -ms-scrollbar-highlight-color -ms-scrollbar-shadow-color -ms-scrollbar-track-color -ms-scroll-chaining -ms-scroll-limit -ms-scroll-limit-x-max -ms-scroll-limit-x-min -ms-scroll-limit-y-max -ms-scroll-limit-y-min -ms-scroll-rails -ms-scroll-snap-points-x -ms-scroll-snap-points-y -ms-scroll-snap-x -ms-scroll-snap-y -ms-scroll-translation -ms-text-autospace -ms-touch-select -ms-wrap-flow -ms-wrap-margin -ms-wrap-through zoom pseudo-elements ::-ms-b...
...rowse ::-ms-check ::-ms-clear ::-ms-expand ::-ms-fill ::-ms-fill-lower ::-ms-fill-upper ::-ms-reveal ::-ms-thumb ::-ms-ticks-after ::-ms-ticks-before ::-ms-tooltip ::-ms-track ::-ms-value media features -ms-high-contrast css-related dom apis mscontentzoomfactor msgetpropertyenabled msgetregioncontent msrangecollection msregionoverflow ...

Mozilla CSS extensions - CSS: Cascading Style Sheets
mozilla-only properties and pseudo-classes (avoid using on websites) note: these properties and pseudo-classes will only work in mozilla applications such as firefox, and are not on a standards track.
...-moz-window-titlebar -moz-window-titlebar-maximized progressbar progresschunk radio radio-container radio-label radiomenuitem resizer resizerpanel scale-horizontal scalethumb-horizontal scalethumb-vertical scale-vertical scrollbarbutton-down scrollbarbutton-left scrollbarbutton-right scrollbarbutton-up scrollbar-small scrollbarthumb-horizontal scrollbarthumb-vertical scrollbartrack-horizontal scrollbartrack-vertical separator spinner spinner-downbutton spinner-textfield spinner-upbutton statusbar statusbarpanel tab tabpanels tab-scroll-arrow-back tab-scroll-arrow-forward textfield textfield-multiline toolbar toolbarbutton-dropdown toolbox tooltip treeheadercell treeheadersortarrow treeitem treetwisty treetwistyopen treeview window background-imag...
...ale-dir(ltr) :-moz-locale-dir(rtl) :-moz-lwtheme :-moz-lwtheme-brighttext :-moz-lwtheme-darktext n – r :-moz-native-anonymous :-moz-only-whitespace ::-moz-page ::-moz-page-sequence ::-moz-pagebreak ::-moz-pagecontent :-moz-placeholderobsolete since gecko 51 ::-moz-placeholderdeprecated since gecko 51 ::-moz-progress-bar ::-moz-range-progress ::-moz-range-thumb ::-moz-range-track :-moz-read-only :-moz-read-write s ::-moz-scrolled-canvas ::-moz-scrolled-content ::-moz-scrolled-page-sequence ::-moz-selectiondeprecated since gecko 62 :-moz-submit-invalid :-moz-suppressed ::-moz-svg-foreign-content t ::-moz-table ::-moz-table-cell ::-moz-table-column ::-moz-table-column-group ::-moz-table-outer ::-moz-table-row ::-moz-table-row-group :-moz-tree-ce...

fit-content() - CSS: Cascading Style Sheets
the function can be used as a track size in css grid properties, where the maximum size is defined by max-content and the minimum size by auto, which is calculated similar to auto (i.e., minmax(auto, max-content)), except that the track size is clamped at argument if it is greater than the auto minimum.
... in grid properties it is relative to the inline size of the grid container in column tracks and to the block size of the grid container for row tracks.
... candidate recommendation defines the function when used as a track size.

Audio and Video Delivery - Developer guides
for further info see cross browser audio basics (html5 audio in detail) html video <video controls width="640" height="480" poster="initialimage.png" autoplay muted> <source src="videofile.mp4" type="video/mp4"> <!-- fallback for browsers that don't support mp4 --> <source src="videofile.webm" type="video/webm"> <!-- specifying subtitle files --> <track src="subtitles_en.vtt" kind="subtitles" srclang="en" label="english"> <track src="subtitles_no.vtt" kind="subtitles" srclang="no" label="norwegian"> <!-- fallback for browsers that don't support video tag --> <a href="videofile.mp4">download video</a> </video> the code above creates a video player of dimensions 640x480 pixels, displaying a poster image until the video is played.
...other functionality such as the track element for subtitles can also be provided through media libraries.
... advanced tutorials adding captions and subtitles to html5 video this article explains how to add captions and subtitles to html5 <video>, using web_video_text_tracks_format and the <track> element.

Touch events (Mozilla experimental) - Developer guides
this api allowed you to track the movement of the user's finger on a touch screen, monitoring the raw touch events generated by the system.
... although touch events were based on — and work similarly to — mouse events, each event included an identifier that allowed you to track multiple fingers moving on the screen at the same time.
...this lets you track each finger's movements on the touch screen independently.

Index - Developer guides
7 adding captions and subtitles to html5 video html5, media, webvtt, captions, subtitles, track in other articles we looked at how to build a cross browser video player using the htmlmediaelement and window.fullscreen apis, and also at how to style the player.
... this article will take the same player and show how to add captions and subtitles to it, using the webvtt format and the <track> element.
...these are special movements that can be made with a mouse or trackpad and can be interpreted to perform specific tasks.

itemprop - HTML: Hypertext Markup Language
property values are either a string or a url and can be associated with a very wide range of elements including <audio>, <embed>, <iframe>, <img>, <link>, <object>, <source> , <track>, and <video>.
... if the element is a meta element the value is the value of the element's content attribute if the element is an audio, embed, iframe, img, source, track, or video element the value is the resulting url string that results from parsing the value of the element's src attribute relative to the node document (part of the microdata dom api) of the element at the time the attribute is set if the element is an a, area, or link element the value is the resulting url string that results from parsing the value of the element's href attrib...
...the url property elements are the a, area, audio, embed, iframe, img, link, object, source, track, and video elements.

HTML documentation index - HTML: Hypertext Markup Language
property values are either a string or a url and can be associated with a very wide range of elements including <audio>, <embed>, <iframe>, <img>, <link>, <object>, <source> , <track>, and <video>.
... 213 <track>: the embed text track element accessibility, cues, element, html, html embedded content, html5, multimedia, reference, texttrack, web, a11y, track the html <track> element is used as a child of the media elements, <audio> and <video>.
... it lets you specify timed text tracks (or time-based data), for example to automatically handle subtitles.

Index - HTTP
56 dnt dnt, http, reference, header the dnt (do not track) request header indicates the user's tracking preference.
... 106 tk dnt, http, reference, response, header, tracking the tk response header indicates the tracking status that applied to the corresponding request.
...it is used for tracking message forwards, avoiding request loops, and identifying the protocol capabilities of senders along the request/response chain.

HTTP headers - HTTP
do not track dnt expresses the user's tracking preference.
... tk indicates the tracking status of the corresponding response.
...it is a structured header whose value is a token with possible values audio, audioworklet, document, embed, empty, font, image, manifest, object, paintworklet, report, script, serviceworker, sharedworker, style, track, video, worker, xslt, and nested-document.

HTTP resources and specifications - HTTP
cookies from non-secure origins ietf draft rfc 2145 use and interpretation of http version numbers informational rfc 6585 additional http status codes proposed standard rfc 7538 the hypertext transfer protocol status code 308 (permanent redirect) proposed standard rfc 7725 an http status code to report legal obstacles on the standard track rfc 2397 the "data" url scheme proposed standard rfc 3986 uniform resource identifier (uri): generic syntax internet standard rfc 5988 web linking defines the link header proposed standard experimental spec hypertext transfer protocol (http) keep-alive header informational (expired) draft spec http client hints ietf dr...
... proposed standard rfc 2817 upgrading to tls within http/1.1 proposed standard rfc 7540 hypertext transfer protocol version 2 (http/2) proposed standard rfc 7541 hpack: header compression for http/2 on the standard track rfc 7838 http alternative services on the standard track rfc 7301 transport layer security (tls) application-layer protocol negotiation extension used to negotiate http/2 at the transport to save an extra request/response round trip.
... proposed standard rfc 2324 hyper text coffee pot control protocol (htcpcp/1.0) april 1st joke spec rfc 7168 the hyper text coffee pot control protocol for tea efflux appliances (htcpcp-tea) april 1st joke spec html living standard html defines extensions of http for server-sent events living standard tracking preference expression dnt header editor's draft / candidate recommendation reporting api report-to header draft draft spec expect-ct extension for http ietf draft ...

Keyed collections - JavaScript
you can get the size of a map easily, while you have to manually keep track of size for an object.
...you don't have to manually keep track of duplicates.
...they will not leak memory, so it can be safe to use dom elements as a key and mark them for tracking purposes, for example.

tabs - Archive of obsolete content
usage open a tab you can open a new tab, specifying various properties including location: var tabs = require("sdk/tabs"); tabs.open("http://www.example.com"); track tabs you can register event listeners to be notified when tabs open, close, finish loading dom content, or are made active or inactive: var tabs = require("sdk/tabs"); // listen for tab openings.
... console.log(tab.title); you can also access individual tabs by index: var tabs = require('sdk/tabs'); tabs.on('ready', function () { console.log('first: ' + tabs[0].title); console.log('last: ' + tabs[tabs.length-1].title); }); you can access the currently active tab: var tabs = require('sdk/tabs'); tabs.on('activate', function () { console.log('active: ' + tabs.activetab.url); }); track a single tab given a tab, you can register event listeners to be notified when the tab is closed, activated or deactivated, or when the page hosted by the tab is loaded or retrieved from the "back-forward cache": var tabs = require("sdk/tabs"); function onopen(tab) { console.log(tab.url + " is open"); tab.on("pageshow", logshow); tab.on("activate", logactivate); tab.on("deactivate", lo...

widget - Archive of obsolete content
this issue is currently tracked as bug 825434.
...this issue is currently tracked as bug 825434.

ui/frame - Archive of obsolete content
this issue is being tracked as bug 982385.
... this is used to generate an id to to keep track of the frame.

Creating annotations - Archive of obsolete content
you should see the highlight appearing when you move the mouse over certain elements: click on the highlight and you should see something like this in the console output: info: show info: http://blog.mozilla.com/addons/2011/02/04/overview-amo-review-process/, post-2249,when you submit a new add-on, you will have to choose between 2 review tracks: full review and preliminary review.
...you should see a panel with a text area for a note: enter the note and press the return key: you should see console output like this: info: http://blog.mozilla.com/addons/2011/02/04/overview-amo-review-process/, post-2249,when you submit a new add-on, you will have to choose between 2 review tracks: full review and preliminary review.

Troubleshooting - Archive of obsolete content
this page lists some starting points that might help you track down your problem.
...you will need to create an account with bugzilla, mozilla's bug tracker.

Examples and demos from articles - Archive of obsolete content
in such a condition is difficult and unnatural to keep track of all events started and then to stop them when appropriate through the cleartimeout() function.
...in such a condition is difficult and unnatural to keep track of all events started and then to stop them when appropriate through the cleartimeout() function.

MMgc - Archive of obsolete content
classic reference counting previous versions of the flash player, up to flash player 7, used reference counting to track object lifetimes.
...reference counting can track relationships between objects, and as long as addref and release are called at the proper times, can reclaim memory from objects that are no longer referenced.

Bookmark Keywords - Archive of obsolete content
searches, lookups, package tracking, and even word definitions can all be retrieved from user-customized bookmarks.
... bookmark suggested keywords find bugzilla entry bug, bugzilla, bz search devmo devmo, de google search google, gg dictionary search dictionary, dict, define, word thesaurus search thesaurus, like fedex tracking fedex ups tracking ups of course, these are just a beginning.

Conclusion - Archive of obsolete content
tinderbox actually keeps track of more than one codebase.
... in particular, it tracks both the main mozilla codebase (the trunk) and a stable branch.

In-Depth - Archive of obsolete content
other sites which list mozilla specific css properties xulplanet.com [dead link, 26.03.13] mozilla-prefixed properties on the standard track 26.03.13 -moz-appearance makes a widget look like it's from your operating system.
...own, listbox, menu, menulist-textfield, menulist-button, menulist, menulist-text, progressbar, progresschunk, radio-container, radio, resizer, resizerpanel, separator, scrollbar, statusbar, statusbarpanel, toolbarbutton, toolbox, toolbar, treeheadercell, treeheadersortarrow, treeview, treeitem, treetwisty, treetwistyopen, tooltip, textfield, tabpanels, tab, tab-left-edge, tab-right-edge, scrollbartrack-horizontal, scrollbartrack-vertical, scrollbarthumb-vertical, scrollbarthumb-horizontal, scrollbarbutton-right, scrollbarbutton-down, scrollbarbutton-left, scrollbarbutton-up, scrollbargripper-vertical, scrollbargripper-horizontal -moz-border-bottom-colors defines a series of colours.

Repackaging Firefox - Archive of obsolete content
using an extension makes it far easier to keep track of your changes easily when the time comes to upgrade to new versions of firefox, and also ensures, when set-up correctly, that users are able to safely receive firefox updates from mozilla.
...they help mozilla track your distribution, and plan upgrades accordingly.

Tamarin build documentation - Archive of obsolete content
what we want is to have the indexer track the currently selected build config (so the correct conditional compiles are highlighted in the editor).
...o workspace' click finish building in eclipse 8 build configurations are included for macos with the gcc 4.0 toolchain: mac-32-release mac-64-release mac-32-debug mac-64-debug mac-32-release-debugger mac-64-release-debugger mac-32-debug-debugger mac-64-debug-debugger the build location will be project_root/build_name/avm note: as discussed above, the c++ indexer has been setup to track the current build config, so the correct conditional compiles are highlighted in the editor run/debug from eclipse for test purposes, a launch config (running the helloworld test from esc) has been included for each of the build configs.

XBL - Archive of obsolete content
xbl bindings have been removed from the firefox codebase and the work was tracked in bug 1397874 and are we xbl still?.
... removal of the xbl implementation is being tracked in bug 1566221.

Building Trees - Archive of obsolete content
as a result, the builder only has a few pieces of information to keep track of.
...these are used to track the current state of the disclosure triangles.

XUL accessibility guidelines - Archive of obsolete content
some users use mouth sticks or movement detection devices such as eye tracking to type.
... media checkpoint pass fail audio transcripts are provided for audio tracks.

prefpane - Archive of obsolete content
void userchangedvalue(in domelement element); the user changed the value in a widget that the preferences system does not automatically track state changes for (1) and the preference element associated with the widget should be updated based on the state held by the widget.
... (1) an example of a widget that has state changes tracked for it includes the checkbox element, whose state is tracked automatically when the "command" event fires.

NPP_Write - Archive of obsolete content
the plug-in can use the offset parameter to track the bytes that are written.
...in a seekable stream with byte range requests, you can use this parameter to track npn_requestread requests.see also npp_destroystream, npp_newstream, npp_writeready, npstream, npp ...

Using workers in extensions - Archive of obsolete content
then it sets the worker's onmessage event handler to a function which looks at the event passed into it, and does one of two things: if there is a data field on the event, the stock symbol being tracked is set to the upper case version of that value.
...it needs to be updated to post a message to the worker to tell it which stock symbol to track.

::-ms-fill-upper - Archive of obsolete content
the ::-ms-fill-upper css pseudo-element is a microsoft extension that represents the upper portion of the track of a slider control; that is, the portion corresponding to values greater than the value currently selected by the thumb.
... see also ::-ms-fill-lower ::-ms-track ::-ms-thumb ::-moz-range-progress css-tricks: styling cross-browser compatible range inputs with css quirksmode: styling and scripting sliders ...

::-ms-thumb - Archive of obsolete content
the ::-ms-thumb css pseudo-element is a microsoft extension that represents the thumb that the user moves within the track of a slider control to alter its numerical value.
... see also ::-ms-track ::-ms-fill-upper ::-ms-fill-lower ::-webkit-slider-thumb ::-moz-range-thumb css-tricks: styling cross-browser compatible range inputs with css quirksmode: styling and scripting sliders ...

::-ms-ticks-after - Archive of obsolete content
the ::-ms-ticks-after css pseudo-element is a microsoft extension that applies one or more styles to the tick marks that appear after the track of a slider control.
... it is possible to use the ::-ms-ticks-after, ::-ms-ticks-before, and ::-ms-track pseudo-elements together.

::-ms-ticks-before - Archive of obsolete content
the ::-ms-ticks-before css pseudo-element is a microsoft extension that applies one or more styles to the tick marks that appear before the track of a slider control.
... it is possible to use the ::-ms-ticks-after, ::-ms-ticks-before, and ::-ms-track pseudo-elements together.

Index - Game development
26 audio for web games audio, games, web audio api, audio sprites, spatialization, syncing tracks audio is an important part of any game; it adds feedback and atmosphere.
... 69 track the score and win beginner, canvas, games, javascript, tutorial, scoring, winning destroying the bricks is really cool, but to be even more awesome the game could award points for every brick a user hits, and keep count of the total score.

Efficient animation for web games - Game development
you must keep track of time and set your animation properties based on elapsed time.
...we would recommend keeping track of when requestanimationframe has been called and only having a single handler for it.

Collision detection - Game development
eft; var bricky = (r*(brickheight+brickpadding))+brickoffsettop; bricks[c][r].x = brickx; bricks[c][r].y = bricky; ctx.beginpath(); ctx.rect(brickx, bricky, brickwidth, brickheight); ctx.fillstyle = "#0095dd"; ctx.fill(); ctx.closepath(); } } } } tracking and updating the status in the collision detection function now we need to involve the brick status property in the collisiondetection() function: if the brick is active (its status is 1) we will check whether the collision happens; if a collision does occur we'll set the status of the given brick to 0 so it won't be painted on the screen.
...in the eighth chapter we will be looking at how to track the score and win.

Grid Cell - MDN Web Docs Glossary: Definitions of Web-related terms
additional row or column tracks will be created to create enough cells to hold all items.
... in the example we have created a three column track grid.

Test your skills: Grid Layout - Learn web development
the grid should have three columns sharing the available space equally, and a 20-pixel gap between the column and row tracks.
...by editing the css rules for the two child elements, cause them to span over several grid tracks each; the second item should overlay the first as in the image below.

Introduction to CSS layout - Learn web development
in addition to using display: grid, we are also defining some row and column tracks on the parent using the grid-template-rows and grid-template-columns properties respectively.
...this causes the items to span multiple tracks.

Beginner's guide to media queries - Learn web development
a fine pointer is something like a mouse or trackpad.
... with the example open in your browser, make the screen wider and narrower to see the number of column tracks change.

What is a Domain Name? - Learn web development
companies called registrars use domain name registries to keep track of technical and administrative information connecting you to your domain name.
... note : for some domain name, it might not be a registrar which is in charge of keeping track.

How to build custom form controls - Learn web development
the script is in conflict with a third party script: this can happen with tracking scripts or any bookmarklets the user uses.
...such a control will keep track of the value with all the built-in controls provided by the browser, and the value will be sent as usual when a form is submitted.

Graceful asynchronous programming with Promises - Learn web development
the code that the video chat application would use might look something like this: function handlecallbutton(evt) { setstatusmessage("calling..."); navigator.mediadevices.getusermedia({video: true, audio: true}) .then(chatstream => { selfviewelem.srcobject = chatstream; chatstream.gettracks().foreach(track => mypeerconnection.addtrack(track, chatstream)); setstatusmessage("connected"); }).catch(err => { setstatusmessage("failed to connect"); }); } this function starts by using a function called setstatusmessage() to update a status display with the message "calling...", indicating that a call is being attempted.
... it then calls getusermedia(), asking for a stream that has both video and audio tracks, then once that's been obtained, sets up a video element to show the stream coming from the camera as a "self view," then takes each of the stream's tracks and adds them to the webrtc rtcpeerconnection representing a connection to another user.

Cooperative asynchronous JavaScript: Timeouts and intervals - Learn web development
you'll want to add a tracking variable to check whether the spinner is spinning or not, clearing the animation frame if it is, and calling it again if it isn't.
... set the variable isover to false, so we can track whether the correct keys were pressed for player 1 or 2 to win.

Drawing graphics - Learn web development
te origin sit in the middle of the canvas: ctx.translate(width/2, height/2); now let's create a new htmlimageelement object, set its src to the image we want to load, and add an onload event handler that will cause the draw() function to fire when the image is loaded: let image = new image(); image.src = 'walk-right.png'; image.onload = draw; now we'll add some variables to keep track of the position the sprite is to be drawn on the screen, and the sprite number we want to display.
...first of all, we keep track of the mouse's x and y coordinates and whether it is being clicked or not with three variables: curx, cury, and pressed.

Adding features to our bouncing balls demo - Learn web development
finally, we want to add a score counter to track the number of balls left to capture.
... it should also define a new property called exists, which is used to track whether the balls exist in the program (have not been eaten by the evil circle).

Inheritance in JavaScript - Learn web development
when using inheritance, you are advised to not have too many levels of inheritance, and to keep careful track of where you define your methods and properties.
...if you find yourself creating a bunch of related variables and functions and want to track them all together and package them neatly, an object is a good idea.

JavaScript performance - Learn web development
often times third party scripts and apis are added, including a/b testing, tracking pixels, and features like maps and support features.
...often times third party scripts and apis are added, including a/b testing, tracking pixels, and features like maps and support features.

Getting started with Ember - Learn web development
the glimmer vm enables extremely fast dom change tracking without the need to manage and diff a cached virtual representation (which is a common approach to mitigating the slow i/o of dom changes).
...todomvc is a basic to-do tracking app implemented in many different technologies.

Accessibility in React - Learn web development
we want this constant to track the previous value of isediting, so we call useprevious with isediting as an argument: const wasediting = useprevious(isediting); with this constant, we can update our useeffect() hook to implement the pseudocode we discussed before — update it as follows: useeffect(() => { if (!wasediting && isediting) { editfieldref.current.focus(); } if (wasediting && !isediting) { editbutto...
...add it to the top of your app.js file, just below the imports: function useprevious(value) { const ref = useref(); useeffect(() => { ref.current = value; }); return ref.current; } now add the following, above the return statement inside the app() function: const prevtasklength = useprevious(tasks.length); here we are invoking useprevious() to track the length of the tasks state, like so: note: since we're now utilizing useprevious() in two files, a good efficiency refactor would be to move the useprevious() function into its own file, export it from that file, and import it where you need it.

Advanced Svelte: Reactivity, lifecycle, accessibility - Learn web development
that's because svelte can't track object references, so we have to explicitly tell it that obj has changed by issuing an assignment.
...add this just below your other variable definitions: let editbuttonpressed = false // track if edit button has been pressed, to give focus to it after cancel or save next, we'll modify the edit button's functionality to save this flag, and create the action for it.

Dynamic behavior in Svelte: working with variables and props - Learn web development
we'll also create two variables to keep track of the total number of tasks and the completed tasks.
...using them often causes side effects and bugs that are hard to track.

Using Vue computed properties - Learn web development
currently, we're not actually tracking the "done" data in any fashion, so the number of completed items does not change.
... tracking changes to "done" we can use events to capture the checkbox update and manage our list accordingly.

Handling common accessibility problems - Learn web development
there is a way to define text tracks (e.g.
... subtitles) and display them when video is being played, in the form of the <track> element, and the webvtt format (see adding captions and subtitles to html5 video for a detailed tutorial).

Introduction to automated testing - Learn web development
note: all the videos and images captured inside a test session are captured inside the gallery, test logs, and issue tracker at lambdatest.
... issue tracker (looks like a deck of cards) — view previously captured bugs/screenshots.

Handling common HTML and CSS problems - Learn web development
this includes linting code, handling css prefixes, using browser dev tools to track down problems, using polyfills to add support into browsers, tackling responsive design problems, and more.
... note: when trying to track down a tricky layout issue, a good technique is to add a brightly colored outline to the offending element, or all the elements nearby.

Handling common JavaScript problems - Learn web development
this includes information on using browser dev tools to track down and fix problems, using polyfills and libraries to work around problems, getting modern javascript features working in older browsers, and more.
...when tracking a device's location using repeated geolocation calls, make sure you turn it off when the user stops using it.

Strategies for carrying out testing - Learn web development
once you've finished filling in everything, press the get tracking id button, then accept the terms of service that appear.
...for a basic website, what you need to do is copy the website tracking code block and paste it into all the different pages you want to track using google analytics on your site.

Cross browser testing - Learn web development
this includes linting code, handing css prefixes, using browser dev tools to track down problems, using polyfills to add support into browsers, tackling responsive design problems, and more.
...this includes information on using browser dev tools to track down and fix problems, using polyfills and libraries to work around problems, getting modern javascript features working in older browsers, and more.

Mozilla accessibility architecture
member variables in nsaccessible that keep track of the number of children (maccchildcount), the parent (mparent), the first child (mfirstchild) and the next sibling (mnextsibling).
...the member variables keeping track of the number of children, parent, first child and next sibling allow us to have instant traversal around accessible nodes that have already been visited.

Testopia
it is designed to be a generic tool for tracking test cases, allowing for testing organizations to integrate bug reporting with their test case run results.
... though it is designed with software testing in mind, it can be used to track testing on virtually anything in the engineering process.

Bugzilla
bugzilla.mozilla.org (often abbreviated b.m.o) is mozilla.org's bug-tracking system, a database for recording bugs and enhancement requests for firefox, thunderbird, seamonkey, camino, and other mozilla.org projects.
... how to tell if a bug has already been reported it's useful (but not mandatory) for you to check if the problem you're reporting has been already tracked.

Debugging
it is slow, but good for tracking down difficult memory safety bugs.
... gecko logging using old-school logging to try to track down what's going on.

Developer guide
tools bugzilla the bugzilla database used to track issues for mozilla projects.
... crash tracking information about the socorro crash reporting system.

Errors
this page lists the errors that can be raised due to firefox's anti-tracking functionality, governed by the storage access policy.
... you can find further information about them by clicking on the links below: a request to access cookies or storage was blocked because of a custom cookie permission blocked because it came from a tracker and content blocking is enabled blocked because we are blocking all storage access requests blocked because we are blocking all third-party storage access requests and content blocking is enabled granted partitioned access because it came from a third-party and dynamic first-party isolation is enabled ...

overflow-clip-box
non-standard this feature is non-standard and is not on a standards track.
...ip-box: padding-box; } js function scrollsomeelements() { var elms = document.queryselectorall('.scroll'); for (i=0; i < elms.length; ++i) { elms[i].scrollleft=80; } } var elt = document.queryelementsbytagname('body')[0]; elt.addeventlistener("load", scrollsomeelements, false); result specifications this property has been proposed to the w3c csswg; it is not yet on the standard track but, if accepted, should appear in css overflow module level 3.

Getting from Content to Layout
restyling the restyletracker maintains a list of restyles to process.
... the restyles accumulated in the restyletracker are dispensed with from various method on the presshell that involve reflow and flushing notifications.

IPDL Tutorial
a sub-protocol is bound to a "manager" which tracks its lifetime and acts as a factory.
...ipdl tracks all active protocols between two endpoints.

Localization technical reviews
tracking your progress you can track your reviews progress two ways: within the bug and through your team's dashboard.
...these bugs are also pulled into the dashboards, which track your revision's progress.

Automated performance testing and sheriffing
we also generate some metrics as part of the build process (like installer size) that are interesting to track over time.
... current list of automated systems we are tracking (at least to some degree): talos: the main performance system, run on virtually every check-in to an integration branch build metrics: a grab bag of performance metrics generated by the build system arewefastyet: a generic javascript and web benchmarking system areweslimyet: a memory benchmarking tool ...

Investigating leaks using DMD heap scan mode
firefox’s dmd heap scan mode tracks the set of all live blocks of malloc-allocated memory and their allocation stacks, and allows you to log these blocks, and the values stored in them, to a file.
...n firefox will look something like this: xpcom_mem_bloat_log=1 moz_cc_log_shutdown=1 moz_disable_content_sandbox=t moz_cc_log_directory=$logdir moz_cc_log_process=content moz_cc_log_thread=main moz_dmd_shutdown_log=$logdir moz_dmd_log_process=tab ./mach run --dmd --mode=scan breaking this down: xpcom_mem_bloat_log=1: this reports a list of the counts of every object created and destroyed and tracked by the xpcom leak tracking system.

Memory Profiler
moreover, they usually don't keep tracks of how objects are allocated.
...naturally, not only javascript objects but also native allocations are tracked.

Refcount tracing and balancing
refcount tracing and balancing are advanced techniques for tracking down leak of refcounted objects found with bloatview.
...when this is set, along with xpcom_mem_log_classes and xpcom_mem_refcnt_log, a stack track will be generated for only the specific objects that you list.

TimerFirings logging
-991946880[7f46c365ba00]: [6775] fn timer (slack 100 ms): layeractivitytracker -991946880[7f46c365ba00]: [6775] fn timer (one_shot 250 ms): presshell::spaintsuppressioncallback -991946880[7f46c365ba00]: [6775] fn timer (one_shot 160 ms): nsbrowserstatusfilter::timeouthandler -991946880[7f46c365ba00]: [6775] iface timer (one_shot 200 ms): 7f46964d7f80 -1340643584[7f46c365ec00]: [6775] obs timer (slack 1000 ms): 7f46a95a0200 each line has the following i...
... 204 fn timer (one_shot): [content] http://widgets.outbrain.com/outbrain.js:20:330 186 fn timer (one_shot): nsbrowserstatusfilter::timeouthandler 138 fn timer (one_shot): [content] https://self-repair.mozilla.org/repair/:7:13669 118 fn timer (one_shot): [content] http://a.visualrevenue.com/vrs.js:6:9423 108 fn timer (slack): layeractivitytracker 104 fn timer (slack): nsidocument::selectorcache 104 fn timer (slack): cctimerfired ...

Performance
awsy) is a memory usage and regression tracker.
... refcount tracing and balancing refcount tracing and balancing are ways to track down leaks caused by incorrect uses of reference counting.

Profile Manager
by default, this means it tracks a list of firefox applications that are installed on your system, and a list of profiles for use by firefox.
... profile manager does not track these backups in the ui, but using profile archives is an easy way to move profiles between machines.

NSPR Contributor Guide
bugfixes use bugzilla to track bugs.
...use bugzilla to track your work.

NSS API Guidelines
estructor_list preprocessor definition, and the code it encloses, are an effort to make the following work together: arenas, letting you allocate stuff and then removing them all at once lazy creation of pure-memory objects from asn.1 blobs, for example use of nsspkixcertificate doesn't drag all the code in for all constituent objects, unless they're actually being used our agressive pointer-tracking facility all these are useful, but they don't combine well.
... now some of the pointer-tracking pressure has eased off, we can drop its use when it becomes too difficult.

AT APIs Support
supported at apis at apis terms microsoft active accessibility (msaa) an api devised by microsoft so that accessibility aids can track what's going on inside the user interface of any software package that supports it.
... assistive technology service provider interface (at-spi) an api devised by sun microsystems so that accessibility aids can track what's going on inside the user interface of any software package that supports it.

Introduction to XPCOM for the DOM
the tracking bug for this document is bug 99592.
...this is why it is very important to keep track of the reference count of each object.

nsIDOMHTMLAudioElement
firefox 4 / thunderbird 3.3 / seamonkey 2.1) inherits from: nsidomhtmlmediaelement method overview unsigned long long mozcurrentsampleoffset(); void mozsetup(in pruint32 channels, in pruint32 rate); [implicit_jscontext] unsigned long mozwriteaudio(in jsval data); methods mozcurrentsampleoffset() non-standard this feature is non-standard and is not on a standards track.
...mozsetup() non-standard this feature is non-standard and is not on a standards track.

nsIDOMMozTouchEvent
this differs from tracking mouse events in that touch events can be generated independently for each finger touching the screen.
... in boolean shiftkeyarg, in boolean metakeyarg, in unsigned short buttonarg, in nsidomeventtarget relatedtargetarg, in unsigned long streamidarg); attributes attribute type description streamid unsigned long a unique identifier for each finger, so that each finger's movement can be tracked separately.

nsIXULWindow
highestz 9 methods addchildwindow() tell this window that it has picked up a child xul window.note that xul windows do not currently track child xul windows.
...note that xul windows do not currently track child xul windows.

Mozilla
bugzilla bugzilla.mozilla.org (often abbreviated b.m.o) is mozilla.org's bug-tracking system, a database for recording bugs and enhancement requests for firefox, thunderbird, seamonkey, camino, and other mozilla.org projects.
... how to get a process dump with windows task manager when tracking down the causes of process hangs, it is often helpful to obtain a process dump while the process is experiencing a hang.

URLs - Plugins
the browser notifies the plug-in by calling the plug-in's npp_urlnotify function and passing it the notifydata value, which may be used to track multiple requests.
...the notifydata parameter contains plug-in-private data passed by npp_urlnotify and may be used for tracking multiple posts.

Debugger - Firefox Developer Tools
(naturally, the debugger.object instance this method returns does hold a strong reference to the added global.) if this debugger is tracking allocation sites and cannot track allocation sites forglobal, this method throws an error.
... if this debugger is tracking allocation sites and cannot track allocation sites for some global, this method throws an error.

AudioBufferSourceNode.loopStart - Web APIs
example in this example, the audiocontext.decodeaudiodata() function is used to decode an audio track and put it into an audiobuffersourcenode.
...for example, if you set their values to 20 and 25, respectively, the audio will start to loop between 20 and 25 seconds in to the track.

AudioConfiguration - Web APIs
channels: the number of channels used by the audio track.
... examples //create media configuration to be tested const mediaconfig = { type : 'file', // 'record', 'transmission', or 'media-source' audio : { contenttype : "audio/ogg", // valid content type channels : 2, // audio channels used by the track bitrate : 132700, // number of bits used to encode 1s of audio samplerate : 5200 // number of audio samples making up that 1s.

AudioProcessingEvent - Web APIs
example the following example shows basic usage of a scriptprocessornode to take a track loaded via audiocontext.decodeaudiodata(), process it, adding a bit of white noise to each audio sample of the input track (buffer) and play it through the audiodestinationnode.
...or('pre'); var playbutton = document.queryselector('button'); // create audiocontext and buffer source var audioctx = new audiocontext(); source = audioctx.createbuffersource(); // create a scriptprocessornode with a buffersize of 4096 and a single input and output channel var scriptnode = audioctx.createscriptprocessor(4096, 1, 1); console.log(scriptnode.buffersize); // load in an audio track via xhr and decodeaudiodata function getdata() { request = new xmlhttprequest(); request.open('get', 'viper.ogg', true); request.responsetype = 'arraybuffer'; request.onload = function() { var audiodata = request.response; audioctx.decodeaudiodata(audiodata, function(buffer) { mybuffer = buffer; source.buffer = mybuffer; }, function(e){"error with decoding audio...

BaseAudioContext.createScriptProcessor() - Web APIs
example the following example shows basic usage of a scriptprocessornode to take a track loaded via audiocontext.decodeaudiodata(), process it, adding a bit of white noise to each audio sample of the input track (buffer) and play it through the audiodestinationnode.
...or('pre'); var playbutton = document.queryselector('button'); // create audiocontext and buffer source var audioctx = new audiocontext(); source = audioctx.createbuffersource(); // create a scriptprocessornode with a buffersize of 4096 and a single input and output channel var scriptnode = audioctx.createscriptprocessor(4096, 1, 1); console.log(scriptnode.buffersize); // load in an audio track via xhr and decodeaudiodata function getdata() { request = new xmlhttprequest(); request.open('get', 'viper.ogg', true); request.responsetype = 'arraybuffer'; request.onload = function() { var audiodata = request.response; audioctx.decodeaudiodata(audiodata, function(buffer) { mybuffer = buffer; source.buffer = mybuffer; }, function(e){"error with decoding audio...

Document.requestStorageAccess() - Web APIs
note: if the requesting origin is not classified as a tracking origin, the access request is automatically given an ephemeral storage access grant, which will go away when the page is reloaded.
...all calls to requeststorageaccess() by origins classified as trackers will trigger a prompt.

GlobalEventHandlers.oncuechange - Web APIs
the cuechange event fires when a texttrack has changed the currently displaying cues.
... the event is sent to both the texttrack and to the <track> element the track is being presented by, if any; in the latter case, its handler is on an htmltrackelement object.

HTMLMediaElement: loadedmetadata event - Web APIs
using addeventlistener(): const video = document.queryselector('video'); video.addeventlistener('loadedmetadata', (event) => { console.log('the duration and dimensions ' + ' of the media and tracks are now known.
... '); }); using the onloadedmetadata event handler property: const video = document.queryselector('video'); video.onloadedmetadata = (event) => { console.log('the duration and dimensions ' + ' of the media and tracks are now known.

In depth: Microtasks and the JavaScript runtime environment - Web APIs
each context additionally tracks the next line in the program that should be run and other information critical to that context's operation.
...this allows the javascript runtime to track the levels of recursion and the return of results through that recursion, but it also means that each time a function recurses, more memory is needed to create the new context.

The HTML DOM API - Web APIs
t htmlpictureelement htmlpreelement htmlprogresselement htmlquoteelement htmlscriptelement htmlselectelement htmlslotelement htmlsourceelement htmlspanelement htmlstyleelement htmltablecaptionelement htmltablecellelement htmltablecolelement htmltableelement htmltablerowelement htmltablesectionelement htmltemplateelement htmltextareaelement htmltimeelement htmltitleelement htmltrackelement htmlulistelement htmlunknownelement htmlvideoelement deprecated html element interfaces htmlmarqueeelement obsolete html element interfaces htmlbasefontelement htmlfontelement htmlframeelement htmlframesetelement htmlisindexelement htmlmenuitemelement web app and browser integration interfaces these interfaces offer access to the browser window and d...
... audiotrack audiotracklist mediaerror texttrack texttrackcue texttrackcuelist texttracklist timeranges trackevent videotrack videotracklist drag and drop interfaces these interfaces are used by the html_drag_and_drop_api to represent individual draggable (or dragged) items, groups of dragged or draggable items, and to handle the drag and drop process.

ImageCapture.getPhotoCapabilities() - Web APIs
this example also shows how the imagecapture object is created using a mediastreamtrack retrieved from a device's mediastream.
... const input = document.queryselector('input[type="range"]'); var imagecapture; navigator.mediadevices.getusermedia({video: true}) .then(mediastream => { document.queryselector('video').srcobject = mediastream; const track = mediastream.getvideotracks()[0]; imagecapture = new imagecapture(track); return imagecapture.getphotocapabilities(); }) .then(photocapabilities => { const settings = imagecapture.track.getsettings(); input.min = photocapabilities.imagewidth.min; input.max = photocapabilities.imagewidth.max; input.step = photocapabilities.imagewidth.step; return imagecapture.getphotosettings(); }) .then(photosettings => { input.value = photosettings.imagewidth; }) .catch(error => console.log('argh!', error.name || error)); specifications specification ...

ImageCapture.getPhotoSettings() - Web APIs
this example also shows how the imagecapture object is created using a mediastreamtrack retrieved from a device's mediastream.
... const input = document.queryselector('input[type="range"]'); var imagecapture; navigator.mediadevices.getusermedia({video: true}) .then(mediastream => { document.queryselector('video').srcobject = mediastream; const track = mediastream.getvideotracks()[0]; imagecapture = new imagecapture(track); return imagecapture.getphotocapabilities(); }) .then(photocapabilities => { const settings = imagecapture.track.getsettings(); input.min = photocapabilities.imagewidth.min; input.max = photocapabilities.imagewidth.max; input.step = photocapabilities.imagewidth.step; return imagecapture.getphotosettings(); }) .then(photosettings => { input.value = photosettings.imagewidth; }) .catch(error => console.log('argh!', error.name || error)); specifications specification ...

Browser storage limits and eviction criteria - Web APIs
in firefox, an internal browser tool called the quota manager keeps track of how much disk space each origin is using up, and deletes data if necessary.
... we track the "last access time" for each origin using temporary storage.

Intersection Observer API - Web APIs
the intersection root and root margin before we can track the intersection of an element with a container, we need to know what that container is.
... finally, in order to track whether the intersection ratio is going up or down, we remember the current ratio in the variable prevratio.

MediaConfiguration - Web APIs
channels: number of channels used by the audio track.
... } }; const audioencoderconfig = { type : 'file', // 'record', 'transmission', or 'media-source' audio : { contenttype : "audio/ogg", // valid content type channels : 2, // audio channels used by the track bitrate : 132700, // number of bits used to encode 1s of audio samplerate : 5200 // number of audio samples making up that 1s.

MediaDevices.getSupportedConstraints() - Web APIs
the getsupportedconstraints() method of the mediadevices interface returns an object based on the mediatracksupportedconstraints dictionary, whose member fields each specify one of the constrainable properties the user agent understands.
... return value a new object based on the mediatracksupportedconstraints dictionary listing the constraints supported by the user agent.

MediaPositionState.position - Web APIs
if the media is still playing when the interval is fired, setpositionstate() is called with an object that specifies the duration, playback rate, and position as reported by a mymedia object that describes the track being played.
... let positioninterval = window.setinterval(() => { if (mymedia.isplaying) { navigator.mediasession.setpositionstate({ duration: mymedia.trackdurationinseconds, playbackrate: mymedia.playbackrate, position: mymedia.trackplaypositioninseconds }); } else { window.clearinterval(positioninterval); } }, 1000); specifications specification status comment media session standardthe definition of 'mediapositionstate.position' in that specification.

MediaRecorder - Web APIs
options are available to do things like set the container's mime type (such as "video/webm" or "video/mp4") and the bit rates of the audio and video tracks or a single overall bit rate.
... mediarecorder.ignoremutedmedia indicates whether the mediarecorder instance will record input when the input mediastreamtrack is muted.

MediaSession.setPositionState() - Web APIs
if the media is still playing when the interval is fired, setpositionstate() is called with an object that specifies the duration, playback rate, and position as reported by a mymedia object that describes the track being played.
... let positioninterval = window.setinterval(() => { if (mymedia.isplaying) { navigator.mediasession.setpositionstate({ duration: mymedia.trackdurationinseconds, playbackrate: mymedia.playbackrate, position: mymedia.trackplaypositioninseconds }); } else { window.clearinterval(positioninterval); } }, 1000); specifications specification status comment media session standardthe definition of 'mediasession.setpositionstate()' in that specification.

MediaSessionActionDetails.action - Web APIs
syntax let mediasessionactiondetails = { action: actiontype }; let actiontype = mediasessionactiondetails.action; value a domstring specifying which of the action types the callback is being invoked for: nexttrack advances playback to the next track.
... previoustrack moves back to the previous track.

MediaSessionActionDetails - Web APIs
the following strings identify the currently available types of media session action: nexttrack advances playback to the next track.
... previoustrack moves back to the previous track.

MediaSource.activeSourceBuffers - Web APIs
the activesourcebuffers read-only property of the mediasource interface returns a sourcebufferlist object containing a subset of the sourcebuffer objects contained within sourcebuffers — the list of objects providing the selected video track, enabled audio tracks, and shown/hidden text tracks.
... syntax var myactivesourcebuffers = mediasource.activesourcebuffers; value a sourcebufferlist containing the sourcebuffer objects for each of the active tracks.

active - Web APIs
a stream is considered active if at least one of its mediastreamtracks is not in the mediastreamtrack.ended state.
... once every track has ended, the stream's active property becomes false.

MediaStream.clone() - Web APIs
this new mediastream object has a new unique id and contains clones of every mediastreamtrack contained by the mediastream on which clone() was called.
... return value a new mediastream instance which has a new unique id and contains clones of every mediastreamtrack contained by the mediastream on which clone() was called.