Element: mouseover event - Web APIs
the mouseover event is fired at an element when a pointing device (such as a mouse or trackpad) is used to move the cursor onto the element or one of its child elements.
... bubbles yes cancelable yes interface mouseevent event handler property onmouseover examples the following example illustrates the difference between mouseover and mouseenter events.
... over the unordered list test.addeventlistener("mouseenter", function( event ) { // highlight the mouseenter target event.target.style.color = "purple"; // reset the color after a short delay settimeout(function() { event.target.style.color = ""; }, 500); }, false); // this handler will be executed every time the cursor // is moved over a different list item test.addeventlistener("mouseover", function( event ) { // highlight the mouseover target event.target.style.color = "orange"; // reset the color after a short delay settimeout(function() { event.target.style.color = ""; }, 500); }, false); result specifications specification status ui eventsthe definition of 'mouseover' in that specification.
... working draft document object model (dom) level 3 events specificationthe definition of 'mouseover' in that specification.

GlobalEventHandlers.onmouseover - Web APIs
the onmouseover property of the globaleventhandlers mixin is an eventhandler that processes mouseover events.
... the mouseover event fires when the user moves the mouse over a particular element.
... syntax element.onmouseover = function; example this example adds an onmouseover and an onmouseout event to a paragraph.
... html <p>test your mouse on me!</p> javascript const p = document.queryselector('p'); p.onmouseover = logmouseover; p.onmouseout = logmouseout; function logmouseover() { p.innerhtml = 'mouse over detected'; } function logmouseout() { p.innerhtml = 'mouse out detected'; } result specifications specification status comment html living standardthe definition of 'onmouseover' in that specification.

Communicating using "postMessage" - Archive of obsolete content
simplify this most content modules provide an onmessage property as an argument to the constructor: panel = require("sdk/panel").panel({ onmessage: function(contentscriptmessage) { // handle message from the content script } }); message events versus user-defined events you can use message events as an alternative to user-defined events: var pagemodscript = "window.addeventlistener('mouseover', function(event) {" + " self.postmessage(event.target.tostring());" + "}, false);"; var pagemod = require('sdk/page-mod').pagemod({ include: ['*'], contentscript: pagemodscript, onattach: function(worker) { worker.on('message', function(message) { console.log('mouseover: ' + message); }); } }); the reason to prefer user-defined ev...
... suppose the content script wants to send mouseout events as well as mouseover.
... now we have to embed the event type in the message payload, and implement a switch function in the receiver to dispatch the message: var pagemodscript = "window.addeventlistener('mouseover', function(event) {" + " self.postmessage({" + " kind: 'mouseover'," + " element: event.target.tostring()" + " });" + "}, false);" + "window.addeventlistener('mouseout', function(event) {" + " self.postmessage({" + " kind: 'mouseout'," + " element: event.target.tostring()" + " });" + " }, false);" var pagemod = require('sdk/page-mod').pagemod({ include: ['*'], contentscript:...
...And 2 more matches

widget - Archive of obsolete content
widgets.widget({ id: "google-link", label: "widget with an image and a click handler", contenturl: "http://www.google.com/favicon.ico", onclick: function() { require("sdk/tabs").activetab.url = "http://www.google.com/"; } }); // a widget that changes display on mouseover.
... widgets.widget({ id: "mouseover-effect", label: "widget with changing image on mouseover", contenturl: "http://www.yahoo.com/favicon.ico", onmouseover: function() { this.contenturl = "http://www.bing.com/favicon.ico"; }, onmouseout: function() { this.contenturl = "http://www.yahoo.com/favicon.ico"; } }); // a widget that updates content on a timer.
... onmouseover function include this to listen to the widget's mouseover event.
...And 2 more matches

Anonymous Content - Archive of obsolete content
mouseover and mouseout events mouseover and mouseout events are retargeted if the mouse genuinely enters or exits the bound element (in addition to entering or exiting some anonymous content).
... for example, if the user enters the html file upload control from the left, a mouseover event is generated for the anonymous textfield.
... because this event also constitutes a mouseover of the file control itself, the event is retargeted when it flows across scopes.
...And 2 more matches

XUL Events - Archive of obsolete content
this event is the reverse of mouseover.
... attribute: onmouseout mouseover this event is sent to an element when the mouse first moves over an element.
... attribute: onmouseover mouseup this event is sent when the mouse is released on an element.
...it is similar to the mouseover event but occurs while dragging.

Advanced animations - Web APIs
, color: 'blue', draw: function() { ctx.beginpath(); ctx.arc(this.x, this.y, this.radius, 0, math.pi * 2, true); ctx.closepath(); ctx.fillstyle = this.color; ctx.fill(); } }; function draw() { ctx.clearrect(0,0, canvas.width, canvas.height); ball.draw(); ball.x += ball.vx; ball.y += ball.vy; raf = window.requestanimationframe(draw); } canvas.addeventlistener('mouseover', function(e) { raf = window.requestanimationframe(draw); }); canvas.addeventlistener('mouseout', function(e) { window.cancelanimationframe(raf); }); ball.draw(); boundaries without any boundary collision testing our ball runs out of the canvas quickly.
... function draw() { ctx.clearrect(0,0, canvas.width, canvas.height); ball.draw(); ball.x += ball.vx; ball.y += ball.vy; if (ball.y + ball.vy > canvas.height || ball.y + ball.vy < 0) { ball.vy = -ball.vy; } if (ball.x + ball.vx > canvas.width || ball.x + ball.vx < 0) { ball.vx = -ball.vx; } raf = window.requestanimationframe(draw); } canvas.addeventlistener('mouseover', function(e) { raf = window.requestanimationframe(draw); }); canvas.addeventlistener('mouseout', function(e) { window.cancelanimationframe(raf); }); ball.draw(); acceleration to make the motion more real, you can play with the velocity like this, for example: ball.vy *= .99; ball.vy += .25; this slows down the vertical velocity each frame, so that the ball will just bounce on the fl...
...,0, canvas.width, canvas.height); ball.draw(); ball.x += ball.vx; ball.y += ball.vy; ball.vy *= .99; ball.vy += .25; if (ball.y + ball.vy > canvas.height || ball.y + ball.vy < 0) { ball.vy = -ball.vy; } if (ball.x + ball.vx > canvas.width || ball.x + ball.vx < 0) { ball.vx = -ball.vx; } raf = window.requestanimationframe(draw); } canvas.addeventlistener('mouseover', function(e) { raf = window.requestanimationframe(draw); }); canvas.addeventlistener('mouseout', function(e) { window.cancelanimationframe(raf); }); ball.draw(); trailing effect until now we have made use of the clearrect method when clearing prior frames.
... 0, canvas.width, canvas.height); ball.draw(); ball.x += ball.vx; ball.y += ball.vy; ball.vy *= .99; ball.vy += .25; if (ball.y + ball.vy > canvas.height || ball.y + ball.vy < 0) { ball.vy = -ball.vy; } if (ball.x + ball.vx > canvas.width || ball.x + ball.vx < 0) { ball.vx = -ball.vx; } raf = window.requestanimationframe(draw); } canvas.addeventlistener('mouseover', function(e) { raf = window.requestanimationframe(draw); }); canvas.addeventlistener('mouseout', function(e) { window.cancelanimationframe(raf); }); ball.draw(); adding mouse control to get some control over the ball, we can make it follow our mouse using the mousemove event, for example.

Element: mouseenter event - Web APIs
bubbles no cancelable no interface mouseevent event handler property onmouseenter usage notes though similar to mouseover, mouseenter differs in that it doesn't bubble and it isn't sent to any descendants when the pointer is moved from one of its descendants' physical space to its own physical space.
... a single mouseover event is sent to the deepest element of the dom tree, then it bubbles up the hierarchy until it is canceled by a handler or reaches the root.
...in such cases, it is better to listen for mouseover events.
... examples the mouseover documentation has an example illustrating the difference between mouseover and mouseenter.

jspage - Archive of obsolete content
de||k.compatmode=="css1compat")?k.html:k.body; var i={x:a.pagex||a.clientx+k.scrollleft,y:a.pagey||a.clienty+k.scrolltop};var c={x:(a.pagex)?a.pagex-f.pagexoffset:a.clientx,y:(a.pagey)?a.pagey-f.pageyoffset:a.clienty}; if(j.match(/dommousescroll|mousewheel/)){var h=(a.wheeldelta)?a.wheeldelta/120:-(a.detail||0)/3;}var e=(a.which==3)||(a.button==2);var l=null;if(j.match(/over|out/)){switch(j){case"mouseover":l=a.relatedtarget||a.fromelement; break;case"mouseout":l=a.relatedtarget||a.toelement;}if(!(function(){while(l&&l.nodetype==3){l=l.parentnode;}return true;}).create({attempt:browser.engine.gecko})()){l=false; }}}}return $extend(this,{event:a,type:j,page:i,client:c,rightclick:e,wheel:h,relatedtarget:l,target:g,code:b,key:m,shift:a.shiftkey,control:a.ctrlkey,alt:a.altkey,meta:a.metakey}); }});even...
...e.create({bind:this,delay:a,"arguments":b})(); },this);return this;},cloneevents:function(d,a){d=document.id(d);var c=d.retrieve("events");if(!c){return this;}if(!a){for(var b in c){this.cloneevents(d,b); }}else{if(c[a]){c[a].keys.each(function(e){this.addevent(a,e);},this);}}return this;}});element.nativeevents={click:2,dblclick:2,mouseup:2,mousedown:2,contextmenu:2,mousewheel:2,dommousescroll:2,mouseover:2,mouseout:2,mousemove:2,selectstart:2,selectend:2,keydown:2,keypress:2,keyup:2,focus:2,blur:2,change:2,reset:2,select:2,submit:2,load:1,unload:1,beforeunload:2,resize:1,move:1,domcontentloaded:1,readystatechange:1,error:1,abort:1,scroll:1}; (function(){var a=function(b){var c=b.relatedtarget;if(c==undefined){return true;}if(c===false){return false;}return($type(this)!="document"&&c!=this&&c.pref...
...ix!="xul"&&!this.haschild(c)); };element.events=new hash({mouseenter:{base:"mouseover",condition:a},mouseleave:{base:"mouseout",condition:a},mousewheel:{base:(browser.engine.gecko)?"dommousescroll":"mousewheel"}}); })();element.properties.styles={set:function(a){this.setstyles(a);}};element.properties.opacity={set:function(a,b){if(!b){if(a==0){if(this.style.visibility!="hidden"){this.style.visibility="hidden"; }}else{if(this.style.visibility!="visible"){this.style.visibility="visible";}}}if(!this.currentstyle||!this.currentstyle.haslayout){this.style.zoom=1;}if(browser.engine.trident){this.style.filter=(a==1)?"":"alpha(opacity="+a*100+")"; }this.style.opacity=a;this.store("opacity",a);},get:function(){return this.retrieve("opacity",1);}};element.implement({setopacity:function(a){return this.set("op...

source-editor.jsm
sourceeditor.events.mouse_over "mouseover" fired when the mouse pointer enters a line annotation.
... mouseover the "mouseover" event is sent when the user moves the mouse pointer enters a line of text content.
... it has the following properties: property type description event mouseevent the dom "mouseover" event.

nsIDOMWindowUtils
the event types supported are: mousedown, mouseup, mousemove, mouseover, mouseout, contextmenu.
... normally at this level of events, the mouseover and mouseout events are only fired when the window is entered or exited.
... for inter-element mouseover and mouseout events, a movemove event fired on the new element should be sufficient to generate the correct over and out events as well.

Comparison of Event Targets - Web APIs
ementbyid('target').innerhtml = e.target; document.getelementbyid('currenttarget').innerhtml = e.currenttarget; document.getelementbyid('relatedtarget').innerhtml = e.relatedtarget; document.getelementbyid('explicitoriginaltarget').innerhtml = e.explicitoriginaltarget; document.getelementbyid('originaltarget').innerhtml = e.originaltarget; } function handlemouseover(e) { document.getelementbyid('target').innerhtml = e.target; document.getelementbyid('relatedtarget').innerhtml = e.relatedtarget; } document.addeventlistener('click', handleclicks, false); document.addeventlistener('mouseover', handlemouseover, false); </script> </body> </html> use of target and relatedtarget the relatedtarget property for the mouseover event holds...
... event type event.target event.relatedtarget mouseover the eventtarget which the pointing device entered the eventtarget which the pointing device exited mouseout the eventtarget which the pointing device exited the eventtarget which the pointing device entered todo: also needs descriptions for dragenter and dragexit events.
... example <hbox id="outer"> <hbox id="inner" onmouseover="dump('mouseover ' + event.relatedtarget.id + ' > ' + event.target.id + '\n');" onmouseout="dump('mouseout ' + event.target.id + ' > ' + event.relatedtarget.id + '\n');" style="margin: 100px; border: 10px solid black; width: 100px; height: 100px;" /> </hbox> ...

Example and tutorial: Simple synth keyboard - Web APIs
assname = "key"; keyelement.dataset["octave"] = octave; keyelement.dataset["note"] = note; keyelement.dataset["frequency"] = freq; labelelement.innerhtml = note + "_{" + octave + "}"; keyelement.appendchild(labelelement); keyelement.addeventlistener("mousedown", notepressed, false); keyelement.addeventlistener("mouseup", notereleased, false); keyelement.addeventlistener("mouseover", notepressed, false); keyelement.addeventlistener("mouseleave", notereleased, false); return keyelement; } after creating the elements that will represent the key and its label, we configure the key's element by setting its class to "key" (which establishes its appearance).
... playing a tone when the mousedown or mouseover event occurs on a key, we want to start playing the corresponding note.
...second, and more importantly, we are using this to handle mouseover for cases where the user is dragging from note to note, and we only want to start playing the note if the mouse is pressed when it enters the element.

Porting the Library Detector - Archive of obsolete content
aries.length * icon_width; } main.js will use the tabs module to update the widget's content when necessary (for example, when the user switches between tabs): tabs.on('activate', function(tab) { updatewidgetview(tab); }); tabs.on('ready', function(tab) { tab.libraries = []; }); showing the library detail the xul library detector displayed the detailed information about each library on mouseover in a tooltip: we can't do this using a widget, so instead will use a panel.
... this means we'll need two additional content scripts: one in the widget's context, which listens for icon mouseover events and sends a message to main.js containing the name of the corresponding library: function setlibraryinfo(element) { self.port.emit('setlibraryinfo', element.target.title); } var elements = document.getelementsbytagname('img'); for (var i = 0; i &lt; elements.length; i++) { elements[i].addeventlistener('mouseover', setlibraryinfo, false); } one in the panel, which updates the panel's content with the library information: self.on("message", function(libraryinfo) { window.document.body.innerhtml = libraryinfo; }); finally main.js relays the library information from the widget to the panel: widget.port.on('setlibraryinfo', function(libraryinfo) { widget.pan...

HTML in XUL for rich tooltips - Archive of obsolete content
ok like, assuming a javascript overlay titled overlay.js: <?xml version="1.0" encoding="utf-8"?> <overlay id="htmltip-overlay" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" xmlns:html="http://www.w3.org/1999/xhtml"> <script type="application/x-javascript" src="overlay.js"/> <popup id="contentareacontextmenu"> <menuitem id="htmltip1" label="foo1" onmouseover="htmltip.onmousetooltip(event)" tooltip="myhtmltip" /> <menuitem id="htmltip2" label="foo2" onmouseover="htmltip.onmousetooltip(event)" tooltip="myhtmltip" /> </popup> <popupset id="mainpopupset"> <tooltip id="myhtmltip"> <html:div id="myhtmltipdiv" type="content"/> </tooltip> </popupset> </overlay> insert your v...
...that tooltip is empty now, but we will use the mouseover event to dynamically populate the tooltip (which is about to be shown) with a different message for each menuitem.