The life of an HTML HTTP request - Archive of obsolete content
[note: passes nswebshell.mobserver as nsistreamobserver and the webshell as nsicontentviewercontainer to the docloader.] (2) the document loader calls ns_openuri with the url to begin transfering the requested file.
...this factory is then told to create a nsicontentviewer.
... (5) the document (nshtmldocument) also creates a nsicontentsink (nshtmlcontentsink) and connects it to the parser and the document.
...And 2 more matches

The Implementation of the Application Object Model - Archive of obsolete content
examples of these interfaces include nsidomelement, nsidomnode, nsixmlcontent, and nsicontent.
...nsicontent, nsidomelement, and all of those interfaces mentioned at the beginning of this document are just that: interfaces!
...nsicontent, nsidomnode, nsidomelement, and nsixmlelement must be implemented at a minimum.
...the various interfaces, nsicontent et.al., are not yet solidified.

nsIFocusManager
st changed in gecko 5.0 (firefox 5.0 / thunderbird 5.0 / seamonkey 2.2) implemented by: @mozilla.org/focus-manager;1 as a service: var focusmanager = components.classes["@mozilla.org/focus-manager;1"] .getservice(components.interfaces.nsifocusmanager); method overview void clearfocus(in nsidomwindow awindow); void contentremoved(in nsidocument adocument, in nsicontent aelement); native code only!
... void focusplugin(in nsicontent aplugin); native code only!
...void contentremoved( in nsidocument adocument, in nsicontent aelement ); parameters adocument aelement native code only!firedelayedevents fire any events that have been delayed due to synchronized actions.
...void focusplugin( in nsicontent aplugin ); parameters aplugin getfocusedelementforwindow() nsidomelement getfocusedelementforwindow( in nsidomwindow awindow, in prbool adeep, out nsidomwindow afocusedwindow ); parameters awindow if equal to the current value of focusedwindow, then the returned element will be the application-wide focused element (the value of focusedelement).

nsIHTMLEditor
inherits from: nsisupports last changed in gecko 5.0 (firefox 5.0 / thunderbird 5.0 / seamonkey 2.2) method overview void adddefaultproperty(in nsiatom aproperty, in astring aattribute, in astring avalue); void addinsertionlistener(in nsicontentfilter infilter); void align(in astring aalign); boolean breakisvisible(in nsidomnode anode); boolean candrag(in nsidomevent aevent); void checkselectionstateforanonymousbuttons(in nsiselection aselection); nsidomelement createanonymouselement(in astring atag, in nsidomnode aparentnode, in astring aanonclass, in boolean aiscreatedhidden); nsidomelement createelementwithdefaults(in astring atagna...
... long aselectiontype); void rebuilddocumentfromsource(in astring asourcestring); void removealldefaultproperties(); void removeallinlineproperties(); void removedefaultproperty(in nsiatom aproperty, in astring aattribute, in astring avalue); void removeinlineproperty(in nsiatom aproperty, in astring aattribute); void removeinsertionlistener(in nsicontentfilter infilter); void removelist(in astring alisttype); void replaceheadcontentswithhtml(in astring asourcetoinsert); void selectelement(in nsidomelement aelement); void setbackgroundcolor(in astring acolor); void setbodyattribute(in astring aattr, in astring avalue); void setcaretafterelement(in nsidomelement aelement); void setcssin...
... void addinsertionlistener( in nsicontentfilter infilter ); parameters infilter function which callers want called during insertion.
... void removeinsertionlistener( in nsicontentfilter infilter ); parameters infilter function which callers do not want called during insertion.

Using content preferences - Archive of obsolete content
the content preferences service, implemented by nsicontentprefservice, offers functions for setting and retrieving preferences for specific sites or in the global preference space; global preferences are used whenever a site-specific preference isn't available.
...var iosvc = components.classes["@mozilla.org/network/io-service;1"] .getservice(components.interfaces.nsiioservice); var prefservice = components.classes["@mozilla.org/content-pref/service;1"] .getservice(components.interfaces.nsicontentprefservice); // create a uri object referencing the site to save a preference for var uri = iosvc.newuri("http://developer.mozilla.org/", null, null); // set the value of the "devmo.somesetting" preference to "foo".
...see also nsicontentprefservice nsicontentprefobserver tosource() (potentially useful for serializing objects for later use with eval()) ...

Limitations of chrome scripts
nsicontentpolicy without the shim in multiprocess firefox, if you register the nsicontentpolicy in the chrome process then it will never see any attempts to load web content, because they happen in the content process.
...it transparently registers an nsicontentpolicy in the content process, whose shouldload just forwards to the chrome process.
... to make the shim unnecessary: define and register nsicontentpolicy in the content process.

Process scripts
for example, in multiprocess firefox, if you need to use nsicontentpolicy to register a content policy, you must do this in the content process.
... docshell tree up to the top window and then retrieving its content message manager, as follows: function contentmmfromcontentwindow(window) { let tree = window.queryinterface(ci.nsiinterfacerequestor).getinterface(ci.nsidocshelltreeitem); let top = tree.sametyperoottreeitem; let iface = queryinterface(ci.nsidocshell).queryinterface(ci.nsiinterfacerequestor); return iface.getinterface(ci.nsicontentframemessagemanager); } this is intended for unprivileged pages running in a content process.
... if the above doesn't work try this: function contentmmfromcontentwindow_method2(acontentwindow) { return acontentwindow.queryinterface(ci.nsiinterfacerequestor) .getinterface(ci.nsidocshell) .queryinterface(ci.nsiinterfacerequestor) .getinterface(ci.nsicontentframemessagemanager); } ...

HTML parser threading
references to dom nodes in tree ops are of type nsicontent** and are called content handles.
...only when the tree op executor executes a node creation tree op, the nsicontent* that points to the node gets written to the memory location pointed to by the nsicontent**.
...nodes created by tree ops are owned by the parser for the lifetime of the parser, so for refcounting purposes, the parser owns each nsicontent object it creates by one reference no matter how many copies of the content handle for the node exist inside the parser.

Introduction to XPCOM for the DOM
here is a simple problem i encountered recently: in a member function of the nshtmlanchorelement class, i had to get a pointer to the nsicontent interface implemented by the nshtmlanchorelement object.
...i had to use the second solution: nscomptr<nsicontent> content = getter_addrefs(ns_static_cast(nsicontent*, this)); // or, if you want to do the refcounting yourself, nsicontent *content = ns_static_cast(nsicontent*, this); the second form should be used with care, and is recommended only for advanced xpcom'ers.
...the interface inheritance chain for nsihtmlcontent looks like this: nsisupports -> nsicontent -> nsistyledcontent -> nsixmlcontent -> nsihtmlcontent nsgenericelement has to implement all of the above interfaces, and all the real classes inheriting from nsgenericelement will automatically implement all those interfaces.

nsIDocShell
method overview void addsessionstorage(in nsiprincipal principal, in nsidomstorage storage); void addstate(in nsivariant adata, in domstring atitle, in domstring aurl, in boolean areplace); void beginrestore(in nsicontentviewer viewer, in boolean top); void createaboutblankcontentviewer(in nsiprincipal aprincipal); void createloadinfo(out nsidocshellloadinfo loadinfo); void detacheditorfromwindow(); violates the xpcom interface guidelines void finishrestore(); void firepagehidenotification(in boolean isunload); native code only!
... contentviewer nsicontentviewer content viewer that is currently loaded for this docshell.
...void beginrestore( in nsicontentviewer viewer, in boolean top ); parameters viewer the content viewer whose document we are starting to load.

nsIIOService
any of the content types defined in nsicontentpolicybase.idl.
...any of the content types defined in nsicontentpolicy.idl return value an nsichannel for the uri.
...any of the content types defined in nsicontentpolicy.

nsIInProcessContentFrameMessageManager
1.0 66 introduced gecko 2.0 inherits from: nsicontentframemessagemanager last changed in gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) method overview nsicontent getownercontent(); violates the xpcom interface guidelines methods violates the xpcom interface guidelines getownercontent() nsicontent getownercontent(); parameters none.
... return value the nsicontent object representing the owner's content.
... see also content process event handling nsicontentframemessagemanager ...

nsISHEntry
nsdocshelleditordataptr forgeteditordata(); violates the xpcom interface guidelines nsicontentviewer getanycontentviewer(out nsishentry ownerentry); void getscrollposition(out long x, out long y); void getviewerbounds(in nsintrect bounds); native code only!
... contentviewer nsicontentviewer content viewer, for fast restoration of presentation.
...nsicontentviewer getanycontentviewer( out nsishentry ownerentry ); parameters ownerentry return value getscrollposition() void getscrollposition( out long x, out long y ); parameters x y native code only!getviewerbounds saved position and dimensions of the content viewer; we must adjust the root view's widget accordingly if this has changed when the presentation is restored.

nsIXULTemplateBuilder
sult, in nsidomnode aquerynode); void resultbindingchanged(in nsixultemplateresult aresult); nsixultemplateresult getresultforid(in astring aid); nsixultemplateresult getresultforcontent(in nsidomelement aelement); boolean hasgeneratedcontent(in nsirdfresource anode, in nsiatom atag); void addrulefilter(in nsidomnode arule, in nsixultemplaterulefilter afilter); [noscript] void init(in nsicontent aelement); [noscript] void createcontents(in nsicontent aelement, in boolean aforcecreation); void addlistener(in nsixulbuilderlistener alistener); void removelistener(in nsixulbuilderlistener alistener); attributes attribute type description root nsidomelement readonly: the root node in the dom to which this builder is attached.
...[noscript] void init( in nsicontent aelement ); parameters aelement the root element from which to derive the data.
...[noscript] void createcontents( in nsicontent aelement, in boolean aforcecreation ); parameters aelement the element whose contents need to be built.

XPCOM Interface Reference by grouping
nsiinprocesscontentframemessagemanager nsiscriptableio nsixpcscriptable future nsixmlhttprequestupload obsolete nsixmlrpcclient nsixmlrpcfault security auth nsiauthmodule nsiauthprompt nsiauthpromptprovider nsiauthpromptwrapper nsiasyncverifyredirectcallback content nsicontentpolicy credentials nsilogininfo nsiloginmanager using nsiloginmanager nsiloginmanagerstorage nsiloginmetainfo history nsiglobalhistory nsiglobalhistory2 nsiglobalhistory3 ssl nsibadcertlistener2 system action nsicancelable...
... environment nsienvironment event nsieventlistenerinfo nsieventlistenerservice nsieventtarget exception nsiexception extention nsiextensionmanager nsiinstalllocation external nsiexternalprotocolservice frame nsicontentframemessagemanager history nsishentry nsishistory idle nsiidleservice internal command nsicommandline nsicommandlinehandler nsicommandlinerunner component nsicomponentmanager preferenc...
...es nsicontentprefobserver nsicontentprefservice nsicomponentregistrar internationalization nsibidikeyboard nsilocale io filesystem nsidirectoryenumerator nsidirectoryiterator nsidirectoryservice nsidirectoryserviceprovider nsidirectoryserviceprovider2 nsidirindex nsidirindexlistener nsidirindexparser nsifile nsilocalfile stream nsiasyncinputstream nsiasyncoutputstream nsiasyncstreamcopier nsibinaryinputstream nsibinaryoutputstream ns...

Updating addons broken by private browsing changes - Archive of obsolete content
if your code refers to any of the following interfaces: ff 15: nsidomstoragemanager ff 16: nsitransferable ff 18: imgicache moziasyncfavicons nsifaviconservice nsiwebbrowserpersist ff 19: nsicontentprefservice nsidownloadmanager nsidownload nsihttpauthmanager nsistricttransportsecurityservice ff 20: nsiprivatebrowsingservice nsirecentbadcertservice furthermore, if your code uses any of these common chrome apis: ff 19: saveurl saveinternal openlinkin ff 20: openbrowserwindow gprivatebrowsingui finally, if your code watches for any of these observer notifications: private-browsing pri...
... nsicontentprefservice: getpref, setpref, haspref, hascachedpref, removepref, removegroupedprefs, removeprefsbyname, getprefs, and getprefsbyname all take a required nsiloadcontext argument to indicate the privacy status of the pref in question.

Document Loading - From Load Start to Finding a Handler - Archive of obsolete content
if we find no content listener willing to handle the data, we look for a content handler (using createinstance on ns_content_handler_contractid_prefix + acontenttype and expecting back an nsicontenthandler).
... if we still do not have a stream listener, that means that we failed to find an nsiuricontentlistener or nsicontenthandler for this type.

browser - Archive of obsolete content
contentvieweredit type: nsicontentvieweredit this read-only property contains the nsicontentvieweredit which handles clipboard operations on the document.
... contentviewerfile type: nsicontentviewerfile reference to the nsicontentviewerfile interface for the document.

tabbrowser - Archive of obsolete content
contentvieweredit type: nsicontentvieweredit this read-only property contains the nsicontentvieweredit which handles clipboard operations on the document.
... contentviewerfile type: nsicontentviewerfile reference to the nsicontentviewerfile interface for the document.

Message manager overview
s addeventlistener() : listen to dom events addmessagelistener() : receive messages from the chrome process sendasyncmessage() : send asynchronous messages to the chrome process sendsyncmessage() : send synchronous messages to the chrome process interfaces nsidomeventtarget nsimessagelistenermanager nsimessagesender nsisyncmessagesender nsicontentframemessagemanager how to access the content frame message manager is the global object in frame scripts.
...and functions are: components : access privileged objects and apis addmessagelistener() : receive messages from the parent process sendasyncmessage() : send asynchronous messages to the parent process sendsyncmessage() : send synchronous messages to the parent process interfaces nsimessagelistenermanager nsimessagesender nsisyncmessagesender nsicontentprocessmessagemanager how to access code running in a child process can access the cpmm with code like this: // child process script let cpmm = cc["@mozilla.org/childprocessmessagemanager;1"] .getservice(ci.nsisyncmessagesender); you can also access it as the cpmm property of services.jsm, if you are in the child process.

Performance
} object.assign(contentypolicy.prototype, { classdescription: ..., classid: ..., contractid: ..., queryinterface: xpcomutils.generateqi([ci.nsicontentpolicy]), shouldload: function(type, location, origin, context) { let resultlist = services.cpmm.sendsyncmessage("my-addon:check-load", {destination: location, source: origin}) // <=== sync message!
... if(resultlist.every((r) => r == true)) return ci.nsicontentpolicy.accept; return ci.nsicontentpolicy.reject_request; } }); // more boilerplate code here this example is a (somewhat condensed) content policy which gets triggered for every network request in a child process to either allow or deny the request.

Introduction to Layout in Mozilla
creates a parser, returned as nsistreamlistener back to the docshell creates a content sink, which is linked to the parser and the document creates a documentviewerimpl object, which is returned as nsicontentviewer back to the docshell documentviewerimpl creates pres context and pres shell content model construction content arrives from network via nsistreamlistener::ondataavailable parser tokenizes & processes content; invokes methods on nsicontentsink with parser node objects some buffering and fixup occurs here opencontainer, closecontainer, addleaf content sin...
...k creates and attaches content nodes using nsicontent interface content sink maintains stack of “live” elements more buffering and fixup occurs here insertchildat, appendchildto, removechildat frame construction content sink uses nsidocument interface to notify of Δs in content model contentappended, contentinserted, contentremoved presshell is registered as document observer receives contentappended, etc.

nsIAccessibilityService
tionaccessible(in nsisupports aframe); nsiaccessible getaccessible(in nsidomnode anode, in nsipresshell apresshell, in nsiweakreference aweakshell, inout nsiframe framehint, out boolean aishidden); nsiaccessible addnativerootaccessible(in voidptr aatkaccessible); void removenativerootaccessible(in nsiaccessible arootaccessible); void invalidatesubtreefor(in nsipresshell apresshell, in nsicontent achangedcontent, in pruint32 aevent); methods removenativerootaccessible() void removenativerootaccessible( in nsiaccessible arootaccessible ); invalidatesubtreefor() invalidate the accessibility cache associated with apresshell, for accessibles that were generated for acontainercontent and it's subtree.
... void invalidatesubtreefor( in nsipresshell apresshell, in nsicontent achangedcontent, in pruint32 aevent ); parameters <tt>apresshell</tt> the presshell where changes occured.

nsIChannelPolicy
attributes attribute type description contentsecuritypolicy nsisupports a nsicontentsecuritypolicy object to determine if the load should be allowed.
... loadtype unsigned long indicates what type of content is being loaded, for example nsicontentpolicy::type_image.

nsIDocumentLoader
d destroy(); obsolete since gecko 1.8 void fireonlocationchange(in nsiwebprogress awebprogress, in nsirequest arequest, in nsiuri auri); obsolete since gecko 1.8 void fireonstatuschange(in nsiwebprogress awebprogress, in nsirequest arequest, in nsresult astatus, in wstring amessage); obsolete since gecko 1.8 void getcontentviewercontainer(in nsisupports adocumentid, out nsicontentviewercontainer aresult); native code only!
...void getcontentviewercontainer( in nsisupports adocumentid, out nsicontentviewercontainer aresult ); parameters adocumentid aresult getloadgroup() obsolete since gecko 1.8 (firefox 1.5 / thunderbird 1.5 / seamonkey 1.0) nsiloadgroup getloadgroup(); parameters none.

nsIEditor
66 introduced gecko 1.0 inherits from: nsisupports last changed in gecko 18.0 (firefox 18.0 / thunderbird 18.0 / seamonkey 2.15) method overview [noscript] void init(in nsidomdocument doc, in nsicontent aroot, in nsiselectioncontroller aselcon, in unsigned long aflags); void setattributeorequivalent(in nsidomelement element, in astring sourceattrname, in astring sourceattrvalue, in boolean asuppresstransaction); void removeattributeorequivalent(in nsidomelement element, in domstring sourceattrname, in boolean asuppresstransaction); void postcreate(); void predestroy(in boolean adestroyingframes); ...
... [noscript] void init( in nsidomdocument doc, in nsipresshellptr shell, obsolete since gecko 5 in nsicontent aroot, in nsiselectioncontroller aselcon, in unsigned long aflags ); parameters doc the document to observe.

nsISelectionPrivate
obsolete since gecko 12.0 long gettableselectiontype(in nsidomrange range); void removeselectionlistener(in nsiselectionlistener listenertoremove); void scrollintoview(in short aregion, in boolean aissynchronous, in short avpercent, in short ahpercent); void setancestorlimiter(in nsicontent acontent); native code only!
... native code only!setancestorlimiter void setancestorlimiter( in nsicontent acontent ); parameters acontent native code only!setpresshell internal utility method to set the pres shell on a newly created selection.

nsIXULSortService
inherits from: nsisupports last changed in gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) method overview void insertcontainernode(in nsirdfcompositedatasource db, in nsrdfsortstate sortstateptr, in nsicontent root, in nsicontent trueparent, in nsicontent container, in nsicontent node, in boolean anotify); native code only!
...void insertcontainernode( in nsirdfcompositedatasource db, in nsrdfsortstate sortstateptr, in nsicontent root, in nsicontent trueparent, in nsicontent container, in nsicontent node, in boolean anotify ); parameters db sortstateptr root trueparent container node anotify sort() sort the contents of the widget containing anode using asortkey as the comparison key, and asorthints as how to sort.

Miscellaneous - Archive of obsolete content
if you wish to block selected scripts based on their uri, implement nsicontentpolicy.

XPCOM Objects - Archive of obsolete content
cc[@mozilla.org/categorymanager;1].getservice(ci.nsicategorymanager); acompmgr.queryinterface(ci.nsicomponentregistrar); acompmgr.registerfactorylocation( class_id, class_name, contract_id, alocation, aloaderstr, atype); categorymanager.addcategoryentry( "content-policy", "xulschool hello world", contract_id, true, true); }, in this case the component would need to implement nsicontentpolicy.

Index - Archive of obsolete content
1997 mozilla.dev.platform faq faq for questions asked on mozilla.dev.platform 1998 nsicontentpolicy interfaces, interfaces:scriptable, needsmarkupwork, reference, xpcom, xpcom interface reference you can observe content that is being loaded into your browser by implementing nsicontentpolicy.

contentViewerEdit - Archive of obsolete content
« xul reference contentvieweredit type: nsicontentvieweredit this read-only property contains the nsicontentvieweredit which handles clipboard operations on the document.

contentViewerFile - Archive of obsolete content
« xul reference contentviewerfile type: nsicontentviewerfile reference to the nsicontentviewerfile interface for the document.

Using the Editor from XUL - Archive of obsolete content
one thing to note about editor initialization is that we pass into the editor's init() method an nsicontent* that corresponds to the root of the content tree that the editor is allowed to work with.

2006-11-10 - Archive of obsolete content
this can be defined within the nsicontentpolicy.

2006-12-01 - Archive of obsolete content
discussions nsicontentpolicy and user interaction the proper way to get user confirmation before trying to load certain file types.

Installing headers using EXPORTS
here is an example <tt>makefile.in</tt> which has both c++ and idl headers: module = content xpidl_module = content_base exports = \ nsicontent.h \ nsidocument.h \ nsistylesheet.h \ $(null) xpidlsrcs = \ nsicontentpolicy.idl \ nsiselectioncontroller.idl \ $(null) include $(topsrcdir)/config/rules.mk ...

Message manager
guides message manager overview frame script loading and lifetime communicating with frame scripts performance best practices frame script environment limitations of frame scripts process scripts api reference nsiframescriptloader nsimessagelistenermanager nsimessagebroadcaster nsimessagesender nsisyncmessagesender nsicontentframemessagemanager nsiprocessscriptloader ...

IME handling guide
imestatemanager asks desired ime state by calling nsicontent::getdesiredimestate() of the node.

Services.jsm
tion service appshell nsiappshellservice application shell service blocklist nsiblocklistservice blocklist service cache nsicacheservice cache service cache2 nsicachestorageservice cache storage service clipboard nsiclipboard clipboard console nsiconsoleservice error console service contentprefs nsicontentprefservice content preferences service cookies nsicookiemanager2 cookie manager 2 service cpmm nsimessagesender child process message manager4 crashmanager crashmanager.jsm dirsvc nsidirectoryservice nsiproperties directory service domstoragemanager nsidomstoragemanager dom storage manager domrequest n...

WebRequest.jsm
you can use this api to implement a content policy in an add-on (for example, an ad or script blocker), as you could using nsicontentpolicy.

DMD
ingautorefcnt::incr(void*, nscyclecollectionparticipant*) (/home/njn/moz/mi5/go64dmd/dom/xul/../../dist/include/nsisupportsimpl.h:250) #05: nsxulelement::create(nsxulprototypeelement*, nsidocument*, bool, bool,mozilla::dom::element**) (/home/njn/moz/mi5/dom/xul/nsxulelement.cpp:287) #06: nsxblcontentsink::createelement(char16_t const**, unsigned int, mozilla::dom::nodeinfo*, unsigned int, nsicontent**, bool*, mozilla::dom::fromparser) (/home/njn/moz/mi5/dom/xbl/nsxblcontentsink.cpp:874) #07: nscomptr<nsicontent>::startassignment() (/home/njn/moz/mi5/go64dmd/dom/xml/../../dist/include/nscomptr.h:753) #08: nsxmlcontentsink::handlestartelement(char16_t const*, char16_t const**, unsigned int, unsigned int, bool) (/home/njn/moz/mi5/dom/xml/nsxmlcontentsink.cpp:1007) } } it tells you th...

XPCOM array guide
example: a content node's list of nsicontent children.

Preface
finish implementing the weblock component: nsicontentpolicy, file i/o, locking, etc.

Creating XPCOM components
ory service modifying paths with nsifile manipulating files with nsifile using nsilocalfile for reading data processing the white list data iweblock method by method lock and unlock addsite removesite setsites getnext getsites hasmoreelements finishing the component using frozen interfaces copying interfaces into your build environment implementing the nsicontentpolicy interface receiving notifications implementing the nsicontentpolicy uniform resource locators checking the white list creating nsiuri objects building the weblock ui user interface package list client code overview xul the xul document the locking ui site adding ui weblock.xul overlaying new user interface into mozilla weblockoverlay.xul oth...

Observer Notifications
message manager topic subject data description message-manager-disconnect nsicontentframemessagemanager null this notification is sent when a message manager disconnects.

nsIChannel
see nsicontentsniffer [en-us] note: channels may ignore this flag; however, new channel implementations should only do so with good reason.

nsIChromeFrameMessageManager
see also content process event handling nsicontentframemessagemanager nsiframeloader nsiframemessagelistener ...

nsIClassInfo
content_node 1 << 6 specifies that this class implements nsicontent.

nsIDOMWindowUtils
the event is dispatched to atarget, which should be an object which implements nsicontent interface (#element, #text, etc).

nsIFrameLoader
1.0 66 introduced gecko 1.8 inherits from: nsisupports last changed in gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) note: this interface works in tandem with the nsicontentview interface to manage frames across processes if electrolysis is in use to support per-frame processes.

nsIMessageListener
if the message was sent from a frame script using a nsicontentframemessagemanager, then this property is the xul <browser> element for the frame from which the message was sent.

nsIPrincipal
obsolete since gecko 1.8 csp nsicontentsecuritypolicy a content security policy associated with this principal.

XPCOM Interface Reference
framemessagemanagernsichromeregistrynsiclassinfonsiclipboardnsiclipboardcommandsnsiclipboarddragdrophooklistnsiclipboarddragdrophooksnsiclipboardhelpernsiclipboardownernsicollectionnsicommandcontrollernsicommandlinensicommandlinehandlernsicommandlinerunnernsicomponentmanagernsicomponentregistrarnsicompositionstringsynthesizernsiconsolelistenernsiconsolemessagensiconsoleservicensicontainerboxobjectnsicontentframemessagemanagernsicontentprefnsicontentprefcallback2nsicontentprefobservernsicontentprefservicensicontentprefservice2nsicontentsecuritypolicynsicontentsniffernsicontentviewnsicontentviewmanagernsicontentviewernsicontrollernsicontrollersnsiconverterinputstreamnsiconverteroutputstreamnsicookiensicookie2nsicookieacceptdialognsicookieconsentnsicookiemanagernsicookiemanager2nsicookiepermissionnsico...

XPCOM category image-sniffing-services
if mozilla's built-in image code cannot identify an image, then any xpcom components implementing the nsicontentsniffer interface may register under the "image-sniffing-services" category, and will be queried to determine the mime type of the image being downloaded.