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Firefox 15 for developers Redirect 1


Firefox 15, based on Gecko , will ship in . This article provides information about the changes in this release that will affect developers. Nightly builds of what will become Firefox 15 are currently available on the channel.

Note: Items listed here are tentatively slated for Firefox 15; however, they may be held for a future release if testing shows they're not ready by the time Firefox 15 is due to ship. Please keep an eye on this page to stay up to date on the plans for Firefox 15.

Want to help document Firefox 15? See the list of bugs that need to be written about and pitch in!

Changes for Web developers


  • The size attribute of the <font> element is now handled according the HTML5 spec. It means that all integer greater than 10 or smaller than -10 are now considered equivalent to 10, respectively -10.
  • Support for font-weight and point-size attributes on the <font> element has been removed; these were non-standard and Gecko was the only engine supporting them.
  • The Opus codec is now supported for audio in Ogg containers for the HTML <audio> and <video> elements.
  • The <source> element now supports the media attribute.
  • The <audio> and <video> elements now support the played attribute, which provides a TimeRanges object listing the time ranges of the media that have been played back so far.


  • The font-feature-settings property has been updated to the latest syntax: font-feature-settings: "lnum" 1;
  • The CSS text-transform property has been extended to correctly handle Unicode ligature characters (like ?).
  • The CSS word-break property has been implemented.
  • The border-image property has been updated to match the latest Specification and properties have been unprefixed. (bug 713643)


  • The DOM Events Level 3 methods KeyboardEvent.getModifierState() and MouseEvent.getModifierState(), which let you query the state of modifier keys, like Ctrl or Shift, have been implemented (bugs 630811 and 731878). But the behavior conforms to the latest D3E draft. So, some modifier key names are different from IE (bug 769190).
  • On mouse events, support for querying the state of the mouse buttons using the MouseEvent.buttons attribute, has been implemented.
  • On keyboard events, support for querying the key location (standard, left or right of modifier key, in the Numpad) using the KeyboardEvent.location attribute, has been implemented (bug 166240).
  • KeyboardEvent.keycode result has been computed from better rules which were almost same on Windows/Linux/Mac. And now they are available on some keyboard layouts which are not ASCII capable layouts on Linux and Mac, such as Arabic, Cyrillic, Thai and so on. See the document for virtual key codes.
  • The range.detach() method has been transformed in a no-op and will probably be removed in the future.
  • The method HTMLVideoElement.mozHasAudio() has been implemented. It indicates if there is an audio track associated to a given video element. (bug 480376)
  • The Performance API has a new method, now(), supporting high resolution timers of type DOMHighResTimeStamp. (bug 539095).
  • The Window.java and Window.packages attributes has been removed. These were never documented, and hopefully you're not using them!
  • The WebSMS API has been updated and now supports a read attribute indicating whether an SMS text message is read or unread.
  • The FileHandle API has been implemented.
  • The Blob constructor now takes ArrayBufferView as a member of blobParts parameter in addition to ArrayBuffer. (bug 752402)


  • Support for the DataView interface from the Typed Arrays specification has been added. This provides low-level access to the data contained in an ArrayBuffer.
  • 添加了对ES6中的Number.isNaN 方法的支持.(bug 749818)
  • 添加了对ES6中的默认参数的支持. (bug 757676)
  • 添加了对ES6中的剩余参数的支持.(bug 574132)


  • Support for the WEBGL_compressed_texture_s3tc extension has been added. Compressed textures reduce the amount of memory needed to store a texture on the GPU, allowing for higher resolution textures or more of the same resolution textures.



  • Support for the SPDY v3 protocol has landed. It is disabled by default and can be enabled by setting the preference network.http.spdy.enabled.v3 to true. (bug 737470)



aModifiers of sendMouseEvent(), sendTouchEvent(), sendMouseEventToWindow(), sendMouseScrollEvent() and sendKeyEvent() supports all modifier keys which are supported by KeyboardEvent.getModifierState(). Use MODIFIER_* values. And now the 5th parameter of sendKeyEvent() is changed from boolean to unsigned long. For backward compatibility, if caller passes true or false to it, the behavior isn't changed. This change allows callers to specify the key's location.
The hidePage() method was never implemented, and has been removed entirely in this release. The addPageWithDetails() method has also been removed as part of the ongoing work to make all Places APIs asynchronous; use mozIAsyncHistory.updatePlaces() instead. Also, the count attribute was removed; it had not returned an actual count in some time (instead, it was simply indicating whether or not any entries existed). You can use nsINavHistoryService.hasHistoryEntries instead.


Provides a way to hint to the networking layer that you are likely to ask to open a connection to a given URI sometime in the near future. This lets the network layer begin the sometimes high-latency process of opening a new network connection ahead of time.


The following interfaces have been removed.



最后编辑者: ethertank,