Firefox 62 for developers

• You now have four options for the location of the Developer Tools. In addition to the default location on the bottom of the window, you can choose to locate the tools on either the left or right sides of the main window or in a separate window.
• You can now split the Rules view out into its own pane, separate from the other tabs on the CSS pane. See Page inspector 3-pane mode (en-US) for more details.
• The Grid inspector has updated features, and all new documentation — see CSS Grid Inspector: Examine grid layouts (en-US).
• The Accessibility inspector has had a couple of minor updates:
  • It no longer exposes the help property, which isn't properly implemented in Gecko (Firefox bug 1467643).
  • The keyboardShortcut property now correctly exposes any keyboard shortcut available to activate the currently inspected node (Firefox bug 1467381).

没有变化。

• :-moz-selection has been unprefixed (Firefox bug 509958).
• x is now supported as a unit for the <resolution> type (Firefox bug 1460655).
• shape-margin, shape-outside, and shape-image-threshold are now enabled by default (Firefox bug 1457297).

No changes.

• The Array.prototype.flat() and Array.prototype.flatMap() methods are now enabled by default (Firefox bug 1435813).
• The import.meta property has been implemented to expose context-specific metadata to a JavaScript module (Firefox bug 1427610).
• JavaScript string literals may now directly contain U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR. As a consequence, JSON syntax is now a subset of JavaScript literal syntax (see Firefox bug 1435828 and the tc39 proposal json-superset).
• For out-of-bounds typed array indexes, Reflect.defineProperty() and Reflect.set() will now return false instead of true (Firefox bug 1308735).

New APIs

• The Speech Synthesis API (Text-to-Speech) is now enabled by default on Firefox for Android (Firefox bug 1463496).

DOM

• The DOMPointReadOnly (en-US) interface now supports the static function DOMPointReadOnly.fromPoint() (en-US), which creates a new point object from a dictionary that's compatible with DOMPointInit (en-US). This function is also available on DOMPoint (Firefox bug 1186265).
• Related to the previous item, the DOMPoint and DOMPointReadOnly constructors no longer support an input parameter of type DOMPointInit; the values of the properties must be specified using the x, y, z, and w parameters (Firefox bug 1186265).
• The URL.createObjectURL() method no longer supports creating object URLs to represent a MediaStream. This capability has been obsolete for some time now, since you can simply set HTMLMediaElement.srcObject to the MediaStream directly now (Firefox bug 1454889).
• For compatibility purposes, the Event.srcElement property is now supported. It is an alias for Event.target (Firefox bug 453968).
• Navigator.registerProtocolHandler() now must only be called from a secure context (Firefox bug 1460506).
• The Navigator.registerContentHandler() method has been disabled by default in preparation for being removed entirely, as it's been obsolete for some time (Firefox bug 1460481).

DOM events

No changes.

Service workers

No changes.

Media, Web Audio, and WebRTC

• The "media.autoplay.enabled" preference now controls automatic playback of both audio and video media, instead of just video media (Firefox bug 1413098).
• The ChannelSplitterNode (en-US) has been fixed to correctly default to having 6 channels with the channelInterpretation set to "discrete" and the channelCountMode set to "explicit" per the specification (Firefox bug 1456265).

Canvas and WebGL

No changes.

• Support for CSSStyleDeclaration.getPropertyCSSValue() has been removed (Firefox bug 1408301).
• Support for CSSValue, CSSPrimitiveValue (en-US), and CSSValueList has been removed (bug ).
• window.getComputedStyle() no longer returns null when called on a Window which has no presentation (Firefox bug 1467722).

• The deprecated CSP referrer (en-US) directive has been removed. Please use the Referrer-Policy header instead (Firefox bug 1302449).

No changes.

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API changes

• webRequest.getSecurityInfo() API to examine details of TLS connections (Firefox bug 1322748).
• browserSettings.newTabPosition (en-US) to customize where new tabs open (Firefox bug 1344749).
• windowTypes has been deprecated in windows.get() (en-US), windows.getCurrent() (en-US) and windows.getLastFocused() (en-US) (Firefox bug 1419132).
• It's now possible to modify a browser action on a per-window basis (Firefox bug 1419893).

Manifest changes

• New open_at_install property of the sidebar_action (en-US) manifest key enables extensions to control whether their sidebars should open automatically on install or not (Firefox bug 1460910).
• Changed to the browser_style property of various manifest keys:
  • in page_action (en-US) and browser_action it defaults to false
  • in sidebar_action (en-US) and options_ui (en-US) it defaults to true.

Theme changes

• New tab_background_separator property of the theme (en-US) manifest key enables extensions to change the color of the tab separator.

Other changes

• Support for unpacked sideloaded extensions has been removed (Firefox bug 1385057).

• Site compatibility for Firefox 62