src/cobalt/CHANGELOG.md - cobalt - Git at Google

 # Cobalt Version Changelog

 This document records all notable changes made to Cobalt since the last release.

 ## Version 20
  - **Improvements and Bug Fixes**
   - Fix bug where Cobalt would not refresh the layout when the textContent
     property of a DOM TextNode is modified.

 ## Version 19
  - **Add support for V8 JavaScript Engine**

    Cobalt now supports V8 (in addition to SpiderMonkey) as JavaScript engines.
    V8 can be enabled by setting the gyp variable 'javascript_engine' to 'v8',
    and additionally setting the gyp variable 'cobalt_enable_jit' to 1.  These
    variables should be set from your `gyp_configuration.py` Python file (and
    not for example your `gyp_configuration.gypi` file).

  - **Add support for animated WebP images with transparency**

    This was not originally supported by Cobalt, and any prior use of animated
    WebP with transparency would have resulted in visual artifacts.

  - **Storage format changed from sqlite3 to protobuf**

    Cobalt's internal representation for persistent storage of cookies and local
    storage entries changed from sqlite3 to protobuf. The header of the
    SbStorageRecord blob was updated from SAV0 to SAV1 and all the data will be
    migrated to the new format the next time Cobalt is launched.
    The schema is available at cobalt/storage/store/storage.proto.

  - **IPv4 Preference**

    Cobalt is now configured to prefer an IPv4 address to IPv6 addresses when
    choosing an initial server address from DNS responses. That is, if a
    DNS response contains both IPv4 addresses and IPv6 addresses, Cobalt will
    now explicitly attempt to connect an IPv4 address before possibly moving onto
    IPv6 on connect failures. Unfortunately, we've discovered common scenarios
    where IPv6 addresses were listed in DNS responses but intervening network
    configurations prevented IPv6 use after connect time. This caused the
    previous implementation to appear as if no network was available.

  - **Enable voice interactions**

    A subset of WebRTC APIs has been added. `getUserMedia` can be used to get
    audio input stream from the microphone. The media stream can then be
    connected to `MediaRecorder` to receive the audio data stored as `Blob`
    objects which can later be sent over the network. This allows web apps to
    implement voice-enabled features without relying on the platform's capability
    to perform speech recognition.

  - **Bison 3 required**

    Support for compiling with version 2.x of the GNU bison parser generator
    has been removed. Please update to version 3.x.

  - **Improvements and Bug Fixes**
   - Fix pointer/mouse events not being dispatched to JavaScript in the same
     order that they are generated by Starboard, relative to other input events
     like key presses.
   - Fix issue with CSS media queries not assigning correct rule indices.
     An issue was discovered and fixed where CSS rules defined within `@media`
     rules would be assigned a CSS rule index relative to their position within
     the nested `@media` rule rather than being assigned an index relative to
     their position within the parent CSS file.  As a result, rules may have been
     assigned incorrect precedence during CSS rule matching.
   - Fix issue where the style attribute would not appear in the string output
     of calls to element.outerHTML.

 ## Version 16
  - **Rebase libwebp to version 1.0.0**

    Update the version of libwebp used by Cobalt from 0.3.1 to 1.0.0.  The new
    version brings with it performance improvements and bug fixes.

  - **Move ``javascript_engine`` and ``cobalt_enable_jit`` build variables**

    Move gyp variables ``javascript_engine`` and ``cobalt_enable_jit``, which
    were previously defined in ``cobalt_configuration.gypi``, to
    ``$PLATFORM/gyp_configuration.py``.  This was done in order to work around
    bindings gyp files' complex usage of gyp variables, which prevented us from
    having a default JavaScript engine at the gyp variable level.  Now, platforms
    will by default use the JavaScript engine selected by
    ``starboard/build/platform_configuration.py``, and can override it by
    providing a different one in their ``GetVariables`` implementation.  See the
    ``linux-x64x11-mozjs`` platform for an override example.

    **IMPORTANT**: While existing gyp files that define ``javascript_engine`` and
    ``cobalt_enable_jit`` may continue to work by chance, it is *strongly*
    preferred to move all declarations of these variables to python instead.

  - **Move test data**

    Static test data is now copied to `content/data/test` instead of
    `content/dir_source_root`.  Tests looking for the path to this data should
    use `BasePathKey::DIR_TEST_DATA` instead of `BasePathKey::DIR_SOURCE_ROOT`.
    Tests in Starboard can find the static data in the `test/` subdirectory of
    `kSbSystemPathContentDirectory`.

  - **Add support for cobalt_media_buffer_max_capacity**

    Allow bounding the max capacity allocated by decoder buffers, by setting the
    gypi variables cobalt_media_buffer_max_capacity_1080p and
    cobalt_media_buffer_max_capacity_4k. 1080p applies to all resolutions 1080p
    and below. Those values default to 0, which imposes no bounds. If non-zero,
    each capacity must be greater than or equal to the sum of the video budget
    and non video budget for that resolution (see
    cobalt_media_buffer_video_buffer_1080p, cobalt_media_buffer_non_video_budget,
    etc.), and the max capacities must be greater than or equal to the
    corresponding initial capacities: cobalt_media_buffer_initial_capacity_1080p
    and cobalt_media_buffer_initial_capacity_4k.

 - **Fix issue with CSS animations not working with the 'outline' property**

    There was a bug in previous versions that resulted in incorrect behavior when
    applying a CSS animation or CSS transition to the 'outline' property.  This
    is fixed now.

 - **Change default minimum frame time to 16.0ms instead of 16.4ms.**

    In case a platform can only wait on millisecond resolution, we would prefer
    that it wait 16ms instead of 17ms, so we round this down.  Many platforms
    will pace themselves to 16.6ms regardless.

 - **Make new rasterizer type "direct-gles" default**

    This is an optimized OpenGLES 2.0 rasterizer that provides a fast path for
    rendering most of the skia primitives that Cobalt uses.  While it was
    available since Version 11, it is now polished and set as the default
    rasterizer.

 - **Added support for the fetch and streams Web APIs**

    A subset of ReadableStream and Fetch Web APIs have been implemented. Fetch
    may be used to get progressive results via a ReadableStream, or the full
    result can be accessed as text, from the Response class.

 - **HTMLMediaElement::loop is supported**

    Now the video plays in a loop if the loop attribute of the video element is
    set.

 - **Add support for MediaDevices.enumerateDevices()**

    It is now possible to enumerate microphone devices from JavaScript via a
    call to navigator.mediaDevices.enumerateDevices().  This returns a promise
    of an array of MediaDeviceInfo objects, each partially implemented to have
    valid `label` and `kind` attributes.

 - **Improvements and Bug Fixes**
   - Fix for pseudo elements not visually updating when their CSS is modified
     (e.g. by switching their classes).

 ## Version 14
  - **Add support for document.hasFocus()**

    While support for firing blur and focus events was implemented, querying
    the current state via document.hasFocus() was not implemented until now.

  - **Implemented Same Origin Policy and removed navigation whitelist**

    - Added Same Origin Policy (SOP) and Cross Origin Resource Sharing (CORS)
      suport to Cobalt.  In particular, it is added to XHR, script elements,
      link elements, style elements, media elements and @font-face CSS rules.
    - Removed hardcoded YouTube navigation whitelist in favor of SOP and CSP.

 ## Version 12
  - **Add support for touchpad not associated with a pointer**

    This adds support for input of type kSbInputDeviceTypeTouchPad for
    touchpads not associated with a pointer.

 ## Version 11
  - **Splash Screen Customization**

    The Cobalt splash screen is customizable. Documents may use a link element
    with attribute rel="splashscreen" to reference the splash screen which will
    be cached if local cache is implemented on the platform. Additionally
    fallbacks may be specified via command line parmeter or gypi variable.
    For more information, see [doc/splash_screen.md](doc/splash_screen.md).

  - **Introduce C\+\+11**

    C\+\+11 is now used within Cobalt code, and so Cobalt must be compiled using
    C\+\+11 toolchains.

  - **Update SpiderMonkey from version 24 to 45; support ECMAScript 6**

    The Mozilla SpiderMonkey JavaScript engine is rebased up to version 45, and
    thus ECMAScript 6 is now supported by Cobalt.  You will need to modify your
    `gyp_configuration.gypi` file to set `'javascript_engine': 'mozjs-45'` to
    enable this.

  - **Fetch/Stream API**

    Cobalt now supports the Fetch/Stream API.

  - **On-device Speech-to-Text support**

    Support for utilizing the new Starboard speech recognizer interface in order
    to allow for on-device speech-to-text support is now added.  The Starboard
    interface is defined in
    [starboard/speech_recognizer.h](../starboard/speech_recognizer.h).

  - **Mouse pointer support**

    Cobalt now supports pointer events and will respond to Starboard
    `kSbInputEventTypeMove` events.  These will be passed into the WebModule to
    be processed by JavaScript.

  - **Custom Web Extension Support**

    Cobalt now allows platforms to inject a custom namespace property into
    the JavaScript global `window` object visible to the web apps.  This allows
    for custom web apps to interface with custom C++ code written outside of
    Cobalt common code.  See
    [doc/webapi_extension.md](doc/webapi_extension.md) for more details.

  - **Playback Rate**

    Cobalt now supports adjusting the video playback rate.

  - **AutoMem - Memory Configuration**

    AutoMem has been added which assists developers in tuning the memory
    settings of the Cobalt app. On startup, memory settings are now printed
    for all builds except gold. Memory settings can be altered via the
    command line, build files and in some instances the Starboard API.
    For more information, see [cobalt/doc/memory_tuning.md](doc/memory_tuning.md).

  - **Page Visibility API Support**

    Cobalt now supports the page visibility API, and will signal visibility and
    focus changes to the web app as the process transitions between Starboard
    lifecycle states. See the
    new [Application Lifecycle Integration](doc/lifecycle.md) document for more
    details.

  - **Opus Support**

    Added support for providing Opus audio-specific config to Starboard. Requires
    Starboard 6.

  - **Linux build now supports 360 video**

    The Linux build linux-x64x11 now supports 360 video, and can be used as a
    reference implementation.

  - **Stop the application if not retrying after a connection error**

    A positive response from `kSbSystemPlatformErrorTypeConnectionError` now
    indicates that Cobalt should retry the failed request. Any other response now
    causes Cobalt to call `SbSystemRequestStop`.

  - **Frame rate counter**

    A frame rate counter is now made accessible.  It actually displays frame
    times, the inverse of frame rate.  In this case, 16.6ms corresponds to 60fps.
    It is accessible both as an overlay on the display by the command line
    option, "--fps_overlay".  The data can also be printed to stdout with the
    command line option "--fps_stdout".  The frame rate statistics will be
    updated each time an animation ends, or after 60 frames have been processed.
    Both command line flags are available in Gold builds.

  - **Add support for rendering `kSbDecodeTargetFormat1PlaneUYVY` (YUV 422)**

    Decode targets with the format `kSbDecodeTargetFormat1PlaneUYVY` will now
    be rendered by Cobalt.  This will allow decoders that produce YUV 422 UYVY
    video frames to now efficiently support 360 video.

  - **Preload Support**

    Support for preloading an application with no graphics resources. See the
    new [Application Lifecycle Integration](doc/lifecycle.md) guide for more
    details.

  - **Improvements and Bug Fixes**
    - Fixed position elements given correct draw order without requiring z-index.
    - Overflow-hidden correctly applied when z-index is used.
    - Padding box forms containing block for fixed position elements within
      transforms.
    - Determine whether a font is bold in more cases, so synthetic bolding isn't
      incorrectly applied.
    - Fix bug where decoding images with large headers would fail.
    - Include missing CSS transforms in `GetClientRects()` calculations.
    - CSS Transitions and Animations not resetting properly when adjusting
      `display: none` on an element.
    - `offset_left` and similar properties are no longer cause many expensive
      re-layouts to query.
    - Fix bug where pseudo-elements were "inheriting" the inline style of their
      parent elements as if it were their own inline style.

 ## Version 9
  - **Improvements and Bug Fixes**
    - Non-fixed position elements given correct draw order without requiring
      z-index.
	# Cobalt Version Changelog

	This document records all notable changes made to Cobalt since the last release.

	## Version 20
	- Improvements and Bug Fixes
	- Fix bug where Cobalt would not refresh the layout when the textContent
	property of a DOM TextNode is modified.

	## Version 19
	- Add support for V8 JavaScript Engine

	Cobalt now supports V8 (in addition to SpiderMonkey) as JavaScript engines.
	V8 can be enabled by setting the gyp variable 'javascript_engine' to 'v8',
	and additionally setting the gyp variable 'cobalt_enable_jit' to 1. These
	variables should be set from your `gyp_configuration.py` Python file (and
	not for example your `gyp_configuration.gypi` file).

	- Add support for animated WebP images with transparency

	This was not originally supported by Cobalt, and any prior use of animated
	WebP with transparency would have resulted in visual artifacts.

	- Storage format changed from sqlite3 to protobuf

	Cobalt's internal representation for persistent storage of cookies and local
	storage entries changed from sqlite3 to protobuf. The header of the
	SbStorageRecord blob was updated from SAV0 to SAV1 and all the data will be
	migrated to the new format the next time Cobalt is launched.
	The schema is available at cobalt/storage/store/storage.proto.

	- IPv4 Preference

	Cobalt is now configured to prefer an IPv4 address to IPv6 addresses when
	choosing an initial server address from DNS responses. That is, if a
	DNS response contains both IPv4 addresses and IPv6 addresses, Cobalt will
	now explicitly attempt to connect an IPv4 address before possibly moving onto
	IPv6 on connect failures. Unfortunately, we've discovered common scenarios
	where IPv6 addresses were listed in DNS responses but intervening network
	configurations prevented IPv6 use after connect time. This caused the
	previous implementation to appear as if no network was available.

	- Enable voice interactions

	A subset of WebRTC APIs has been added. `getUserMedia` can be used to get
	audio input stream from the microphone. The media stream can then be
	connected to `MediaRecorder` to receive the audio data stored as `Blob`
	objects which can later be sent over the network. This allows web apps to
	implement voice-enabled features without relying on the platform's capability
	to perform speech recognition.

	- Bison 3 required

	Support for compiling with version 2.x of the GNU bison parser generator
	has been removed. Please update to version 3.x.

	- Improvements and Bug Fixes
	- Fix pointer/mouse events not being dispatched to JavaScript in the same
	order that they are generated by Starboard, relative to other input events
	like key presses.
	- Fix issue with CSS media queries not assigning correct rule indices.
	An issue was discovered and fixed where CSS rules defined within `@media`
	rules would be assigned a CSS rule index relative to their position within
	the nested `@media` rule rather than being assigned an index relative to
	their position within the parent CSS file. As a result, rules may have been
	assigned incorrect precedence during CSS rule matching.
	- Fix issue where the style attribute would not appear in the string output
	of calls to element.outerHTML.

	## Version 16
	- Rebase libwebp to version 1.0.0

	Update the version of libwebp used by Cobalt from 0.3.1 to 1.0.0. The new
	version brings with it performance improvements and bug fixes.

	- Move ``javascript_engine`` and ``cobalt_enable_jit`` build variables

	Move gyp variables ``javascript_engine`` and ``cobalt_enable_jit``, which
	were previously defined in ``cobalt_configuration.gypi``, to
	``$PLATFORM/gyp_configuration.py``. This was done in order to work around
	bindings gyp files' complex usage of gyp variables, which prevented us from
	having a default JavaScript engine at the gyp variable level. Now, platforms
	will by default use the JavaScript engine selected by
	``starboard/build/platform_configuration.py``, and can override it by
	providing a different one in their ``GetVariables`` implementation. See the
	``linux-x64x11-mozjs`` platform for an override example.

	IMPORTANT: While existing gyp files that define ``javascript_engine`` and
	``cobalt_enable_jit`` may continue to work by chance, it is strongly
	preferred to move all declarations of these variables to python instead.

	- Move test data

	Static test data is now copied to `content/data/test` instead of
	`content/dir_source_root`. Tests looking for the path to this data should
	use `BasePathKey::DIR_TEST_DATA` instead of `BasePathKey::DIR_SOURCE_ROOT`.
	Tests in Starboard can find the static data in the `test/` subdirectory of
	`kSbSystemPathContentDirectory`.

	- Add support for cobalt_media_buffer_max_capacity

	Allow bounding the max capacity allocated by decoder buffers, by setting the
	gypi variables cobalt_media_buffer_max_capacity_1080p and
	cobalt_media_buffer_max_capacity_4k. 1080p applies to all resolutions 1080p
	and below. Those values default to 0, which imposes no bounds. If non-zero,
	each capacity must be greater than or equal to the sum of the video budget
	and non video budget for that resolution (see
	cobalt_media_buffer_video_buffer_1080p, cobalt_media_buffer_non_video_budget,
	etc.), and the max capacities must be greater than or equal to the
	corresponding initial capacities: cobalt_media_buffer_initial_capacity_1080p
	and cobalt_media_buffer_initial_capacity_4k.

	- Fix issue with CSS animations not working with the 'outline' property

	There was a bug in previous versions that resulted in incorrect behavior when
	applying a CSS animation or CSS transition to the 'outline' property. This
	is fixed now.

	- Change default minimum frame time to 16.0ms instead of 16.4ms.

	In case a platform can only wait on millisecond resolution, we would prefer
	that it wait 16ms instead of 17ms, so we round this down. Many platforms
	will pace themselves to 16.6ms regardless.

	- Make new rasterizer type "direct-gles" default

	This is an optimized OpenGLES 2.0 rasterizer that provides a fast path for
	rendering most of the skia primitives that Cobalt uses. While it was
	available since Version 11, it is now polished and set as the default
	rasterizer.

	- Added support for the fetch and streams Web APIs

	A subset of ReadableStream and Fetch Web APIs have been implemented. Fetch
	may be used to get progressive results via a ReadableStream, or the full
	result can be accessed as text, from the Response class.

	- HTMLMediaElement::loop is supported

	Now the video plays in a loop if the loop attribute of the video element is
	set.

	- Add support for MediaDevices.enumerateDevices()

	It is now possible to enumerate microphone devices from JavaScript via a
	call to navigator.mediaDevices.enumerateDevices(). This returns a promise
	of an array of MediaDeviceInfo objects, each partially implemented to have
	valid `label` and `kind` attributes.

	- Improvements and Bug Fixes
	- Fix for pseudo elements not visually updating when their CSS is modified
	(e.g. by switching their classes).

	## Version 14
	- Add support for document.hasFocus()

	While support for firing blur and focus events was implemented, querying
	the current state via document.hasFocus() was not implemented until now.

	- Implemented Same Origin Policy and removed navigation whitelist

	- Added Same Origin Policy (SOP) and Cross Origin Resource Sharing (CORS)
	suport to Cobalt. In particular, it is added to XHR, script elements,
	link elements, style elements, media elements and @font-face CSS rules.
	- Removed hardcoded YouTube navigation whitelist in favor of SOP and CSP.

	## Version 12
	- Add support for touchpad not associated with a pointer

	This adds support for input of type kSbInputDeviceTypeTouchPad for
	touchpads not associated with a pointer.

	## Version 11
	- Splash Screen Customization

	The Cobalt splash screen is customizable. Documents may use a link element
	with attribute rel="splashscreen" to reference the splash screen which will
	be cached if local cache is implemented on the platform. Additionally
	fallbacks may be specified via command line parmeter or gypi variable.
	For more information, see [doc/splash_screen.md](doc/splash_screen.md).

	- Introduce C\+\+11

	C\+\+11 is now used within Cobalt code, and so Cobalt must be compiled using
	C\+\+11 toolchains.

	- Update SpiderMonkey from version 24 to 45; support ECMAScript 6

	The Mozilla SpiderMonkey JavaScript engine is rebased up to version 45, and
	thus ECMAScript 6 is now supported by Cobalt. You will need to modify your
	`gyp_configuration.gypi` file to set `'javascript_engine': 'mozjs-45'` to
	enable this.

	- Fetch/Stream API

	Cobalt now supports the Fetch/Stream API.

	- On-device Speech-to-Text support

	Support for utilizing the new Starboard speech recognizer interface in order
	to allow for on-device speech-to-text support is now added. The Starboard
	interface is defined in
	[starboard/speech_recognizer.h](../starboard/speech_recognizer.h).

	- Mouse pointer support

	Cobalt now supports pointer events and will respond to Starboard
	`kSbInputEventTypeMove` events. These will be passed into the WebModule to
	be processed by JavaScript.

	- Custom Web Extension Support

	Cobalt now allows platforms to inject a custom namespace property into
	the JavaScript global `window` object visible to the web apps. This allows
	for custom web apps to interface with custom C++ code written outside of
	Cobalt common code. See
	[doc/webapi_extension.md](doc/webapi_extension.md) for more details.

	- Playback Rate

	Cobalt now supports adjusting the video playback rate.

	- AutoMem - Memory Configuration

	AutoMem has been added which assists developers in tuning the memory
	settings of the Cobalt app. On startup, memory settings are now printed
	for all builds except gold. Memory settings can be altered via the
	command line, build files and in some instances the Starboard API.
	For more information, see [cobalt/doc/memory_tuning.md](doc/memory_tuning.md).

	- Page Visibility API Support

	Cobalt now supports the page visibility API, and will signal visibility and
	focus changes to the web app as the process transitions between Starboard
	lifecycle states. See the
	new [Application Lifecycle Integration](doc/lifecycle.md) document for more
	details.

	- Opus Support

	Added support for providing Opus audio-specific config to Starboard. Requires
	Starboard 6.

	- Linux build now supports 360 video

	The Linux build linux-x64x11 now supports 360 video, and can be used as a
	reference implementation.

	- Stop the application if not retrying after a connection error

	A positive response from `kSbSystemPlatformErrorTypeConnectionError` now
	indicates that Cobalt should retry the failed request. Any other response now
	causes Cobalt to call `SbSystemRequestStop`.

	- Frame rate counter

	A frame rate counter is now made accessible. It actually displays frame
	times, the inverse of frame rate. In this case, 16.6ms corresponds to 60fps.
	It is accessible both as an overlay on the display by the command line
	option, "--fps_overlay". The data can also be printed to stdout with the
	command line option "--fps_stdout". The frame rate statistics will be
	updated each time an animation ends, or after 60 frames have been processed.
	Both command line flags are available in Gold builds.

	- Add support for rendering `kSbDecodeTargetFormat1PlaneUYVY` (YUV 422)

	Decode targets with the format `kSbDecodeTargetFormat1PlaneUYVY` will now
	be rendered by Cobalt. This will allow decoders that produce YUV 422 UYVY
	video frames to now efficiently support 360 video.

	- Preload Support

	Support for preloading an application with no graphics resources. See the
	new [Application Lifecycle Integration](doc/lifecycle.md) guide for more
	details.

	- Improvements and Bug Fixes
	- Fixed position elements given correct draw order without requiring z-index.
	- Overflow-hidden correctly applied when z-index is used.
	- Padding box forms containing block for fixed position elements within
	transforms.
	- Determine whether a font is bold in more cases, so synthetic bolding isn't
	incorrectly applied.
	- Fix bug where decoding images with large headers would fail.
	- Include missing CSS transforms in `GetClientRects()` calculations.
	- CSS Transitions and Animations not resetting properly when adjusting
	`display: none` on an element.
	- `offset_left` and similar properties are no longer cause many expensive
	re-layouts to query.
	- Fix bug where pseudo-elements were "inheriting" the inline style of their
	parent elements as if it were their own inline style.

	## Version 9
	- Improvements and Bug Fixes
	- Non-fixed position elements given correct draw order without requiring
	z-index.