Flutter's accessibility APIs consist of three main calls from the
embedder to the Dart application:
1. FlutterEngineUpdateSemanticsEnabled: enables/disables semantics support.
2. FlutterEngineUpdateAccessibilityFeatures: sets embedder-specific
accessibility features.
3. FlutterEngineDispatchSemanticsAction: dispatches an action (tap,
long-press, scroll, etc.) to a semantics node.
and two main callbacks triggered by Dart code:
1. FlutterUpdateSemanticsNodeCallback: notifies the embedder of
updates to the properties of a given semantics node.
2. FlutterUpdateSemanticsCustomActionCallback: notifies the embedder
of updates to custom semantics actions registered in Dart code.
In the Flutter framework, when accessibility is first enabled, the
embedder will receive a stream of update callbacks notifying the
embedder of the full semantics tree. On further changes in the Dart
application, only updates will be sent.
Adds 'add', 'remove', and 'hover' to the set of pointer phases that are
available to embedders. This is necessary for them to send hover events
to the engine.
From build log:
```
../../flutter/shell/platform/android/io/flutter/view/FlutterView.java:95: error: cannot find symbol
private final LocalizationChannel localizationChannel;
^
symbol: class LocalizationChannel
location: class FlutterView
../../flutter/shell/platform/android/io/flutter/view/FlutterView.java:172: error: cannot find symbol
localizationChannel = new LocalizationChannel(dartExecutor);
^
symbol: class LocalizationChannel
location: class FlutterView
2 errors
```
This reverts commit 256db4bc23.
Added `FlutterPluginRegistrantCallback` typedef and optional `setPluginRegistrantCallback` static method in `FlutterPlugin`. `setPluginRegistrantCallback` is used to set a callback defined in AppDelegate.m which registers some subset of plugins with a `FlutterPluginRegistry` (for example, a headless FlutterEngine). This allows for plugins which utilize background execution functionality to enable the use of other plugins on the background isolate. This puts iOS on par with Android for background execution.
Along with updated examples and Medium posts, this fixes [flutter/flutter#21925](https://github.com/flutter/flutter/issues/21925).
In 9345274 (#7642), //shell/platform/darwin:framework_shared was added
without the root flutter config, causing a build breakage in Fuchsia,
where flutter sits under //third_party/flutter as opposed to at the
root. The flutter root config is required to set -I../../third_party as
an include path.