Delegate a11y events and action to/from embedded Android platfrom views.
This handles delegation of:
* AccessibilityNodeProvider#performAction
* ViewGroup#requestSendAccessibilityEvent
* View#onHoverEvent
Additionally updates the currently input accessibility focused node state that is
tracked by the a11y bridge when an embedded view's node is focused.
This PR mirrors virtual a11y tree of embedded platform views in the Flutter
a11y tree.
Non virtual hierarchies are not currently supported.
Only works on Android versions earlier than Android P as it relies on
reflection access to hidden system APIs which cannot be done starting
Android P.
A11y is not yet working as we also need to delegate a11y events from the
platform view to the FlutterView. This will be done in a following PR to
keep the change size a little saner.
PlatformViewsDelegate.
Since onDetachedFromWindow can be called after the activity was
destroyed, the previous call to detach the accessibility bridge could
have crash as the NativeFlutterView was already null.
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 256db4bc23b7931509233df0dc04e44e16608229.
After bumping the targetSdk of Flutter apps to 28, the keyboard doesn't open anymore when inputting text on an Android Pie devices. The problem is caused by a change on the way the focus in handled: when the call `mImm.showSoftInput(view, 0);` is made, the currently focused view is the `DecorView` from the `Activity` hosting Flutter but the passed view reference (`view` argument) is the `FlutterView`. As the `InputMethodManager` checks if both views are the same before showing the keyboard, it never appears because the `FlutterView` never has focus.
As Flutter doesn't have any input views as far as the Android side is concerned, the focus should always stay on the `FlutterView` itself and thus, this PR changes the `TextInputPlugin` to focus on the `FlutterView` as soon as it's created, fixing the keyboard issue.
Co-authored-by: Igor Borges <igorborges12@gmail.com>
Decouple PlatformViewsController from FlutterView.
Instead of getting a FlutterView instance, depend on the specific interfaces required by
PlatformViewsController (BinaryMessenger, TextureRegistry, and Context).
This allows using PlatformViewsControlling in the flutter/embedding
code.
The default WindowManager implementation in Android's Presentation is
delegating addView/removeView/updateViewLayout calls to the global
WindowManager.
This can result in a crash when an embedded view is trying to e.g show a
PopupWindow.
This change adds a custom WindowManager that overrides
addView (and removeView/updateViewLayout) and adds the view to the
presentation's view tree.
Note that views might keep a reference to the window manager which
might be an issue when we move a view from one virtual display to
another (due to a resize). For this reason when re-sizing we are not
creating a new window manager for the new presentation, but updating the
window manager's references to be relevant for the new presentation and
re-use it.
This allows the framework to know that a frame with the resized view is
ready and to behave deterministically to workaround the jank issue
described in flutter/flutter/19572
* Flush all embedded Android view on hot restart.
Adds an OnEngineRestarted method to PlatformView, this is currently only
implemented for Android where we need to use it for embedded views.
* review comments followup
* rename to OnPreEngineRestart, call before Clone
When the FlutterView's window loses focus Flutter cannot bring up the
keyboard (so e.g tapping on text fields doesn't work).
This workaround makes sure that Flutter text fields are working but
unfortunately now the embedded Android view cannot bring up the keyboard
as it's window is not focused.
Submitting this until as a stop gap while we're trying to figure out if
it's possible to allow both windows to bring up the keyboard.
Each platform view created (by a plugin supplied factory) is attached to
a virtual display.
The virtual displays are controlled by VirtualDisplayController objects.
The PlatformViewsController maintains a mapping from a platform view's
id to its VirtualDisplayController, which allows it to operate on the
virtual display for a given platform view ID when asked so over the
method channel.
This is using API level 20 APIs, on lower API levels all platform views
method channel calls are noops.
We can make this work on API 19 with some refactoring to the
TextureRegistry (allow the engine Java code to recycle a texture entry
id).
This CL also adds a platform view id parameter to the
PlatformViewFactory#create() method. This allows plugins to route
platform channel messages to specific instances of a platform view.
TBD in future CLs:
* Forward touch events to the platform views.
* Support accessibility for platform views.
flutter/flutter#19030
To keep the scope of this CL as small of possible I'm leaving the actual
implementation of the platform view mechanics to a following CL.
This CL introduces:
* A PlatformViewsController class which will be responsible for creating,
resizing, and disposing platform views.
* A PlatformViewRegistry which is exposed through the PluginRegistry
and allows plugins to register factories for platform views.
Android plugin code will add support for a new platform view type by
implementing PlatformViewFactory, and registering a factory with the
registry, e.g:
```java
registrar.platformViewRegistry().registerViewFactory(
'webview',
new FlutterWebViewFactory()
);
```
On the Dart side, the framework will ask the engine to create new
platform views by sending a create message over the platformviews method
channel with the unique platform view type id, dimensions, and a unique
id allocated by the framework for the new platform view instance.
The platformviews method channel is also used for resizing and disposing
platform views.
