This reverts commit 19ebd61442fd3bf6a69af2156c8b118fc8578ec2.
Additionally, the following _flutter.runInView deadlock is fixed.
Previously, a deadlock would occur when service protocol
_flutter.runInView is used to restart the engine wihtout tearing down
the shell: the shared mutex of the service protocol will be locked
during the restart as it's in the middle of handling a service protocol
message; if ServiceProtocol::AddHandler is also called during the
restart, the deadlock happens as AddHandler also requires such lock.
test/integration.shard/background_isolate_test.dart would fail
without this fix.
This is a PR for converting the dart:ui code in the engine to use a multi-window API. The goal here is to convert from the window singleton to an API that has the concept of multiple windows. Also, I'm matching up the new PlatformDispatcher class to talk directly to the PlatformConfiguration class in the engine. I'm not attempting to actually enable creating multiple windows here, just migrate to an API that has a concept of multiple windows. The multi-window API in this PR currently only ever creates one window.
The design doc for this change is here.
The major changes in this PR:
Move the platfom-specific attributes out of Window, and into the new PlatformDispatcher class that holds all of the platform state, so that the platform code need only update the configuration on this class.
Create FlutterView, FlutterWindow, and SingletonFlutterWindow classes to separate out the concepts of a view (of which there may be multiple in a window), a window (of which there may be multiple on a screen, and they host views), and a window where there is only ever expected to be one (this hosts the entire API of the former Window class, and will eventually be the type of the window singleton).
Next step after this PR lands:
Remove the Window class entirely (it is replaced by SingletonFlutterWindow). Some minor changes in the Framework are needed to switch to using SingletonFlutterWindow directly first.
The Window class still exists in this PR, but will be removed as soon as the framework is converted to point to the SingletonFlutterWindow class instead. They share the same API, just have different names (Window is currently a subclass of SingletonFlutterWindow). The intention is that the Window name will be freed up to use as a widget class name in the framework for managing windows. The singleton called window will remain, and keep the same API it has now.
* Move shader.dart into shaders directory
* Add Shader builder basic structure and decls
* rewrite drawVertices with ShaderBuilder
* Fix in parameters in fragment shader to use varying for webgl1
Follow up from #21436 . That PR works for all embeddings except for Android, which creates a special JNI AssetResolver. Since the shell cannot recreate this resolver, update the logic to preserve existing resolvers instead.
Previously, the selection base and extent were stored internally as
iterators over text_. Since iterators must be treated as invalidated
whenever the underlying container changes, this requires that
selection_base_ and selection_extent_ be re-assigned after every change
to text_.
This is not currently particularly problematic, but once we add fields
to track the base and extent of the composing region for multi-step
input method support, as well as support for the sub-range within the
composing region to which edits/completions apply, we end up having to
regenerate a lot of iterators with each change, many of which are
logically unchanged in position.
A side benefit is that this simplifies inspection of these fields when
debugging.
