This PR refactors `Rasterizer` so that it's more suitable for multi-view.
Design doc: [flutter.dev/go/multi-view-pipeline-and-rasterizer](http://flutter.dev/go/multi-view-pipeline-and-rasterizer)
With this change, `Rasterizer::DrawToSurfaces` has a structure that can handle drawing to multiple views, although the lack of some functionality still blocks it, mostly related to `ExternalViewEmbedder` and `RasterCache`.
[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style
Fixes https://github.com/flutter/flutter/issues/126878
This disables device private upload on iOS when backgrounded, and disables mipmap generation when backgrounded.
We don't have a good way to test the core problem in this repo because it only reproduces on physical iOS hardware - simulators don't really care if you do this stuff in the background.
I'll write a devicelab test in the framework to capture this. In the mean time it can be reviewed.
We could consider making the IOManager a shared_ptr instead of having an fml::WeakPtr and that'd clean up some of the extra arguments to engine construction - or we could consider vending the sync switch from impeller::Context unconditionally, but it's pretty iOS specific...
Fixes https://github.com/flutter/flutter/issues/123307 - for Android, iOS, and Web, for the main display only (https://github.com/flutter/flutter/issues/125938 tracks supporting multiple displays, https://github.com/flutter/flutter/issues/125939 for desktop).
Desktop will need to be implemented for this, but given priority for a couple of our customers targetting foldable devices on Android I'm inclined to get this in before desktop can be finished.
The main concern for this right now is that on some Android foldable devices, setting a preferred orientation will cause letterboxing and the `MediaQuery` will _never_ get the full screen size when unfolded. This causes apps to think the screen is smaller than it is, as they've mainly been using `MediaQueryData.size` to figure this out. Android's recommendation is to not set a preferred orientation, and if you must to use the new method introduced in `ViewUtil.java` to calculate the maximal window size.
This introduces `PlatformDispatcher.implicitView`, a low-level primitive for the framework's bootstrapping. Most code, including the framework after bootstrapping, will use `View.of(context)` instead of this new API. This new primitive will let us deprecate the `window` global.
Goals:
1. **Enable multi-window**. The `PlatformDispatcher.implicitView` is nullable. If `null`, the app must create a window to get a view it can draw into.
2. **Backwards compatibility**. For "single window" apps, `PlatformDispatcher.instance.implicitView` should behave as similar to `window` as possible.
1. The `PlatformDispatcher.instance.implicitView.viewId` should be `0`.
1. The `PlatformDispatcher.instance.implicitView` must be available synchronously at root isolate startup. This allows the framework to determine if it can make single window assumptions at startup.
2. The `PlatformDispatcher.instance.implicitView` reference must not change after startup: if it is null at startup, it must always be null; if it is non-null at startup, it must always be non-null. If "single window" app enters headless mode, the implicit view must remain non-null.
In the future, the embedder will control whether an implicit view is created: mobile & legacy desktop apps will have an implicit view, multi-window desktop apps won't have an implicit view. This requires updating the engine's embedder API and is out-of-scope for this change. For now, all apps will have an implicit view.
Part of https://github.com/flutter/flutter/issues/120306
This patch also eliminates some extraneous tracing that is happening
every frame. It is possible to get the same trace calls by enabling
the API stream if needed.
Also refactors the NotifyIdle callsites to just always work in
TimeDeltas rather than converting back and forth between them and
TimePoints, which I think reads more clearly.
* Add calls to Dart_NotifyDestroyed when the flutter view is destroyed.
* Add unit test case.
* Format.
* Ensure the destroy task runs.
* Address code review comments.
Update Picture rasterization for toImage to accept a layer tree, optionally flattening on the raster thread if present.
Update Deferred GPU image for toImageSync to accept a layer tree, flattening it the first time it creates an image, storing the resulting display list.
This is also a performance fix for the zoom page transition, which currently does too much work on the UI thread on frame 1
This PR changes how embedder API's SendKeyData sends ui.KeyData to the framework. The packets are now sent over the existing platform messenger, reusing the entirety of its code path and functionalities while keeping the embedder API unchanged
Group together externally-managed UIDartState.
It's a frequent pattern to enable access to shell resources from the
framework via UIDartState. These handles are passed through several
other objects, where they lay mostly dormant. This refactor just aims
to ease maintenance of this state.
UIDartState is essentially just an easy to extend bus for dropping
off the shell kids in UIDartState, with constructors/operators that
remove the need for providing a full initializer lists in unittests.
