Fixes https://github.com/flutter/flutter/issues/89683.
The changes to `getFlutterView` in `FlutterDeviceScreenshot` are the fix that was required, everything else was done to get tests running (such as re-generating some lockfiles and modifying the android manifest).
The code was all currently not unit tested, and there were no other easy examples to base these java unit tests off in flutter/flutter, so let me know if this approach to testing is wrong.
This change enables Flutter to generate multiple Scenes to be rendered into separate FlutterViews from a single widget tree. Each Scene is described by a separate render tree, which are all associated with the single widget tree.
This PR implements the framework-side mechanisms to describe the content to be rendered into multiple views. Separate engine-side changes are necessary to provide these views to the framework and to draw the framework-generated Scene into them.
## Summary of changes
The details of this change are described in [flutter.dev/go/multiple-views](https://flutter.dev/go/multiple-views). Below is a high-level summary organized by layers.
### Rendering layer changes
* The `RendererBinding` no longer owns a single `renderView`. In fact, it doesn't OWN any `RenderView`s at all anymore. Instead, it offers an API (`addRenderView`/`removeRenderView`) to add and remove `RenderView`s that then will be MANAGED by the binding. The `RenderView` itself is now owned by a higher-level abstraction (e.g. the `RawView` Element of the widgets layer, see below), who is also in charge of adding it to the binding. When added, the binding will interact with the `RenderView` to produce a frame (e.g. by calling `compositeFrame` on it) and to perform hit tests for incoming pointer events. Multiple `RenderView`s can be added to the binding (typically one per `FlutterView`) to produce multiple Scenes.
* Instead of owning a single `pipelineOwner`, the `RendererBinding` now owns the root of the `PipelineOwner` tree (exposed as `rootPipelineOwner` on the binding). Each `PipelineOwner` in that tree (except for the root) typically manages its own render tree typically rooted in one of the `RenderView`s mentioned in the previous bullet. During frame production, the binding will instruct each `PipelineOwner` of that tree to flush layout, paint, semantics etc. A higher-level abstraction (e.g. the widgets layer, see below) is in charge of adding `PipelineOwner`s to this tree.
* Backwards compatibility: The old `renderView` and `pipelineOwner` properties of the `RendererBinding` are retained, but marked as deprecated. Care has been taken to keep their original behavior for the deprecation period, i.e. if you just call `runApp`, the render tree bootstrapped by this call is rooted in the deprecated `RendererBinding.renderView` and managed by the deprecated `RendererBinding.pipelineOwner`.
### Widgets layer changes
* The `WidgetsBinding` no longer attaches the widget tree to an existing render tree. Instead, it bootstraps a stand-alone widget tree that is not backed by a render tree. For this, `RenderObjectToWidgetAdapter` has been replaced by `RootWidget`.
* Multiple render trees can be bootstrapped and attached to the widget tree with the help of the `View` widget, which internally is backed by a `RawView` widget. Configured with a `FlutterView` to render into, the `RawView` creates a new `PipelineOwner` and a new `RenderView` for the new render tree. It adds the new `RenderView` to the `RendererBinding` and its `PipelineOwner` to the pipeline owner tree.
* The `View` widget can only appear in certain well-defined locations in the widget tree since it bootstraps a new render tree and does not insert a `RenderObject` into an ancestor. However, almost all Elements expect that their children insert `RenderObject`s, otherwise they will not function properly. To produce a good error message when the `View` widget is used in an illegal location, the `debugMustInsertRenderObjectIntoSlot` method has been added to Element, where a child can ask whether a given slot must insert a RenderObject into its ancestor or not. In practice, the `View` widget can be used as a child of the `RootWidget`, inside the `view` slot of the `ViewAnchor` (see below) and inside a `ViewCollection` (see below). In those locations, the `View` widget may be wrapped in other non-RenderObjectWidgets (e.g. InheritedWidgets).
* The new `ViewAnchor` can be used to create a side-view inside a parent `View`. The `child` of the `ViewAnchor` widget renders into the parent `View` as usual, but the `view` slot can take on another `View` widget, which has access to all inherited widgets above the `ViewAnchor`. Metaphorically speaking, the view is anchored to the location of the `ViewAnchor` in the widget tree.
* The new `ViewCollection` widget allows for multiple sibling views as it takes a list of `View`s as children. It can be used in all the places that accept a `View` widget.
## Google3
As of July 5, 2023 this change passed a TAP global presubmit (TGP) in google3: tap/OCL:544707016:BASE:545809771:1688597935864:e43dd651
## Note to reviewers
This change is big (sorry). I suggest focusing the initial review on the changes inside of `packages/flutter` first. The majority of the changes describe above are implemented in (listed in suggested review order):
* `rendering/binding.dart`
* `widgets/binding.dart`
* `widgets/view.dart`
* `widgets/framework.dart`
All other changes included in the PR are basically the fallout of what's implemented in those files. Also note that a lot of the lines added in this PR are documentation and tests.
I am also very happy to walk reviewers through the code in person or via video call, if that is helpful.
I appreciate any feedback.
## Feedback to address before submitting ("TODO")
Manual roll is needed because incoming dart sdk requires updated version
vm_snapshot_analysis (>=0.7.4).
5ae09b8b4f...7c83ea3e85
```
7c83ea3e85 Reland "Manual roll Dart SDK from 2d98d9e27dae to 0b07debd5862 (21 revisions) (#43457)" (#43472)
9ef3e8d533 Roll Skia from 5eba922297bb to 93c92f97f5ab (2 revisions) (#43471)
```
Remove implementation of SuitePlatform from the test as well. Remove use
of fake cwd from SuitePlatform as it can't be properly faked.
- Bumps `vm_service` from `11.6.0` to `11.7.1`
- Bumps `web` from `0.1.3-beta` to `0.1.4-beta` and adds it everywhere.
- Moves `js` from `dependencies` to `dev_dependencies`
Syncs our lints with https://github.com/dart-lang/linter/blob/master/example/all.yaml:
* removed the deprecated `iterable_contains_unrelated_type` and `list_remove_unrelated_type` lints (their replacement `collection_methods_unrelated_type` was already enabled for us)
* enabled the new `no_self_assignments` and fixed one issue triggered by the lint.
- Set exported proguard rules for consumers of integration_test using AGP 8.0
- Updated proguard usage in example to test setting custom proguard rules works.
#127388
Documentation for how consumerProguardFiles works. https://developer.android.com/studio/projects/android-library#Considerations
Unknown why we had to use ** instead of matching exactly.
1. Add iOS and macOS migration to mark "last upgraded" Xcode version to 14.3 to prevent `Update to recommended settings` warning.
2. Update iOS and macOS templates to same.
3. Update iOS template to set `BuildIndependentTargetsInParallel` to YES as suggested. I didn't add a migration for this since it seems like a minor optimization and I don't think it's worth a potentially botched/corrupted migration.
4. Run all example/integration test project to see migrator work.
5. Add some missing test projects to the build shard since I noticed they were missing and I had to build those manually outside `SHARD=build_tests`.
Fixes https://github.com/flutter/flutter/issues/125817
See https://github.com/flutter/flutter/pull/90304 for Xcode 13 example.
See https://docs.flutter.dev/reference/supported-platforms
I don't expect this to break anything, but if it does we can revert and figure out what else needs to happen first.
Without this change, engine changes upstream will get flagged in default flutter created apps.
