This measures the wall clock time between a new frame being scheduled in dart code to the Vsync callback in the engine
It's an important source of lag which isn't shown in the top-level UI / Build time graphs, and can correlate with "invisible" missed/non-scheduled frames
I had to change a few unrelated timings in the test, it was only passing based on luck of sort order, and broke when I added more entries to the timeline.
Part of #129150
## Description
This removes all of the comments that are of the form "so-and-so (must not be null|can ?not be null|must be non-null)" from the cases where those values are defines as non-nullable values.
This PR removes them from the animation, cupertino, foundation, gestures, semantics, and services libraries. Each of them only had a few, so I lumped them together.
This was done by hand, since it really didn't lend itself to scripting, so it needs to be more than just spot-checked, I think. I was careful to leave any comment that referred to parameters that were nullable, but I may have missed some.
In addition to being no longer relevant after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.
This did create a number of constructor comments which basically say "Creates a [Foo].", but I don't really know how to avoid that in a large scale change, since there's not much you can really say in a lot of cases. I think we might consider some leniency for constructors to the "Comment must be meaningful" style guidance (which we de facto have already, since there are a bunch of these).
## Related PRs
- https://github.com/flutter/flutter/pull/134991
- https://github.com/flutter/flutter/pull/134992
- https://github.com/flutter/flutter/pull/134993
- https://github.com/flutter/flutter/pull/134994
## Tests
- Documentation only change.
## Description
This removes all of the comments that are of the form "so-and-so must not be null" or "so-and-so must be non-null" from the cases where those values are defines as non-nullable values.
This PR removes them from the library in the repo that don't have anything to do with the framework.
This was done by hand, since it really didn't lend itself to scripting, so it needs to be more than just spot-checked, I think. I was careful to leave any comment that referred to parameters that were nullable, but I may have missed some.
In addition to being no longer relevant after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.
This did create a number of constructor comments which basically say "Creates a [Foo].", but I don't really know how to avoid that in a large scale change, since there's not much you can really say in a lot of cases. I think we might consider some leniency for constructors to the "Comment must be meaningful" style guidance (which we de facto have already, since there are a bunch of these).
## Related PRs
- https://github.com/flutter/flutter/pull/134984
- https://github.com/flutter/flutter/pull/134991
- https://github.com/flutter/flutter/pull/134992
- https://github.com/flutter/flutter/pull/134993
## Tests
- Documentation only change.
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`
Sync lints with https://github.com/dart-lang/linter/blob/master/example/all.yaml and enable `implicit_reopen` and `type_literal_in_constant_pattern` (which have no violations). Also contains some clean-up work towards enabling `matching_super_parameters`, which is not quite ready yet due to its handling of "private" arguments.
Most of these imports were never appropriate. The `test_api` package was never intended for use in `_test.dart` files.
Where possible move imports to `matcher`, otherwise move them to `test` or `flutter_test`.
Leave uses of `test_api` from `flutter_test` library code.
Update test expectations from application/javascript -> text/javascript
`package:mime` now uses `text/javascript` and not `application/javascript`.
See https://github.com/dart-lang/mime/pull/76.
See https://datatracker.ietf.org/doc/html/rfc9239.
> This document defines equivalent processing requirements for the various script media types. The most widely supported media type in use is `text/javascript`; all others are considered historical and obsolete aliases of `text/javascript`.
* Roll Flutter Engine from 67254d6e4b03 to 8d83b98c55b3
* Roll Dart SDK from 35a9facce191 to e517487c5679 (Dart 3.0) (#38105)
* Bump SDK versions.
* Bump Dart SDK version constraints
* Update shrine package to 2.0.1 (null safe version)
* Fix more tests.
* Include patches from Jason for min android sdk version
* Fix analyzer warning
* Test the case when main Isolate is in `None` state for long time
* Wait for isolate to become runnable
* Handle `PausePostRequest` as a normal "paused" event
* Use `-= 1` instead of `--`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_driver`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_goldens`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_goldens_client`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_localizations`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_test`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_web_plugins`
* fix comments
* Use `curly_braces_in_flow_control_structures` for `packages/integration_test`
* fix indentation
Roll dependendencies
This rolls depdendencies to latest using
flutter update-packages --force-upgrade
This change includes three code changes:
* Removes charcode from the dependencies allowlist since it no longer
appears in the transitive closure of dependencies of the flutter,
flutter_test, flutter_driver, flutter_localizations, and
integration_test packages.
* Uses Resolver.create instead of the deprecated Resolver constructor.
The default Resolver constructor has been deprecated in favour of the
static Resolver.create() factory function, which unfortunately happens
to be async. Propagated the async-ness up the chain.
This change was partially reverted and the deprecation ignored in this
patch until package:coverage can be rolled internally at Google.
* Eliminates the use of the deprecated packagesPath parameter to
HitMap.parseJson. This parameter was deprecated and replaced with
packagePath in https://github.com/dart-lang/coverage/pull/370 which
was part of the overall deprecation of the .packages file in Dart
itself https://github.com/dart-lang/sdk/issues/48272. The overall goal
being that end-user code shouldn't need to know about implementation
details such as whether dependency information is stored in a
.packages file or a package_info.json file, but rather use the
package_config package to obtain the package metadata and perform
other functions such as resolving its dependencies to filesystem
paths. packagesPath was replaced by packagePath, which takes the path
to the package directory itself. Internally, package:coverage then
uses package_config to do the rest of the package/script URI
resolution to filesystem paths.
This change was partially reverted and the deprecation ignored in this
patch until package:coverage can be rolled internally at Google.
This is a pre-update prior to updating flutter_template_images in
https://github.com/flutter/flutter/pull/103739
Issue: https://github.com/flutter/flutter/issues/103371
Issue: https://github.com/flutter/flutter/issues/103775
Issue: https://github.com/flutter/flutter/issues/103830
When re-applying the partially-reverted changes to code coverage,
we'll need to patch host_entrypoint.dart internally to await the Future
that we'll be returning rather than a non-async value.
