Some render box subclasses have a specific layout contract that is tightly coupled with other render box subclasses (e.g. two private classes in a local project file). In these cases, it is also possible that they use a constraints object that is a subclass of `BoxConstraints`. To allow for this, this change makes the `constraints` argument to `RenderBox.computeDryLayout()` a covariant argument.
For completeness' sake, this updates the other render objects in the rendering package to also use the covariant keyword for this argument.
This change collapses the selection at the clicked/tapped location on single click down for desktop platforms, and on single click/tap up for mobile platforms to match native.
This is a change from how `SelectionArea` previously worked. Before this change a single click down would clear the selection. From observing a native browser it looks like when tapping on static text the selection is not cleared but collapsed. A user can still attain the selection from static text using the `window.getSelection` API.
https://jsfiddle.net/juepasn3/11/ You can try this demo out here to observe this behavior yourself. When clicking on static text the selection will change.
This change also allows `Paragraph.selections` to return selections that are collapsed. This for testing purposes to confirm where the selection has been collapsed.
Partially fixes: #129583
Fixes https://github.com/flutter/flutter/issues/59413
This relocates `mock_canvas.dart` and `recording_canvas.dart` from `flutter/test/rendering` to `flutter_test`.
The testing functionality afforded by mock_canvas should be available to everyone, not just the framework. :)
mock_canvas.dart needed a bit of cleanup - things like formatting and super parameters.
Fixes https://github.com/flutter/flutter/issues/131467
An error in the flex methods of min and max column width would produce different results based on the position of the widths that were provided:
`MaxColumnWidth(a, b) != MaxColumnWidth(b, a)`
This fixes that.
Deprecate `textScaleFactor` in favor of `textScaler`, in preparation for Android 14 [Non-linear font scaling to 200%](https://developer.android.com/about/versions/14/features#non-linear-font-scaling). The `TextScaler` class can be moved to `dart:ui` in the future, if we decide to use the Android platform API or AndroidX to get the scaling curve instead of hard coding the curve in the framework.
I haven't put the Flutter version in the deprecation message so the analyzer checks are failing. Will do so after I finish the migration guide.
**Why `TextScaler.textScaleFactor`**
The author of a `TextScaler` subclass should provide a fallback `textScaleFactor`. By making `TextScaler` also contain the `textScaleFactor` information it also makes it easier to migrate: if a widget overrides `MediaQueryData.textScaler` in the tree, for unmigrated widgets in the subtree it would also have to override `MediaQueryData.textScaleFactor`, and that makes it difficult to remove `MediaQueryData.textScaleFactor` in the future.
## A full list of affected APIs in this PR
Deprecated: The method/getter/setter/argument is annotated with a `@Deprecated()` annotation in this PR, and the caller should replace it with `textScaler` instead. Unless otherwise specified there will be a Flutter fix available to help with migration but it's still recommended to migrate case-by-case.
**Replaced**: The method this `textScaleFactor` argument belongs to is rarely called directly by user code and is not overridden by any of the registered custom tests, so the argument is directly replaced by `TextScaler`.
**To Be Deprecated**: The method/getter/setter/argument can't be deprecated in this PR because a registered customer test depends on it and a Flutter fix isn't available (or the test was run without applying flutter fixes first). This method/getter/setter/argument will be deprecated in a followup PR once the registered test is migrated.
### `Painting` Library
| Affected API | State of `textScaleFactor` | Comment |
| --- | --- | --- |
| `InlineSpan.build({ double textScaleFactor = 1.0 })` argument | **Replaced** | |
| `TextStyle.getParagraphStyle({ double TextScaleFactor = 1.0 })` argument | **Replaced** | |
| `TextStyle.getTextStyle({ double TextScaleFactor = 1.0 })` argument| Deprecated | Can't replace: c47fd38dca/super_editor/lib/src/infrastructure/super_textfield/desktop/desktop_textfield.dart (L1903-L1905)|
| `TextPainter({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `TextPainter.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
| `TextPainter.computeWidth({ double TextScaleFactor = 1.0 })` argument | Deprecated | |
| `TextPainter.computeMaxIntrinsicWidth({ double TextScaleFactor = 1.0 })` argument | Deprecated | |
### `Rendering` Library
| Affected API | State of `textScaleFactor` | Comment |
| --- | --- | --- |
| `RenderEditable({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `RenderEditable.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
| `RenderParagraph({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `RenderParagraph.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
### `Widgets` Library
| Affected API | State of `textScaleFactor` | Comment |
| --- | --- | --- |
| `MediaQueryData({ double TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | cd7b93532e/packages/flutter_markdown/test/text_scale_factor_test.dart (LL39C21-L39C35) |
| `MediaQueryData.textScaleFactor` getter | Deprecated | |
| `MediaQueryData.copyWith({ double? TextScaleFactor })` argument | Deprecated | |
| `MediaQuery.maybeTextScaleFactorOf(BuildContext context)` static method | Deprecated | No Flutter Fix, not expressible yet |
| `MediaQuery.textScaleFactorOf(BuildContext context)` static method | **To Be Deprecated** | cd7b93532e/packages/flutter_markdown/lib/src/_functions_io.dart (L68-L70), No Flutter Fix, not expressible yet |
| `RichText({ double TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | cd7b93532e/packages/flutter_markdown/lib/src/builder.dart (L829-L843) |
| `RichText.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away|
| `Text({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | 914d120da1/packages/rfw/lib/src/flutter/core_widgets.dart (L647) , No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `Text.rich({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | The default constructor has an argument that can't be deprecated right away. No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `Text.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away |
| `EditableText({ double? TextScaleFactor = 1.0 })` constructor argument | Deprecated | No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `EditableText.textScaleFactor` getter | Deprecated | |
### `Material` Library
| Affected API | State of `textScaleFactor` | Comment |
| --- | --- | --- |
| `SelectableText({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | cd7b93532e/packages/flutter_markdown/lib/src/builder.dart (L829-L843), No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `SelectableText.rich({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | The default constructor has an argument that can't be deprecated right away. No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `SelectableText.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away |
A lot of material widgets (`Slider`, `RangeSlider`, `TimePicker`, and different types of buttons) also change their layout based on `textScaleFactor`. These need to be handled in a case-by-case fashion and will be migrated in follow-up PRs.
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")
issue:#126652
in Chinese text, word length is 1 and (position.offset == word.end) happens a lot.
Update if (position.offset >= word.end) to if (position.offset > word.end) to resolve the issue that Chinese characters are not selected.
This is a refactor to make `MouseTracker` use the same callback for both kinds of device update. Instead of using two different callbacks for the two device updating methods, `MouseTracker` now receives a hit testing callback at construction, which is the same hit testing method as the one used for other gestures.
This PR not only makes the code cleaner, but also removes the single view assumption from `MouseTracker`, whose code no longer refers to `RendererBinding.renderView`. In the future, we only need to modify `hitTest` (which we will have to do to support gestures for multi-view anyway) to make mouse tracker support multi-view.
In the multi view world, `RenderViews` are created by the `View` widget and no longer owned by the binding. Prior to this change, the `LiveTestWidgetsFlutterBinding` owned and managed a special subclass of `RenderView`, the `_LiveTestRenderView`. In the new world, where `RenderView`s can be created anywhere in the widget tree where a `View` widget is used, this setup is no longer feasible. This change removes this special `_LiveTestRenderView` and instead adds debug hocks to `RenderView` to allow the `LiveTestWidgetsFlutterBinding` to draw a debug overlay on top of the content of any `RenderView`.
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.
- Added `InlineWidgetContainerDefaults` for deduping inline widget code
- Added a helper function `WidgetSpan.extractFromInlineSpan` for extracting `WidgetSpan`s and automatically applying text scaling (at widget level)
- Removed `TextPainter.inlinePlaceholderScales`. I'm going to deprecate the `scale` argument in `TextPainter.addPlaceholder` next, as scaling is now done at the widget level.
- Added runtime check and comments to make sure nobody is extending `PlaceholderSpan` directly (unfortunately we can't remove `PlaceholderSpan` without moving RenderEditable and RenderParagraph to the widgets library).
As preparation for #125945.
The PR improves tests itself which allows the `arc` method to be available to check whether corresponding rects are drawn during tests.
Engine PR: https://github.com/flutter/engine/pull/41593
This must land first
We should remove these, as they've been deprecated for a while. On the engine side of things, the physical model layer is the only one which requires the device pixel ratio, so deleting it will allow us to simplify the layer tree code in https://github.com/flutter/engine/pull/41559
Reverts flutter/flutter#119495
We'll managed to optimize almost all of the cases that made this slow. Actually, it will soon be harder to optimize shader tiling...
* Revert "Remove references to BindingBase.window (#122119)"
This reverts commit c7681f00cf1fb1c63bebb27d715f29feb77b78b7.
* Revert "Remove another reference to BindingBase.window (#122341)"
This reverts commit 6ec444506375cfa94535a45c2320e01094c295e0.
* Revert "Reland (2): Removes single window assumptions from `flutter_test` (#122233)"
This reverts commit eb3d317ea06e59fadc379210f5c6e685505d8e0f.
* Revert "Remove single view assumption from TestViewConfiguration (#122352)"
This reverts commit 927289fb4e5b25a71f794bc808a8c31554859a50.
* Revert "Updates `flutter/test/cupertino` to no longer use `TestWindow` (#122325)"
This reverts commit 67e17e45f05271c6c409183c1d33806683cb9e4d.
* Revert "Updates `flutter/test/gestures` to no longer reference `TestWindow` (#122327)"
This reverts commit c2a5111cc0f9bcb104982b38a1a0a9c4210b601f.
* Revert "Updates `flutter/test/rendering` to no longer use `TestWindow` (#122347)"
This reverts commit 28b65e089b3f8e8c21572cd8a73184858b6360c3.
* Revert "Updates `flutter_localizations/test` to stop using `TestWindow` (#122321)"
This reverts commit 01367d52d7886f51a8921c9dc4a8e4c541686e98.
