This reverts commit 2fc716d, and updates the cross-axis size of the
`_scrollOverflowElement` to be 1px (non-zero), so it is taken into
account by the scrollable elements scrollHeight.
Fixes#160217
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
---------
Co-authored-by: Renzo Olivares <roliv@google.com>
<!-- start_original_pr_link -->
Reverts: flutter/flutter#165589
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: Renzo-Olivares
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: breaking internal tests
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: Renzo-Olivares
<!-- end_original_pr_author -->
<!-- start_reviewers -->
Reviewed By: {Piinks}
<!-- end_reviewers -->
<!-- start_revert_body -->
This change reverts the following previous change:
Currently when using a `CustomScrollView`, screen readers cannot list or
move focus to elements that are outside the current Viewport and cache
extent because we do not create semantic nodes for these elements.
This change introduces `SliverEnsureSemantics` which ensures its sliver
child is included in the semantics tree, whether or not it is currently
visible on the screen or within the cache extent. This way screen
readers are aware the elements are there and can navigate to them /
create accessibility traversal menus with this information.
* Under the hood a new flag has been added to `RenderSliver` called
`ensureSemantics`. `RenderViewportBase` uses this in its
`visitChildrenForSemantics` to ensure a sliver is visited when creating
the semantics tree. Previously a sliver was not visited if it was not
visible or within the cache extent. `RenderViewportBase` also uses this
in `describeSemanticsClip` and `describeApproximatePaintClip` to ensure
a sliver child that wants to "ensure semantics" is not clipped out if it
is not currently visible in the viewport or outside the cache extent.
* `RenderSliverMultiBoxAdaptor.semanticBounds` now leverages its first
child as an anchor for assistive technologies to be able to reach it if
the Sliver is a child of `SliverEnsureSemantics`. If not it will still
be dropped from the semantics tree.
* `RenderProxySliver` now considers child overrides of `semanticBounds`.
On the engine side we move from using a joystick method to scroll with
`SemanticsAction.scrollUp` and `SemanticsAction.scrollDown` to using
`SemanticsAction.scrollToOffset` completely letting the browser drive
the scrolling with its current dom scroll position "scrollTop" or
"scrollLeft". This is possible by calculating the total quantity of
content under the scrollable and sizing the scroll element based on
that.
<details open><summary>Code sample</summary>
```dart
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
/// Flutter code sample for [SliverEnsureSemantics].
void main() => runApp(const SliverEnsureSemanticsExampleApp());
class SliverEnsureSemanticsExampleApp extends StatelessWidget {
const SliverEnsureSemanticsExampleApp({super.key});
@override
Widget build(BuildContext context) {
return const MaterialApp(home: SliverEnsureSemanticsExample());
}
}
class SliverEnsureSemanticsExample extends StatefulWidget {
const SliverEnsureSemanticsExample({super.key});
@override
State<SliverEnsureSemanticsExample> createState() =>
_SliverEnsureSemanticsExampleState();
}
class _SliverEnsureSemanticsExampleState
extends State<SliverEnsureSemanticsExample> {
@override
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
return Scaffold(
appBar: AppBar(
backgroundColor: theme.colorScheme.inversePrimary,
title: const Text('SliverEnsureSemantics Demo'),
),
body: Center(
child: CustomScrollView(
semanticChildCount: 106,
slivers: <Widget>[
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 0,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Steps to reproduce',
style: theme.textTheme.headlineSmall,
),
),
const Text('Issue description'),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Expected Results',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Actual Results',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Code Sample',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Screenshots',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Logs',
style: theme.textTheme.headlineSmall,
),
),
],
),
),
),
),
),
),
SliverFixedExtentList(
itemExtent: 44.0,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Item $index'),
),
);
},
childCount: 50,
semanticIndexOffset: 1,
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 51,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Semantics(
header: true,
child: const Text('Footer 1'),
),
),
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 52,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Semantics(
header: true,
child: const Text('Footer 2'),
),
),
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 53,
child: Semantics(link: true, child: const Text('Link #1')),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 54,
child: OverflowBar(
children: <Widget>[
TextButton(
onPressed: () {},
child: const Text('Button 1'),
),
TextButton(
onPressed: () {},
child: const Text('Button 2'),
),
],
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 55,
child: Semantics(link: true, child: const Text('Link #2')),
),
),
),
SliverEnsureSemantics(
sliver: SliverSemanticsList(
sliver: SliverFixedExtentList(
itemExtent: 44.0,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Semantics(
role: SemanticsRole.listItem,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Second List Item $index'),
),
),
);
},
childCount: 50,
semanticIndexOffset: 56,
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 107,
child: Semantics(link: true, child: const Text('Link #3')),
),
),
),
],
),
),
);
}
}
// A sliver that assigns the role of SemanticsRole.list to its sliver child.
class SliverSemanticsList extends SingleChildRenderObjectWidget {
const SliverSemanticsList({super.key, required Widget sliver})
: super(child: sliver);
@override
RenderSliverSemanticsList createRenderObject(BuildContext context) =>
RenderSliverSemanticsList();
}
class RenderSliverSemanticsList extends RenderProxySliver {
@override
void describeSemanticsConfiguration(SemanticsConfiguration config) {
super.describeSemanticsConfiguration(config);
config.role = SemanticsRole.list;
}
}
```
</details>
Fixes: #160217
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
<!-- end_revert_body -->
Co-authored-by: auto-submit[bot] <flutter-engprod-team@google.com>
Currently when using a `CustomScrollView`, screen readers cannot list or
move focus to elements that are outside the current Viewport and cache
extent because we do not create semantic nodes for these elements.
This change introduces `SliverEnsureSemantics` which ensures its sliver
child is included in the semantics tree, whether or not it is currently
visible on the screen or within the cache extent. This way screen
readers are aware the elements are there and can navigate to them /
create accessibility traversal menus with this information.
* Under the hood a new flag has been added to `RenderSliver` called
`ensureSemantics`. `RenderViewportBase` uses this in its
`visitChildrenForSemantics` to ensure a sliver is visited when creating
the semantics tree. Previously a sliver was not visited if it was not
visible or within the cache extent. `RenderViewportBase` also uses this
in `describeSemanticsClip` and `describeApproximatePaintClip` to ensure
a sliver child that wants to "ensure semantics" is not clipped out if it
is not currently visible in the viewport or outside the cache extent.
* `RenderSliverMultiBoxAdaptor.semanticBounds` now leverages its first
child as an anchor for assistive technologies to be able to reach it if
the Sliver is a child of `SliverEnsureSemantics`. If not it will still
be dropped from the semantics tree.
* `RenderProxySliver` now considers child overrides of `semanticBounds`.
On the engine side we move from using a joystick method to scroll with
`SemanticsAction.scrollUp` and `SemanticsAction.scrollDown` to using
`SemanticsAction.scrollToOffset` completely letting the browser drive
the scrolling with its current dom scroll position "scrollTop" or
"scrollLeft". This is possible by calculating the total quantity of
content under the scrollable and sizing the scroll element based on
that.
<details open><summary>Code sample</summary>
```dart
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
/// Flutter code sample for [SliverEnsureSemantics].
void main() => runApp(const SliverEnsureSemanticsExampleApp());
class SliverEnsureSemanticsExampleApp extends StatelessWidget {
const SliverEnsureSemanticsExampleApp({super.key});
@override
Widget build(BuildContext context) {
return const MaterialApp(home: SliverEnsureSemanticsExample());
}
}
class SliverEnsureSemanticsExample extends StatefulWidget {
const SliverEnsureSemanticsExample({super.key});
@override
State<SliverEnsureSemanticsExample> createState() =>
_SliverEnsureSemanticsExampleState();
}
class _SliverEnsureSemanticsExampleState
extends State<SliverEnsureSemanticsExample> {
@override
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
return Scaffold(
appBar: AppBar(
backgroundColor: theme.colorScheme.inversePrimary,
title: const Text('SliverEnsureSemantics Demo'),
),
body: Center(
child: CustomScrollView(
semanticChildCount: 106,
slivers: <Widget>[
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 0,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Steps to reproduce',
style: theme.textTheme.headlineSmall,
),
),
const Text('Issue description'),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Expected Results',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Actual Results',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Code Sample',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Screenshots',
style: theme.textTheme.headlineSmall,
),
),
Semantics(
header: true,
headingLevel: 3,
child: Text(
'Logs',
style: theme.textTheme.headlineSmall,
),
),
],
),
),
),
),
),
),
SliverFixedExtentList(
itemExtent: 44.0,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Item $index'),
),
);
},
childCount: 50,
semanticIndexOffset: 1,
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 51,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Semantics(
header: true,
child: const Text('Footer 1'),
),
),
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 52,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Semantics(
header: true,
child: const Text('Footer 2'),
),
),
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 53,
child: Semantics(link: true, child: const Text('Link #1')),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 54,
child: OverflowBar(
children: <Widget>[
TextButton(
onPressed: () {},
child: const Text('Button 1'),
),
TextButton(
onPressed: () {},
child: const Text('Button 2'),
),
],
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 55,
child: Semantics(link: true, child: const Text('Link #2')),
),
),
),
SliverEnsureSemantics(
sliver: SliverSemanticsList(
sliver: SliverFixedExtentList(
itemExtent: 44.0,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Semantics(
role: SemanticsRole.listItem,
child: Card(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Second List Item $index'),
),
),
);
},
childCount: 50,
semanticIndexOffset: 56,
),
),
),
),
SliverEnsureSemantics(
sliver: SliverToBoxAdapter(
child: IndexedSemantics(
index: 107,
child: Semantics(link: true, child: const Text('Link #3')),
),
),
),
],
),
),
);
}
}
// A sliver that assigns the role of SemanticsRole.list to its sliver child.
class SliverSemanticsList extends SingleChildRenderObjectWidget {
const SliverSemanticsList({super.key, required Widget sliver})
: super(child: sliver);
@override
RenderSliverSemanticsList createRenderObject(BuildContext context) =>
RenderSliverSemanticsList();
}
class RenderSliverSemanticsList extends RenderProxySliver {
@override
void describeSemanticsConfiguration(SemanticsConfiguration config) {
super.describeSemanticsConfiguration(config);
config.role = SemanticsRole.list;
}
}
```
</details>
Fixes: #160217
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
---------
Co-authored-by: Renzo Olivares <roliv@google.com>
This PR adds a `RawMenuAnchor()` widget to widgets.dart. The purpose of
this widget is to provide a menu primitive for the Material and
Cupertino libraries (and others) to build upon. Additionally, this PR
makes MenuController an inherited widget to simplify nested access to
the menu (e.g. if you want to launch a context menu from a deeply-nested
widget).
This PR:
* Centralizes core menu logic to a private class,` _RawMenuAnchor()`,
* Provides the internals for interacting with menus:
* TapRegion interop
* DismissMenuAction handler
* Close on scroll/resize
* Focus traversal information, if applicable
* Subclasses override `_open`, `_close`, `_isOpen`, `_buildAnchor`, and
`_menuScopeNode`
* State is accessible by descendents via
`MenuController.maybeOf(context)._anchor`
* Adds 2 public constructors, backed by a `_RawMenuAnchor()` that
contains shared logic.
* `RawMenuAnchor()`
* Users build the overlay from scratch.
* Provides anchor/overlay position information and TapRegionGroupId to
builder
* Does not provide FocusScope management.
* `RawMenuAnchorGroup()`
* A primitive for menus that do not have overlays (menu bars).
* This was previously called RawMenuAnchor.node(), but @dkwingsmt made a
good case for splitting out the constructor.
<s>Documentation examples have been added, and can be viewed at
https://menu-anchor.web.app/</s>
<s>https://github.com/user-attachments/assets/25d35f23-2aad-4d07-9172-5c3fd65d53cf</s>
@dkwingsmt
List which issues are fixed by this PR.
https://github.com/flutter/flutter/pull/143712
Some issues that need to be addressed:
Semantics:
<img width="1027" alt="image"
src="https://github.com/user-attachments/assets/d69661c9-8435-4d9c-b200-474968cb57eb">
I'm basing the menu semantics off of the comment
[here](ef3ca70db2/lib/web_ui/lib/src/engine/semantics/semantics.dart (L382)),
but I'm unsure whether the route should be given a name. There is no
menubar/menu/menuitem role in Flutter, so I'm assuming the menu should
be composed of nested dialogs
<s>Unlike the menubar pattern from
[W3C](https://www.w3.org/WAI/ARIA/apg/patterns/menubar/examples/menubar-navigation/),
the RawMenuAnchor
- does not close on tab/shift-tab. I left this behavior out of the menu
so that users could customize tab behavior, but I'm not opinionated
either way
- does not open on ArrowUp/ArrowDown, because this could interfere with
user focus behavior in unconventional menu setups (e.g. a vertical
menu).
- does not automatically focus the first item in a menu overlay when
activated via enter/spacebar, but does focus the first item when
horizontal traversal opens a submenu. Automatically focusing the first
item whenever an overlay opens interferes with hover traversal, and I
couldn't think of a good way to only focus the first item when an
overlay is triggered via enter/spacebar.
- doesn't focus disabled items (I wasn't sure how to address this
without editing MenuItemButton)
While it is possible to nest menus -- for example, a dropdown anchor
within a full-app context menu area -- nested menus behave as a single
group. I was considering adding an additional parameter that separates
nested root menus from their parents, and am interested to hear your
feedback.</s>
*If you had to change anything in the [flutter/tests] repo, include a
link to the migration guide as per the [breaking change policy].*
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
If you need help, consider asking for advice on the #hackers-new channel
on [Discord].
<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
---------
Co-authored-by: Bruno Leroux <bruno.leroux@gmail.com>
Co-authored-by: chunhtai <47866232+chunhtai@users.noreply.github.com>
This auto-formats all *.dart files in the repository outside of the
`engine` subdirectory and enforces that these files stay formatted with
a presubmit check.
**Reviewers:** Please carefully review all the commits except for the
one titled "formatted". The "formatted" commit was auto-generated by
running `dev/tools/format.sh -a -f`. The other commits were hand-crafted
to prepare the repo for the formatting change. I recommend reviewing the
commits one-by-one via the "Commits" tab and avoiding Github's "Files
changed" tab as it will likely slow down your browser because of the
size of this PR.
---------
Co-authored-by: Kate Lovett <katelovett@google.com>
Co-authored-by: LongCatIsLooong <31859944+LongCatIsLooong@users.noreply.github.com>
Revised comments to clarify that clipping of child depends on clipBehavior of the parent widget, typically scrollable widgets that default to Clips.hard.
Noted that decoration features such as shadows , which render outside the widget boundary, may lead to undesirable effects.
Recommended using Clips.none in scenarios where shadow effects are used to avoid clipping issues.
Fixing Issue #156819
Inspired by the review on #146182.
This PR adds boundary feature to the drag gestures, including `MultiDragGestureRecognizer` and `DragGestureRecognizer`. The `GestureDetector` widget will also benefit from this.
Fixes#33799
Allows for a route to inform the route below it in the navigation stack how to animate when the topmost route enters are leaves the stack.
It does this by making a `DelegatedTransition` available for the previous route to look up and use. If available, the route lower in the stack will wrap it's transition builders with that delegated transition and use it instead of it's default secondary transition.
This is what the sample code in this PR shows an app that is able to use both a Material zoom transition and a Cupertino slide transition in one app. It also includes a custom vertical transition. Every page animates off the screen in a way to match up with the incoming page's transition. When popped, the correct transitions play in reverse.
https://github.com/user-attachments/assets/1fc910fa-8cde-4e05-898e-daad8ff4a697
The below video shows this logic making a pseudo iOS styled sheet transition.
https://github.com/flutter/flutter/assets/58190796/207163d8-d87f-48b1-aad9-7e770d1d96c5
All existing page transitions in Flutter will be overwritten by the incoming route if a `delegatedTransition` is provided. This can be opted out of through `canTransitionTo` for a new route widget. Of Flutter's existing page transitions, this PR only adds a `DelegatedTransition` for the Zoom and Cupertino transitions. The other transitions possible in Material will get delegated transitions in a later PR.
Fixes https://github.com/flutter/flutter/issues/155551
### Description
- Adds example for `WidgetStateMouseCursor`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_mouse_cursor.0.dart`
Fixes https://github.com/flutter/flutter/issues/155557
### Description
- Adds example for `WidgetStateBorderSide`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_border_side.0.dart`
This PR contributes to https://github.com/flutter/flutter/issues/155313
### Description
- Adds example for `WidgetStateProperty`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_property.0.dart`
