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
## 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after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.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.
Reverts flutter/flutter#125927
context: b/300804374
Looks like a g3 fix might involve changing the names of widget on the customer app, and I am not sure if that would be the right approach forward. Putting up a revert to be safe for now.
New example for `InputChip` that demonstrate how to create/delete them based on user text inputs.
The sample application shows a custom text area where user can enter text. After the user has typed and hits _Enter_ the text will be replaced with an `InputChip` that contains that text. Is it possible to continue typing and add more chips in this way. All of them will be placed in a scrollable horizontal row. Also is it possible to have suggestion displayed below the text input field in case the typed text match some of the available suggestions.
Issue I'm trying to solve:
- https://github.com/flutter/flutter/issues/128247
**Code structure:**
The example app is composed of 2 main components that find places inside `MainScreen`:
- `ChipsInput`
- `ListView`
`ChipsInput` emulates a `TextField` where you can enter text. This text field accepts also a list of values of generic type T (`Topping` in my example), that gets rendered as `InputChip` inside the text field, before the text inserted by the user. This widgets is basically an `InputDecorator` widget that implements `TextInputClient` to get `TextEditingValue` events from the user keyboard. At the end of the input field there is another component, the `TextCursor`, that is displayed just when the user give the focus to the field and emulates the carrets that `TextField` has.
There are also some available callbacks that the user can use to capture events in the `ChipsInput` field like: `onChanged`, `onChipTapped`, `onSubmitted` and `onTextChanged`. This last callback is used to build a list of suggestion that will be placed just below the `ChipsInput` field inside the `ListView`.
- slightly improved assert message when row cell counts don't match column count.
- more breadcrumbs in API documentation. more documentation in general.
- added more documentation for the direction of the "ascending" arrow.
- two samples for PaginatedDataTable.
- make PaginatedDataTable support hot reloading across changes to the number of columns.
- introduce matrix3MoreOrLessEquals. An earlier version of this PR used it in tests, but eventually it was not needed. The function seems useful to keep though.
Migrate tests in flutter/flutter. Once the tests here and in `*_customer_testing` are migrated, the default value of the migration flag will be changed from false to true, making the rounding hack disabled by default.
This PR aims to support Android's predictive back gesture when popping the entire Flutter app. Predictive route transitions between routes inside of a Flutter app will come later.
<img width="200" src="https://user-images.githubusercontent.com/389558/217918109-945febaa-9086-41cc-a476-1a189c7831d8.gif" />
### Trying it out
If you want to try this feature yourself, here are the necessary steps:
1. Run Android 33 or above.
1. Enable the feature flag for predictive back on the device under "Developer
options".
1. Create a Flutter project, or clone [my example project](https://github.com/justinmc/flutter_predictive_back_examples).
1. Set `android:enableOnBackInvokedCallback="true"` in
android/app/src/main/AndroidManifest.xml (already done in the example project).
1. Check out this branch.
1. Run the app. Perform a back gesture (swipe from the left side of the
screen).
You should see the predictive back animation like in the animation above and be able to commit or cancel it.
### go_router support
go_router works with predictive back out of the box because it uses a Navigator internally that dispatches NavigationNotifications!
~~go_router can be supported by adding a listener to the router and updating SystemNavigator.setFrameworkHandlesBack.~~
Similar to with nested Navigators, nested go_routers is supported by using a PopScope widget.
<details>
<summary>Full example of nested go_routers</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:go_router/go_router.dart';
import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
void main() => runApp(_MyApp());
class _MyApp extends StatelessWidget {
final GoRouter router = GoRouter(
routes: <RouteBase>[
GoRoute(
path: '/',
builder: (BuildContext context, GoRouterState state) => _HomePage(),
),
GoRoute(
path: '/nested_navigators',
builder: (BuildContext context, GoRouterState state) => _NestedGoRoutersPage(),
),
],
);
@override
Widget build(BuildContext context) {
return MaterialApp.router(
routerConfig: router,
);
}
}
class _HomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Nested Navigators Example'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text('Home Page'),
const Text('A system back gesture here will exit the app.'),
const SizedBox(height: 20.0),
ListTile(
title: const Text('Nested go_router route'),
subtitle: const Text('This route has another go_router in addition to the one used with MaterialApp above.'),
onTap: () {
context.push('/nested_navigators');
},
),
],
),
),
);
}
}
class _NestedGoRoutersPage extends StatefulWidget {
@override
State<_NestedGoRoutersPage> createState() => _NestedGoRoutersPageState();
}
class _NestedGoRoutersPageState extends State<_NestedGoRoutersPage> {
late final GoRouter _router;
final GlobalKey<NavigatorState> _nestedNavigatorKey = GlobalKey<NavigatorState>();
// If the nested navigator has routes that can be popped, then we want to
// block the root navigator from handling the pop so that the nested navigator
// can handle it instead.
bool get _popEnabled {
// canPop will throw an error if called before build. Is this the best way
// to avoid that?
return _nestedNavigatorKey.currentState == null ? true : !_router.canPop();
}
void _onRouterChanged() {
// Here the _router reports the location correctly, but canPop is still out
// of date. Hence the post frame callback.
SchedulerBinding.instance.addPostFrameCallback((Duration duration) {
setState(() {});
});
}
@override
void initState() {
super.initState();
final BuildContext rootContext = context;
_router = GoRouter(
navigatorKey: _nestedNavigatorKey,
routes: [
GoRoute(
path: '/',
builder: (BuildContext context, GoRouterState state) => _LinksPage(
title: 'Nested once - home route',
backgroundColor: Colors.indigo,
onBack: () {
rootContext.pop();
},
buttons: <Widget>[
TextButton(
onPressed: () {
context.push('/two');
},
child: const Text('Go to another route in this nested Navigator'),
),
],
),
),
GoRoute(
path: '/two',
builder: (BuildContext context, GoRouterState state) => _LinksPage(
backgroundColor: Colors.indigo.withBlue(255),
title: 'Nested once - page two',
),
),
],
);
_router.addListener(_onRouterChanged);
}
@override
void dispose() {
_router.removeListener(_onRouterChanged);
super.dispose();
}
@override
Widget build(BuildContext context) {
return PopScope(
popEnabled: _popEnabled,
onPopped: (bool success) {
if (success) {
return;
}
_router.pop();
},
child: Router<Object>.withConfig(
restorationScopeId: 'router-2',
config: _router,
),
);
}
}
class _LinksPage extends StatelessWidget {
const _LinksPage ({
required this.backgroundColor,
this.buttons = const <Widget>[],
this.onBack,
required this.title,
});
final Color backgroundColor;
final List<Widget> buttons;
final VoidCallback? onBack;
final String title;
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: backgroundColor,
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(title),
//const Text('A system back here will go back to Nested Navigators Page One'),
...buttons,
TextButton(
onPressed: onBack ?? () {
context.pop();
},
child: const Text('Go back'),
),
],
),
),
);
}
}
```
</details>
### Resources
Fixes https://github.com/flutter/flutter/issues/109513
Depends on engine PR https://github.com/flutter/engine/pull/39208✔️
Design doc: https://docs.google.com/document/d/1BGCWy1_LRrXEB6qeqTAKlk-U2CZlKJ5xI97g45U7azk/edit#
Migration guide: https://github.com/flutter/website/pull/8952
## Description
This modifies the `MenuAnchor` `onPressed` activation to delay until after the current frame is built, and resolve any focus changes before it invokes the `onPressed`, so that actions that operate on the `primaryFocus` can have a chance of working on the focused item they were meant to work on.
## Related Issues
- Fixes https://github.com/flutter/flutter/issues/118731
## Tests
- No tests yet (hence draft still)
