## Description
Continuing the work from @jamilsaadeh97 to replace verbose null checks
with modern
[null_aware_elements](https://dart.dev/tools/linter-rules/use_null_aware_elements)
syntax.
This PR cleans up the remaining files not covered in the previous parts,
making the code more concise.
## Related PRs
- https://github.com/flutter/flutter/pull/172198
- https://github.com/flutter/flutter/pull/172306
- https://github.com/flutter/flutter/pull/172307
- https://github.com/flutter/flutter/pull/172322
## 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.
This PR is to make `InputDecorationTheme` conform to Flutter Material's
conventions for component themes:
- Added a `InputDecorationThemeData` class which defines overrides for
the defaults for `InputDecorator` properties.
- Added `InputDecorationTheme` constructor parameters:
`InputDecorationThemeData? data` and `Widget? child`. This is now the
preferred way to configure a `InputDecorationTheme`:
```dart
InputDecorationTheme(
data: InputDecorationThemeData(
filled: true,
fillColor: Colors.amber,
...
),
child: const TextField()
)
```
These two properties are made nullable to not break existing apps which
has customized `ThemeData.inputDecorationTheme`.
- Update `InputDecorationTheme` to be an `InheritedTheme` subclass.
- Changed the type of component theme defaults from
`InputDecorationTheme` to `InputDecorationThemeData`.
- Changed the `InputDecorationTheme bottomAppBarTheme` property to
`Object? bottomAppBarTheme` in `ThemeData` and `ThemeData.copyWith()`
(Object? is used for the moment to minimize Google tests failure. A
follow-up PR will replace `Object?` with `InputDecorationThemeData`.
- Addresses the "theme normalization" sub-project within #91772.
A migration guide will be created on website repo.
Refactor: Migrate to Theme.brightnessOf method
fixes: #163837
## 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 `///`).
- [ ] 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.
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>
This pull request aims to improve code readability, based on feedback gathered in a recent design doc.
<br>
There are two factors that hugely impact how easy it is to understand a piece of code: **verbosity** and **complexity**.
Reducing **verbosity** is important, because boilerplate makes a project more difficult to navigate. It also has a tendency to make one's eyes gloss over, and subtle typos/bugs become more likely to slip through.
Reducing **complexity** makes the code more accessible to more people. This is especially important for open-source projects like Flutter, where the code is read by those who make contributions, as well as others who read through source code as they debug their own projects.
<hr>
<br>
The following examples show how pattern-matching might affect these two factors:
<details> <summary><h3>Example 1 (GOOD)</h3> [click to expand]</summary>
```dart
if (ancestor case InheritedElement(:final InheritedTheme widget)) {
themes.add(widget);
}
```
Without using patterns, this might expand to
```dart
if (ancestor is InheritedElement) {
final InheritedWidget widget = ancestor.widget;
if (widget is InheritedTheme) {
themes.add(widget);
}
}
```
Had `ancestor` been a non-local variable, it would need to be "converted" as well:
```dart
final Element ancestor = this.ancestor;
if (ancestor is InheritedElement) {
final InheritedWidget inheritedWidget = ancestor.widget;
if (widget is InheritedTheme) {
themes.add(theme);
}
}
```
</details>
<details> <summary><h3>Example 2 (BAD) </h3> [click to expand]</summary>
```dart
if (widget case PreferredSizeWidget(preferredSize: Size(:final double height))) {
return height;
}
```
Assuming `widget` is a non-local variable, this would expand to:
```dart
final Widget widget = this.widget;
if (widget is PreferredSizeWidget) {
return widget.preferredSize.height;
}
```
<br>
</details>
In both of the examples above, an `if-case` statement simultaneously verifies that an object meets the specified criteria and performs a variable assignment accordingly.
But there are some differences: Example 2 uses a more deeply-nested pattern than Example 1 but makes fewer useful checks.
**Example 1:**
- checks that `ancestor` is an `InheritedElement`
- checks that the inherited element's `widget` is an `InheritedTheme`
**Example 2:**
- checks that `widget` is a `PreferredSizeWidget`
(every `PreferredSizeWidget` has a `size` field, and every `Size` has a `height` field)
<br>
<hr>
I feel hesitant to try presenting a set of cut-and-dry rules as to which scenarios should/shouldn't use pattern-matching, since there are an abundance of different types of patterns, and an abundance of different places where they might be used.
But hopefully the conversations we've had recently will help us converge toward a common intuition of how pattern-matching can best be utilized for improved readability.
<br><br>
- resolves https://github.com/flutter/flutter/issues/152313
- Design Doc: [flutter.dev/go/dart-patterns](https://flutter.dev/go/dart-patterns)
Removes these two discontinued plugins from `dev/integration_tests/flutter_gallery`
[`device_info`](https://pub.dev/packages/device_info):
Apparently the video playback doesn't work on iOS simulators (I wasn't able to verify this, as I don't have an iOS simulator installed). I removed the guard against running on those simulators, and replaced with a note in the README.
[`connectivity`](https://pub.dev/packages/connectivity):
This plugin was used to play the bee video from the network. I changed the demo so that the bee video is instead also played from an asset (like its friend the butterfly), and then removed the use of the plugin.
Unblocks the re-land of https://github.com/flutter/engine/pull/53462 (itself a reland ð), because of https://github.com/flutter/flutter/pull/150465#issuecomment-2181403712.
### fixes#136139
<br>
<details open> <summary><b>getting sentimental in the PR description</b> (click to collapse)<br><br></summary>
The past 7 months have been quite the journeyâI made some huge blunders and some huge accomplishmentsâa very fun time overall.
I really appreciate the people who took the time to perform code review for my refactoring shenanigans: **christopherfujino**, **andrewkolos**, **LongCatIsLooong**, **gspencergoog**, **loic-sharma**, **Piinks**, **bernaferrari**, **bartekpacia**, **bleroux**, **kevmoo**, **rakudrama**, **XilaiZhang**, **QuncCccccc**, **MominRaza**, and **victorsanni**.
And a huge shoutout to 2 individuals:
- @justinmc, for offering to sponsor me for commit access (words could not describe my excitement)
- @goderbauer, for being super duper proactive and consistent with code review
<br>
</details>
This pull request makes 13 "switch statements â switch expressions" PRs in total, reducing the LOC in this repo by **1,974**!
From now on, I'll make sure to request a test exemption for each refactoring PR ð
PR #147801 introduced some convenient `AnimationStatus` getters, but I just realized that `AnimationController` now has 2 getters for the same thing: `isAnimating` and `isRunning`.
The intent of this pull request is to correct that mistake, and implement the getters in the appropriate places.
This PR is step 12 in the journey to solve issue #136139 and make the
entire Flutter repo more readable.
Most of it involves implementing switch expressions, and there's also a
few other random things that I wanted to clean up a bit.
Prepares for a fix to the `use_build_context_synchronously` lint (https://dart-review.googlesource.com/c/sdk/+/365541) that will complain about these unsafe usages.
The lint rule cannot tell that the `mounted` field is shorthand for `context.mounted`.
Reverts: flutter/flutter#139164
Initiated by: chunhtai
Reason for reverting: hard breaking change
Original PR Author: chunhtai
Reviewed By: {justinmc}
This change reverts the following previous change:
Adds a generic type and pop result to popscope and its friend.
The use cases are to be able to capture the result when the pop is called.
migration guide: https://github.com/flutter/website/pull/9872
Adds a generic type and pop result to popscope and its friend.
The use cases are to be able to capture the result when the pop is called.
migration guide: https://github.com/flutter/website/pull/9872
This pull request aims for improved readability, based on issue #146600.
```dart
// before
Set<Color> _distinctVisibleColors() {
final Set<Color> distinctVisibleColors = <Color>{};
if (top.style != BorderStyle.none) {
distinctVisibleColors.add(top.color);
}
if (right.style != BorderStyle.none) {
distinctVisibleColors.add(right.color);
}
if (bottom.style != BorderStyle.none) {
distinctVisibleColors.add(bottom.color);
}
if (left.style != BorderStyle.none) {
distinctVisibleColors.add(left.color);
}
return distinctVisibleColors;
}
// after
Set<Color> _distinctVisibleColors() {
return <Color>{
if (top.style != BorderStyle.none) top.color,
if (right.style != BorderStyle.none) right.color,
if (bottom.style != BorderStyle.none) bottom.color,
if (left.style != BorderStyle.none) left.color,
};
}
```
Most of the repo should be covered in this PR (aside from `flutter_tools/`, since there was a lot going on in there).
Originally, my aim was just to refactor (as per usual), but while messing around with the `TableBorder.symmetric` constructor, I realized that `borderRadius` was missing!
This pull request makes a few class constructors more efficient, and it fixes#144277 by adding the missing parameter.
<br>
Reverts flutter/flutter#144001
Initiated by: Piinks
Reason for reverting: Failing goldens at the tip of tree
Original PR Author: QuncCccccc
Reviewed By: {HansMuller}
This change reverts the following previous change:
Original Description:
Reverts flutter/flutter#143973
This is a reland for #138521 with an updated g3fix(cl/605555997). Local test: cl/609608958.
This pull request fixes#143803 by taking advantage of Dart's null-aware operators.
And unlike `switch` expressions ([9 PRs](https://github.com/flutter/flutter/pull/143634) and counting), the Flutter codebase is already fantastic when it comes to null-aware coding. After refactoring the entire repo, all the changes involving `?.` and `??` can fit into a single pull request.
Addresses #63507, and is a follow up to the engine PR https://github.com/flutter/engine/pull/46857
Changes the font family string when attempting to use Apple system fonts to the new proxies added by the engine. For the "Text" font this will be more secure in the future against possible changes to Apple's API. For the "Display" font, this will now work correctly when it didn't before.
I checked the letter spacing values against a native app for all font sizes between 17-28. I made a few adjustments to better match native, but especially for the "Text" font we were either really close, or close enough to not make a large breaking change to default fonts worth it.
| Before | After |
| ------------- | ------------- |
| <img width="466" alt="Screenshot 2023-11-02 at 11 45 12â¯AM" src="https://github.com/flutter/flutter/assets/58190796/627ed8ac-d848-4f71-aa62-a467b8aac62d"> | <img width="383" alt="Screenshot 2023-11-02 at 11 46 25â¯AM" src="https://github.com/flutter/flutter/assets/58190796/9a502021-7d2b-4e14-98f1-86971b3830a5"> |
The smaller text in both the before and after should be the same. The large system font that Flutter used before was incorrect, which caused it to look more spread out. Now we use the correct font.
I previously made a PR (#136140) that used `switch` expressions to make some parts of the Flutter codebase easier to understand. It was assigned to the framework team, and @christopherfujino let me know that it was too large to effectively review and recommended breaking it up into smaller pull requests.
Here's a PR that only targets files in the `dev/` directory. Hopefully this will be easier to work with!
(solves issue https://github.com/flutter/flutter/issues/136139)
Fixes in preparation for https://dart-review.googlesource.com/c/sdk/+/330561.
The change referenced above tightens the `use_build_context_synchronously` to ensure that `mounted` is checked on the appropriate `BuildContext` or `State`. This change fixes up the flutter/flutter in preparation of this new enforcement.
This enables our various date picker classes to have a null `initialDate`.
It also fixes the logic of some of the widgets which used to do something when you _changed_ the `initial*` parameters, which is wrong for `initial*` properties (they by definition should only impact the initial state) and wrong for properties in general (behaviour should not change based on whether the widget was built with a new value or not, that violates the reactive design principles).
Fixes https://github.com/flutter/flutter/issues/638.
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
