flutter/dev/tools/gen_defaults/lib/checkbox_template.dart
Taha Tesser 9d7d36cfba
Fix Checkbox default visual density to meet Material 3 guidelines (#159081)
Fixes [Compact Visual Density is wrongfully applied to Checkboxes with
`MaterialTapTargetSize.padded` on desktop platforms according to
Material 3 Guidelines](https://github.com/flutter/flutter/issues/156408)

### Description

This PR updates default `Checkbox` visual density to not depend on
`ThemeData.visualDenSity` as it will return `VisualDensity.compact` on
desktop and break Material 3 guidelines for `Checkbox`.

> [!NOTE]  
> This makes a similar fix as
https://github.com/flutter/flutter/pull/110722.

### Code sample

<details>
<summary>expand to view the code sample</summary> 

```dart
import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              ColoredBox(
                color: Colors.amber,
                child: Checkbox(
                  materialTapTargetSize: MaterialTapTargetSize.padded,
                  value: true,
                  onChanged: (bool? value) {},
                ),
              ),
              Container(
                width: 48,
                height: 48,
                color: Colors.red,
                alignment: Alignment.center,
                child: const Text(
                  '48x48px',
                  style: TextStyle(fontSize: 10, color: Colors.white),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
}
```

</details>


<img width="577" alt="Screenshot 2024-11-18 at 18 02 01"
src="https://github.com/user-attachments/assets/d390c92f-dd62-4c42-b6b7-d4f101078618">



<img width="577" alt="Screenshot 2024-11-18 at 18 01 49"
src="https://github.com/user-attachments/assets/632e8d19-11bf-45c7-9be9-5c4fc308f3ea">


## 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].
- [ ] 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
2025-01-30 20:03:56 +00:00

146 lines
6.0 KiB
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 'template.dart';
class CheckboxTemplate extends TokenTemplate {
const CheckboxTemplate(
super.blockName,
super.fileName,
super.tokens, {
super.colorSchemePrefix = '_colors.',
});
@override
String generate() => '''
class _${blockName}DefaultsM3 extends CheckboxThemeData {
_${blockName}DefaultsM3(BuildContext context)
: _theme = Theme.of(context),
_colors = Theme.of(context).colorScheme;
final ThemeData _theme;
final ColorScheme _colors;
@override
MaterialStateBorderSide? get side {
return MaterialStateBorderSide.resolveWith((Set<MaterialState> states) {
if (states.contains(MaterialState.disabled)) {
if (states.contains(MaterialState.selected)) {
return const BorderSide(width: ${getToken('md.comp.checkbox.unselected.disabled.outline.width')}, color: Colors.transparent);
}
return BorderSide(width: ${getToken('md.comp.checkbox.unselected.disabled.outline.width')}, color: ${componentColor('md.comp.checkbox.unselected.disabled.outline')}.withOpacity(${getToken('md.comp.checkbox.unselected.disabled.container.opacity')}));
}
if (states.contains(MaterialState.selected)) {
return const BorderSide(width: ${getToken('md.comp.checkbox.selected.outline.width')}, color: Colors.transparent);
}
if (states.contains(MaterialState.error)) {
return BorderSide(width: ${getToken('md.comp.checkbox.unselected.disabled.outline.width')}, color: ${componentColor('md.comp.checkbox.unselected.error.outline')});
}
if (states.contains(MaterialState.pressed)) {
return BorderSide(width: ${getToken('md.comp.checkbox.unselected.pressed.outline.width')}, color: ${componentColor('md.comp.checkbox.unselected.pressed.outline')});
}
if (states.contains(MaterialState.hovered)) {
return BorderSide(width: ${getToken('md.comp.checkbox.unselected.hover.outline.width')}, color: ${componentColor('md.comp.checkbox.unselected.hover.outline')});
}
if (states.contains(MaterialState.focused)) {
return BorderSide(width: ${getToken('md.comp.checkbox.unselected.focus.outline.width')}, color: ${componentColor('md.comp.checkbox.unselected.focus.outline')});
}
return BorderSide(width: ${getToken('md.comp.checkbox.unselected.outline.width')}, color: ${componentColor('md.comp.checkbox.unselected.outline')});
});
}
@override
MaterialStateProperty<Color> get fillColor {
return MaterialStateProperty.resolveWith((Set<MaterialState> states) {
if (states.contains(MaterialState.disabled)) {
if (states.contains(MaterialState.selected)) {
return ${componentColor('md.comp.checkbox.selected.disabled.container')};
}
return Colors.transparent;
}
if (states.contains(MaterialState.selected)) {
if (states.contains(MaterialState.error)) {
return ${componentColor('md.comp.checkbox.selected.error.container')};
}
return ${componentColor('md.comp.checkbox.selected.container')};
}
return Colors.transparent;
});
}
@override
MaterialStateProperty<Color> get checkColor {
return MaterialStateProperty.resolveWith((Set<MaterialState> states) {
if (states.contains(MaterialState.disabled)) {
if (states.contains(MaterialState.selected)) {
return ${componentColor('md.comp.checkbox.selected.disabled.icon')};
}
return Colors.transparent; // No icons available when the checkbox is unselected.
}
if (states.contains(MaterialState.selected)) {
if (states.contains(MaterialState.error)) {
return ${componentColor('md.comp.checkbox.selected.error.icon')};
}
return ${componentColor('md.comp.checkbox.selected.icon')};
}
return Colors.transparent; // No icons available when the checkbox is unselected.
});
}
@override
MaterialStateProperty<Color> get overlayColor {
return MaterialStateProperty.resolveWith((Set<MaterialState> states) {
if (states.contains(MaterialState.error)) {
if (states.contains(MaterialState.pressed)) {
return ${componentColor('md.comp.checkbox.error.pressed.state-layer')};
}
if (states.contains(MaterialState.hovered)) {
return ${componentColor('md.comp.checkbox.error.hover.state-layer')};
}
if (states.contains(MaterialState.focused)) {
return ${componentColor('md.comp.checkbox.error.focus.state-layer')};
}
}
if (states.contains(MaterialState.selected)) {
if (states.contains(MaterialState.pressed)) {
return ${componentColor('md.comp.checkbox.selected.pressed.state-layer')};
}
if (states.contains(MaterialState.hovered)) {
return ${componentColor('md.comp.checkbox.selected.hover.state-layer')};
}
if (states.contains(MaterialState.focused)) {
return ${componentColor('md.comp.checkbox.selected.focus.state-layer')};
}
return Colors.transparent;
}
if (states.contains(MaterialState.pressed)) {
return ${componentColor('md.comp.checkbox.unselected.pressed.state-layer')};
}
if (states.contains(MaterialState.hovered)) {
return ${componentColor('md.comp.checkbox.unselected.hover.state-layer')};
}
if (states.contains(MaterialState.focused)) {
return ${componentColor('md.comp.checkbox.unselected.focus.state-layer')};
}
return Colors.transparent;
});
}
@override
double get splashRadius => ${getToken('md.comp.checkbox.state-layer.size')} / 2;
@override
MaterialTapTargetSize get materialTapTargetSize => _theme.materialTapTargetSize;
@override
VisualDensity get visualDensity => VisualDensity.standard;
@override
OutlinedBorder get shape => const RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(${getToken('md.comp.checkbox.unselected.outline.width')})),
);
}
''';
}