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6ff806d74e
Currently, there are 21 `.resolveWith()` calls in example files.
This pull request changes 11 of them to use the new `.fromMap()` constructor. (Seven of them are now `const`!)
```dart
ListTile(
iconColor: WidgetStateColor.fromMap(<WidgetStatesConstraint, Color>{
WidgetState.disabled: Colors.red,
WidgetState.selected: Colors.green,
WidgetState.any: Colors.black,
}),
// The same can be achieved using the .resolveWith() constructor.
// The text color will be identical to the icon color above.
textColor: WidgetStateColor.resolveWith((Set<WidgetState> states) {
if (states.contains(WidgetState.disabled)) {
return Colors.red;
}
if (states.contains(WidgetState.selected)) {
return Colors.green;
}
return Colors.black;
}),
),
```
71 lines
2.0 KiB
Dart
71 lines
2.0 KiB
Dart
// Copyright 2014 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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import 'package:flutter/material.dart';
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/// Flutter code sample for [Switch].
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void main() => runApp(const SwitchApp());
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class SwitchApp extends StatelessWidget {
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const SwitchApp({super.key});
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@override
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Widget build(BuildContext context) {
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return MaterialApp(
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theme: ThemeData(useMaterial3: true),
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home: Scaffold(
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appBar: AppBar(title: const Text('Switch Sample')),
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body: const Center(
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child: SwitchExample(),
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),
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),
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);
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}
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}
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class SwitchExample extends StatefulWidget {
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const SwitchExample({super.key});
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@override
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State<SwitchExample> createState() => _SwitchExampleState();
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}
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class _SwitchExampleState extends State<SwitchExample> {
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bool light = true;
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@override
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Widget build(BuildContext context) {
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// This object sets amber as the track color when the switch is selected.
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// Otherwise, it resolves to null and defers to values from the theme data.
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const WidgetStateProperty<Color?> trackColor = WidgetStateProperty<Color?>.fromMap(
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<WidgetStatesConstraint, Color>{
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WidgetState.selected: Colors.amber,
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},
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);
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// This object sets the track color based on two WidgetState attributes.
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// If neither state applies, it resolves to null.
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final WidgetStateProperty<Color?> overlayColor = WidgetStateProperty<Color?>.fromMap(
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<WidgetState, Color>{
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WidgetState.selected: Colors.amber.withOpacity(0.54),
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WidgetState.disabled: Colors.grey.shade400,
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},
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);
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return Switch(
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// This bool value toggles the switch.
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value: light,
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overlayColor: overlayColor,
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trackColor: trackColor,
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thumbColor: const WidgetStatePropertyAll<Color>(Colors.black),
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onChanged: (bool value) {
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// This is called when the user toggles the switch.
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setState(() {
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light = value;
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});
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},
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);
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}
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}
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