102 lines
2.2 KiB
Dart
102 lines
2.2 KiB
Dart
import 'package:flutter/material.dart';
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import 'package:provider/provider.dart';
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class SelectorPage extends StatelessWidget {
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const SelectorPage({super.key});
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@override
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Widget build(BuildContext context) {
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return ChangeNotifierProvider(
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create: (_) => ComplexState(),
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child: Scaffold(
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appBar: AppBar(
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title: const Text('Selector Example'),
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),
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body: const Center(
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child: Column(
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mainAxisAlignment: MainAxisAlignment.center,
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children: [
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CountSelector(),
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NameSelector(),
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UpdateButtons(),
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],
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),
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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 ComplexState extends ChangeNotifier {
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int _count = 0;
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String _name = "John";
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int get count => _count;
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String get name => _name;
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void incrementCount() {
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_count++;
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notifyListeners();
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}
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void changeName() {
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_name = _name == "John" ? "Jane" : "John";
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notifyListeners();
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}
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}
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class CountSelector extends StatelessWidget {
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const CountSelector({super.key});
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@override
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Widget build(BuildContext context) {
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return Selector<ComplexState, int>(
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selector: (_, state) => state.count,
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builder: (context, count, child) {
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print('Count rebuild');
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return Text('Count: $count');
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},
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);
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}
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}
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class NameSelector extends StatelessWidget {
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const NameSelector({super.key});
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@override
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Widget build(BuildContext context) {
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return Selector<ComplexState, String>(
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selector: (_, state) => state.name,
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builder: (context, name, child) {
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print('Name rebuild');
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return Text('Name: $name');
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},
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);
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}
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}
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class UpdateButtons extends StatelessWidget {
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const UpdateButtons({super.key});
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@override
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Widget build(BuildContext context) {
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return Column(
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children: [
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ElevatedButton(
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onPressed: () {
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context.read<ComplexState>().incrementCount();
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context.read<ComplexState>().changeName();
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},
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child: const Text('Increment Count'),
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),
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ElevatedButton(
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onPressed: () {
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context.read<ComplexState>().changeName();
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},
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child: const Text('Change Name'),
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),
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],
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);
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}
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}
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