InheritedNotifier

Author: toly1994328

lib/awesome/listenable/change_notifier_02/main.dart

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+import 'package:app/app.dart';
+import 'package:flutter/material.dart';
+
+import 'notifier/download_data_scope.dart';
+import 'notifier/progress_value_notifier.dart';
+import 'page/home/home_page.dart';
+
+void main(){
+  WidgetsFlutterBinding.ensureInitialized();
+  runApp(const MyApp());
+  WindowsAdapter.setSize();
+}
+
+class MyApp extends StatelessWidget{
+  const MyApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return DownloadDataScope(
+      notifier: ProgressValueNotifier(),
+      child: MaterialApp(
+        debugShowCheckedModeBanner: false,
+        theme: ThemeData(
+          colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+          useMaterial3: true,
+        ),
+        home: const ChangeNotifierHome02(),
+      ),
+    );
+  }
+}
+
+
+
+
+
+
+

lib/awesome/listenable/change_notifier_02/notifier/download_data_scope.dart

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+import 'package:flutter/cupertino.dart';
+
+import 'progress_value_notifier.dart';
+
+class DownloadDataScope extends InheritedNotifier<ProgressValueNotifier>{
+
+  const DownloadDataScope({super.key, required super.child,super.notifier});
+
+  static ProgressValueNotifier of(BuildContext context) {
+    return context.dependOnInheritedWidgetOfExactType<DownloadDataScope>()!.notifier!;
+  }
+
+  static ProgressValueNotifier read(BuildContext context) {
+    return context.getInheritedWidgetOfExactType<DownloadDataScope>()!.notifier!;
+  }
+}

lib/awesome/listenable/change_notifier_02/notifier/progress_value_notifier.dart

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+import 'package:flutter/material.dart';
+
+class ProgressValueNotifier with ChangeNotifier{
+
+  double _value = 0;
+
+  double get value =>_value;
+
+  String get valueStr => '${(value*100).toStringAsFixed(1)}%';
+
+  set value(double value){
+    _value = value.clamp(0, 1);
+    notifyListeners();
+  }
+}

lib/awesome/listenable/change_notifier_02/page/detail/detail_progress_view.dart

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+
+import 'package:flutter/material.dart';
+
+import '../../notifier/download_data_scope.dart';
+import '../../notifier/progress_value_notifier.dart';
+
+class DetailProgressView extends StatelessWidget{
+  const DetailProgressView({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    ProgressValueNotifier progress = DownloadDataScope.of(context);
+    return Stack(
+      alignment: Alignment.center,
+      children:[
+        SizedBox(
+          width: 200,
+          height: 50,
+          child: LinearProgressIndicator(
+            value: progress.value,
+            backgroundColor: Colors.grey,
+          ),
+        ),
+        Text(progress.valueStr,style: TextStyle(color: Colors.white),)
+      ],
+    );
+  }
+}

lib/awesome/listenable/change_notifier_02/page/detail/download_detail.dart

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+import 'package:flutter/material.dart';
+
+import 'detail_progress_view.dart';
+
+class DownloadDetailPage extends StatelessWidget {
+  const DownloadDetailPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('下载详情页'),
+      ),
+      body: Center(child: DetailProgressView()),
+    );
+  }
+}

lib/awesome/listenable/change_notifier_02/page/home/home_page.dart

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+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import '../../notifier/download_data_scope.dart';
+import '../../notifier/progress_value_notifier.dart';
+import '../detail/download_detail.dart';
+import 'home_progress_view.dart';
+
+class ChangeNotifierHome02 extends StatefulWidget {
+  const ChangeNotifierHome02({super.key});
+
+  @override
+  State<ChangeNotifierHome02> createState() => _ChangeNotifierHome02State();
+}
+
+class _ChangeNotifierHome02State extends State<ChangeNotifierHome02> {
+
+  TextEditingController c = TextEditingController();
+  @override
+  Widget build(BuildContext context) {
+    print("=========_ChangeNotifierHome02State#build===========");
+    return Scaffold(
+      floatingActionButton: FloatingActionButton(
+        onPressed: _startTimer,
+        child: const Icon(Icons.restart_alt),
+      ),
+      appBar: AppBar(
+        title: const Text('下载进度通知模拟'),
+        actions: [
+          IconButton(onPressed: (){
+            Navigator.of(context).push(MaterialPageRoute(builder: (_)=>const DownloadDetailPage()));
+          }, icon: const Icon(Icons.info_outline))
+        ],
+      ),
+      body: const Center(child: HomeProgressView()),
+    );
+  }
+
+  Timer? _timer;
+
+  ProgressValueNotifier get progress => DownloadDataScope.read(context);
+
+  void _startTimer(){
+    if(_timer!=null) return;
+    if(progress.value==1.0){
+      progress.value=0;
+    }
+    _timer = Timer.periodic(const Duration(milliseconds: 200),_updateProgress);
+  }
+
+
+  void _updateProgress(Timer timer) {
+    if(progress.value>=1.0){
+      timer.cancel();
+      _timer = null;
+      return;
+    }
+    progress.value += 0.01;
+  }
+}
+

lib/awesome/listenable/change_notifier_02/page/home/home_progress_view.dart

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+
+import 'package:flutter/material.dart';
+import 'package:flutter_unit/awesome/listenable/change_notifier_02/notifier/download_data_scope.dart';
+
+import '../../notifier/progress_value_notifier.dart';
+
+class HomeProgressView extends StatelessWidget{
+  const HomeProgressView({super.key});
+
+
+  @override
+  Widget build(BuildContext context) {
+    ProgressValueNotifier progress = DownloadDataScope.of(context);
+    return Stack(
+      alignment: Alignment.center,
+      children:[
+        SizedBox(
+          width: 100,
+          height: 100,
+          child: CircularProgressIndicator(
+            value: progress.value,
+            backgroundColor: Colors.grey,
+          ),
+        ),
+        Text(progress.valueStr)
+      ],
+    );
+  }
+
+
+
+}