example

Author: devxpy

example/lib/main.dart

@@ -9,76 +9,79 @@ final SharedValue<int> counter = SharedValue(
 );
 
 Future<void> main() async {
-  runApp(SharedValue.wrapApp(MyApp())); //  don't forget this!
+  WidgetsFlutterBinding.ensureInitialized();
+
+  // load previous value from shared prefs
+  counter.load();
+
+  runApp(
+    // don't forget this!
+    SharedValue.wrapApp(
+      MyApp(),
+    ),
+  );
 }
 
 class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
+    print("MyApp.build()");
+
     return MaterialApp(
       title: 'Flutter Demo',
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: MyHomePage(
-        title: 'Flutter Demo Home Page',
+      home: Scaffold(
+        appBar: AppBar(
+          title: Text("Shared value demo"),
+        ),
+        body: Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              Text(
+                'You have pushed the button this many times:',
+              ),
+              CounterText(),
+            ],
+          ),
+        ),
+        floatingActionButton: CounterButton(),
       ),
     );
   }
 }
 
-class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
-
-  final String title;
-
-  @override
-  _MyHomePageState createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
+class CounterText extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    // The .of(context) bit makes this widget rebuild everytime counter is changed
+    print("CounterText.build()");
+
+    // The .of(context) bit makes this widget rebuild automatically
     int counterValue = counter.of(context);
-    counter.value = counterValue;
 
-    return Scaffold(
-      appBar: AppBar(
-        title: Text(widget.title),
-      ),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            Text(
-              'You have pushed the button this many times:',
-            ),
-            Text(
-              '$counterValue',
-              style: Theme.of(context).textTheme.display1,
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: Icon(Icons.add),
-      ),
+    return Text(
+      '$counterValue',
+      style: Theme.of(context).textTheme.headline4,
     );
   }
+}
 
+class CounterButton extends StatelessWidget {
   @override
-  void initState() {
-    super.initState();
+  Widget build(BuildContext context) {
+    print("Button.build()");
 
-    // load previous value from shared prefs
-    counter.load();
+    return FloatingActionButton(
+      onPressed: _incrementCounter,
+      tooltip: 'Increment',
+      child: Icon(Icons.add),
+    );
   }
 
-  Future<void> _incrementCounter() async {
-    // update counter value and rebuild all widgets using that value
-    counter.update((value) => value + 1);
+  void _incrementCounter() {
+    // update counter value and rebuild widgets
+    counter.$ += 1;
   }
 }