Updated Flutter min sdk of example to match plugin. Updated README.md

example/README.md

@@ -52,20 +52,7 @@ class _QRViewExampleState extends State<QRViewExample> {
     return Scaffold(
       body: Column(
         children: <Widget>[
-          Expanded(
-            flex: 4,
-            child: QRView(
-              key: qrKey,
-              onQRViewCreated: _onQRViewCreated,
-              overlay: QrScannerOverlayShape(
-                borderColor: Colors.red,
-                borderRadius: 10,
-                borderLength: 30,
-                borderWidth: 10,
-                cutOutSize: 300,
-              ),
-            ),
-          ),
+          Expanded(flex: 4, child: _buildQrView(context)),
           Expanded(
             flex: 1,
             child: FittedBox(
@@ -163,6 +150,29 @@ class _QRViewExampleState extends State<QRViewExample> {
     return backCamera == current;
   }
 
+  Widget _buildQrView(BuildContext context) {
+    // To ensure the Scanner view is properly sizes after rotation
+    // we need to listen for Flutter SizeChanged notification and update controller
+    return NotificationListener<SizeChangedLayoutNotification>(
+        onNotification: (notification) {
+          Future.microtask(() => controller?.updateDimensions(qrKey));
+          return false;
+        },
+        child: SizeChangedLayoutNotifier(
+            key: const Key('qr-size-notifier'),
+            child: QRView(
+              key: qrKey,
+              onQRViewCreated: _onQRViewCreated,
+              overlay: QrScannerOverlayShape(
+                borderColor: Colors.red,
+                borderRadius: 10,
+                borderLength: 30,
+                borderWidth: 10,
+                cutOutSize: 300,
+              ),
+            )));
+  }
+
   void _onQRViewCreated(QRViewController controller) {
     this.controller = controller;
     controller.scannedDataStream.listen((scanData) {

example/lib/main.dart

@@ -129,7 +129,7 @@ class _QRViewExampleState extends State<QRViewExample> {
 
   Widget _buildQrView(BuildContext context) {
     // To ensure the Scanner view is properly sizes after rotation
-    // we need to listen for Flutter SizeChanged notifiation and update controller
+    // we need to listen for Flutter SizeChanged notification and update controller
     return NotificationListener<SizeChangedLayoutNotification>(
         onNotification: (notification) {
           Future.microtask(() => controller?.updateDimensions(qrKey));

example/pubspec.yaml

@@ -3,7 +3,7 @@ description: Demonstrates how to use the flutter_qr plugin.
 publish_to: 'none'
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: ">=2.3.0 <3.0.0"
 
 dependencies:
   flutter: