Migrate hybrid_android_views to null safety (#84140)

dev/integration_tests/hybrid_android_views/lib/android_platform_view.dart

@@ -15,9 +15,9 @@ class AndroidPlatformView extends StatelessWidget {
   /// native view.
   /// `viewType` identifies the type of Android view to create.
   const AndroidPlatformView({
-    Key key,
+    Key? key,
     this.onPlatformViewCreated,
-    @required this.viewType,
+    required this.viewType,
   })  : assert(viewType != null),
         super(key: key);
 
@@ -29,7 +29,7 @@ class AndroidPlatformView extends StatelessWidget {
   /// Callback to invoke after the platform view has been created.
   ///
   /// May be null.
-  final PlatformViewCreatedCallback onPlatformViewCreated;
+  final PlatformViewCreatedCallback? onPlatformViewCreated;
 
   @override
   Widget build(BuildContext context) {
@@ -52,7 +52,7 @@ class AndroidPlatformView extends StatelessWidget {
           )
           ..addOnPlatformViewCreatedListener(params.onPlatformViewCreated);
         if (onPlatformViewCreated != null) {
-          controller.addOnPlatformViewCreatedListener(onPlatformViewCreated);
+          controller.addOnPlatformViewCreatedListener(onPlatformViewCreated!);
         }
         return controller..create();
       },

dev/integration_tests/hybrid_android_views/lib/future_data_handler.dart

@@ -19,15 +19,15 @@ class FutureDataHandler {
   /// Registers a lazy handler that will be invoked on the next message from the driver.
   Completer<DriverHandler> registerHandler(String key) {
     _handlers[key] = Completer<DriverHandler>();
-    return _handlers[key];
+    return _handlers[key]!;
   }
 
-  Future<String> handleMessage(String message) async {
+  Future<String> handleMessage(String? message) async {
     if (_handlers[message] == null) {
       return 'Unsupported driver message: $message.\n'
              'Supported messages are: ${_handlers.keys}.';
     }
-    final DriverHandler handler = await _handlers[message].future;
+    final DriverHandler handler = await _handlers[message]!.future;
     return handler();
   }
 }

dev/integration_tests/hybrid_android_views/lib/main.dart

@@ -21,7 +21,7 @@ void main() {
 }
 
 class Home extends StatelessWidget {
-  const Home({Key key}) : super(key: key);
+  const Home({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

dev/integration_tests/hybrid_android_views/lib/motion_events_page.dart

@@ -17,7 +17,7 @@ import 'page.dart';
 const String kEventsFileName = 'touchEvents';
 
 class MotionEventsPage extends PageWidget {
-  const MotionEventsPage({Key key})
+  const MotionEventsPage({Key? key})
       : super('Motion Event Tests', const ValueKey<String>('MotionEventsListTile'), key: key);
 
   @override
@@ -27,7 +27,7 @@ class MotionEventsPage extends PageWidget {
 }
 
 class MotionEventsBody extends StatefulWidget {
-  const MotionEventsBody({Key key}) : super(key: key);
+  const MotionEventsBody({Key? key}) : super(key: key);
 
   @override
   State createState() => MotionEventsBodyState();
@@ -36,7 +36,7 @@ class MotionEventsBody extends StatefulWidget {
 class MotionEventsBodyState extends State<MotionEventsBody> {
   static const int kEventsBufferSize = 1000;
 
-  MethodChannel viewChannel;
+  MethodChannel? viewChannel;
 
   /// The list of motion events that were passed to the FlutterView.
   List<Map<String, dynamic>> flutterViewEvents = <Map<String, dynamic>>[];
@@ -87,7 +87,7 @@ class MotionEventsBodyState extends State<MotionEventsBody> {
                 onPressed: () {
                   const StandardMessageCodec codec = StandardMessageCodec();
                   saveRecordedEvents(
-                    codec.encodeMessage(flutterViewEvents), context);
+                    codec.encodeMessage(flutterViewEvents)!, context);
                 },
               ),
             ),
@@ -120,13 +120,13 @@ class MotionEventsBodyState extends State<MotionEventsBody> {
           .cast<Map<dynamic, dynamic>>()
           .map<Map<String, dynamic>>((Map<dynamic, dynamic> e) =>e.cast<String, dynamic>())
           .toList();
-      await viewChannel.invokeMethod<void>('pipeTouchEvents');
+      await viewChannel!.invokeMethod<void>('pipeTouchEvents');
       print('replaying ${recordedEvents.length} motion events');
       for (final Map<String, dynamic> event in recordedEvents.reversed) {
         await channel.invokeMethod<void>('synthesizeEvent', event);
       }
 
-      await viewChannel.invokeMethod<void>('stopTouchEvents');
+      await viewChannel!.invokeMethod<void>('stopTouchEvents');
 
       if (flutterViewEvents.length != embeddedViewEvents.length)
         return 'Synthesized ${flutterViewEvents.length} events but the embedded view received ${embeddedViewEvents.length} events';
@@ -153,13 +153,13 @@ class MotionEventsBodyState extends State<MotionEventsBody> {
   }
 
   Future<void> saveRecordedEvents(ByteData data, BuildContext context) async {
-    if (!await channel.invokeMethod<bool>('getStoragePermission')) {
+    if (await channel.invokeMethod<bool>('getStoragePermission') != true) {
       showMessage(
           context, 'External storage permissions are required to save events');
       return;
     }
     try {
-      final Directory outDir = await getExternalStorageDirectory();
+      final Directory outDir = (await getExternalStorageDirectory())!;
       // This test only runs on Android so we can assume path separator is '/'.
       final File file = File('${outDir.path}/$kEventsFileName');
       await file.writeAsBytes(data.buffer.asUint8List(0, data.lengthInBytes), flush: true);
@@ -177,15 +177,15 @@ class MotionEventsBodyState extends State<MotionEventsBody> {
   }
 
   void onPlatformViewCreated(int id) {
-    viewChannel = MethodChannel('simple_view/$id');
-    viewChannel.setMethodCallHandler(onViewMethodChannelCall);
+    viewChannel = MethodChannel('simple_view/$id')
+        ..setMethodCallHandler(onViewMethodChannelCall);
     driverDataHandler.registerHandler('run test').complete(playEventsFile);
   }
 
   void listenToFlutterViewEvents() {
-    viewChannel.invokeMethod<void>('pipeTouchEvents');
+    viewChannel!.invokeMethod<void>('pipeTouchEvents');
     Timer(const Duration(seconds: 3), () {
-      viewChannel.invokeMethod<void>('stopTouchEvents');
+      viewChannel!.invokeMethod<void>('stopTouchEvents');
     });
   }
 
@@ -225,7 +225,7 @@ class MotionEventsBodyState extends State<MotionEventsBody> {
 }
 
 class TouchEventDiff extends StatelessWidget {
-  const TouchEventDiff(this.originalEvent, this.synthesizedEvent, {Key key}) : super(key: key);
+  const TouchEventDiff(this.originalEvent, this.synthesizedEvent, {Key? key}) : super(key: key);
 
   final Map<String, dynamic> originalEvent;
   final Map<String, dynamic> synthesizedEvent;

dev/integration_tests/hybrid_android_views/lib/nested_view_event_page.dart

@@ -12,7 +12,7 @@ import 'future_data_handler.dart';
 import 'page.dart';
 
 class NestedViewEventPage extends PageWidget {
-  const NestedViewEventPage({Key key})
+  const NestedViewEventPage({Key? key})
       : super('Nested View Event Tests', const ValueKey<String>('NestedViewEventTile'), key: key);
 
   @override
@@ -20,7 +20,7 @@ class NestedViewEventPage extends PageWidget {
 }
 
 class NestedViewEventBody extends StatefulWidget {
-  const NestedViewEventBody({Key key}) : super(key: key);
+  const NestedViewEventBody({Key? key}) : super(key: key);
 
   @override
   State<NestedViewEventBody> createState() => NestedViewEventBodyState();
@@ -33,10 +33,10 @@ enum _LastTestStatus {
 }
 
 class NestedViewEventBodyState extends State<NestedViewEventBody> {
-  MethodChannel viewChannel;
+  MethodChannel? viewChannel;
   _LastTestStatus _lastTestStatus = _LastTestStatus.pending;
-  String lastError;
-  int id;
+  String? lastError;
+  int? id;
   int nestedViewClickCount = 0;
   bool showPlatformView = true;
 
@@ -96,7 +96,7 @@ class NestedViewEventBodyState extends State<NestedViewEventBody> {
 
   Widget _statusWidget() {
     assert(_lastTestStatus != _LastTestStatus.pending);
-    final String message = _lastTestStatus == _LastTestStatus.success ? 'Success' : lastError;
+    final String message = _lastTestStatus == _LastTestStatus.success ? 'Success' : lastError!;
     return Container(
       color: _lastTestStatus == _LastTestStatus.success ? Colors.green : Colors.red,
       child: Text(
@@ -116,7 +116,7 @@ class NestedViewEventBodyState extends State<NestedViewEventBody> {
       });
     }
     try {
-      await viewChannel.invokeMethod<void>('showAndHideAlertDialog');
+      await viewChannel!.invokeMethod<void>('showAndHideAlertDialog');
       setState(() {
         _lastTestStatus = _LastTestStatus.success;
       });
@@ -136,7 +136,7 @@ class NestedViewEventBodyState extends State<NestedViewEventBody> {
 
   Future<void> onChildViewPressed() async {
     try {
-      await viewChannel.invokeMethod<void>('addChildViewAndWaitForClick');
+      await viewChannel!.invokeMethod<void>('addChildViewAndWaitForClick');
       setState(() {
         nestedViewClickCount++;
       });
@@ -167,6 +167,6 @@ class NestedViewEventBodyState extends State<NestedViewEventBody> {
       viewChannel = MethodChannel('simple_view/$id');
     });
     driverDataHandler.registerHandler('hierarchy')
-      .complete(() => channel.invokeMethod<String>('getViewHierarchy'));
+      .complete(() async => (await channel.invokeMethod<String>('getViewHierarchy'))!);
   }
 }

dev/integration_tests/hybrid_android_views/lib/page.dart

@@ -8,7 +8,7 @@ import 'package:flutter/material.dart';
 //
 /// A testing page has to override this in order to be put as one of the items in the main page.
 abstract class PageWidget extends StatelessWidget {
-  const PageWidget(this.title, this.tileKey, {Key key}) : super(key: key);
+  const PageWidget(this.title, this.tileKey, {Key? key}) : super(key: key);
 
   /// The title of the testing page
   ///

dev/integration_tests/hybrid_android_views/pubspec.yaml

@@ -4,7 +4,7 @@ publish_to: none
 description: An integration test for hybrid composition on Android
 version: 1.0.0+1
 environment:
-  sdk: '>=2.9.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:

dev/integration_tests/hybrid_android_views/test_driver/main_test.dart

@@ -6,7 +6,7 @@ import 'package:flutter_driver/flutter_driver.dart';
 import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
 
 Future<void> main() async {
-  FlutterDriver driver;
+  late FlutterDriver driver;
 
   setUpAll(() async {
     driver = await FlutterDriver.connect();