Null safety support (#893)

* fix: added temporary & env files to .gitignore and updated example/pubspec.yaml

* feat: Migrate library and example project to null-safety

* Update version to 1.0.0-nullsafety.0

* fix: Update flutter-version in workflows

* fix: replace mocktail with mockito

* fix: Replace Future<Null> return types with Future<void>

Author: themisir

.github/workflows/android_ut.yml

@@ -14,7 +14,7 @@ jobs:
           java-version: '12.x'
       - uses: subosito/flutter-action@v1
         with:
-          flutter-version: '1.7.8+hotfix.4'
+          flutter-version: '2.0.4'
       - run: flutter doctor
       - run: flutter pub get
       - run: sh android_test.sh 

.github/workflows/flutter_ut.yml

@@ -14,7 +14,7 @@ jobs:
           java-version: '12.x'
       - uses: subosito/flutter-action@v1
         with:
-          flutter-version: '1.7.8+hotfix.4'
+          flutter-version: '2.0.4'
       - run: flutter doctor
       - run: flutter pub get
       - run: flutter test

.gitignore

@@ -9,6 +9,7 @@ build/
 ios/.generated/
 packages
 pubspec.lock
+.dart_tool/
 
 example/ios/Podfile.lock
 **/Flutter/App.framework/

example/.gitignore

@@ -8,3 +8,4 @@ ios/.generated/
 packages
 pubspec.lock
 .flutter-plugins
+.flutter-plugins-dependencies

example/lib/main.dart

@@ -84,7 +84,7 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
-  const MyHomePage({Key key, this.title}) : super(key: key);
+  const MyHomePage({Key? key, required this.title}) : super(key: key);
 
   final String title;
 
@@ -97,21 +97,21 @@ class _MyHomePageState extends State<MyHomePage> {
   final flutterWebViewPlugin = FlutterWebviewPlugin();
 
   // On destroy stream
-  StreamSubscription _onDestroy;
+  late StreamSubscription _onDestroy;
 
   // On urlChanged stream
-  StreamSubscription<String> _onUrlChanged;
+  late StreamSubscription<String> _onUrlChanged;
 
   // On urlChanged stream
-  StreamSubscription<WebViewStateChanged> _onStateChanged;
+  late StreamSubscription<WebViewStateChanged> _onStateChanged;
 
-  StreamSubscription<WebViewHttpError> _onHttpError;
+  late StreamSubscription<WebViewHttpError> _onHttpError;
 
-  StreamSubscription<double> _onProgressChanged;
+  late StreamSubscription<double> _onProgressChanged;
 
-  StreamSubscription<double> _onScrollYChanged;
+  late StreamSubscription<double> _onScrollYChanged;
 
-  StreamSubscription<double> _onScrollXChanged;
+  late StreamSubscription<double> _onScrollXChanged;
 
   final _urlCtrl = TextEditingController(text: selectedUrl);
 
@@ -135,8 +135,8 @@ class _MyHomePageState extends State<MyHomePage> {
     _onDestroy = flutterWebViewPlugin.onDestroy.listen((_) {
       if (mounted) {
         // Actions like show a info toast.
-        _scaffoldKey.currentState.showSnackBar(
-            const SnackBar(content: const Text('Webview Destroyed')));
+        ScaffoldMessenger.of(context)
+            .showSnackBar(const SnackBar(content: Text('Webview Destroyed')));
       }
     });
 
@@ -226,7 +226,7 @@ class _MyHomePageState extends State<MyHomePage> {
               padding: const EdgeInsets.all(24.0),
               child: TextField(controller: _urlCtrl),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 flutterWebViewPlugin.launch(
                   selectedUrl,
@@ -239,19 +239,19 @@ class _MyHomePageState extends State<MyHomePage> {
               },
               child: const Text('Open Webview (rect)'),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 flutterWebViewPlugin.launch(selectedUrl, hidden: true);
               },
               child: const Text('Open "hidden" Webview'),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 flutterWebViewPlugin.launch(selectedUrl);
               },
               child: const Text('Open Fullscreen Webview'),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 Navigator.of(context).pushNamed('/widget');
               },
@@ -261,30 +261,31 @@ class _MyHomePageState extends State<MyHomePage> {
               padding: const EdgeInsets.all(24.0),
               child: TextField(controller: _codeCtrl),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 final future =
                     flutterWebViewPlugin.evalJavascript(_codeCtrl.text);
-                future.then((String result) {
+                future.then((String? result) {
                   setState(() {
                     _history.add('eval: $result');
                   });
                 });
               },
               child: const Text('Eval some javascript'),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
-                final future = flutterWebViewPlugin.evalJavascript('alert("Hello World");');
-                future.then((String result) {
+                final future = flutterWebViewPlugin
+                    .evalJavascript('alert("Hello World");');
+                future.then((String? result) {
                   setState(() {
                     _history.add('eval: $result');
                   });
                 });
               },
               child: const Text('Eval javascript alert()'),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 setState(() {
                   _history.clear();
@@ -293,7 +294,7 @@ class _MyHomePageState extends State<MyHomePage> {
               },
               child: const Text('Close'),
             ),
-            RaisedButton(
+            ElevatedButton(
               onPressed: () {
                 flutterWebViewPlugin.getCookies().then((m) {
                   setState(() {

example/pubspec.yaml

@@ -1,5 +1,10 @@
 name: flutter_webview_plugin_example
 description: Demonstrates how to use the flutter_webview_plugin plugin.
+version: 1.0.0+1
+publish_to: 'none'
+
+environment:
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter: