Merge pull request #16 from ValeteTech/master

Added support to null safety. Fixes #13.

Author: pmundt

example/lib/main.dart

@@ -24,7 +24,7 @@ class _MyAppState extends State<MyApp> {
             crossAxisAlignment: CrossAxisAlignment.center,
             children: <Widget>[
               Text('Secure Mode: ${_secureMode.toString()}\n'),
-              RaisedButton(
+              ElevatedButton(
                   onPressed: () async {
                     final secureModeToggle = !_secureMode;
 

pubspec.yaml

@@ -6,7 +6,7 @@ repository: https://github.com/adaptant-labs/flutter_windowmanager
 issue_tracker: https://github.com/adaptant-labs/flutter_windowmanager/issues
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
   # Flutter versions prior to 1.10 did not support
   # the flutter.plugin.platforms map.
   flutter: ">=1.10.0"

test/flutter_windowmanager_test.dart

@@ -3,12 +3,14 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_windowmanager/flutter_windowmanager.dart';
 
 void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
   const MethodChannel channel = MethodChannel('flutter_windowmanager');
-  final List<MethodCall> log = List<MethodCall>();
+  final List<MethodCall> log = <MethodCall>[];
 
   setUp(() {
     channel.setMockMethodCallHandler((MethodCall methodCall) async {
       log.add(methodCall);
+      return true;
     });
   });