Get basic timer notifications working

lib/main.dart

@@ -1,4 +1,7 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
 void main() {
   runApp(const MyApp());
@@ -48,17 +51,10 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
+  static const platform = MethodChannel('com.massive/android');
 
-  void _incrementCounter() async {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
+  Future<void> _timer() async {
+    await platform.invokeMethod('timer', [3000]);
   }
 
   @override
@@ -99,14 +95,14 @@ class _MyHomePageState extends State<MyHomePage> {
               'You have pushed the button this many times:',
             ),
             Text(
-              '$_counter',
+              'Tap to start timer',
               style: Theme.of(context).textTheme.headlineMedium,
             ),
           ],
         ),
       ),
       floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
+        onPressed: _timer,
         tooltip: 'Increment',
         child: const Icon(Icons.add),
       ), // This trailing comma makes auto-formatting nicer for build methods.