initial commit

lib/main.dart

@@ -0,0 +1,226 @@
+import 'dart:async';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:android_notification_listener2/android_notification_listener2.dart';
+import 'package:flutter_local_notifications/flutter_local_notifications.dart';
+
+final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
+    FlutterLocalNotificationsPlugin();
+
+const spotifyPackage = "com.spotify.music";
+const notificationId = 0;
+
+Future<void> main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  // TODO: do the preconfiguration for the android notifications.
+  // e.g: notification icon
+  const AndroidInitializationSettings initializationSettingsAndroid =
+      AndroidInitializationSettings('@mipmap/ic_launcher');
+  const InitializationSettings initializationSettings = InitializationSettings(
+      android: initializationSettingsAndroid
+  );
+  await flutterLocalNotificationsPlugin.initialize(
+      initializationSettings,
+      onSelectNotification: onNotificationClick
+  );
+
+  runApp(const LyricsGrabbr());
+}
+
+void onNotificationClick(String? payload) async {
+  if (payload != null) {
+    print('notification payload: $payload');
+  }
+  print('notification pressed');
+}
+
+class LyricsGrabbr extends StatelessWidget {
+  const LyricsGrabbr({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Lyrics Grabbr',
+      theme: ThemeData(
+        primarySwatch: Colors.blue,
+      ),
+      home: const HomePage(title: 'Lyrics Grabbr'),
+    );
+  }
+}
+
+class HomePage extends StatefulWidget {
+  const HomePage({Key? key, required this.title}) : super(key: key);
+
+  final String title;
+
+  @override
+  State<HomePage> createState() => _HomePageState();
+}
+
+class _HomePageState extends State<HomePage> with WidgetsBindingObserver {
+  late AndroidNotificationListener _notifications;
+  late StreamSubscription<NotificationEventV2> _subscription;
+  BuildContext? permissionDialogCtx;
+  final List<NotificationEventV2> _notifs = [];
+  bool running = false;
+
+  @override
+  void initState() {
+    WidgetsBinding.instance?.addObserver(this);
+    initPlatformState();
+    super.initState();
+  }
+
+  @override
+  void dispose() {
+    WidgetsBinding.instance?.removeObserver(this);
+    super.dispose();
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) async {
+    if (state == AppLifecycleState.resumed) {
+      if (permissionDialogCtx == null) {
+        return;
+      }
+
+      var perm = await AndroidNotificationListener.hasPermission;
+
+      if (perm != null && perm) {
+        Navigator.pop(permissionDialogCtx!);
+        startListening();
+      }
+    }
+  }
+
+  void showNotificationPermDialog() {
+      showDialog(
+          context: context,
+          barrierDismissible: false,
+          builder: (BuildContext buildCtx) {
+            permissionDialogCtx = buildCtx;
+
+            return WillPopScope(
+              onWillPop: () {
+                SystemNavigator.pop();
+                return Future.value(false);
+              },
+              child: Expanded(
+                  child: AlertDialog(
+                      title: const Text(
+                          'Notifications Access Permission',
+                          style: TextStyle(
+                              fontWeight: FontWeight.bold
+                          ),
+                      ),
+                      content: const Text(
+                          'This app requires permission to listen to notifications to function properly. Please grant permission in the next screen.',
+                          style: TextStyle(
+                              color: Colors.blueGrey
+                          ),
+                      ),
+                      actions: [
+                        TextButton(
+                            onPressed: () async {
+                              await AndroidNotificationListener.openPermissionSettings();
+                            },
+                            child: const Text("OK")
+                        ),
+                      ],
+                  ),
+              ),
+            );
+          });
+  }
+
+  Future<void> initPlatformState() async {
+    var perm = await AndroidNotificationListener.hasPermission;
+
+    if (perm != null && perm) {
+      startListening();
+    } else {
+      showNotificationPermDialog();
+    }
+  }
+
+  void onData(NotificationEventV2 event) {
+    if (event.packageName == spotifyPackage) {
+      // TODO: if the app is in the background, only update our notif
+      // if the app is in the foreground, update the notif, and 
+      // fetch the new lyrics and display them.
+      var song = event.packageText;
+      var artist = event.packageMessage;
+      sendNotification(song, artist);
+      setState(() {
+        _notifs.add(event);
+      });
+    }
+  }
+
+  Future<void> sendNotification(String title, String body) async {
+    const AndroidNotificationDetails androidNotification = AndroidNotificationDetails(
+        "Lyrics",
+        "Lyrics",
+        importance: Importance.low,
+        priority: Priority.min,
+        showWhen: false,
+        ongoing: true,
+        playSound: false,
+    );
+
+    const NotificationDetails notificationDetails = NotificationDetails(
+        android: androidNotification
+    );
+
+    await flutterLocalNotificationsPlugin.show(
+        notificationId,
+        title,
+        body,
+        notificationDetails,
+    );
+  }
+
+  void startListening() {
+    // TODO: make the FAB start and stop a local notification service
+    // that keeps track of which song is playing
+    // and if pressed will fetch the lyrics and display them.
+
+    _notifications = AndroidNotificationListener();
+
+    _subscription = _notifications.notificationStream.listen(onData);
+    setState(() => running = true);
+  }
+
+  void stopListening() {
+    setState(() => running = false);
+    _subscription.cancel();
+    flutterLocalNotificationsPlugin.cancel(notificationId);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+      ),
+      body: ListView.builder(
+          itemCount: _notifs.length,
+          reverse: true,
+          itemBuilder: (BuildContext context, int idx) {
+            final entry = _notifs[idx];
+            return ListTile(
+              leading: Text(entry.packageText),
+              trailing: Text(entry.packageMessage),
+            );
+          }
+        ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: running ? stopListening : startListening,
+        tooltip: running ? 'Stop service' : "Start service",
+        child: running ? const Icon(Icons.stop) : const Icon(Icons.play_arrow),
+      ),
+    );
+  }
+}