feat: integrate the notification listener into the project

android/app/src/main/AndroidManifest.xml

@@ -27,7 +27,7 @@
         </activity>
         <service
             android:label="Lyrics Grabbr Notifications Listener"
-            android:name="com.emilecode.android_notification_listener2.NotificationListener"
+            android:name=".NotificationListener"
             android:permission="android.permission.BIND_NOTIFICATION_LISTENER_SERVICE"
             android:exported="false">
             <intent-filter>

android/app/src/main/kotlin/com/illusionware/lyricsgrabbr/lyricsgrabbr/MainActivity.kt

@@ -1,6 +1,55 @@
 package com.illusionware.lyricsgrabbr.lyricsgrabbr
 
+import android.content.Intent
+import android.text.TextUtils
+import androidx.core.app.NotificationManagerCompat
 import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.plugin.common.EventChannel
+import io.flutter.plugin.common.MethodChannel
 
 class MainActivity: FlutterActivity() {
+    companion object {
+        private const val ACTION_NOTIFICATION_LISTENER_SETTINGS = "android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS"
+        private const val EVENT_CHANNEL_NAME = "notifications.eventChannel"
+        private const val METHOD_CHANNEL_NAME = "notifications/method"
+    }
+
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        super.configureFlutterEngine(flutterEngine)
+
+        val methodChannel = MethodChannel(flutterEngine.dartExecutor.binaryMessenger, METHOD_CHANNEL_NAME)
+        methodChannel.setMethodCallHandler { call, result ->
+            when (call.method) {
+                "plugin.hasPermission" -> {
+                    result.success(isPermissionGranted())
+                }
+                "plugin.openPermissionSettings" -> {
+                    result.success(openPermissionSettings())
+                }
+                else -> result.notImplemented()
+            }
+        }
+
+        val eventChannel = EventChannel(flutterEngine.dartExecutor.binaryMessenger, EVENT_CHANNEL_NAME)
+        val streamHandler = NotificationStreamHandler(context)
+        eventChannel.setStreamHandler(streamHandler)
+    }
+
+    private fun isPermissionGranted(): Boolean {
+        val packageName = context.packageName
+        val pkgs = NotificationManagerCompat.getEnabledListenerPackages(context)
+        for (name in pkgs) {
+            if (TextUtils.equals(packageName, name)) {
+                return true
+            }
+        }
+
+        return false
+    }
+
+    private fun openPermissionSettings(): Boolean {
+        context.startActivity(Intent(ACTION_NOTIFICATION_LISTENER_SETTINGS).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK))
+        return true
+    }
 }

android/app/src/main/kotlin/com/illusionware/lyricsgrabbr/lyricsgrabbr/NotificationListener.kt

@@ -0,0 +1,78 @@
+package com.illusionware.lyricsgrabbr.lyricsgrabbr
+
+import android.app.Notification
+import android.content.Intent
+import android.service.notification.NotificationListenerService
+import android.service.notification.StatusBarNotification
+import org.json.JSONException
+import org.json.JSONObject
+import android.os.Bundle
+
+/**
+ * Notification listening service. Intercepts notifications if permission is given to do so.
+ */
+class NotificationListener : NotificationListenerService() {
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        getCurrentNotifications()
+        return super.onStartCommand(intent, flags, startId)
+    }
+
+    override fun onListenerConnected() {
+        getCurrentNotifications()
+    }
+
+    override fun onNotificationPosted(sbn: StatusBarNotification) {
+        sendNotificationBroadcast(sbn)
+    }
+
+    private fun getCurrentNotifications() {
+        val sbns = activeNotifications
+        for (sbn in sbns) {
+            // TODO: remove this check and figure out a way to send a fucking list instead
+            if (sbn.packageName == "com.spotify.music") {
+                sendNotificationBroadcast(sbn)
+            }
+        }
+    }
+
+    private fun sendNotificationBroadcast(sbn: StatusBarNotification) {
+        // TODO: get specific media player notification data
+        // such as onPlay and onNextSong or whatever tf
+
+        // Retrieve package name to set as title.
+        val packageName = sbn.packageName
+        // Retrieve extra object from notification to extract payload.
+        val extras = sbn.notification.extras
+        val packageMessage = extras?.getCharSequence(Notification.EXTRA_TEXT).toString()
+        val packageText = extras?.getCharSequence("android.title").toString()
+        val packageExtra = convertBundleToJsonString(sbn.notification.extras)
+        // Pass data from one activity to another.
+        val intent = Intent(NOTIFICATION_INTENT)
+        intent.putExtra(NOTIFICATION_PACKAGE_NAME, packageName)
+        intent.putExtra(NOTIFICATION_PACKAGE_MESSAGE, packageMessage)
+        intent.putExtra(NOTIFICATION_PACKAGE_TEXT, packageText)
+        intent.putExtra(NOTIFICATION_PACKAGE_EXTRA, packageExtra)
+        sendBroadcast(intent)
+    }
+
+    companion object {
+        const val NOTIFICATION_INTENT = "notification_event"
+        const val NOTIFICATION_PACKAGE_NAME = "package_name"
+        const val NOTIFICATION_PACKAGE_MESSAGE = "package_message"
+        const val NOTIFICATION_PACKAGE_TEXT = "package_text"
+        const val NOTIFICATION_PACKAGE_EXTRA = "package_extra"
+    }
+
+    private fun convertBundleToJsonString(extra: Bundle): String {
+        val json = JSONObject()
+        val keys = extra.keySet()
+        for (key in keys) {
+            try {
+                json.put(key, JSONObject.wrap(extra.get(key)))
+            } catch (e: JSONException) {
+                //Handle exception here
+            }
+        }
+        return json.toString()
+    }
+}

android/app/src/main/kotlin/com/illusionware/lyricsgrabbr/lyricsgrabbr/NotificationStreamHandler.kt

@@ -0,0 +1,46 @@
+package com.illusionware.lyricsgrabbr.lyricsgrabbr
+
+import io.flutter.plugin.common.EventChannel.StreamHandler
+import io.flutter.plugin.common.EventChannel.EventSink
+import android.content.*
+
+class NotificationStreamHandler(private val context: Context) : StreamHandler {
+  private var eventSink: EventSink? = null
+  private var receiver: NotificationReceiver? = null
+  private val listenerIntent = Intent(context, NotificationListener::class.java)
+
+  // Called whenever the event channel is subscribed to in Flutter
+  override fun onListen(o: Any?, eventSink: EventSink?) {
+    this.eventSink = eventSink
+
+    receiver = NotificationReceiver()
+    val intentFilter = IntentFilter()
+    intentFilter.addAction(NotificationListener.NOTIFICATION_INTENT)
+    context.registerReceiver(receiver, intentFilter)
+
+    context.startService(listenerIntent)
+  }
+
+  // Called whenever the event channel subscription is cancelled in Flutter
+  override fun onCancel(o: Any?) {
+    eventSink = null
+
+    context.stopService(listenerIntent)
+    context.unregisterReceiver(receiver)
+  }
+
+  internal inner class NotificationReceiver : BroadcastReceiver() {
+    override fun onReceive(context: Context, intent: Intent) {
+      val packageName = intent.getStringExtra(NotificationListener.NOTIFICATION_PACKAGE_NAME)
+      val packageMessage = intent.getStringExtra(NotificationListener.NOTIFICATION_PACKAGE_MESSAGE)
+      val packageText = intent.getStringExtra(NotificationListener.NOTIFICATION_PACKAGE_TEXT)
+      val packageExtra = intent.getStringExtra(NotificationListener.NOTIFICATION_PACKAGE_EXTRA)
+      val map = HashMap<String, Any>()
+      map["packageName"] = packageName!!
+      map["packageMessage"] = packageMessage!!
+      map["packageText"] = packageText!!
+      map["packageExtra"] = packageExtra!!
+      eventSink?.success(map)
+    }
+  }
+}