Playback state tracking improvements

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/externalevents/MediaStateReceiver.java

@@ -0,0 +1,124 @@
+/*  Copyright (C) 2024 Aleksandr Ivanov
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>. */
+
+package nodomain.freeyourgadget.gadgetbridge.externalevents;
+
+import android.media.MediaMetadata;
+import android.media.session.MediaController;
+import android.media.session.PlaybackState;
+
+import androidx.annotation.Nullable;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.model.MusicSpec;
+import nodomain.freeyourgadget.gadgetbridge.model.MusicStateSpec;
+import nodomain.freeyourgadget.gadgetbridge.util.MediaManager;
+
+public class MediaStateReceiver extends MediaController.Callback {
+    private long lastPosition = 0;
+    private long lastUpdateTime = 0;
+
+    private MediaController mMediaController;
+
+    public MediaStateReceiver(MediaController mediaController) {
+        mMediaController = mediaController;
+    }
+
+    public boolean isPlaybackActive() {
+        // https://developer.android.com/reference/android/media/session/PlaybackState#isActive()
+
+        switch (mMediaController.getPlaybackState().getState()) {
+            case PlaybackState.STATE_BUFFERING:
+            case PlaybackState.STATE_CONNECTING:
+            case PlaybackState.STATE_FAST_FORWARDING:
+            case PlaybackState.STATE_PLAYING:
+            case PlaybackState.STATE_REWINDING:
+            case PlaybackState.STATE_SKIPPING_TO_NEXT:
+            case PlaybackState.STATE_SKIPPING_TO_PREVIOUS:
+            case PlaybackState.STATE_SKIPPING_TO_QUEUE_ITEM:
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    public void startReceiving() {
+        setMetadata(mMediaController.getMetadata());
+        setPlaybackState(mMediaController.getPlaybackState());
+        mMediaController.registerCallback(this);
+    }
+
+    public void stopReceiving() {
+        mMediaController.unregisterCallback(this);
+    }
+
+    @Override
+    public void onMetadataChanged(@Nullable MediaMetadata metadata) {
+        super.onMetadataChanged(metadata);
+        setMetadata(metadata);
+    }
+
+    @Override
+    public void onPlaybackStateChanged(@Nullable PlaybackState state) {
+        super.onPlaybackStateChanged(state);
+        setPlaybackState(state);
+    }
+
+    private void setMetadata(@Nullable MediaMetadata metadata) {
+        final MusicSpec musicSpec = MediaManager.extractMusicSpec(metadata);
+
+        if (musicSpec != null) {
+            GBApplication.deviceService().onSetMusicInfo(musicSpec);
+        }
+    }
+
+    private void setPlaybackState(@Nullable PlaybackState state) {
+        if (state.getState() == PlaybackState.STATE_PLAYING && !doStateUpdate(state)) {
+            return;
+        }
+
+        final MusicStateSpec stateSpec = MediaManager.extractMusicStateSpec(state);
+
+        if (stateSpec != null) {
+            GBApplication.deviceService().onSetMusicState(stateSpec);
+        }
+    }
+
+    private boolean doStateUpdate(PlaybackState state)
+    {
+        // To prevent spamming device with state updates
+
+        float speed = state.getPlaybackSpeed();
+
+        long currentTime = System.currentTimeMillis();
+        long currentPosition = state.getPosition();
+
+        long timeDiff = (long) (speed * (currentTime - lastUpdateTime));
+        long positionDiff = currentPosition - lastPosition;
+
+        long epsilon = (long) Math.abs(speed * 50);
+
+        if (Math.abs(timeDiff - positionDiff) > epsilon)
+        {
+            lastUpdateTime = currentTime;
+            lastPosition = currentPosition;
+            return true;
+        }
+
+        return false;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/externalevents/NotificationListener.java

@@ -36,7 +36,6 @@ import android.graphics.drawable.Drawable;
 import android.media.session.MediaController;
 import android.media.session.MediaSession;
 import android.os.Bundle;
-import android.os.Handler;
 import android.os.PowerManager;
 import android.os.Process;
 import android.os.UserHandle;
@@ -75,14 +74,11 @@ import nodomain.freeyourgadget.gadgetbridge.externalevents.notifications.GoogleM
 import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
 import nodomain.freeyourgadget.gadgetbridge.model.AppNotificationType;
 import nodomain.freeyourgadget.gadgetbridge.model.CallSpec;
-import nodomain.freeyourgadget.gadgetbridge.model.MusicSpec;
-import nodomain.freeyourgadget.gadgetbridge.model.MusicStateSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.NotificationSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.NotificationType;
 import nodomain.freeyourgadget.gadgetbridge.service.DeviceCommunicationService;
 import nodomain.freeyourgadget.gadgetbridge.util.BitmapUtil;
 import nodomain.freeyourgadget.gadgetbridge.util.LimitedQueue;
-import nodomain.freeyourgadget.gadgetbridge.util.MediaManager;
 import nodomain.freeyourgadget.gadgetbridge.util.NotificationUtils;
 import nodomain.freeyourgadget.gadgetbridge.util.PebbleUtils;
 import nodomain.freeyourgadget.gadgetbridge.util.Prefs;
@@ -126,9 +122,7 @@ public class NotificationListener extends NotificationListenerService {
     private long activeCallPostTime;
     private int mLastCallCommand = CallSpec.CALL_UNDEFINED;
 
-    private final Handler mHandler = new Handler();
+    private MediaStateReceiver mMediaStateReceiver = null;
-    private Runnable mSetMusicInfoRunnable = null;
-    private Runnable mSetMusicStateRunnable = null;
 
     private GoogleMapsNotificationHandler googleMapsNotificationHandler = new GoogleMapsNotificationHandler();
 
@@ -245,6 +239,11 @@ public class NotificationListener extends NotificationListenerService {
         LocalBroadcastManager.getInstance(this).unregisterReceiver(mReceiver);
         notificationStack.clear();
         notificationsActive.clear();
+
+        if (mMediaStateReceiver != null) {
+            mMediaStateReceiver.stopReceiving();
+        }
+
         super.onDestroy();
     }
 
@@ -669,7 +668,7 @@ public class NotificationListener extends NotificationListenerService {
 
     private boolean handleMediaSessionNotification(final StatusBarNotification sbn) {
         final MediaSession.Token token = sbn.getNotification().extras.getParcelable(Notification.EXTRA_MEDIA_SESSION);
-        return token != null && handleMediaSessionNotification(token);
+        return handleMediaSessionNotification(token);
     }
 
     /**
@@ -680,38 +679,29 @@ public class NotificationListener extends NotificationListenerService {
      */
     public boolean handleMediaSessionNotification(MediaSession.Token mediaSession) {
         try {
-            final MediaController c = new MediaController(getApplicationContext(), mediaSession);
+            if (mediaSession == null)
-            if (c.getMetadata() == null) {
+            {
+                if (mMediaStateReceiver != null) {
+                    mMediaStateReceiver.stopReceiving();
+                    mMediaStateReceiver = null;
+                }
+
                 return false;
             }
 
-            final MusicStateSpec stateSpec = MediaManager.extractMusicStateSpec(c.getPlaybackState());
+            MediaController mediaController = new MediaController(getApplicationContext(), mediaSession);
-            final MusicSpec musicSpec = MediaManager.extractMusicSpec(c.getMetadata());
+            MediaStateReceiver mediaStateReceiver = new MediaStateReceiver(mediaController);
 
-            // finally, tell the device about it
+            if (mMediaStateReceiver != null && mediaStateReceiver.isPlaybackActive())
-            if (mSetMusicInfoRunnable != null) {
+            {
-                mHandler.removeCallbacks(mSetMusicInfoRunnable);
+                mMediaStateReceiver.stopReceiving();
+                mMediaStateReceiver = null;
             }
-            mSetMusicInfoRunnable = new Runnable() {
-                @Override
-                public void run() {
-                    GBApplication.deviceService().onSetMusicInfo(musicSpec);
-                }
-            };
-            mHandler.postDelayed(mSetMusicInfoRunnable, 100);
 
-            if (stateSpec != null) {
+            if (mMediaStateReceiver == null) {
-                if (mSetMusicStateRunnable != null) {
+                mMediaStateReceiver = mediaStateReceiver;
-                    mHandler.removeCallbacks(mSetMusicStateRunnable);
+                mMediaStateReceiver.startReceiving();
-                }
-                mSetMusicStateRunnable = new Runnable() {
-                    @Override
-                    public void run() {
-                        GBApplication.deviceService().onSetMusicState(stateSpec);
-                    }
-                };
             }
-            mHandler.postDelayed(mSetMusicStateRunnable, 100);
 
             return true;
         } catch (final NullPointerException | SecurityException e) {