now playing page can remove tracks from play queue

backend/playbackmanager.go

@@ -64,6 +64,7 @@ func NewPlaybackManager(ctx context.Context, s *ServerManager, p *player.Player)
 		pm.checkScrobble(pm.playTimeStopwatch.Elapsed())
 		pm.playTimeStopwatch.Reset()
 		pm.stopPollTimePos()
+		pm.doUpdateTimePos()
 		for _, cb := range pm.onSongChange {
 			cb(nil)
 		}
@@ -171,14 +172,43 @@ func (p *PlaybackManager) GetPlayQueue() []*subsonic.Child {
 	return pq
 }
 
+// trackIdxs must be sorted
 func (p *PlaybackManager) RemoveTracksFromQueue(trackIdxs []int) {
-	// TODO
+	newQueue := make([]*subsonic.Child, 0, len(p.playQueue)-len(trackIdxs))
+	rmCount := 0
+	rmIdx := 0
+	for i, tr := range p.playQueue {
+		if rmIdx < len(trackIdxs) && trackIdxs[rmIdx] == i {
+			// removing this track
+			rmIdx++
+			if err := p.player.RemoveTrackAt(i - rmCount); err == nil {
+				rmCount++
+			} else {
+				log.Printf("error removing track: %v", err.Error())
+				// did not remove this track
+				newQueue = append(newQueue, tr)
+			}
+		} else {
+			// not removing this track
+			newQueue = append(newQueue, tr)
+		}
+	}
+	p.playQueue = newQueue
+	p.nowPlayingIdx = p.player.GetStatus().PlaylistPos
+	// fire on song change callbacks in case the playing track was removed
+	// TODO: only call this if the playing track actually was removed
+	for _, cb := range p.onSongChange {
+		cb(p.NowPlaying())
+	}
 }
 
 func (p *PlaybackManager) checkScrobble(playDur time.Duration) {
-	if playDur.Seconds() < 0.1 || p.curTrackTime < 0.1 {
+	if len(p.playQueue) == 0 || p.nowPlayingIdx < 0 {
 		return
 	}
+	if playDur.Seconds() < 0.1 || p.curTrackTime < 0.1 {
+		return // ignore spurious onTrackChange callbacks
+	}
 	song := p.playQueue[p.nowPlayingIdx]
 	if playDur.Seconds()/p.curTrackTime > ScrobbleThreshold {
 		log.Printf("Scrobbling %q", song.Title)

player/player.go

@@ -131,6 +131,14 @@ func (p *Player) PlayFile(url string) error {
 	return err
 }
 
+// Removes the item at the given index from the internal playqueue.
+func (p *Player) RemoveTrackAt(idx int) error {
+	if p.mpv == nil {
+		return ErrUnitialized
+	}
+	return p.mpv.Command([]string{"playlist-remove", strconv.Itoa(idx)})
+}
+
 // Stops playback and clears the play queue.
 func (p *Player) Stop() error {
 	if p.mpv == nil {

ui/browsing/nowplayingpage.go

@@ -43,6 +43,9 @@ func NewNowPlayingPage(
 	a.tracklist.DisablePlaybackMenu = true
 	a.tracklist.OnPlayTrackAt = a.onPlayTrackAt
 	a.tracklist.OnAddToPlaylist = a.contr.DoAddTracksToPlaylistWorkflow
+	a.tracklist.AuxiliaryMenuItems = []*fyne.MenuItem{
+		fyne.NewMenuItem("Remove from queue", a.onRemoveSelectedFromQueue),
+	}
 	a.title = widget.NewRichTextWithText("Now Playing")
 	a.title.Segments[0].(*widget.TextSegment).Style.SizeName = widget.RichTextStyleHeading.SizeName
 	a.container = container.New(&layouts.MaxPadLayout{PadLeft: 15, PadRight: 15, PadTop: 5, PadBottom: 15},
@@ -89,6 +92,12 @@ func (a *NowPlayingPage) onPlayTrackAt(tracknum int) {
 	_ = a.pm.PlayTrackAt(tracknum)
 }
 
+func (a *NowPlayingPage) onRemoveSelectedFromQueue() {
+	a.pm.RemoveTracksFromQueue(a.tracklist.SelectedTrackIndexes())
+	a.tracklist.UnselectAll()
+	go a.Reload()
+}
+
 func (a *NowPlayingPage) loadAsync() {
 	go func() {
 		queue := a.pm.GetPlayQueue()