class DetachTransitions;
class MuteSelection;
class TrimSelection;
+class MixerItems;
+class MixerViewer;
class TileMixers;
class AddAudioTrack;
class DeleteAudioTrack;
class MoveTracksDown;
class DeleteTracks;
class ConcatenateTracks;
-class DeleteTrack;
+class DeleteFirstTrack;
+class DeleteLastTrack;
class LoopPlayback;
class SetBRenderActive;
class LabelsFollowEdits;
class TileWindows;
class SplitX;
class SplitY;
-class MixerViewer;
class LoadLayoutItem;
class LoadLayout;
class LoadLayoutDialog;