M_CHANNEL_PREV
PostMessage(M_CHANNEL_PREV);
PostMessage(M_CHANNEL_PREV);
PostMessage(M_CHANNEL_PREV);
PostMessage(M_CHANNEL_PREV);
if (dx > 0.1) PostMessage(inv ? M_VOLUME_DOWN : M_CHANNEL_PREV);
if (dy > 0.1) PostMessage(inv ? M_CHANNEL_PREV : M_VOLUME_DOWN);
case M_CHANNEL_PREV:
new BMessage(M_CHANNEL_PREV), '-', B_COMMAND_KEY));