ags_drum_output_line_callbacks
void ags_drum_output_line_resize_pads_callback (AgsDrum *drum, GType channel_type, guint pads_new, guint pads_old, AgsDrumOutputLine *output_line);
AgsDrum *drum
GType channel_type
guint pads_new
guint pads_old
AgsDrumOutputLine *output_line