current->bump_value(v, gui->edge, gui->span);
if( track->is_ganged() ) {
TrackCanvas *track_canvas = gui->patchbay->pane->canvas;
current->bump_value(v, gui->edge, gui->span);
if( track->is_ganged() ) {
TrackCanvas *track_canvas = gui->patchbay->pane->canvas;