reset some internally-setup clipping so that drawing can overlap
the canvas that it's on. Fixes #1769.
wxDouble lab_leading;
gc->SetFont (gc->CreateFont (*wxNORMAL_FONT, foreground_colour ()));
gc->GetTextExtent (lab, &lab_width, &lab_height, &lab_descent, &lab_leading);
wxDouble lab_leading;
gc->SetFont (gc->CreateFont (*wxNORMAL_FONT, foreground_colour ()));
gc->GetTextExtent (lab, &lab_width, &lab_height, &lab_descent, &lab_leading);
gc->Clip (wxRegion (time_x (position), y_pos (_track.get()), len.seconds() * _timeline.pixels_per_second().get_value_or(0), _timeline.pixels_per_track()));
gc->DrawText (lab, time_x (position) + 12, y_pos (_track.get() + 1) - lab_height - 4);
gc->Clip (wxRegion (time_x (position), y_pos (_track.get()), len.seconds() * _timeline.pixels_per_second().get_value_or(0), _timeline.pixels_per_track()));
gc->DrawText (lab, time_x (position) + 12, y_pos (_track.get() + 1) - lab_height - 4);