compute_bbt_ruler_scale (pending_visual_change.time_origin, pending_visual_change.time_origin + current_page_samples(),
current_bbt_points_begin, current_bbt_points_end);
update_tempo_based_rulers (current_bbt_points_begin, current_bbt_points_end);
compute_bbt_ruler_scale (pending_visual_change.time_origin, pending_visual_change.time_origin + current_page_samples(),
current_bbt_points_begin, current_bbt_points_end);
update_tempo_based_rulers (current_bbt_points_begin, current_bbt_points_end);