VSE: Add option to limit timeline view height

When height is limited, it is defined by space occupied by strips,
but at least channels 1 to 7 will be always visible. This allows it to
easily overview timeline content by zooming out to maximum extent in Y
axis and panning in X axis.

More channels can be "created" on demand by moving strip to higher
channel. When strip is removed and highest channel becomes empty, view
will stay as is until it is moved down. Then new highest point is
remembered and it is not possible to pan upwards until strip is moved to
higher channel.

Limiting takes into account height of scrubbing and markers area as
well as scrollers. This means that when zoomed out to maximum extent,
no strips are obstructed by fixed UI element.

Fixes T57976

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D14263

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_time_scrub_ui.h b/source/blender/editors/include/ED_time_scrub_ui.h
index 596fdd87afc..efc972ef69d 100644
--- a/source/blender/editors/include/ED_time_scrub_ui.h
+++ b/source/blender/editors/include/ED_time_scrub_ui.h
@@ -14,6 +14,7 @@ extern "C" {
 struct bContext;
 struct bDopeSheet;
 struct wmEvent;
+struct rcti;
 
 void ED_time_scrub_draw_current_frame(const struct ARegion *region,
                                       const struct Scene *scene,
@@ -29,6 +30,7 @@ bool ED_time_scrub_event_in_region(const struct ARegion *region, const struct wm
 void ED_time_scrub_channel_search_draw(const struct bContext *C,
                                        struct ARegion *region,
                                        struct bDopeSheet *dopesheet);
+void ED_time_scrub_region_rect_get(const struct ARegion *region, struct rcti *rect);
 
 #ifdef __cplusplus
 }