VSE: Reduce transform code complexity

Reduce complexity of sequencer transform code by removing recursivity.
This is possible by treating meta strips (mostly) as any other strip and
containing all transform code within SEQ_ functions.

Unfortunately internally meta strips still require special treatment,
but all complexity from code all over transform code seems to be
possible to contain within one function.

Functional change:
Previously adjusting handle of single image strip moved animation.
Now animation is not moved, which is behavior for all other strips.

Reviewed By: sergey, mano-wii

Differential Revision: https://developer.blender.org/D11493

1 files changed, 9 insertions, 1 deletions

diff --git a/source/blender/sequencer/intern/strip_transform.c b/source/blender/sequencer/intern/strip_transform.c
index a02d8a1428e..b969f531e68 100644
--- a/source/blender/sequencer/intern/strip_transform.c
+++ b/source/blender/sequencer/intern/strip_transform.c
@@ -233,14 +233,22 @@ void SEQ_transform_translate_sequence(Scene *evil_scene, Sequence *seq, int delt
   SEQ_offset_animdata(evil_scene, seq, delta);
   seq->start += delta;
 
+  /* Meta strips requires special handling: their content is to be translated, and then frame range
+   * of the meta is to be updated for the updated content. */
   if (seq->type == SEQ_TYPE_META) {
     Sequence *seq_child;
     for (seq_child = seq->seqbase.first; seq_child; seq_child = seq_child->next) {
       SEQ_transform_translate_sequence(evil_scene, seq_child, delta);
     }
+    /* Ensure that meta bounds are updated, but this function prevents resets seq->start and
+     * start/end point in timeline. */
+    SEQ_time_update_meta_strip_range(evil_scene, seq);
+    /* Move meta start/end points. */
+    SEQ_transform_set_left_handle_frame(seq, seq->startdisp + delta);
+    SEQ_transform_set_right_handle_frame(seq, seq->enddisp + delta);
   }
 
-  SEQ_time_update_sequence_bounds(evil_scene, seq);
+  SEQ_time_update_sequence(evil_scene, seq);
 }
 
 /* return 0 if there weren't enough space */