VSE: Add API function to select displayed meta strip

Use function `sequence_editor.display_stack(meta_strip)` to set
displayed timeline content.

To view top-level timeline, that does not belong to any meta strip, pass
`None` as argument.

Differential Revision: https://developer.blender.org/D12048

1 files changed, 8 insertions, 11 deletions

diff --git a/source/blender/sequencer/SEQ_sequencer.h b/source/blender/sequencer/SEQ_sequencer.h
index 70cba58007f..a77ca1c7baf 100644
--- a/source/blender/sequencer/SEQ_sequencer.h
+++ b/source/blender/sequencer/SEQ_sequencer.h
@@ -70,27 +70,24 @@ void SEQ_seqbase_active_set(struct Editing *ed, struct ListBase *seqbase);
 struct Sequence *SEQ_sequence_alloc(ListBase *lb, int timeline_frame, int machine, int type);
 void SEQ_sequence_free(struct Scene *scene, struct Sequence *seq);
 /**
- * Create and initialize #MetaStack, append it to `ed->metastack` ListBase
+ * Get #MetaStack that corresponds to current level that is being viewed
  *
- * \param ed: sequence editor data
- * \param seq_meta: meta strip
- * \return pointer to created meta stack
+ * \return pointer to meta stack
  */
-struct MetaStack *SEQ_meta_stack_alloc(struct Editing *ed, struct Sequence *seq_meta);
+struct MetaStack *SEQ_meta_stack_active_get(const struct Editing *ed);
 /**
- * Get #MetaStack that corresponds to current level that is being viewed
+ * Open Meta strip content for editing.
  *
  * \param ed: sequence editor data
- * \return pointer to meta stack
+ * \param seqm: meta sequence or NULL for top level view
  */
-struct MetaStack *SEQ_meta_stack_active_get(const struct Editing *ed);
+void SEQ_meta_stack_set(const struct Scene *scene, struct Sequence *dst_seq);
 /**
- * Free #MetaStack and remove it from `ed->metastack` ListBase.
+ * Close last Meta strip open for editing.
  *
  * \param ed: sequence editor data
- * \param ms: meta stack
  */
-void SEQ_meta_stack_free(struct Editing *ed, struct MetaStack *ms);
+struct Sequence *SEQ_meta_stack_pop(struct Editing *ed);
 struct Sequence *SEQ_sequence_dupli_recursive(const struct Scene *scene_src,
                                               struct Scene *scene_dst,
                                               struct ListBase *new_seq_list,