VSE: Add meta.separate() Python API function

This function can be used to "dissolve" meta strip anywhere in strip
hierarchy. This has same effect as `meta_separate` operator.

Reviewed By: ISS

Differential Revision: https://developer.blender.org/T91005

source/blender/makesrna/intern/rna_sequencer.c

@@ -1366,6 +1366,28 @@ static float rna_Sequence_fps_get(PointerRNA *ptr)
   return SEQ_time_sequence_get_fps(scene, seq);
 }
 
+static void rna_Sequence_separate(ID *id, Sequence *seqm, Main *bmain)
+{
+  Scene *scene = (Scene *)id;
+
+  /* Find the appropriate seqbase */
+  Editing *ed = SEQ_editing_get(scene);
+  ListBase *seqbase = SEQ_get_seqbase_by_seq(&ed->seqbase, seqm);
+
+  LISTBASE_FOREACH_MUTABLE (Sequence *, seq, &seqm->seqbase) {
+    SEQ_edit_move_strip_to_seqbase(scene, &seqm->seqbase, seq, seqbase);
+  }
+
+  SEQ_edit_flag_for_removal(scene, seqbase, seqm);
+  SEQ_edit_remove_flagged_sequences(scene, seqbase);
+
+  /* Update depsgraph. */
+  DEG_relations_tag_update(bmain);
+  DEG_id_tag_update(&scene->id, ID_RECALC_SEQUENCER_STRIPS);
+
+  WM_main_add_notifier(NC_SCENE | ND_SEQUENCER, scene);
+}
+
 #else
 
 static void rna_def_strip_element(BlenderRNA *brna)
@@ -2439,6 +2461,7 @@ static void rna_def_image(BlenderRNA *brna)
 static void rna_def_meta(BlenderRNA *brna)
 {
   StructRNA *srna;
+  FunctionRNA *func;
   PropertyRNA *prop;
 
   srna = RNA_def_struct(brna, "MetaSequence", "Sequence");
@@ -2452,6 +2475,10 @@ static void rna_def_meta(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Sequences", "Sequences nested in meta strip");
   RNA_api_sequences(brna, prop, true);
 
+  func = RNA_def_function(srna, "separate", "rna_Sequence_separate");
+  RNA_def_function_flag(func, FUNC_USE_SELF_ID | FUNC_USE_MAIN);
+  RNA_def_function_ui_description(func, "Separate meta");
+
   rna_def_filter_video(srna);
   rna_def_proxy(srna);
   rna_def_input(srna);

source/blender/sequencer/SEQ_edit.h

@@ -33,10 +33,15 @@ struct Scene;
 struct Sequence;
 
 int SEQ_edit_sequence_swap(struct Sequence *seq_a, struct Sequence *seq_b, const char **error_str);
+bool SEQ_edit_move_strip_to_seqbase(struct Scene *scene,
+                                    ListBase *seqbase,
+                                    struct Sequence *src_seq,
+                                    ListBase *dst_seqbase);
 bool SEQ_edit_move_strip_to_meta(struct Scene *scene,
                                  struct Sequence *src_seq,
                                  struct Sequence *dst_seqm,
                                  const char **error_str);
+bool SEQ_meta_separate(struct Scene *scene, struct Sequence *src_meta, const char **error_str);
 void SEQ_edit_flag_for_removal(struct Scene *scene,
                                struct ListBase *seqbase,
                                struct Sequence *seq);

source/blender/sequencer/intern/strip_edit.c

@@ -221,6 +221,40 @@ static bool seq_exists_in_seqbase(Sequence *seq, ListBase *seqbase)
   return false;
 }
 
+/**
+ * Move sequence to seqbase.
+ *
+ * \param scene: Scene containing the editing
+ * \param dst_seqbase: seqbase where `seq` is located
+ * \param seq: Sequence to move
+ * \param dst_seqbase: Target seqbase
+ */
+bool SEQ_edit_move_strip_to_seqbase(Scene *scene,
+                                    ListBase *seqbase,
+                                    Sequence *seq,
+                                    ListBase *dst_seqbase)
+{
+  /* Move to meta. */
+  BLI_remlink(seqbase, seq);
+  BLI_addtail(dst_seqbase, seq);
+  SEQ_relations_invalidate_cache_preprocessed(scene, seq);
+
+  /* Update meta. */
+  if (SEQ_transform_test_overlap(dst_seqbase, seq)) {
+    SEQ_transform_seqbase_shuffle(dst_seqbase, seq, scene);
+  }
+
+  return true;
+}
+
+/**
+ * Move sequence to meta sequence.
+ *
+ * \param scene: Scene containing the editing
+ * \param src_seq: Sequence to move
+ * \param dst_seqm: Target Meta sequence
+ * \param error_str: Error message
+ */
 bool SEQ_edit_move_strip_to_meta(Scene *scene,
                                  Sequence *src_seq,
                                  Sequence *dst_seqm,
@@ -262,17 +296,7 @@ bool SEQ_edit_move_strip_to_meta(Scene *scene,
   Sequence *seq;
   SEQ_ITERATOR_FOREACH (seq, collection) {
     /* Move to meta. */
-    BLI_remlink(seqbase, seq);
-    BLI_addtail(&dst_seqm->seqbase, seq);
-    SEQ_relations_invalidate_cache_preprocessed(scene, seq);
-
-    /* Update meta. */
-    ListBase *meta_seqbase = SEQ_get_seqbase_by_seq(&ed->seqbase, dst_seqm);
-    SEQ_time_update_meta_strip_range(scene, dst_seqm);
-    SEQ_time_update_sequence(scene, meta_seqbase, dst_seqm);
-    if (SEQ_transform_test_overlap(&dst_seqm->seqbase, seq)) {
-      SEQ_transform_seqbase_shuffle(&dst_seqm->seqbase, seq, scene);
-    }
+    SEQ_edit_move_strip_to_seqbase(scene, seqbase, seq, &dst_seqm->seqbase);
   }
 
   SEQ_collection_free(collection);