VSE: Refactor meta operators

Move low level logic to module code and versioning logic to versioning code.

Metas strip position was handled in diffrent way compared to other strips.
This was introduced in c8b0d25794be as bugfix for T28158.
I disagree with such design. Meta strips should be handled in same way as
any other strips.

I have tested this change and haven't found any problems.
No problems after checking T28158 as well.
There should be no functional changes on user level.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D9972

3 files changed, 56 insertions, 22 deletions

diff --git a/source/blender/sequencer/SEQ_sequencer.h b/source/blender/sequencer/SEQ_sequencer.h
index ccadfc54e1d..85513faf3e6 100644
--- a/source/blender/sequencer/SEQ_sequencer.h
+++ b/source/blender/sequencer/SEQ_sequencer.h
@@ -62,8 +62,12 @@ struct Editing *SEQ_editing_get(struct Scene *scene, bool alloc);
 struct Editing *SEQ_editing_ensure(struct Scene *scene);
 void SEQ_editing_free(struct Scene *scene, const bool do_id_user);
 struct ListBase *SEQ_active_seqbase_get(const struct Editing *ed);
+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, const bool do_clean_animdata);
+struct MetaStack *SEQ_meta_stack_alloc(struct Editing *ed, struct Sequence *seq_meta);
+struct MetaStack *SEQ_meta_stack_active_get(const struct Editing *ed);
+void SEQ_meta_stack_free(struct Editing *ed, struct MetaStack *ms);
 void SEQ_offset_animdata(struct Scene *scene, struct Sequence *seq, int ofs);
 void SEQ_dupe_animdata(struct Scene *scene, const char *name_src, const char *name_dst);
 struct Sequence *SEQ_sequence_dupli_recursive(const struct Scene *scene_src,
diff --git a/source/blender/sequencer/intern/sequencer.c b/source/blender/sequencer/intern/sequencer.c
index 4a0e4f1d9ad..8bb0bf8fb63 100644
--- a/source/blender/sequencer/intern/sequencer.c
+++ b/source/blender/sequencer/intern/sequencer.c
@@ -344,6 +344,58 @@ ListBase *SEQ_active_seqbase_get(const Editing *ed)
 
   return ed->seqbasep;
 }
+
+/**
+ * Set seqbase that is being viewed currently. This can be main seqbase or meta strip seqbase
+ *
+ * \param ed: sequence editor data
+ * \param seqbase: ListBase with strips
+ */
+void SEQ_seqbase_active_set(Editing *ed, ListBase *seqbase)
+{
+  ed->seqbasep = seqbase;
+}
+
+/**
+ * Create and initialize MetaStack, append it to ed->metastack ListBase
+ *
+ * \param ed: sequence editor data
+ * \param seq_meta: meta strip
+ * \return pointer to created meta stack
+ */
+MetaStack *SEQ_meta_stack_alloc(Editing *ed, Sequence *seq_meta)
+{
+  MetaStack *ms = MEM_mallocN(sizeof(MetaStack), "metastack");
+  BLI_addtail(&ed->metastack, ms);
+  ms->parseq = seq_meta;
+  ms->oldbasep = ed->seqbasep;
+  copy_v2_v2_int(ms->disp_range, &ms->parseq->startdisp);
+  return ms;
+}
+
+/**
+ * Free MetaStack and remoove it from ed->metastack ListBase
+ *
+ * \param ed: sequence editor data
+ * \param ms: meta stack
+ */
+void SEQ_meta_stack_free(Editing *ed, MetaStack *ms)
+{
+  BLI_remlink(&ed->metastack, ms);
+  MEM_freeN(ms);
+}
+
+/**
+ * Get MetaStack that coresponds to current level that is being viewed
+ *
+ * \param ed: sequence editor data
+ * \return pointer to meta stack
+ */
+MetaStack *SEQ_meta_stack_active_get(const Editing *ed)
+{
+  return ed->metastack.last;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/sequencer/intern/strip_time.c b/source/blender/sequencer/intern/strip_time.c
index c495ad6d8f1..21dc9aa2cdd 100644
--- a/source/blender/sequencer/intern/strip_time.c
+++ b/source/blender/sequencer/intern/strip_time.c
@@ -164,7 +164,6 @@ void SEQ_time_update_sequence_bounds(Scene *scene, Sequence *seq)
 void SEQ_time_update_sequence(Scene *scene, Sequence *seq)
 {
   Sequence *seqm;
-  int min, max;
 
   /* check all metas recursively */
   seqm = seq->seqbase.first;
@@ -212,27 +211,6 @@ void SEQ_time_update_sequence(Scene *scene, Sequence *seq)
     }
   }
   else {
-    if (seq->type == SEQ_TYPE_META) {
-      seqm = seq->seqbase.first;
-      if (seqm) {
-        min = MAXFRAME * 2;
-        max = -MAXFRAME * 2;
-        while (seqm) {
-          if (seqm->startdisp < min) {
-            min = seqm->startdisp;
-          }
-          if (seqm->enddisp > max) {
-            max = seqm->enddisp;
-          }
-          seqm = seqm->next;
-        }
-        seq->start = min + seq->anim_startofs;
-        seq->len = max - min;
-        seq->len -= seq->anim_startofs;
-        seq->len -= seq->anim_endofs;
-      }
-      seq_update_sound_bounds_recursive(scene, seq);
-    }
     SEQ_time_update_sequence_bounds(scene, seq);
   }
 }