VSE: Support copy-pasting strips with animation

When copying strips between 2 scenes, it wasn't possible to copy
animation curves along with strips.

In this patch curves are copied into clipboard `ListBase`. When pasted,
original curves are moved into temporary `ListBase` and curves in
clipboard are moved into scene action. This is because when strips from
clipboard have to be renamed, function `SEQ_ensure_unique_name()` does
fix RNA paths of curves, but this is done globally for all curves within
action. After strips are renamed, restore original curves from backup.

Note: This patch handles only fcurves. Drivers and actions are currently
not handled anywhere in VSE.

Fixes T77530

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D13845

2 files changed, 10 insertions, 4 deletions

diff --git a/source/blender/sequencer/SEQ_clipboard.h b/source/blender/sequencer/SEQ_clipboard.h
index 72388c5db64..dc78f8cc1a2 100644
--- a/source/blender/sequencer/SEQ_clipboard.h
+++ b/source/blender/sequencer/SEQ_clipboard.h
@@ -33,6 +33,7 @@ struct Scene;
 struct Sequence;
 
 extern struct ListBase seqbase_clipboard;
+extern struct ListBase fcurves_clipboard;
 extern int seqbase_clipboard_frame;
 void SEQ_clipboard_pointers_store(struct Main *bmain, struct ListBase *seqbase);
 void SEQ_clipboard_pointers_restore(struct ListBase *seqbase, struct Main *bmain);
diff --git a/source/blender/sequencer/intern/clipboard.c b/source/blender/sequencer/intern/clipboard.c
index f4c7077d4c6..886ee89595b 100644
--- a/source/blender/sequencer/intern/clipboard.c
+++ b/source/blender/sequencer/intern/clipboard.c
@@ -28,6 +28,7 @@
 
 #include "MEM_guardedalloc.h"
 
+#include "DNA_anim_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_sequence_types.h"
 #include "DNA_sound_types.h"
@@ -35,6 +36,7 @@
 #include "BLI_listbase.h"
 #include "BLI_string.h"
 
+#include "BKE_fcurve.h"
 #include "BKE_main.h"
 #include "BKE_movieclip.h"
 #include "BKE_scene.h"
@@ -58,6 +60,7 @@
  */
 
 ListBase seqbase_clipboard;
+ListBase fcurves_clipboard;
 int seqbase_clipboard_frame;
 static char seq_clipboard_active_seq_name[SEQ_NAME_MAXSTR];
 
@@ -65,15 +68,17 @@ void seq_clipboard_pointers_free(struct ListBase *seqbase);
 
 void SEQ_clipboard_free(void)
 {
-  Sequence *seq, *nseq;
-
   seq_clipboard_pointers_free(&seqbase_clipboard);
 
-  for (seq = seqbase_clipboard.first; seq; seq = nseq) {
-    nseq = seq->next;
+  LISTBASE_FOREACH_MUTABLE (Sequence *, seq, &seqbase_clipboard) {
     seq_free_sequence_recurse(NULL, seq, false);
   }
   BLI_listbase_clear(&seqbase_clipboard);
+
+  LISTBASE_FOREACH_MUTABLE (FCurve *, fcu, &fcurves_clipboard) {
+    BKE_fcurve_free(fcu);
+  }
+  BLI_listbase_clear(&fcurves_clipboard);
 }
 
 #define ID_PT (*id_pt)