LibOverride: Add initial support for adding new NLA tracks.

Also makes NLA tracks and strips overridable.

User can either edit existing strips in existing NLA tracks (but not add or remove them), and/or add new NLA tracks after those comming from the linked data.

Most of the work was as usual checking operators and adding protections against illegal operations in override context.

Note that since we can only rely on indices to deal with local added tracks, we forbid any local track being before any linked/original track.

Maniphest Tasks: T72629

Differential Revision: https://developer.blender.org/D9611

1 files changed, 12 insertions, 5 deletions

diff --git a/source/blender/editors/space_nla/nla_channels.c b/source/blender/editors/space_nla/nla_channels.c
index 561de5e82a6..9832ca975cf 100644
--- a/source/blender/editors/space_nla/nla_channels.c
+++ b/source/blender/editors/space_nla/nla_channels.c
@@ -292,7 +292,7 @@ static int mouse_nla_channels(
           /* TODO: make this use the operator instead of calling the function directly
            * however, calling the operator requires that we supply the args,
            * and that works with proper buttons only */
-          BKE_nla_action_pushdown(adt);
+          BKE_nla_action_pushdown(adt, ID_IS_OVERRIDE_LIBRARY(ale->id));
         }
         else {
           /* when in tweakmode, this button becomes the toggle for mapped editing */
@@ -516,7 +516,7 @@ static int nlachannels_pushdown_exec(bContext *C, wmOperator *op)
   }
 
   /* 'push-down' action - only usable when not in TweakMode */
-  BKE_nla_action_pushdown(adt);
+  BKE_nla_action_pushdown(adt, ID_IS_OVERRIDE_LIBRARY(id));
 
   struct Main *bmain = CTX_data_main(C);
   DEG_id_tag_update_ex(bmain, id, ID_RECALC_ANIMATION);
@@ -648,19 +648,21 @@ bool nlaedit_add_tracks_existing(bAnimContext *ac, bool above_sel)
       NlaTrack *nlt = (NlaTrack *)ale->data;
       AnimData *adt = ale->adt;
 
+      const bool is_liboverride = ID_IS_OVERRIDE_LIBRARY(ale->id);
+
       /* check if just adding a new track above this one,
        * or whether we're adding a new one to the top of the stack that this one belongs to
        */
       if (above_sel) {
         /* just add a new one above this one */
-        BKE_nlatrack_add(adt, nlt);
+        BKE_nlatrack_add(adt, nlt, is_liboverride);
         ale->update = ANIM_UPDATE_DEPS;
         added = true;
       }
       else if ((lastAdt == NULL) || (adt != lastAdt)) {
         /* add one track to the top of the owning AnimData's stack,
          * then don't add anymore to this stack */
-        BKE_nlatrack_add(adt, NULL);
+        BKE_nlatrack_add(adt, NULL, is_liboverride);
         lastAdt = adt;
         ale->update = ANIM_UPDATE_DEPS;
         added = true;
@@ -698,7 +700,7 @@ bool nlaedit_add_tracks_empty(bAnimContext *ac)
     /* ensure it is empty */
     if (BLI_listbase_is_empty(&adt->nla_tracks)) {
       /* add new track to this AnimData block then */
-      BKE_nlatrack_add(adt, NULL);
+      BKE_nlatrack_add(adt, NULL, ID_IS_OVERRIDE_LIBRARY(ale->id));
       ale->update = ANIM_UPDATE_DEPS;
       added = true;
     }
@@ -796,6 +798,11 @@ static int nlaedit_delete_tracks_exec(bContext *C, wmOperator *UNUSED(op))
       NlaTrack *nlt = (NlaTrack *)ale->data;
       AnimData *adt = ale->adt;
 
+      if (BKE_nlatrack_is_nonlocal_in_liboverride(ale->id, nlt)) {
+        /* No deletion of non-local tracks of override data. */
+        continue;
+      }
+
       /* if track is currently 'solo', then AnimData should have its
        * 'has solo' flag disabled
        */