UI: List library overrides in the Outliner

Having a centeral place to find a list of all library overrides should be
useful for managing production scenes where library overrides are used a lot.
This change adds the individually overridden properties of a data-block under
the data-block itself. Just how we show modifiers, constraints or pose channels
there. This way we can also expose library override operations/options better
in future.

There's also a filter option for the library overrides now, so they can be
hidden. It is only available in the View Layer display mode though, like the
other filter options.

One internal change this has to do is adding more informative return values to
undo pushes and the library override functions called by it. That way we can
send a notifier when library overrides change for the Outliner to know when to
rebuild the tree.

Differential Revision: https://developer.blender.org/D7631

Reviewed by: Andy Goralczyk, Bastien Montagne, William Reynish

1 files changed, 11 insertions, 5 deletions

diff --git a/source/blender/blenkernel/BKE_undo_system.h b/source/blender/blenkernel/BKE_undo_system.h
index 58872d6be58..b13a0580a55 100644
--- a/source/blender/blenkernel/BKE_undo_system.h
+++ b/source/blender/blenkernel/BKE_undo_system.h
@@ -96,6 +96,12 @@ typedef struct UndoStep {
   /* Over alloc 'type->struct_size'. */
 } UndoStep;
 
+typedef enum UndoPushReturn {
+  UNDO_PUSH_RET_FAILURE = 0,
+  UNDO_PUSH_RET_SUCCESS = (1 << 0),
+  UNDO_PUSH_RET_OVERRIDE_CHANGED = (1 << 1),
+} UndoPushReturn;
+
 typedef void (*UndoTypeForEachIDRefFn)(void *user_data, struct UndoRefID *id_ref);
 
 typedef struct UndoType {
@@ -172,11 +178,11 @@ UndoStep *BKE_undosys_step_push_init_with_type(UndoStack *ustack,
                                                const UndoType *ut);
 UndoStep *BKE_undosys_step_push_init(UndoStack *ustack, struct bContext *C, const char *name);
 
-bool BKE_undosys_step_push_with_type(UndoStack *ustack,
-                                     struct bContext *C,
-                                     const char *name,
-                                     const UndoType *ut);
-bool BKE_undosys_step_push(UndoStack *ustack, struct bContext *C, const char *name);
+UndoPushReturn BKE_undosys_step_push_with_type(UndoStack *ustack,
+                                               struct bContext *C,
+                                               const char *name,
+                                               const UndoType *ut);
+UndoPushReturn BKE_undosys_step_push(UndoStack *ustack, struct bContext *C, const char *name);
 
 UndoStep *BKE_undosys_step_find_by_name_with_type(UndoStack *ustack,
                                                   const char *name,