Fix T39156 part 2: Add support for image paint operations in undo

history operator (Ctrl + Alt + Z).

This will only show paint operations now while in an image paint mode.
The caveat is that user can delete previous paint operations too (even
on images not on the canvas currently) so it needs some care. This is
consistent with regular undo behaviour though.

Sculpting also suffers from lack of Undo history support, this will be
added in a separate commit.

1 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_sculpt.h b/source/blender/editors/include/ED_sculpt.h
index ba69be5b4c0..6105db14d6a 100644
--- a/source/blender/editors/include/ED_sculpt.h
+++ b/source/blender/editors/include/ED_sculpt.h
@@ -67,8 +67,11 @@ typedef void (*UndoRestoreCb)(struct bContext *C, struct ListBase *lb);
 typedef void (*UndoFreeCb)(struct ListBase *lb);
 
 int ED_undo_paint_step(struct bContext *C, int type, int step, const char *name);
+void ED_undo_paint_step_num(struct bContext *C, int type, int num);
+const char *ED_undo_paint_get_name(int type, int nr, int *active);
 void ED_undo_paint_free(void);
 int ED_undo_paint_valid(int type, const char *name);
+bool ED_undo_paint_empty(int type);
 void ED_undo_paint_push_begin(int type, const char *name, UndoRestoreCb restore, UndoFreeCb free);
 void ED_undo_paint_push_end(int type);