IMB_metadata improvements

- Metadata handling is now separate from `ImBuf *`, allowing it to be
  used with a generic `IDProperty *`.
- Merged `IMB_metadata_add_field()` and `IMB_metadata_change_field()`
  into a more robust `IMB_metadata_set_field()`. This new function
  doesn't return any status (it now always succeeds, and the previously
  existing return value was never checked anyway).
- Removed `IMB_metadata_del_field()` as it was never actually used
  anywhere.
- Use `IMB_metadata_ensure()` instead of having
  `IMB_metadata_set_field()` create the containing `IDProperty` for
  you.
- Deduplicated function declarations, moved `intern/IMB_metadata.h` out
  of `intern/`. Note that this does mean that we have some extra
  `#include "IMB_metadata.h"` lines now, as the metadata functions are
  no longer declared in `IMB_imbuf.h`.
- Deduplicated function declarations, all metadata-related declarations
  are now in imbuf/IMB_metadata.h.

Part of: https://developer.blender.org/D2273

Reviewed by: @campbellbarton

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/editors/screen/area.c b/source/blender/editors/screen/area.c
index fc0922c7b7c..caae803100b 100644
--- a/source/blender/editors/screen/area.c
+++ b/source/blender/editors/screen/area.c
@@ -63,6 +63,7 @@
 
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
+#include "IMB_metadata.h"
 
 #include "UI_interface.h"
 #include "UI_interface_icons.h"
@@ -2138,7 +2139,7 @@ static const char *meta_data_list[] =
 
 BLI_INLINE bool metadata_is_valid(ImBuf *ibuf, char *r_str, short index, int offset)
 {
-	return (IMB_metadata_get_field(ibuf, meta_data_list[index], r_str + offset, MAX_METADATA_STR - offset) && r_str[0]);
+	return (IMB_metadata_get_field(ibuf->metadata, meta_data_list[index], r_str + offset, MAX_METADATA_STR - offset) && r_str[0]);
 }
 
 static void metadata_draw_imbuf(ImBuf *ibuf, const rctf *rect, int fontid, const bool is_top)