Datablock ID Properties

The absence of datablock properties "will certainly be resolved soon as the need for them is becoming obvious" said the [[http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.67/Python_Nodes|Python Nodes release notes]]. So this patch allows Python scripts to create ID Properties which reference datablocks.
This functionality is implemented for `PointerProperty` and now such properties can be created with Python.

In addition to the standard update callback, `PointerProperty` can have a `poll` callback (standard RNA) which is useful for search menus. For details see the test included in this patch.

Original author: @artfunkel

Alexander (Blend4Web Team)

Reviewers: brecht, artfunkel, mont29, campbellbarton

Reviewed By: mont29, campbellbarton

Subscribers: jta, sergey, campbellbarton, wisaac, poseidon4o, mont29, homyachetser, Evgeny_Rodygin, AlexKowel, yurikovelenov, fjuhec, sharlybg, cardboard, duarteframos, blueprintrandom, a.romanov, BYOB, disnel, aditiapratama, bliblubli, dfelinto, lukastoenne

Maniphest Tasks: T37754

Differential Revision: https://developer.blender.org/D113

1 files changed, 29 insertions, 0 deletions

diff --git a/source/blender/editors/object/object_relations.c b/source/blender/editors/object/object_relations.c
index b5fbe4ba586..861e249b0ee 100644
--- a/source/blender/editors/object/object_relations.c
+++ b/source/blender/editors/object/object_relations.c
@@ -72,6 +72,7 @@
 #include "BKE_global.h"
 #include "BKE_group.h"
 #include "BKE_fcurve.h"
+#include "BKE_idprop.h"
 #include "BKE_lamp.h"
 #include "BKE_lattice.h"
 #include "BKE_library.h"
@@ -2101,6 +2102,34 @@ void ED_object_single_users(Main *bmain, Scene *scene, const bool full, const bo
 		single_tex_users_expand(bmain);
 	}
 
+	/* Relink datablock pointer properties */
+	{
+		IDP_RelinkProperty(scene->id.properties);
+
+		for (Base *base = scene->base.first; base; base = base->next) {
+			Object *ob = base->object;
+			if (!ID_IS_LINKED_DATABLOCK(ob)) {
+					IDP_RelinkProperty(ob->id.properties);
+			}
+		}
+
+		if (scene->nodetree) {
+			IDP_RelinkProperty(scene->nodetree->id.properties);
+			for (bNode *node = scene->nodetree->nodes.first; node; node = node->next) {
+				IDP_RelinkProperty(node->prop);
+			}
+		}
+
+		if (scene->gpd) {
+			IDP_RelinkProperty(scene->gpd->id.properties);
+		}
+
+		IDP_RelinkProperty(scene->world->id.properties);
+
+		if (scene->clip) {
+			IDP_RelinkProperty(scene->clip->id.properties);
+		}
+	}
 	BKE_main_id_clear_newpoins(bmain);
 	DAG_relations_tag_update(bmain);
 }