3 files changed, 87 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_scene.h b/source/blender/blenkernel/BKE_scene.h
index 865d6b31dc1..9c462523c18 100644
--- a/source/blender/blenkernel/BKE_scene.h
+++ b/source/blender/blenkernel/BKE_scene.h
@@ -100,6 +100,8 @@ void BKE_scene_base_flag_from_objects(struct Scene *scene);
 /* base functions */
 struct Base *BKE_scene_layer_base_find_by_name(struct SceneLayer *sl, const char *name);
 struct Base *BKE_scene_layer_base_find(struct SceneLayer *sl, struct Object *ob);
+struct Base *BKE_scene_layer_collection_base_find(struct LayerCollection *lc, struct Object *ob);
+struct Base *BKE_scene_layer_base_add(struct SceneLayer *sl, struct LayerCollection *lc, struct Object *ob);
 void         BKE_scene_layer_base_deselect_all(struct SceneLayer *sl);
 void         BKE_scene_layer_base_select(struct SceneLayer *sl, struct Base *selbase);
 
diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 6ea9825b33e..1cb628a4750 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -890,6 +890,44 @@ Base *BKE_scene_layer_base_find(SceneLayer *sl, Object *ob)
 	return BLI_findptr(&sl->base, ob, offsetof(Base, object));
 }
 
+Base *BKE_scene_layer_collection_base_find(LayerCollection *lc, Object *ob)
+{
+	for (LinkData *link = lc->elements.first; link; link = link->next) {
+		Base *base = link->data;
+
+		if (base->object == ob) {
+			return base;
+		}
+	}
+	return NULL;
+}
+
+static Base *scene_layer_base_add(SceneLayer *sl, Object *ob)
+{
+	Base *b = MEM_callocN(sizeof(*b), __func__);
+	BLI_addhead(&sl->base, b);
+
+	b->object = ob;
+	b->flag = ob->flag;
+	b->lay = ob->lay;
+
+	return b;
+}
+
+Base *BKE_scene_layer_base_add(SceneLayer *sl, LayerCollection *lc, Object *ob)
+{
+	Base *base = BKE_scene_layer_base_find(sl, ob);
+
+	if (base == NULL) {
+		base = scene_layer_base_add(sl, ob);
+	}
+
+	/* only bump id count for collection */
+	id_us_plus(&ob->id);
+	BLI_addtail(&lc->elements, BLI_genericNodeN(base));
+	return base;
+}
+
 /**
  * Sets the active scene, mainly used when running in background mode (``--scene`` command line argument).
  * This is also called to set the scene directly, bypassing windowing code.
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index 60156a60c1e..dcb8ce2892c 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -632,6 +632,31 @@ static void rna_Scene_object_unlink(Scene *scene, ReportList *reports, Object *o
 	WM_main_add_notifier(NC_SCENE | ND_OB_ACTIVE, scene);
 }
 
+static Base *rna_LayerCollection_object_link(ID *id, LayerCollection *lc, Main *bmain, ReportList *reports, Object *ob)
+{
+	Base *base;
+	Scene *scene = (Scene *)id;
+	SceneLayer *sl = BKE_scene_layer_from_collection(scene, lc);
+
+	if (BKE_scene_layer_collection_base_find(lc, ob)) {
+		BKE_reportf(reports, RPT_ERROR, "Object '%s' is already in collection '%s'", ob->id.name + 2, lc->name);
+		return NULL;
+	}
+
+	base = BKE_scene_layer_base_add(sl, lc, ob);
+
+	/* TODO(sergey): Only update relations for the current scene layer. */
+	DAG_relations_tag_update(bmain);
+	DAG_id_tag_update(&ob->id, OB_RECALC_OB | OB_RECALC_DATA | OB_RECALC_TIME);
+
+	/* slows down importers too much, run scene.update() */
+	/* DAG_srelations_tag_update(G.main); */
+
+	WM_main_add_notifier(NC_SCENE | ND_OB_ACTIVE, scene);
+
+	return base;
+}
+
 static int rna_Scene_layer_object_bases_lookup_string(PointerRNA *ptr, const char *key, PointerRNA *r_ptr)
 {
 	SceneLayer *sl = (SceneLayer *)ptr->data;
@@ -5187,6 +5212,27 @@ static void rna_def_layer_objects(BlenderRNA *brna, PropertyRNA *cprop)
 	RNA_def_property_update(prop, NC_SCENE | ND_OB_ACTIVE, NULL);
 }
 
+/* collection.objects */
+static void rna_def_layer_collection_objects(BlenderRNA *brna, PropertyRNA *cprop)
+{
+	StructRNA *srna;
+	FunctionRNA *func;
+	PropertyRNA *parm;
+
+	RNA_def_property_srna(cprop, "CollectionObjects");
+	srna = RNA_def_struct(brna, "CollectionObjects", NULL);
+	RNA_def_struct_sdna(srna, "LayerCollection");
+	RNA_def_struct_ui_text(srna, "Collection Objects", "Collection of collection objects");
+
+	func = RNA_def_function(srna, "link", "rna_LayerCollection_object_link");
+	RNA_def_function_ui_description(func, "Link object to collection, run scene.update() after");
+	RNA_def_function_flag(func, FUNC_USE_SELF_ID | FUNC_USE_REPORTS | FUNC_USE_MAIN);
+	parm = RNA_def_pointer(func, "object", "Object", "", "Object to add to collection");
+	RNA_def_property_flag(parm, PROP_REQUIRED | PROP_NEVER_NULL);
+	parm = RNA_def_pointer(func, "base", "ObjectBase", "", "The newly created base");
+	RNA_def_function_return(func, parm);
+}
+
 static void rna_def_layer_nested_collections(BlenderRNA *brna, PropertyRNA *cprop)
 {
 	StructRNA *srna;
@@ -5233,6 +5279,7 @@ static void rna_def_layer_collection(BlenderRNA *brna)
 	RNA_def_property_struct_type(prop, "Object");
 	RNA_def_property_ui_text(prop, "Objects", "");
 	RNA_def_property_collection_funcs(prop, NULL, NULL, NULL, "rna_LayerCollection_objects_get", NULL, NULL, NULL, NULL);
+	rna_def_layer_collection_objects(brna, prop);
 
 	/* TODO overrides */