Implement support for Append objects in Blender 2.8

Note for users
==============

The active_layer option used for the filebrowser operators is now called
active_collection.

If there is no collections in the scenelayer or if this option is not selected
we automatically create a new collection for the new objects.

This is the same behaviour of trying to add a new object when there is
no collection.

Note for developers
===================

For those cases I moved the object user count handling from readfile to
the scene collection system. It's working fine for those, but we still
need to re-visit this for Add objects, and Duplicate - In those cases
the usercount is 2 when it should be 1.

Reviewers: mont29, sergey

Differential Revision: https://developer.blender.org/D2686

6 files changed, 92 insertions, 67 deletions

diff --git a/source/blender/blenkernel/intern/blender_copybuffer.c b/source/blender/blenkernel/intern/blender_copybuffer.c
index 964825f86d3..206b0f2a8cc 100644
--- a/source/blender/blenkernel/intern/blender_copybuffer.c
+++ b/source/blender/blenkernel/intern/blender_copybuffer.c
@@ -118,7 +118,7 @@ bool BKE_copybuffer_paste(bContext *C, const char *libname, const short flag, Re
 {
 	Main *bmain = CTX_data_main(C);
 	Scene *scene = CTX_data_scene(C);
-	View3D *v3d = CTX_wm_view3d(C);
+	SceneLayer *sl = CTX_data_scene_layer(C);
 	Main *mainl = NULL;
 	Library *lib;
 	BlendHandle *bh;
@@ -143,7 +143,7 @@ bool BKE_copybuffer_paste(bContext *C, const char *libname, const short flag, Re
 
 	BLO_library_link_copypaste(mainl, bh);
 
-	BLO_library_link_end(mainl, &bh, flag, scene, v3d);
+	BLO_library_link_end(mainl, &bh, flag, scene, sl);
 
 	/* mark all library linked objects to be updated */
 	BKE_main_lib_objects_recalc_all(bmain);
diff --git a/source/blender/blenloader/BLO_readfile.h b/source/blender/blenloader/BLO_readfile.h
index e6fc4703248..0213a4ee997 100644
--- a/source/blender/blenloader/BLO_readfile.h
+++ b/source/blender/blenloader/BLO_readfile.h
@@ -43,6 +43,7 @@ struct Main;
 struct MemFile;
 struct ReportList;
 struct Scene;
+struct SceneLayer;
 struct UserDef;
 struct View3D;
 struct bContext;
@@ -114,9 +115,9 @@ struct ID *BLO_library_link_named_part(struct Main *mainl, BlendHandle **bh, con
 struct ID *BLO_library_link_named_part_ex(
         struct Main *mainl, BlendHandle **bh,
         const short idcode, const char *name, const short flag,
-        struct Scene *scene, struct View3D *v3d,
+        struct Scene *scene, struct SceneLayer *sl,
         const bool use_placeholders, const bool force_indirect);
-void BLO_library_link_end(struct Main *mainl, BlendHandle **bh, short flag, struct Scene *scene, struct View3D *v3d);
+void BLO_library_link_end(struct Main *mainl, BlendHandle **bh, short flag, struct Scene *scene, struct SceneLayer *sl);
 
 void BLO_library_link_copypaste(struct Main *mainl, BlendHandle *bh);
 
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index cd8cbabc2d7..60b77a25646 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -9956,11 +9956,11 @@ static bool object_in_any_scene(Main *mainvar, Object *ob)
 	return false;
 }
 
-static void give_base_to_objects(Main *mainvar, Scene *scene, View3D *v3d, Library *lib, const short flag)
+static void give_base_to_objects(
+        Main *mainvar, Scene *scene, SceneLayer *sl, SceneCollection *sc, Library *lib, const short flag)
 {
 	Object *ob;
-	BaseLegacy *base;
-	const unsigned int active_lay = (flag & FILE_ACTIVELAY) ? BKE_screen_view3d_layer_active(v3d, scene) : 0;
+	Base *base;
 	const bool is_link = (flag & FILE_LINK) != 0;
 
 	BLI_assert(scene);
@@ -9980,25 +9980,22 @@ static void give_base_to_objects(Main *mainvar, Scene *scene, View3D *v3d, Libra
 			}
 
 			if (do_it) {
-				base = MEM_callocN(sizeof(BaseLegacy), __func__);
-				BLI_addtail(&scene->base, base);
+				CLAMP_MIN(ob->id.us, 0);
+
+				BKE_collection_object_add(scene, sc, ob);
+				base = BKE_scene_layer_base_find(sl, ob);
+				BKE_scene_object_base_flag_sync_from_base(base);
 
-				if (active_lay) {
-					ob->lay = active_lay;
-				}
 				if (flag & FILE_AUTOSELECT) {
 					/* Note that link_object_postprocess() already checks for FILE_AUTOSELECT flag,
 					 * but it will miss objects from non-instanciated groups... */
-					ob->flag |= SELECT;
+					if (base->flag & BASE_SELECTABLED) {
+						base->flag |= BASE_SELECTED;
+						BKE_scene_base_flag_sync_from_base(base);
+					}
 					/* do NOT make base active here! screws up GUI stuff, if you want it do it on src/ level */
 				}
 
-				base->object = ob;
-				base->lay = ob->lay;
-				BKE_scene_base_flag_sync_from_object(base);
-
-				CLAMP_MIN(ob->id.us, 0);
-				id_us_plus_no_lib((ID *)ob);
 
 				ob->id.tag &= ~LIB_TAG_INDIRECT;
 				ob->id.tag |= LIB_TAG_EXTERN;
@@ -10008,12 +10005,12 @@ static void give_base_to_objects(Main *mainvar, Scene *scene, View3D *v3d, Libra
 }
 
 static void give_base_to_groups(
-        Main *mainvar, Scene *scene, View3D *v3d, Library *UNUSED(lib), const short UNUSED(flag))
+        Main *mainvar, Scene *scene, SceneLayer *sl, SceneCollection *sc,
+        Library *UNUSED(lib), const short UNUSED(flag))
 {
 	Group *group;
-	BaseLegacy *base;
+	Base *base;
 	Object *ob;
-	const unsigned int active_lay = BKE_screen_view3d_layer_active(v3d, scene);
 
 	/* give all objects which are tagged a base */
 	for (group = mainvar->group.first; group; group = group->id.next) {
@@ -10024,14 +10021,17 @@ static void give_base_to_groups(
 			/* BKE_object_add(...) messes with the selection */
 			ob = BKE_object_add_only_object(mainvar, OB_EMPTY, group->id.name + 2);
 			ob->type = OB_EMPTY;
-			ob->lay = active_lay;
 
-			/* assign the base */
-			base = BKE_scene_base_add(scene, ob);
-			base->flag_legacy |= SELECT;
-			BKE_scene_base_flag_sync_from_base(base);
+			BKE_collection_object_add(scene, sc, ob);
+			base = BKE_scene_layer_base_find(sl, ob);
+
+			if (base->flag & BASE_SELECTABLED) {
+				base->flag |= BASE_SELECTED;
+			}
+
+			BKE_scene_object_base_flag_sync_from_base(base);
 			DEG_id_tag_update(&ob->id, OB_RECALC_OB | OB_RECALC_DATA | OB_RECALC_TIME);
-			scene->basact = base;
+			sl->basact = base;
 
 			/* assign the group */
 			ob->dup_group = group;
@@ -10108,31 +10108,42 @@ static ID *link_named_part(
 	return id;
 }
 
-static void link_object_postprocess(ID *id, Scene *scene, View3D *v3d, const short flag)
+static SceneCollection *get_scene_collection_active_or_create(struct Scene *scene, struct SceneLayer *sl, const short flag)
 {
-	if (scene) {
-		BaseLegacy *base;
-		Object *ob;
+	LayerCollection *lc = NULL;
 
-		base = MEM_callocN(sizeof(BaseLegacy), "app_nam_part");
-		BLI_addtail(&scene->base, base);
+	if (flag & FILE_ACTIVELAY) {
+		lc = BKE_layer_collection_get_active_ensure(scene, sl);
+	}
+	else {
+		SceneCollection *sc = BKE_collection_add(scene, NULL, NULL);
+		lc = BKE_collection_link(sl, sc);
+	}
 
-		ob = (Object *)id;
+	return lc->scene_collection;
+}
 
-		/* link at active layer (view3d if available in context, else scene one */
-		if (flag & FILE_ACTIVELAY) {
-			ob->lay = BKE_screen_view3d_layer_active(v3d, scene);
-		}
+static void link_object_postprocess(ID *id, Scene *scene, SceneLayer *sl, const short flag)
+{
+	if (scene) {
+		/* link to scene */
+		Base *base;
+		Object *ob;
+		SceneCollection *sc;
 
+		ob = (Object *)id;
 		ob->mode = OB_MODE_OBJECT;
-		base->lay = ob->lay;
-		base->object = ob;
-		base->flag_legacy = ob->flag;
-		id_us_plus_no_lib((ID *)ob);
+
+		sc =  get_scene_collection_active_or_create(scene, sl, flag);
+		BKE_collection_object_add(scene, sc, ob);
+		base = BKE_scene_layer_base_find(sl, ob);
+		BKE_scene_object_base_flag_sync_from_base(base);
 
 		if (flag & FILE_AUTOSELECT) {
-			base->flag_legacy |= SELECT;
-			BKE_scene_base_flag_sync_from_base(base);
+			if (base->flag & BASE_SELECTABLED) {
+				base->flag |= BASE_SELECTED;
+				BKE_scene_base_flag_sync_from_base(base);
+			}
 			/* do NOT make base active here! screws up GUI stuff, if you want it do it on src/ level */
 		}
 	}
@@ -10175,12 +10186,12 @@ void BLO_library_link_copypaste(Main *mainl, BlendHandle *bh)
 
 static ID *link_named_part_ex(
         Main *mainl, FileData *fd, const short idcode, const char *name, const short flag,
-		Scene *scene, View3D *v3d, const bool use_placeholders, const bool force_indirect)
+		Scene *scene, SceneLayer *sl, const bool use_placeholders, const bool force_indirect)
 {
 	ID *id = link_named_part(mainl, fd, idcode, name, use_placeholders, force_indirect);
 
 	if (id && (GS(id->name) == ID_OB)) {	/* loose object: give a base */
-		link_object_postprocess(id, scene, v3d, flag);
+		link_object_postprocess(id, scene, sl, flag);
 	}
 	else if (id && (GS(id->name) == ID_GR)) {
 		/* tag as needing to be instantiated */
@@ -10224,11 +10235,11 @@ ID *BLO_library_link_named_part(Main *mainl, BlendHandle **bh, const short idcod
 ID *BLO_library_link_named_part_ex(
         Main *mainl, BlendHandle **bh,
         const short idcode, const char *name, const short flag,
-        Scene *scene, View3D *v3d,
+        Scene *scene, SceneLayer *sl,
         const bool use_placeholders, const bool force_indirect)
 {
 	FileData *fd = (FileData*)(*bh);
-	return link_named_part_ex(mainl, fd, idcode, name, flag, scene, v3d, use_placeholders, force_indirect);
+	return link_named_part_ex(mainl, fd, idcode, name, flag, scene, sl, use_placeholders, force_indirect);
 }
 
 static void link_id_part(ReportList *reports, FileData *fd, Main *mainvar, ID *id, ID **r_id)
@@ -10341,7 +10352,7 @@ static void split_main_newid(Main *mainptr, Main *main_newid)
 }
 
 /* scene and v3d may be NULL. */
-static void library_link_end(Main *mainl, FileData **fd, const short flag, Scene *scene, View3D *v3d)
+static void library_link_end(Main *mainl, FileData **fd, const short flag, Scene *scene, SceneLayer *sl)
 {
 	Main *mainvar;
 	Library *curlib;
@@ -10397,10 +10408,11 @@ static void library_link_end(Main *mainl, FileData **fd, const short flag, Scene
 	 * Only directly linked objects & groups are instantiated by `BLO_library_link_named_part_ex()` & co,
 	 * here we handle indirect ones and other possible edge-cases. */
 	if (scene) {
-		give_base_to_objects(mainvar, scene, v3d, curlib, flag);
+		SceneCollection *sc = get_scene_collection_active_or_create(scene, sl, FILE_ACTIVELAY);
+		give_base_to_objects(mainvar, scene, sl, sc, curlib, flag);
 
 		if (flag & FILE_GROUP_INSTANCE) {
-			give_base_to_groups(mainvar, scene, v3d, curlib, flag);
+			give_base_to_groups(mainvar, scene, sl, sc, curlib, flag);
 		}
 	}
 	else {
@@ -10426,12 +10438,12 @@ static void library_link_end(Main *mainl, FileData **fd, const short flag, Scene
  * \param bh The blender file handle (WARNING! may be freed by this function!).
  * \param flag Options for linking, used for instantiating.
  * \param scene The scene in which to instantiate objects/groups (if NULL, no instantiation is done).
- * \param v3d The active View3D (only to define active layers for instantiated objects & groups, can be NULL).
+ * \param sl The scene layer in which to instantiate objects/groups (if NULL, no instantiation is done).
  */
-void BLO_library_link_end(Main *mainl, BlendHandle **bh, short flag, Scene *scene, View3D *v3d)
+void BLO_library_link_end(Main *mainl, BlendHandle **bh, short flag, Scene *scene, SceneLayer *sl)
 {
 	FileData *fd = (FileData*)(*bh);
-	library_link_end(mainl, &fd, flag, scene, v3d);
+	library_link_end(mainl, &fd, flag, scene, sl);
 	*bh = (BlendHandle*)fd;
 }
 
diff --git a/source/blender/editors/space_file/filesel.c b/source/blender/editors/space_file/filesel.c
index 7abe5ff5070..96b241647b6 100644
--- a/source/blender/editors/space_file/filesel.c
+++ b/source/blender/editors/space_file/filesel.c
@@ -228,7 +228,7 @@ short ED_fileselect_set_params(SpaceFile *sfile)
 		if (params->type == FILE_LOADLIB) {
 			params->flag |= RNA_boolean_get(op->ptr, "link") ? FILE_LINK : 0;
 			params->flag |= RNA_boolean_get(op->ptr, "autoselect") ? FILE_AUTOSELECT : 0;
-			params->flag |= RNA_boolean_get(op->ptr, "active_layer") ? FILE_ACTIVELAY : 0;
+			params->flag |= RNA_boolean_get(op->ptr, "active_collection") ? FILE_ACTIVELAY : 0;
 		}
 
 		if ((prop = RNA_struct_find_property(op->ptr, "display_type"))) {
diff --git a/source/blender/editors/space_view3d/view3d_ops.c b/source/blender/editors/space_view3d/view3d_ops.c
index f6abc40959b..e2b19075f95 100644
--- a/source/blender/editors/space_view3d/view3d_ops.c
+++ b/source/blender/editors/space_view3d/view3d_ops.c
@@ -119,7 +119,7 @@ static int view3d_pastebuffer_exec(bContext *C, wmOperator *op)
 
 	if (RNA_boolean_get(op->ptr, "autoselect"))
 		flag |= FILE_AUTOSELECT;
-	if (RNA_boolean_get(op->ptr, "active_layer"))
+	if (RNA_boolean_get(op->ptr, "active_collection"))
 		flag |= FILE_ACTIVELAY;
 
 	BLI_make_file_string("/", str, BKE_tempdir_base(), "copybuffer.blend");
@@ -152,7 +152,7 @@ static void VIEW3D_OT_pastebuffer(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 
 	RNA_def_boolean(ot->srna, "autoselect", true, "Select", "Select pasted objects");
-	RNA_def_boolean(ot->srna, "active_layer", true, "Active Layer", "Put pasted objects on the active layer");
+	RNA_def_boolean(ot->srna, "active_collection", true, "Active Collection", "Put pasted objects on the active collection");
 }
 
 /* ************************** registration **********************************/
diff --git a/source/blender/windowmanager/intern/wm_files_link.c b/source/blender/windowmanager/intern/wm_files_link.c
index e4f88b255ac..871c817384c 100644
--- a/source/blender/windowmanager/intern/wm_files_link.c
+++ b/source/blender/windowmanager/intern/wm_files_link.c
@@ -59,6 +59,7 @@
 #include "BLO_readfile.h"
 
 #include "BKE_context.h"
+#include "BKE_layer.h"
 #include "BKE_library.h"
 #include "BKE_library_remap.h"
 #include "BKE_global.h"
@@ -68,6 +69,7 @@
 
 #include "BKE_idcode.h"
 
+#include "DEG_depsgraph.h"
 #include "DEG_depsgraph_build.h"
 
 #include "IMB_colormanagement.h"
@@ -131,7 +133,7 @@ static short wm_link_append_flag(wmOperator *op)
 
 	if (RNA_boolean_get(op->ptr, "autoselect"))
 		flag |= FILE_AUTOSELECT;
-	if (RNA_boolean_get(op->ptr, "active_layer"))
+	if (RNA_boolean_get(op->ptr, "active_collection"))
 		flag |= FILE_ACTIVELAY;
 	if ((prop = RNA_struct_find_property(op->ptr, "relative_path")) && RNA_property_boolean_get(op->ptr, prop))
 		flag |= FILE_RELPATH;
@@ -212,7 +214,7 @@ static WMLinkAppendDataItem *wm_link_append_data_item_add(
 }
 
 static void wm_link_do(
-        WMLinkAppendData *lapp_data, ReportList *reports, Main *bmain, Scene *scene, View3D *v3d,
+        WMLinkAppendData *lapp_data, ReportList *reports, Main *bmain, Scene *scene, SceneLayer *sl,
         const bool use_placeholders, const bool force_indirect)
 {
 	Main *mainl;
@@ -261,7 +263,7 @@ static void wm_link_do(
 			}
 
 			new_id = BLO_library_link_named_part_ex(
-			             mainl, &bh, item->idcode, item->name, flag, scene, v3d, use_placeholders, force_indirect);
+			             mainl, &bh, item->idcode, item->name, flag, scene, sl, use_placeholders, force_indirect);
 
 			if (new_id) {
 				/* If the link is successful, clear item's libs 'todo' flags.
@@ -271,7 +273,7 @@ static void wm_link_do(
 			}
 		}
 
-		BLO_library_link_end(mainl, &bh, flag, scene, v3d);
+		BLO_library_link_end(mainl, &bh, flag, scene, sl);
 		BLO_blendhandle_close(bh);
 	}
 }
@@ -280,6 +282,7 @@ static int wm_link_append_exec(bContext *C, wmOperator *op)
 {
 	Main *bmain = CTX_data_main(C);
 	Scene *scene = CTX_data_scene(C);
+	SceneLayer *sl = CTX_data_scene_layer(C);
 	PropertyRNA *prop;
 	WMLinkAppendData *lapp_data;
 	char path[FILE_MAX_LIBEXTRA], root[FILE_MAXDIR], libname[FILE_MAX], relname[FILE_MAX];
@@ -334,8 +337,8 @@ static int wm_link_append_exec(bContext *C, wmOperator *op)
 
 	/* from here down, no error returns */
 
-	if (scene && RNA_boolean_get(op->ptr, "autoselect")) {
-		BKE_scene_base_deselect_all(scene);
+	if (sl && RNA_boolean_get(op->ptr, "autoselect")) {
+		BKE_scene_layer_base_deselect_all(sl);
 	}
 	
 	/* tag everything, all untagged data can be made local
@@ -405,7 +408,7 @@ static int wm_link_append_exec(bContext *C, wmOperator *op)
 	/* XXX We'd need re-entrant locking on Main for this to work... */
 	/* BKE_main_lock(bmain); */
 
-	wm_link_do(lapp_data, op->reports, bmain, scene, CTX_wm_view3d(C), false, false);
+	wm_link_do(lapp_data, op->reports, bmain, scene, sl, false, false);
 
 	/* BKE_main_unlock(bmain); */
 
@@ -445,6 +448,15 @@ static int wm_link_append_exec(bContext *C, wmOperator *op)
 	 * link into other scenes from this blend file */
 	BKE_main_id_tag_all(bmain, LIB_TAG_PRE_EXISTING, false);
 
+	/* TODO(sergey): Use proper flag for tagging here. */
+
+	/* TODO (dalai): Temporary solution!
+	 * Ideally we only need to tag the new objects themselves, not the scene. This way we'll avoid flush of
+	 * collection properties to all objects and limit update to the particular object only.
+	 * But afraid first we need to change collection evaluation in DEG according to depsgraph manifesto.
+	 */
+	DEG_id_tag_update(&scene->id, 0);
+
 	/* recreate dependency graph to include new objects */
 	DEG_scene_relations_rebuild(bmain, scene);
 	
@@ -471,8 +483,8 @@ static void wm_link_append_properties_common(wmOperatorType *ot, bool is_link)
 	prop = RNA_def_boolean(ot->srna, "autoselect", true,
 	                       "Select", "Select new objects");
 	RNA_def_property_flag(prop, PROP_SKIP_SAVE);
-	prop = RNA_def_boolean(ot->srna, "active_layer", true,
-	                       "Active Layer", "Put new objects on the active layer");
+	prop = RNA_def_boolean(ot->srna, "active_collection", true,
+	                       "Active Collection", "Put new objects on the active collection");
 	RNA_def_property_flag(prop, PROP_SKIP_SAVE);
 	prop = RNA_def_boolean(ot->srna, "instance_groups", is_link,
 	                       "Instance Groups", "Create Dupli-Group instances for each group");