Support displaying collections in outliner

Adds a new outliner display mode "Collections" which draws the active
collection. We might want to rename it to "Active Collection" if we don't
plan to support showing other collections there.
Also added the buttons for restricting visibility and selectability.

@dfelinto, code in restrictbutton_collection_hide_cb and
restrictbutton_collection_hide_select_cb is duplicated from
rna_LayerCollection_hide_update and
rna_LayerCollection_hide_select_update, maybe utility functions would be
handy for this?

2 files changed, 76 insertions, 2 deletions

diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index 6db1a513a05..f6e1f911c62 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -51,6 +51,7 @@
 #include "BKE_depsgraph.h"
 #include "BKE_fcurve.h"
 #include "BKE_global.h"
+#include "BKE_layer.h"
 #include "BKE_library.h"
 #include "BKE_main.h"
 #include "BKE_modifier.h"
@@ -247,6 +248,34 @@ static void restrictbutton_gp_layer_flag_cb(bContext *C, void *UNUSED(poin), voi
 	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
 }
 
+static void restrictbutton_collection_hide_cb(bContext *C, void *poin, void *poin2)
+{
+	Scene *scene = poin;
+	LayerCollection *collection = poin2;
+	SceneLayer *sl = BKE_scene_layer_find_from_collection(scene, collection);
+
+	/* hide and deselect bases that are directly influenced by this LayerCollection */
+	BKE_scene_layer_base_flag_recalculate(sl);
+	BKE_scene_layer_engine_settings_collection_recalculate(sl, collection);
+	WM_event_add_notifier(C, NC_SCENE | ND_OB_SELECT, scene);
+	WM_event_add_notifier(C, NC_SCENE | ND_LAYER_CONTENT, NULL);
+}
+
+static void restrictbutton_collection_hide_select_cb(bContext *C, void *poin, void *poin2)
+{
+	Scene *scene = poin;
+	LayerCollection *collection = poin2;
+
+	if ((collection->flag & COLLECTION_SELECTABLE) == 0) {
+		SceneLayer *sl = BKE_scene_layer_find_from_collection(scene, collection);
+
+		/* deselect bases that are directly influenced by this LayerCollection */
+		BKE_scene_layer_base_flag_recalculate(sl);
+		WM_event_add_notifier(C, NC_SCENE | ND_OB_SELECT, CTX_data_scene(C));
+	}
+	WM_event_add_notifier(C, NC_SCENE | ND_LAYER_CONTENT, NULL);
+}
+
 static void restrictbutton_id_user_toggle(bContext *UNUSED(C), void *poin, void *UNUSED(poin2))
 {
 	ID *id = (ID *)poin;
@@ -539,6 +568,27 @@ static void outliner_draw_restrictbuts(uiBlock *block, Scene *scene, ARegion *ar
 				
 				UI_block_emboss_set(block, UI_EMBOSS);
 			}
+			else if (tselem->type == TSE_COLLECTION) {
+				LayerCollection *collection = te->directdata;
+
+				UI_block_emboss_set(block, UI_EMBOSS_NONE);
+
+				bt = uiDefIconButBitS(block, UI_BTYPE_ICON_TOGGLE_N, COLLECTION_VISIBLE, 0, ICON_RESTRICT_VIEW_OFF,
+				                      (int)(ar->v2d.cur.xmax - OL_TOG_RESTRICT_VIEWX), te->ys, UI_UNIT_X,
+				                      UI_UNIT_Y, &collection->flag, 0, 0, 0, 0,
+				                      TIP_("Restrict/Allow 3D View visibility of objects in the collection"));
+				UI_but_func_set(bt, restrictbutton_collection_hide_cb, scene, collection);
+				UI_but_flag_enable(bt, UI_BUT_DRAG_LOCK);
+
+				bt = uiDefIconButBitS(block, UI_BTYPE_ICON_TOGGLE_N, COLLECTION_SELECTABLE, 0, ICON_RESTRICT_SELECT_OFF,
+				                      (int)(ar->v2d.cur.xmax - OL_TOG_RESTRICT_SELECTX), te->ys, UI_UNIT_X,
+				                      UI_UNIT_Y, &collection->flag, 0, 0, 0, 0,
+				                      TIP_("Restrict/Allow 3D View selection of objects in the collection"));
+				UI_but_func_set(bt, restrictbutton_collection_hide_select_cb, scene, collection);
+				UI_but_flag_enable(bt, UI_BUT_DRAG_LOCK);
+
+				UI_block_emboss_set(block, UI_EMBOSS);
+			}
 		}
 		
 		if (TSELEM_OPEN(tselem, soops)) outliner_draw_restrictbuts(block, scene, ar, soops, &te->subtree);
diff --git a/source/blender/editors/space_outliner/outliner_tree.c b/source/blender/editors/space_outliner/outliner_tree.c
index a4f59f60f31..c96d7f970ed 100644
--- a/source/blender/editors/space_outliner/outliner_tree.c
+++ b/source/blender/editors/space_outliner/outliner_tree.c
@@ -904,8 +904,8 @@ static TreeElement *outliner_add_element(SpaceOops *soops, ListBase *lb, void *i
 		id = TREESTORE(parent)->id;
 	}
 
-	/* One exception */
-	if (type == TSE_ID_BASE) {
+	/* exceptions */
+	if (ELEM(type, TSE_ID_BASE, TSE_COLLECTION)) {
 		/* pass */
 	}
 	else if (id == NULL) {
@@ -942,6 +942,9 @@ static TreeElement *outliner_add_element(SpaceOops *soops, ListBase *lb, void *i
 	else if (type == TSE_GP_LAYER) {
 		/* pass */
 	}
+	else if (type == TSE_COLLECTION) {
+		/* pass */
+	}
 	else if (type == TSE_ID_BASE) {
 		/* pass */
 	}
@@ -1371,6 +1374,24 @@ static void outliner_add_orphaned_datablocks(Main *mainvar, SpaceOops *soops)
 	}
 }
 
+static void outliner_add_collections_recursive(SpaceOops *soops, ListBase *tree, ListBase *layer_collections,
+                                               TreeElement *parent_ten)
+{
+	for (LayerCollection *collection = layer_collections->first; collection; collection = collection->next) {
+		TreeElement *ten = outliner_add_element(soops, tree, NULL, parent_ten, TSE_COLLECTION, 0);
+
+		ten->name = collection->scene_collection->name;
+		ten->directdata = collection;
+
+		outliner_add_collections_recursive(soops, &ten->subtree, &collection->layer_collections, ten);
+	}
+}
+
+static void outliner_add_collections(SpaceOops *soops, SceneLayer *layer)
+{
+	outliner_add_collections_recursive(soops, &soops->tree, &layer->layer_collections, NULL);
+}
+
 /* ======================================================= */
 /* Generic Tree Building helpers - order these are called is top to bottom */
 
@@ -1832,6 +1853,9 @@ void outliner_build_tree(Main *mainvar, Scene *scene, SceneLayer *sl, SpaceOops
 	else if (soops->outlinevis == SO_ID_ORPHANS) {
 		outliner_add_orphaned_datablocks(mainvar, soops);
 	}
+	else if (soops->outlinevis == SO_COLLECTIONS) {
+		outliner_add_collections(soops, BLI_findlink(&scene->render_layers, scene->active_layer));
+	}
 	else {
 		ten = outliner_add_element(soops, &soops->tree, OBACT_NEW, NULL, 0, 0);
 	}