UI: Add template_search (version of template_ID for non-IDs)

Adds a version of template_ID that can be used for non-ID properties.
The property to search for and the collection to search in has to be
passed to it.
Like template_ID it also takes arguments to define a 'new' and 'unlink'
operator. They will be displayed as icon-only buttons then.
Also added a version that can display preview thumbnails.

Had to do some additional changes to make text-buttons support
displaying/modifying empty RNA properties.

This will be needed for workspaces, see D2451.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D2666

12 files changed, 518 insertions, 192 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index ee15413b4d0..b3c95aa0712 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -912,6 +912,17 @@ void uiTemplateIDPreview(uiLayout *layout, struct bContext *C, struct PointerRNA
                          const char *newop, const char *openop, const char *unlinkop, int rows, int cols);
 void uiTemplateAnyID(uiLayout *layout, struct PointerRNA *ptr, const char *propname, 
                      const char *proptypename, const char *text);
+void uiTemplateSearch(
+        uiLayout *layout, struct bContext *C,
+        struct PointerRNA *ptr, const char *propname,
+        struct PointerRNA *searchptr, const char *searchpropname,
+        const char *newop, const char *unlinkop);
+void uiTemplateSearchPreview(
+        uiLayout *layout, struct bContext *C,
+        struct PointerRNA *ptr, const char *propname,
+        struct PointerRNA *searchptr, const char *searchpropname,
+        const char *newop, const char *unlinkop,
+        const int rows, const int cols);
 void uiTemplatePathBuilder(uiLayout *layout, struct PointerRNA *ptr, const char *propname, 
                            struct PointerRNA *root_ptr, const char *text);
 uiLayout *uiTemplateModifier(uiLayout *layout, struct bContext *C, struct PointerRNA *ptr);
diff --git a/source/blender/editors/interface/interface.c b/source/blender/editors/interface/interface.c
index e1ca6c60a74..562a2f6e32c 100644
--- a/source/blender/editors/interface/interface.c
+++ b/source/blender/editors/interface/interface.c
@@ -2373,7 +2373,7 @@ static void ui_but_string_free_internal(uiBut *but)
 
 bool ui_but_string_set(bContext *C, uiBut *but, const char *str)
 {
-	if (but->rnaprop && ELEM(but->type, UI_BTYPE_TEXT, UI_BTYPE_SEARCH_MENU)) {
+	if (but->rnaprop && but->rnapoin.data && ELEM(but->type, UI_BTYPE_TEXT, UI_BTYPE_SEARCH_MENU)) {
 		if (RNA_property_editable(&but->rnapoin, but->rnaprop)) {
 			PropertyType type;
 
@@ -2420,8 +2420,15 @@ bool ui_but_string_set(bContext *C, uiBut *but, const char *str)
 	}
 	else if (but->type == UI_BTYPE_TEXT) {
 		/* string */
-		if (ui_but_is_utf8(but)) BLI_strncpy_utf8(but->poin, str, but->hardmax);
-		else BLI_strncpy(but->poin, str, but->hardmax);
+		if (!but->poin || (str[0] == '\0')) {
+			str = "";
+		}
+		else if (ui_but_is_utf8(but)) {
+			BLI_strncpy_utf8(but->poin, str, but->hardmax);
+		}
+		else {
+			BLI_strncpy(but->poin, str, but->hardmax);
+		}
 
 		return true;
 	}
@@ -2627,6 +2634,10 @@ static void ui_but_free(const bContext *C, uiBut *but)
 		MEM_freeN(but->tip_argN);
 	}
 
+	if (!but->editstr && but->free_search_arg) {
+		MEM_SAFE_FREE(but->search_arg);
+	}
+
 	if (but->active) {
 		/* XXX solve later, buttons should be free-able without context ideally,
 		 * however they may have open tooltips or popup windows, which need to
@@ -3499,7 +3510,7 @@ static uiBut *ui_def_but_rna(
 	}
 
 	const char *info;
-	if (!RNA_property_editable_info(&but->rnapoin, prop, &info)) {
+	if (but->rnapoin.data && !RNA_property_editable_info(&but->rnapoin, prop, &info)) {
 		ui_def_but_rna__disable(but, info);
 	}
 
@@ -4522,7 +4533,7 @@ void UI_but_string_info_get(bContext *C, uiBut *but, ...)
 				tmp = BLI_strdup(RNA_property_identifier(but->rnaprop));
 		}
 		else if (type == BUT_GET_RNASTRUCT_IDENTIFIER) {
-			if (but->rnaprop)
+			if (but->rnaprop && but->rnapoin.data)
 				tmp = BLI_strdup(RNA_struct_identifier(but->rnapoin.type));
 			else if (but->optype)
 				tmp = BLI_strdup(but->optype->idname);
diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index ca0a5ffcbfc..6dcdb312256 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -3159,6 +3159,9 @@ static void ui_textedit_end(bContext *C, uiBut *but, uiHandleButtonData *data)
 
 			ui_searchbox_free(C, data->searchbox);
 			data->searchbox = NULL;
+			if (but->free_search_arg) {
+				MEM_SAFE_FREE(but->search_arg);
+			}
 		}
 		
 		but->editstr = NULL;
diff --git a/source/blender/editors/interface/interface_intern.h b/source/blender/editors/interface/interface_intern.h
index 68bb48f66fb..ace3bb5b4f8 100644
--- a/source/blender/editors/interface/interface_intern.h
+++ b/source/blender/editors/interface/interface_intern.h
@@ -259,6 +259,7 @@ struct uiBut {
 	
 	uiButSearchCreateFunc search_create_func;
 	uiButSearchFunc search_func;
+	bool free_search_arg;
 	void *search_arg;
 
 	uiButHandleRenameFunc rename_func;
@@ -278,7 +279,7 @@ struct uiBut {
 	BIFIconID icon;
 	char dt; /* drawtype: UI_EMBOSS, UI_EMBOSS_NONE ... etc, copied from the block */
 	signed char pie_dir; /* direction in a pie menu, used for collision detection (RadialDirection) */
-	char changed; /* could be made into a single flag */
+	bool changed; /* could be made into a single flag */
 	unsigned char unit_type; /* so buttons can support unit systems which are not RNA */
 	short modifier_key;
 	short iconadd;
@@ -748,4 +749,20 @@ void UI_OT_eyedropper_id(struct wmOperatorType *ot);
 void UI_OT_eyedropper_depth(struct wmOperatorType *ot);
 void UI_OT_eyedropper_driver(struct wmOperatorType *ot);
 
+/* interface_util.c */
+
+/**
+ * For use with #ui_rna_collection_search_cb.
+ */
+typedef struct uiRNACollectionSearch {
+	PointerRNA target_ptr;
+	PropertyRNA *target_prop;
+
+	PointerRNA search_ptr;
+	PropertyRNA *search_prop;
+
+	bool *but_changed; /* pointer to uiBut.changed */
+} uiRNACollectionSearch;
+void ui_rna_collection_search_cb(const struct bContext *C, void *arg, const char *str, uiSearchItems *items);
+
 #endif  /* __INTERFACE_INTERN_H__ */
diff --git a/source/blender/editors/interface/interface_layout.c b/source/blender/editors/interface/interface_layout.c
index 30a2094fee7..5462043c961 100644
--- a/source/blender/editors/interface/interface_layout.c
+++ b/source/blender/editors/interface/interface_layout.c
@@ -1574,95 +1574,6 @@ void uiItemsEnumR(uiLayout *layout, struct PointerRNA *ptr, const char *propname
 
 /* Pointer RNA button with search */
 
-typedef struct CollItemSearch {
-	struct CollItemSearch *next, *prev;
-	char *name;
-	int index;
-	int iconid;
-} CollItemSearch;
-
-static int sort_search_items_list(const void *a, const void *b)
-{
-	const CollItemSearch *cis1 = a;
-	const CollItemSearch *cis2 = b;
-	
-	if (BLI_strcasecmp(cis1->name, cis2->name) > 0)
-		return 1;
-	else
-		return 0;
-}
-
-static void rna_search_cb(const struct bContext *C, void *arg_but, const char *str, uiSearchItems *items)
-{
-	uiBut *but = arg_but;
-	char *name;
-	int i = 0, iconid = 0, flag = RNA_property_flag(but->rnaprop);
-	ListBase *items_list = MEM_callocN(sizeof(ListBase), "items_list");
-	CollItemSearch *cis;
-	const bool skip_filter = !but->changed;
-
-	/* build a temporary list of relevant items first */
-	RNA_PROP_BEGIN (&but->rnasearchpoin, itemptr, but->rnasearchprop)
-	{
-		if (flag & PROP_ID_SELF_CHECK)
-			if (itemptr.data == but->rnapoin.id.data)
-				continue;
-
-		/* use filter */
-		if (RNA_property_type(but->rnaprop) == PROP_POINTER) {
-			if (RNA_property_pointer_poll(&but->rnapoin, but->rnaprop, &itemptr) == 0)
-				continue;
-		}
-
-		if (itemptr.type && RNA_struct_is_ID(itemptr.type)) {
-			ID *id = itemptr.data;
-			char name_ui[MAX_ID_NAME];
-
-#if 0       /* this name is used for a string comparison and can't be modified, TODO */
-			/* if ever enabled, make name_ui be MAX_ID_NAME+1 */
-			BKE_id_ui_prefix(name_ui, id);
-#else
-			BLI_strncpy(name_ui, id->name + 2, sizeof(name_ui));
-#endif
-			name = BLI_strdup(name_ui);
-			iconid = ui_id_icon_get(C, id, false);
-		}
-		else {
-			name = RNA_struct_name_get_alloc(&itemptr, NULL, 0, NULL); /* could use the string length here */
-			iconid = 0;
-		}
-
-		if (name) {
-			if (skip_filter || BLI_strcasestr(name, str)) {
-				cis = MEM_callocN(sizeof(CollItemSearch), "CollectionItemSearch");
-				cis->name = MEM_dupallocN(name);
-				cis->index = i;
-				cis->iconid = iconid;
-				BLI_addtail(items_list, cis);
-			}
-			MEM_freeN(name);
-		}
-
-		i++;
-	}
-	RNA_PROP_END;
-	
-	BLI_listbase_sort(items_list, sort_search_items_list);
-	
-	/* add search items from temporary list */
-	for (cis = items_list->first; cis; cis = cis->next) {
-		if (false == UI_search_item_add(items, cis->name, SET_INT_IN_POINTER(cis->index), cis->iconid)) {
-			break;
-		}
-	}
-
-	for (cis = items_list->first; cis; cis = cis->next) {
-		MEM_freeN(cis->name);
-	}
-	BLI_freelistN(items_list);
-	MEM_freeN(items_list);
-}
-
 static void search_id_collection(StructRNA *ptype, PointerRNA *ptr, PropertyRNA **prop)
 {
 	StructRNA *srna;
@@ -1703,6 +1614,8 @@ void ui_but_add_search(uiBut *but, PointerRNA *ptr, PropertyRNA *prop, PointerRN
 
 	/* turn button into search button */
 	if (searchprop) {
+		uiRNACollectionSearch *coll_search = MEM_mallocN(sizeof(*coll_search), __func__);
+
 		but->type = UI_BTYPE_SEARCH_MENU;
 		but->hardmax = MAX2(but->hardmax, 256.0f);
 		but->rnasearchpoin = *searchptr;
@@ -1712,13 +1625,22 @@ void ui_but_add_search(uiBut *but, PointerRNA *ptr, PropertyRNA *prop, PointerRN
 			but->flag |= UI_BUT_VALUE_CLEAR;
 		}
 
+		coll_search->target_ptr = *ptr;
+		coll_search->target_prop = prop;
+		coll_search->search_ptr = *searchptr;
+		coll_search->search_prop = searchprop;
+		coll_search->but_changed = &but->changed;
+
 		if (RNA_property_type(prop) == PROP_ENUM) {
 			/* XXX, this will have a menu string,
 			 * but in this case we just want the text */
 			but->str[0] = 0;
 		}
 
-		UI_but_func_search_set(but, ui_searchbox_create_generic, rna_search_cb, but, NULL, NULL);
+		UI_but_func_search_set(
+		            but, ui_searchbox_create_generic, ui_rna_collection_search_cb,
+		            coll_search, NULL, NULL);
+		but->free_search_arg = true;
 	}
 }
 
diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index e3a71feb1a9..266d8aacae3 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -89,10 +89,126 @@
 
 #include "PIL_time.h"
 
+/* defines for templateID/TemplateSearch */
+#define TEMPLATE_SEARCH_TEXTBUT_WIDTH  (UI_UNIT_X * 6)
+#define TEMPLATE_SEARCH_TEXTBUT_HEIGHT  UI_UNIT_Y
+
+
 void UI_template_fix_linking(void)
 {
 }
 
+/**
+ * Add a block button for the search menu for templateID and templateSearch.
+ */
+static void template_add_button_search_menu(
+        const bContext *C, uiLayout *layout, uiBlock *block,
+        PointerRNA *ptr, PropertyRNA *prop,
+        uiBlockCreateFunc block_func, void *block_argN, const char * const tip,
+        const bool use_previews, const bool editable)
+{
+	PointerRNA active_ptr = RNA_property_pointer_get(ptr, prop);
+	ID *id = (active_ptr.data && RNA_struct_is_ID(active_ptr.type)) ? active_ptr.data : NULL;
+	const ID *idfrom = ptr->id.data;
+	const StructRNA *type = active_ptr.type ? active_ptr.type : RNA_property_pointer_type(ptr, prop);
+	uiBut *but;
+
+	if (use_previews) {
+		ARegion *region = CTX_wm_region(C);
+		const bool use_big_size = (region->regiontype != RGN_TYPE_HEADER); /* silly check, could be more generic */
+		/* Ugly exception for screens here, drawing their preview in icon size looks ugly/useless */
+		const bool use_preview_icon = use_big_size || (id && (GS(id->name) != ID_SCR));
+		const short width = UI_UNIT_X * (use_big_size ? 6 : 1.6f);
+		const short height = UI_UNIT_Y * (use_big_size ? 6: 1);
+
+		but = uiDefBlockButN(block, block_func, block_argN, "", 0, 0, width, height, tip);
+		if (use_preview_icon) {
+			int icon = id ? ui_id_icon_get(C, id, use_big_size) : RNA_struct_ui_icon(type);
+			ui_def_but_icon(but, icon, UI_HAS_ICON | UI_BUT_ICON_PREVIEW);
+		}
+		else {
+			ui_def_but_icon(but, RNA_struct_ui_icon(type), UI_HAS_ICON);
+			UI_but_drawflag_enable(but, UI_BUT_ICON_LEFT);
+		}
+
+		if ((idfrom && idfrom->lib) || !editable)
+			UI_but_flag_enable(but, UI_BUT_DISABLED);
+		if (use_big_size) {
+			uiLayoutRow(layout, true);
+		}
+	}
+	else {
+		but = uiDefBlockButN(block, block_func, block_argN, "", 0, 0, UI_UNIT_X * 1.6, UI_UNIT_Y, tip);
+		ui_def_but_icon(but, RNA_struct_ui_icon(type), UI_HAS_ICON);
+		if (id) {
+			/* default dragging of icon for id browse buttons */
+			UI_but_drag_set_id(but, id);
+		}
+		UI_but_drawflag_enable(but, UI_BUT_ICON_LEFT);
+
+		if ((idfrom && idfrom->lib) || !editable)
+			UI_but_flag_enable(but, UI_BUT_DISABLED);
+	}
+}
+
+static uiBlock *template_common_search_menu(
+        const bContext *C, ARegion *region,
+        uiButSearchFunc search_func, void *search_arg,
+        uiButHandleFunc handle_func, void *active_item,
+        const int preview_rows, const int preview_cols)
+{
+	static char search[256];
+	wmWindow *win = CTX_wm_window(C);
+	uiBlock *block;
+	uiBut *but;
+
+	/* clear initial search string, then all items show */
+	search[0] = 0;
+
+	block = UI_block_begin(C, region, "_popup", UI_EMBOSS);
+	UI_block_flag_enable(block, UI_BLOCK_LOOP | UI_BLOCK_SEARCH_MENU);
+
+	/* preview thumbnails */
+	if (preview_rows > 0 && preview_cols > 0) {
+		const int w = 4 * U.widget_unit * preview_cols;
+		const int h = 5 * U.widget_unit * preview_rows;
+
+		/* fake button, it holds space for search items */
+		uiDefBut(block, UI_BTYPE_LABEL, 0, "", 10, 26, w, h, NULL, 0, 0, 0, 0, NULL);
+
+		but = uiDefSearchBut(
+		        block, search, 0, ICON_VIEWZOOM, sizeof(search), 10, 0, w, UI_UNIT_Y,
+		        preview_rows, preview_cols, "");
+	}
+	/* list view */
+	else {
+		const int searchbox_width  = UI_searchbox_size_x();
+		const int searchbox_height = UI_searchbox_size_y();
+
+		/* fake button, it holds space for search items */
+		uiDefBut(
+		        block, UI_BTYPE_LABEL, 0, "", 10, 15, searchbox_width, searchbox_height,
+		        NULL, 0, 0, 0, 0, NULL);
+		but = uiDefSearchBut(
+		        block, search, 0, ICON_VIEWZOOM, sizeof(search), 10, 0,
+		        searchbox_width, UI_UNIT_Y - 1, 0, 0, "");
+	}
+	UI_but_func_search_set(
+	        but, ui_searchbox_create_generic, search_func,
+	        search_arg, handle_func, active_item);
+
+
+	UI_block_bounds_set_normal(block, 0.3f * U.widget_unit);
+	UI_block_direction_set(block, UI_DIR_DOWN);
+
+	/* give search-field focus */
+	UI_but_focus_on_enter_event(win, but);
+	/* this type of search menu requires undo */
+	but->flag |= UI_BUT_UNDO;
+
+	return block;
+}
+
 /********************** Header Template *************************/
 
 void uiTemplateHeader(uiLayout *layout, bContext *C)
@@ -174,61 +290,16 @@ static void id_search_cb(const bContext *C, void *arg_template, const char *str,
 /* ID Search browse menu, open */
 static uiBlock *id_search_menu(bContext *C, ARegion *ar, void *arg_litem)
 {
-	static char search[256];
 	static TemplateID template;
-	PointerRNA idptr;
-	wmWindow *win = CTX_wm_window(C);
-	uiBlock *block;
-	uiBut *but;
-	
-	/* clear initial search string, then all items show */
-	search[0] = 0;
+	PointerRNA active_item_ptr;
+
 	/* arg_litem is malloced, can be freed by parent button */
 	template = *((TemplateID *)arg_litem);
-	
-	/* get active id for showing first item */
-	idptr = RNA_property_pointer_get(&template.ptr, template.prop);
+	active_item_ptr = RNA_property_pointer_get(&template.ptr, template.prop);
 
-	block = UI_block_begin(C, ar, "_popup", UI_EMBOSS);
-	UI_block_flag_enable(block, UI_BLOCK_LOOP | UI_BLOCK_SEARCH_MENU);
-	
-	/* preview thumbnails */
-	if (template.prv_rows > 0 && template.prv_cols > 0) {
-		int w = 4 * U.widget_unit * template.prv_cols;
-		int h = 5 * U.widget_unit * template.prv_rows;
-		
-		/* fake button, it holds space for search items */
-		uiDefBut(block, UI_BTYPE_LABEL, 0, "", 10, 26, w, h, NULL, 0, 0, 0, 0, NULL);
-		
-		but = uiDefSearchBut(block, search, 0, ICON_VIEWZOOM, sizeof(search), 10, 0, w, UI_UNIT_Y,
-		                     template.prv_rows, template.prv_cols, "");
-		UI_but_func_search_set(
-		        but, ui_searchbox_create_generic, id_search_cb,
-		        &template, id_search_call_cb, idptr.data);
-	}
-	/* list view */
-	else {
-		const int searchbox_width  = UI_searchbox_size_x();
-		const int searchbox_height = UI_searchbox_size_y();
-		
-		/* fake button, it holds space for search items */
-		uiDefBut(block, UI_BTYPE_LABEL, 0, "", 10, 15, searchbox_width, searchbox_height, NULL, 0, 0, 0, 0, NULL);
-		but = uiDefSearchBut(block, search, 0, ICON_VIEWZOOM, sizeof(search), 10, 0, searchbox_width, UI_UNIT_Y - 1, 0, 0, "");
-		UI_but_func_search_set(
-		        but, ui_searchbox_create_generic, id_search_cb,
-		        &template, id_search_call_cb, idptr.data);
-	}
-		
-	
-	UI_block_bounds_set_normal(block, 0.3f * U.widget_unit);
-	UI_block_direction_set(block, UI_DIR_DOWN);
-	
-	/* give search-field focus */
-	UI_but_focus_on_enter_event(win, but);
-	/* this type of search menu requires undo */
-	but->flag |= UI_BUT_UNDO;
-	
-	return block;
+	return template_common_search_menu(
+	               C, ar, id_search_cb, &template, id_search_call_cb, active_item_ptr.data,
+	               template.prv_rows, template.prv_cols);
 }
 
 /************************ ID Template ***************************/
@@ -345,7 +416,7 @@ static void template_id_cb(bContext *C, void *arg_litem, void *arg_event)
 	}
 }
 
-static const char *template_id_browse_tip(StructRNA *type)
+static const char *template_id_browse_tip(const StructRNA *type)
 {
 	if (type) {
 		switch (RNA_type_to_ID_code(type)) {
@@ -406,6 +477,7 @@ static void template_ID(
 	// ListBase *lb; // UNUSED
 	ID *id, *idfrom;
 	const bool editable = RNA_property_editable(&template->ptr, template->prop);
+	const bool use_previews = template->preview = (flag & UI_ID_PREVIEWS) != 0;
 
 	idptr = RNA_property_pointer_get(&template->ptr, template->prop);
 	id = idptr.data;
@@ -418,43 +490,11 @@ static void template_ID(
 	if (idptr.type)
 		type = idptr.type;
 
-	if (flag & UI_ID_PREVIEWS) {
-		ARegion *region = CTX_wm_region(C);
-		const bool use_big_size = (region->regiontype != RGN_TYPE_HEADER); /* silly check, could be more generic */
-		/* Ugly exception for screens here, drawing their preview in icon size looks ugly/useless */
-		const bool use_preview_icon = use_big_size || (id && (GS(id->name) != ID_SCR));
-		const short width = UI_UNIT_X * (use_big_size ? 6 : 1.6f);
-		const short height = UI_UNIT_Y * (use_big_size ? 6: 1);
-
-		template->preview = true;
-
-		but = uiDefBlockButN(block, id_search_menu, MEM_dupallocN(template), "", 0, 0, width, height,
-		                     TIP_(template_id_browse_tip(type)));
-		if (use_preview_icon) {
-			int icon = id ? ui_id_icon_get(C, id, use_big_size) : RNA_struct_ui_icon(type);
-			ui_def_but_icon(but, icon, UI_HAS_ICON | UI_BUT_ICON_PREVIEW);
-		}
-		else {
-			ui_def_but_icon(but, RNA_struct_ui_icon(type), UI_HAS_ICON);
-			UI_but_drawflag_enable(but, UI_BUT_ICON_LEFT);
-		}
-
-		if ((idfrom && idfrom->lib) || !editable)
-			UI_but_flag_enable(but, UI_BUT_DISABLED);
-		if (use_big_size) {
-			uiLayoutRow(layout, true);
-		}
-	}
-	else if (flag & UI_ID_BROWSE) {
-		but = uiDefBlockButN(block, id_search_menu, MEM_dupallocN(template), "", 0, 0, UI_UNIT_X * 1.6, UI_UNIT_Y,
-		                     TIP_(template_id_browse_tip(type)));
-		ui_def_but_icon(but, RNA_struct_ui_icon(type), UI_HAS_ICON);
-		/* default dragging of icon for id browse buttons */
-		UI_but_drag_set_id(but, id);
-		UI_but_drawflag_enable(but, UI_BUT_ICON_LEFT);
-
-		if ((idfrom && idfrom->lib) || !editable)
-			UI_but_flag_enable(but, UI_BUT_DISABLED);
+	if (flag & UI_ID_BROWSE) {
+		template_add_button_search_menu(
+		        C, layout, block, &template->ptr, template->prop,
+		        id_search_menu, MEM_dupallocN(template), TIP_(template_id_browse_tip(type)),
+		        use_previews, editable);
 	}
 
 	/* text button with name */
@@ -464,8 +504,9 @@ static void template_ID(
 
 		//text_idbutton(id, name);
 		name[0] = '\0';
-		but = uiDefButR(block, UI_BTYPE_TEXT, 0, name, 0, 0, UI_UNIT_X * 6, UI_UNIT_Y,
-		                &idptr, "name", -1, 0, 0, -1, -1, RNA_struct_ui_description(type));
+		but = uiDefButR(
+		        block, UI_BTYPE_TEXT, 0, name, 0, 0, TEMPLATE_SEARCH_TEXTBUT_WIDTH, TEMPLATE_SEARCH_TEXTBUT_HEIGHT,
+		        &idptr, "name", -1, 0, 0, -1, -1, RNA_struct_ui_description(type));
 		UI_but_funcN_set(but, template_id_cb, MEM_dupallocN(template), SET_INT_IN_POINTER(UI_ID_RENAME));
 		if (user_alert) UI_but_flag_enable(but, UI_BUT_REDALERT);
 
@@ -751,6 +792,204 @@ void uiTemplateAnyID(
 	uiItemFullR(sub, ptr, propID, 0, 0, 0, "", ICON_NONE);
 }
 
+/********************* Search Template ********************/
+
+typedef struct TemplateSearch {
+	uiRNACollectionSearch search_data;
+
+	bool use_previews;
+	int preview_rows, preview_cols;
+} TemplateSearch;
+
+static void template_search_handle_cb(bContext *C, void *arg_template, void *item)
+{
+	TemplateSearch *template_search = arg_template;
+	uiRNACollectionSearch *coll_search = &template_search->search_data;
+	StructRNA *type = RNA_property_pointer_type(&coll_search->target_ptr, coll_search->target_prop);
+	PointerRNA item_ptr;
+
+	RNA_pointer_create(NULL, type, item, &item_ptr);
+	RNA_property_pointer_set(&coll_search->target_ptr, coll_search->target_prop, item_ptr);
+	RNA_property_update(C, &coll_search->target_ptr, coll_search->target_prop);
+}
+
+static uiBlock *template_search_menu(bContext *C, ARegion *region, void *arg_template)
+{
+	static TemplateSearch template_search;
+	PointerRNA active_ptr;
+
+	/* arg_template is malloced, can be freed by parent button */
+	template_search = *((TemplateSearch *)arg_template);
+	active_ptr = RNA_property_pointer_get(&template_search.search_data.target_ptr,
+	                                      template_search.search_data.target_prop);
+
+	return template_common_search_menu(
+	               C, region, ui_rna_collection_search_cb, &template_search,
+	               template_search_handle_cb, active_ptr.data,
+	               template_search.preview_rows, template_search.preview_cols);
+}
+
+static void template_search_add_button_searchmenu(
+        const bContext *C, uiLayout *layout, uiBlock *block,
+        TemplateSearch *template_search, const bool editable)
+{
+	const char *ui_description = RNA_property_ui_description(template_search->search_data.target_prop);
+
+	template_add_button_search_menu(
+	        C, layout, block,
+	        &template_search->search_data.target_ptr, template_search->search_data.target_prop,
+	        template_search_menu, MEM_dupallocN(template_search), ui_description,
+	        template_search->use_previews, editable);
+}
+
+static void template_search_add_button_name(
+        uiBlock *block, PointerRNA *active_ptr, const StructRNA *type)
+{
+	uiDefAutoButR(
+	        block, active_ptr, RNA_struct_name_property(type), 0, "", ICON_NONE,
+	        0, 0, TEMPLATE_SEARCH_TEXTBUT_WIDTH, TEMPLATE_SEARCH_TEXTBUT_HEIGHT);
+}
+
+static void template_search_add_button_operator(
+        uiBlock *block, const char * const operator_name,
+        const int opcontext, const int icon, const bool editable)
+{
+	if (!operator_name) {
+		return;
+	}
+
+	uiBut *but = uiDefIconButO(
+	        block, UI_BTYPE_BUT, operator_name, opcontext, icon,
+	        0, 0, UI_UNIT_X, UI_UNIT_Y, NULL);
+
+	if (!editable) {
+		UI_but_drawflag_enable(but, UI_BUT_DISABLED);
+	}
+}
+
+static void template_search_buttons(
+        const bContext *C, uiLayout *layout, TemplateSearch *template_search,
+        const char *newop, const char *unlinkop)
+{
+	uiBlock *block = uiLayoutGetBlock(layout);
+	uiRNACollectionSearch *search_data = &template_search->search_data;
+	StructRNA *type = RNA_property_pointer_type(&search_data->target_ptr, search_data->target_prop);
+	const bool editable = RNA_property_editable(&search_data->target_ptr, search_data->target_prop);
+	PointerRNA active_ptr = RNA_property_pointer_get(&search_data->target_ptr, search_data->target_prop);
+
+	if (active_ptr.type) {
+		/* can only get correct type when there is an active item */
+		type = active_ptr.type;
+	}
+
+	uiLayoutRow(layout, true);
+	UI_block_align_begin(block);
+
+	template_search_add_button_searchmenu(C, layout, block, template_search, editable);
+	template_search_add_button_name(block, &active_ptr, type);
+	template_search_add_button_operator(block, newop, WM_OP_INVOKE_DEFAULT, ICON_ZOOMIN, editable);
+	template_search_add_button_operator(block, unlinkop, WM_OP_INVOKE_REGION_WIN, ICON_X, editable);
+
+	UI_block_align_end(block);
+}
+
+static PropertyRNA *template_search_get_searchprop(
+        PointerRNA *targetptr, PropertyRNA *targetprop,
+        PointerRNA *searchptr, const char * const searchpropname)
+{
+	PropertyRNA *searchprop;
+
+	if (searchptr && !searchptr->data) {
+		searchptr = NULL;
+	}
+
+	if (!searchptr && !searchpropname) {
+		/* both NULL means we don't use a custom rna collection to search in */
+	}
+	else if (!searchptr && searchpropname) {
+		RNA_warning("searchpropname defined (%s) but searchptr is missing", searchpropname);
+	}
+	else if (searchptr && !searchpropname) {
+		RNA_warning("searchptr defined (%s) but searchpropname is missing", RNA_struct_identifier(searchptr->type));
+	}
+	else if (!(searchprop = RNA_struct_find_property(searchptr, searchpropname))) {
+		RNA_warning("search collection property not found: %s.%s",
+		            RNA_struct_identifier(searchptr->type), searchpropname);
+	}
+	else if (RNA_property_type(searchprop) != PROP_COLLECTION) {
+		RNA_warning("search collection property is not a collection type: %s.%s",
+		            RNA_struct_identifier(searchptr->type), searchpropname);
+	}
+	/* check if searchprop has same type as targetprop */
+	else if (RNA_property_pointer_type(searchptr, searchprop) != RNA_property_pointer_type(targetptr, targetprop)) {
+		RNA_warning("search collection items from %s.%s are not of type %s",
+		            RNA_struct_identifier(searchptr->type), searchpropname,
+		            RNA_struct_identifier(RNA_property_pointer_type(targetptr, targetprop)));
+	}
+	else {
+		return searchprop;
+	}
+
+	return NULL;
+}
+
+static TemplateSearch *template_search_setup(
+        PointerRNA *ptr, const char * const propname,
+        PointerRNA *searchptr, const char * const searchpropname)
+{
+	TemplateSearch *template_search;
+	PropertyRNA *prop, *searchprop;
+
+	prop = RNA_struct_find_property(ptr, propname);
+
+	if (!prop || RNA_property_type(prop) != PROP_POINTER) {
+		RNA_warning("pointer property not found: %s.%s", RNA_struct_identifier(ptr->type), propname);
+		return NULL;
+	}
+	searchprop = template_search_get_searchprop(ptr, prop, searchptr, searchpropname);
+
+	template_search = MEM_callocN(sizeof(*template_search), __func__);
+	template_search->search_data.target_ptr = *ptr;
+	template_search->search_data.target_prop = prop;
+	template_search->search_data.search_ptr = *searchptr;
+	template_search->search_data.search_prop = searchprop;
+
+	return template_search;
+}
+
+/**
+ * Search menu to pick an item from a collection.
+ * A version of uiTemplateID that works for non-ID types.
+ */
+void uiTemplateSearch(
+        uiLayout *layout, bContext *C,
+        PointerRNA *ptr, const char *propname,
+        PointerRNA *searchptr, const char *searchpropname,
+        const char *newop, const char *unlinkop)
+{
+	TemplateSearch *template_search = template_search_setup(ptr, propname, searchptr, searchpropname);
+	template_search_buttons(C, layout, template_search, newop, unlinkop);
+	MEM_freeN(template_search);
+}
+
+void uiTemplateSearchPreview(
+        uiLayout *layout, bContext *C,
+        PointerRNA *ptr, const char *propname,
+        PointerRNA *searchptr, const char *searchpropname,
+        const char *newop, const char *unlinkop,
+        const int rows, const int cols)
+{
+	TemplateSearch *template_search = template_search_setup(ptr, propname, searchptr, searchpropname);
+
+	template_search->use_previews = true;
+	template_search->preview_rows = rows;
+	template_search->preview_cols = cols;
+
+	template_search_buttons(C, layout, template_search, newop, unlinkop);
+
+	MEM_freeN(template_search);
+}
+
 /********************* RNA Path Builder Template ********************/
 
 /* ---------- */
diff --git a/source/blender/editors/interface/interface_utils.c b/source/blender/editors/interface/interface_utils.c
index 636b7e4e9ce..f2e79ec0c7f 100644
--- a/source/blender/editors/interface/interface_utils.c
+++ b/source/blender/editors/interface/interface_utils.c
@@ -214,6 +214,91 @@ int uiDefAutoButsRNA(
 
 	return tot;
 }
+/* *** RNA collection search menu *** */
+
+typedef struct CollItemSearch {
+	struct CollItemSearch *next, *prev;
+	ID *id;
+	char *name;
+	int index;
+	int iconid;
+} CollItemSearch;
+
+static int sort_search_items_list(const void *a, const void *b)
+{
+	const CollItemSearch *cis1 = a;
+	const CollItemSearch *cis2 = b;
+
+	if (BLI_strcasecmp(cis1->name, cis2->name) > 0)
+		return 1;
+	else
+		return 0;
+}
+
+void ui_rna_collection_search_cb(const struct bContext *C, void *arg, const char *str, uiSearchItems *items)
+{
+	uiRNACollectionSearch *data = arg;
+	char *name;
+	int i = 0, iconid = 0, flag = RNA_property_flag(data->target_prop);
+	ListBase *items_list = MEM_callocN(sizeof(ListBase), "items_list");
+	CollItemSearch *cis;
+	const bool skip_filter = !(data->but_changed && *data->but_changed);
+
+	/* build a temporary list of relevant items first */
+	RNA_PROP_BEGIN (&data->search_ptr, itemptr, data->search_prop)
+	{
+		ID *id = NULL;
+
+		if (flag & PROP_ID_SELF_CHECK)
+			if (itemptr.data == data->target_ptr.id.data)
+				continue;
+
+		/* use filter */
+		if (RNA_property_type(data->target_prop) == PROP_POINTER) {
+			if (RNA_property_pointer_poll(&data->target_ptr, data->target_prop, &itemptr) == 0)
+				continue;
+		}
+
+		name = RNA_struct_name_get_alloc(&itemptr, NULL, 0, NULL); /* could use the string length here */
+		iconid = 0;
+		if (itemptr.type && RNA_struct_is_ID(itemptr.type)) {
+			id = itemptr.data;
+			iconid = ui_id_icon_get(C, id, false);
+		}
+
+		if (name) {
+			if (skip_filter || BLI_strcasestr(name, str)) {
+				cis = MEM_callocN(sizeof(CollItemSearch), "CollectionItemSearch");
+				cis->id = id;
+				cis->name = MEM_dupallocN(name);
+				cis->index = i;
+				cis->iconid = iconid;
+				BLI_addtail(items_list, cis);
+			}
+			MEM_freeN(name);
+		}
+
+		i++;
+	}
+	RNA_PROP_END;
+
+	BLI_listbase_sort(items_list, sort_search_items_list);
+
+	/* add search items from temporary list */
+	for (cis = items_list->first; cis; cis = cis->next) {
+		void *poin = cis->id ? cis->id : SET_INT_IN_POINTER(cis->index);
+		if (UI_search_item_add(items, cis->name, poin, cis->iconid) == false) {
+			break;
+		}
+	}
+
+	for (cis = items_list->first; cis; cis = cis->next) {
+		MEM_freeN(cis->name);
+	}
+	BLI_freelistN(items_list);
+	MEM_freeN(items_list);
+}
+
 
 /***************************** ID Utilities *******************************/
 
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 1a6b3008a79..7f919ef058a 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -751,7 +751,7 @@ const char *RNA_struct_ui_description_raw(const StructRNA *type);
 const char *RNA_struct_translation_context(const StructRNA *type);
 int RNA_struct_ui_icon(const StructRNA *type);
 
-PropertyRNA *RNA_struct_name_property(StructRNA *type);
+PropertyRNA *RNA_struct_name_property(const StructRNA *type);
 PropertyRNA *RNA_struct_iterator_property(StructRNA *type);
 StructRNA *RNA_struct_base(StructRNA *type);
 
@@ -1191,7 +1191,7 @@ int RNA_function_call_direct_va_lookup(struct bContext *C, struct ReportList *re
 
 /* ID */
 
-short RNA_type_to_ID_code(StructRNA *type);
+short RNA_type_to_ID_code(const StructRNA *type);
 StructRNA *ID_code_to_RNA_type(short idcode);
 
 
diff --git a/source/blender/makesrna/intern/rna_ID.c b/source/blender/makesrna/intern/rna_ID.c
index a74758a4f71..4291e5b63ae 100644
--- a/source/blender/makesrna/intern/rna_ID.c
+++ b/source/blender/makesrna/intern/rna_ID.c
@@ -136,7 +136,7 @@ static int rna_ID_name_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 	return PROP_EDITABLE;
 }
 
-short RNA_type_to_ID_code(StructRNA *type)
+short RNA_type_to_ID_code(const StructRNA *type)
 {
 	if (RNA_struct_is_a(type, &RNA_Action)) return ID_AC;
 	if (RNA_struct_is_a(type, &RNA_Armature)) return ID_AR;
diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index bd91315ed11..facb7116b67 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -560,7 +560,7 @@ const char *RNA_struct_translation_context(const StructRNA *type)
 	return type->translation_context;
 }
 
-PropertyRNA *RNA_struct_name_property(StructRNA *type)
+PropertyRNA *RNA_struct_name_property(const StructRNA *type)
 {
 	return type->nameproperty;
 }
@@ -2765,6 +2765,9 @@ char *RNA_property_string_get_alloc(PointerRNA *ptr, PropertyRNA *prop,
 	int length;
 
 	BLI_assert(RNA_property_type(prop) == PROP_STRING);
+	if (!ptr->data) {
+		return NULL;
+	}
 
 	length = RNA_property_string_length(ptr, prop);
 
diff --git a/source/blender/makesrna/intern/rna_ui_api.c b/source/blender/makesrna/intern/rna_ui_api.c
index 6ef4bc6a371..abad70a46d2 100644
--- a/source/blender/makesrna/intern/rna_ui_api.c
+++ b/source/blender/makesrna/intern/rna_ui_api.c
@@ -671,7 +671,31 @@ void RNA_api_ui_layout(StructRNA *srna)
 	                      "Identifier of property in data giving the type of the ID-blocks to use");
 	RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
 	api_ui_item_common_text(func);
-	
+
+	func = RNA_def_function(srna, "template_search", "uiTemplateSearch");
+	RNA_def_function_flag(func, FUNC_USE_CONTEXT);
+	api_ui_item_rna_common(func);
+	parm = RNA_def_pointer(func, "search_data", "AnyType", "", "Data from which to take collection to search in");
+	RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED | PARM_RNAPTR);
+	parm = RNA_def_string(func, "search_property", NULL, 0, "", "Identifier of search collection property");
+	RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
+	RNA_def_string(func, "new", NULL, 0, "", "Operator identifier to create a new item for the collection");
+	RNA_def_string(func, "unlink", NULL, 0, "", "Operator identifier to unlink or delete the active "
+	               "item from the collection");
+
+	func = RNA_def_function(srna, "template_search_preview", "uiTemplateSearchPreview");
+	RNA_def_function_flag(func, FUNC_USE_CONTEXT);
+	api_ui_item_rna_common(func);
+	parm = RNA_def_pointer(func, "search_data", "AnyType", "", "Data from which to take collection to search in");
+	RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED | PARM_RNAPTR);
+	parm = RNA_def_string(func, "search_property", NULL, 0, "", "Identifier of search collection property");
+	RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
+	RNA_def_string(func, "new", NULL, 0, "", "Operator identifier to create a new item for the collection");
+	RNA_def_string(func, "unlink", NULL, 0, "", "Operator identifier to unlink or delete the active "
+	               "item from the collection");
+	RNA_def_int(func, "rows", 0, 0, INT_MAX, "Number of thumbnail preview rows to display", "", 0, INT_MAX);
+	RNA_def_int(func, "cols", 0, 0, INT_MAX, "Number of thumbnail preview columns to display", "", 0, INT_MAX);
+
 	func = RNA_def_function(srna, "template_path_builder", "rna_uiTemplatePathBuilder");
 	parm = RNA_def_pointer(func, "data", "AnyType", "", "Data from which to take property");
 	RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED | PARM_RNAPTR);
diff --git a/source/blenderplayer/bad_level_call_stubs/stubs.c b/source/blenderplayer/bad_level_call_stubs/stubs.c
index 642140d1b00..8790e73d039 100644
--- a/source/blenderplayer/bad_level_call_stubs/stubs.c
+++ b/source/blenderplayer/bad_level_call_stubs/stubs.c
@@ -623,6 +623,17 @@ struct uiLayout *uiTemplateConstraint(struct uiLayout *layout, struct PointerRNA
 void uiTemplatePreview(struct uiLayout *layout, struct bContext *C, struct ID *id, int show_buttons, struct ID *parent,
                        struct MTex *slot, const char *preview_id) RET_NONE
 void uiTemplateIDPreview(uiLayout *layout, struct bContext *C, struct PointerRNA *ptr, const char *propname, const char *newop, const char *openop, const char *unlinkop, int rows, int cols) RET_NONE
+void uiTemplateSearch(
+        uiLayout *layout, struct bContext *C,
+        PointerRNA *ptr, const char *propname,
+        PointerRNA *searchptr, const char *searchpropname,
+        const char *newop, const char *unlinkop) RET_NONE
+void uiTemplateSearchPreview(
+        uiLayout *layout, struct bContext *C,
+        PointerRNA *ptr, const char *propname,
+        PointerRNA *searchptr, const char *searchpropname,
+        const char *newop, const char *unlinkop,
+        const int rows, const int cols) RET_NONE
 void uiTemplateCurveMapping(uiLayout *layout, struct PointerRNA *ptr, const char *propname, int type, int levels, int brush, int neg_slope) RET_NONE
 void uiTemplateColorRamp(uiLayout *layout, struct PointerRNA *ptr, const char *propname, int expand) RET_NONE
 void uiTemplateLayers(uiLayout *layout, struct PointerRNA *ptr, const char *propname, PointerRNA *used_ptr, const char *used_propname, int active_layer) RET_NONE