feat(gui): add Widget_CollectReferences()

Author: lc-soft

include/LCUI/gui/widget_helper.h

@@ -93,6 +93,9 @@ LCUI_API void Widget_SetOpacity(LCUI_Widget w, float opacity);
 
 LCUI_API void Widget_SetBoxSizing(LCUI_Widget w, LCUI_StyleValue sizing);
 
+/** Collect all child widget that have a ref attribute specified */
+LCUI_API Dict *Widget_CollectReferences(LCUI_Widget w);
+
 /**
  * Get the first widget that match the type by testing the widget itself and
  * traversing up through its ancestors.

src/gui/widget_helper.c

@@ -244,3 +244,21 @@ LCUI_Widget Widget_GetClosest(LCUI_Widget w, const char *type)
 	}
 	return NULL;
 }
+
+static void Widget_CollectReference(LCUI_Widget w, void *arg)
+{
+	const char *ref = Widget_GetAttribute(w, "ref");
+
+	if (ref) {
+		Dict_Add(arg, (void*)ref, w);
+	}
+}
+
+Dict *Widget_CollectReferences(LCUI_Widget w)
+{
+	Dict *dict;
+
+	dict = Dict_Create(&DictType_StringKey, NULL);
+	Widget_Each(w, Widget_CollectReference, dict);
+	return dict;
+}