fix(xml): handle nested 'extends' handling with components

src/others/xml/lv_xml.c

@@ -144,7 +144,8 @@ void * lv_xml_create_from_ctx(lv_obj_t * parent, lv_xml_component_ctx_t * parent
     state.item = state.view;
 
     if(attrs) {
-        ctx->root_widget->apply_cb(&state, attrs);
+        lv_widget_processor_t * proc = lv_xml_widget_get_extended_widget_processor(ctx->extends);
+        proc->apply_cb(&state, attrs);
     }
 
     lv_ll_clear(&state.parent_ll);
@@ -610,4 +611,5 @@ static void view_end_element_handler(void * user_data, const char * name)
     }
 }
 
+
 #endif /* LV_USE_XML */

src/others/xml/lv_xml_component.c

@@ -90,7 +90,8 @@ lv_obj_t * lv_xml_component_process(lv_xml_parser_state_t * state, const char *
 
     /* Apply the properties of the component, e.g. <my_button x="20" styles="red"/> */
     state->item = item;
-    ctx->root_widget->apply_cb(state, attrs);
+    lv_widget_processor_t * extended_proc = lv_xml_widget_get_extended_widget_processor(ctx->extends);
+    extended_proc->apply_cb(state, attrs);
 
     return item;
 }
@@ -628,17 +629,7 @@ static void start_metadata_handler(void * user_data, const char * name, const ch
         const char * extends = lv_xml_get_value_of(attrs, "extends");
         if(extends == NULL) extends = "lv_obj";
 
-        state->ctx.root_widget = lv_xml_widget_get_processor(extends);
+        state->ctx.extends = lv_strdup(extends);
-        if(state->ctx.root_widget == NULL) {
-            lv_xml_component_ctx_t * extended_component = lv_xml_component_get_ctx(extends);
-            if(extended_component) {
-                state->ctx.root_widget = extended_component->root_widget;
-            }
-            else {
-                LV_LOG_WARN("The 'extend'ed widget is not found, using `lv_obj` as a fall back");
-                state->ctx.root_widget = lv_xml_widget_get_processor("lv_obj");
-            }
-        }
     }
 
     if(lv_streq(name, "widget")) state->ctx.is_widget = 1;

src/others/xml/lv_xml_component_private.h

@@ -38,7 +38,7 @@ struct _lv_xml_component_ctx_t {
     lv_ll_t image_ll;
     lv_ll_t event_ll;
     const char * view_def;
-    struct _lv_widget_processor_t * root_widget;
+    const char * extends;
     uint32_t is_widget : 1;                         /*1: not component but widget registered as a component for preview*/
     struct _lv_xml_component_ctx_t * next;
 };

src/others/xml/lv_xml_widget.c

@@ -70,6 +70,30 @@ lv_widget_processor_t * lv_xml_widget_get_processor(const char * name)
     return NULL;
 }
 
+lv_widget_processor_t * lv_xml_widget_get_extended_widget_processor(const char * extends)
+{
+    lv_widget_processor_t * proc = NULL;
+    while(extends) {
+        proc = lv_xml_widget_get_processor(extends);
+        if(proc) break;
+
+        lv_xml_component_ctx_t * extended_component = lv_xml_component_get_ctx(extends);
+        if(extended_component) {
+            extends = extended_component->extends;
+        }
+        else {
+            /*Not extending a known component or widget.*/
+            break;
+        }
+    }
+
+    if(proc == NULL) {
+        LV_LOG_WARN("The 'extend'ed widget is not found, using `lv_obj` as a fall back");
+        proc = lv_xml_widget_get_processor("lv_obj");
+    }
+
+    return proc;
+}
 
 /**********************
  *   STATIC FUNCTIONS

src/others/xml/lv_xml_widget.h

@@ -42,6 +42,7 @@ lv_result_t lv_xml_widget_register(const char * name, lv_xml_widget_create_cb_t
 
 lv_widget_processor_t * lv_xml_widget_get_processor(const char * name);
 
+lv_widget_processor_t * lv_xml_widget_get_extended_widget_processor(const char * extends);
 /**********************
  *      MACROS
  **********************/