fix(layer): update the cached layer type on state change (#5801)

src/core/lv_obj.c

@@ -740,7 +740,7 @@ static void update_obj_state(lv_obj_t * obj, lv_state_t new_state)
     lv_obj_invalidate(obj);
 
     obj->state = new_state;
-
+    _lv_obj_update_layer_type(obj);
     _lv_obj_style_transition_dsc_t * ts = lv_malloc_zeroed(sizeof(_lv_obj_style_transition_dsc_t) * STYLE_TRANSITION_MAX);
     uint32_t tsi = 0;
     uint32_t i;

src/core/lv_obj_style.c

@@ -300,12 +300,7 @@ void lv_obj_refresh_style(lv_obj_t * obj, lv_style_selector_t selector, lv_style
 
     /*Cache the layer type*/
     if((part == LV_PART_ANY || part == LV_PART_MAIN) && is_layer_refr) {
-        lv_layer_type_t layer_type = calculate_layer_type(obj);
-        if(obj->spec_attr) obj->spec_attr->layer_type = layer_type;
-        else if(layer_type != LV_LAYER_TYPE_NONE) {
-            lv_obj_allocate_spec_attr(obj);
-            obj->spec_attr->layer_type = layer_type;
-        }
+        _lv_obj_update_layer_type(obj);
     }
 
     if(prop == LV_STYLE_PROP_ANY || is_ext_draw) {
@@ -670,6 +665,16 @@ lv_opa_t lv_obj_get_style_opa_recursive(const lv_obj_t * obj, lv_part_t part)
     return opa_final;
 }
 
+void _lv_obj_update_layer_type(lv_obj_t * obj)
+{
+    lv_layer_type_t layer_type = calculate_layer_type(obj);
+    if(obj->spec_attr) obj->spec_attr->layer_type = layer_type;
+    else if(layer_type != LV_LAYER_TYPE_NONE) {
+        lv_obj_allocate_spec_attr(obj);
+        obj->spec_attr->layer_type = layer_type;
+    }
+}
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/

src/core/lv_obj_style.h

@@ -352,6 +352,13 @@ static inline int32_t lv_obj_get_style_transform_scale_y_safe(const lv_obj_t * o
  */
 lv_opa_t lv_obj_get_style_opa_recursive(const lv_obj_t * obj, lv_part_t part);
 
+/**
+ * Update the layer type of a widget bayed on its current styles.
+ * The result will be stored in `obj->spec_attr->layer_type`
+ * @param obj       the object whose layer should be updated
+ */
+void _lv_obj_update_layer_type(lv_obj_t * obj);
+
 /**********************
  *      MACROS
  **********************/

tests/src/test_cases/draw/test_layer_transform.c

@@ -41,4 +41,21 @@ void test_no_residual_border_on_scale_down(void)
 
 }
 
+void test_update_layer_type_on_state_change(void)
+{
+    static lv_style_t style;
+    lv_style_init(&style);
+    lv_style_set_transform_rotation(&style, 90);
+    lv_style_set_transform_scale_x(&style, 100);
+
+    lv_obj_t * obj = lv_obj_create(lv_screen_active());
+    lv_obj_center(obj);
+    lv_obj_add_style(obj, &style, LV_STATE_CHECKED);
+    lv_refr_now(NULL);
+
+    lv_obj_add_state(obj, LV_STATE_CHECKED);
+    TEST_ASSERT_EQUAL_SCREENSHOT("draw/layer_transform_2.png");
+
+}
+
 #endif