Merge pull request #1386 from ShenRen/dev-7.0

add a object`s user data free interface (redo)

lv_conf_template.h

@@ -405,8 +405,17 @@ typedef void * lv_font_user_data_t;
  *  LV_OBJ SETTINGS
  *==================*/
 
+#if LV_USE_USER_DATA
 /*Declare the type of the user data of object (can be e.g. `void *`, `int`, `struct`)*/
 typedef void * lv_obj_user_data_t;
+/*Provide a function to free user data*/
+#define LV_USE_USER_DATA_FREE 0
+#if LV_USE_USER_DATA_FREE
+#  define LV_USER_DATA_FREE_INCLUDE  "something.h"  /*Header for user data free function*/
+/* Function prototype : void user_data_free(lv_obj_t * obj); */
+#  define LV_USER_DATA_FREE  (user_data_free)       /*Invoking for user data free function*/
+#endif
+#endif
 
 /*1: enable `lv_obj_realaign()` based on `lv_obj_align()` parameters*/
 #define LV_USE_OBJ_REALIGN          1

src/lv_core/lv_obj.c

@@ -31,6 +31,11 @@
 #include LV_GC_INCLUDE
 #endif /* LV_ENABLE_GC */
 
+
+#if defined(LV_USER_DATA_FREE_INCLUDE)
+#include LV_USER_DATA_FREE_INCLUDE
+#endif /* LV_USE_USER_DATA_FREE */
+
 /*********************
  *      DEFINES
  *********************/
@@ -372,6 +377,11 @@ lv_res_t lv_obj_del(lv_obj_t * obj)
     lv_anim_del(obj, NULL);
 #endif
 
+    /*Delete the user data*/
+#if LV_USE_USER_DATA_FREE
+    LV_USER_DATA_FREE(obj);
+#endif
+
     /*Recursively delete the children*/
     lv_obj_t * i;
     lv_obj_t * i_next;