prevent refresh after drag is no movement happened

lv_core/lv_refr.h

@@ -65,6 +65,17 @@ void lv_refr_set_monitor_cb(void (*cb)(uint32_t, uint32_t));
  */
 void lv_refr_set_round_cd(void(*cb)(lv_area_t*));
 
+/**
+ * Get the number of areas in the buffer
+ * @return number of invalid areas
+ */
+uint16_t lv_refr_get_buf_size(void);
+
+/**
+ * Pop (delete) the last 'num' invalidated areas from the buffer
+ * @param num number of areas to delete
+ */
+void lv_refr_pop_from_buf(uint16_t num);
 /**********************
  *   STATIC FUNCTIONS
  **********************/