From 076540752b7664d1d3d7920f5c60b7f6f54806d8 Mon Sep 17 00:00:00 2001
From: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
Date: Sat, 24 Feb 2018 15:36:06 +0100
Subject: [PATCH] prevent refresh after drag is no movement happened

---
 lv_core/lv_indev.c | 10 ++++++++--
 lv_core/lv_refr.c  | 19 +++++++++++++++++++
 lv_core/lv_refr.h  | 11 +++++++++++
 3 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/lv_core/lv_indev.c b/lv_core/lv_indev.c
index e5fa5b14d..4b6a875e9 100644
--- a/lv_core/lv_indev.c
+++ b/lv_core/lv_indev.c
@@ -11,6 +11,7 @@
 
 #include "../lv_hal/lv_hal_tick.h"
 #include "../lv_core/lv_group.h"
+#include "../lv_core/lv_refr.h"
 #include "../lv_misc/lv_task.h"
 #include "../lv_misc/lv_math.h"
 #include "../lv_draw/lv_draw_rbasic.h"
@@ -646,9 +647,10 @@ static void indev_drag(lv_indev_proc_t * state)
         /*Set new position if the vector is not zero*/
         if(state->vect.x != 0 ||
            state->vect.y != 0) {
-            /*Get the coordinates of the object end modify them*/
+            /*Get the coordinates of the object and modify them*/
             lv_coord_t act_x = lv_obj_get_x(drag_obj);
             lv_coord_t act_y = lv_obj_get_y(drag_obj);
+            uint16_t inv_buf_size = lv_refr_get_buf_size(); /*Get the number of currently invalidated areas*/
 
             lv_obj_set_pos(drag_obj, act_x + state->vect.x, act_y + state->vect.y);
 
@@ -660,7 +662,11 @@ static void indev_drag(lv_indev_proc_t * state)
                 }
                 state->drag_in_prog = 1;
             }
-
+            /*If the object didn't moved then clear the invalidated areas*/
+            else {
+                uint16_t new_inv_buf_size = lv_refr_get_buf_size();
+                lv_refr_pop_from_buf(new_inv_buf_size - inv_buf_size);
+            }
         }
     }
 }
diff --git a/lv_core/lv_refr.c b/lv_core/lv_refr.c
index fe204e2e9..fe6f065de 100644
--- a/lv_core/lv_refr.c
+++ b/lv_core/lv_refr.c
@@ -139,6 +139,25 @@ void lv_refr_set_round_cd(void(*cb)(lv_area_t*))
     round_cb = cb;
 }
 
+/**
+ * Get the number of areas in the buffer
+ * @return number of invalid areas
+ */
+uint16_t lv_refr_get_buf_size(void)
+{
+    return inv_buf_p;
+}
+
+/**
+ * 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)
+{
+    if(inv_buf_p < num) inv_buf_p = 0;
+    else inv_buf_p -= num;
+}
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
diff --git a/lv_core/lv_refr.h b/lv_core/lv_refr.h
index f0b5ab079..5b3d67e7c 100644
--- a/lv_core/lv_refr.h
+++ b/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
  **********************/