From 08f7baab26b686937130ec6f8851570782160b12 Mon Sep 17 00:00:00 2001
From: Vincent Torri <vincent.torri@gmail.com>
Date: Sun, 29 Jun 2014 17:57:20 +0200
Subject: ecore_win32: discard WM_MOUSEMOVE message if it has the same mouse
 coordinates than the previous one. See link in commit for an explanation

---
 src/lib/ecore_win32/ecore_win32.c         | 16 ++++++++++++++--
 src/lib/ecore_win32/ecore_win32_private.h |  4 +++-
 src/lib/ecore_win32/ecore_win32_window.c  |  2 ++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/lib/ecore_win32/ecore_win32.c b/src/lib/ecore_win32/ecore_win32.c
index c6312a34b9..2c20ae9bdb 100644
--- a/src/lib/ecore_win32/ecore_win32.c
+++ b/src/lib/ecore_win32/ecore_win32.c
@@ -144,10 +144,22 @@ _ecore_win32_window_procedure(HWND   window,
           RECT                rect;
           Ecore_Win32_Window *w = NULL;
 
-          INF("moue move message");
-
           w = (Ecore_Win32_Window *)GetWindowLongPtr(window, GWLP_USERDATA);
 
+          /*
+           * Windows can send several WM_MOUSEMOVE messages, see:
+           * http://blogs.msdn.com/b/oldnewthing/archive/2003/10/01/55108.aspx
+           * so we discard those which have the same mouse coordinates
+           */
+          if ((w->drag.current_mouse_x == GET_X_LPARAM(data_param)) &&
+              (w->drag.current_mouse_y == GET_Y_LPARAM(data_param)))
+            return 0;
+
+          w->drag.current_mouse_x = GET_X_LPARAM(data_param);
+          w->drag.current_mouse_y = GET_Y_LPARAM(data_param);
+
+          INF("mouse move message");
+
           if (w->drag.dragging)
             {
                POINT pt;
diff --git a/src/lib/ecore_win32/ecore_win32_private.h b/src/lib/ecore_win32/ecore_win32_private.h
index 759ea79b92..af2d86a558 100644
--- a/src/lib/ecore_win32/ecore_win32_private.h
+++ b/src/lib/ecore_win32/ecore_win32_private.h
@@ -114,13 +114,15 @@ struct _Ecore_Win32_Window
    } shape;
 
    struct {
-      DWORD        type;
+      DWORD type;
       int x;
       int y;
       int w;
       int h;
       int px;
       int py;
+      int current_mouse_x;
+      int current_mouse_y;
       unsigned int dragging : 1;
    } drag;
 
diff --git a/src/lib/ecore_win32/ecore_win32_window.c b/src/lib/ecore_win32/ecore_win32_window.c
index 81c6c52c5c..00b7ff21e3 100644
--- a/src/lib/ecore_win32/ecore_win32_window.c
+++ b/src/lib/ecore_win32/ecore_win32_window.c
@@ -143,6 +143,8 @@ ecore_win32_window_internal_new(Ecore_Win32_Window *parent,
    w->drag.y = y;
    w->drag.w = rect.right - rect.left;
    w->drag.h = rect.bottom - rect.top;
+   w->drag.current_mouse_x = -32768;
+   w->drag.current_mouse_y = -32768;
 
    return w;
 }
-- 
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