From eb33840de624681eb7337ad50aba2516fb8d37e3 Mon Sep 17 00:00:00 2001
From: James Tabor <james.tabor@reactos.org>
Date: Thu, 13 Sep 2012 01:22:33 +0000
Subject: [PATCH] [Win32SS] - Based on wine Alexandre Julliard: ScrollWindow
 should not use a cached DC, unlike ScrollWindowEx.

svn path=/trunk/; revision=57290
---
 reactos/win32ss/user/ntuser/painting.c       | 21 +++++++++++++++++++-
 reactos/win32ss/user/user32/windows/window.c |  8 +++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/reactos/win32ss/user/ntuser/painting.c b/reactos/win32ss/user/ntuser/painting.c
index 8007e3d0c3c..57506a6e6f0 100644
--- a/reactos/win32ss/user/ntuser/painting.c
+++ b/reactos/win32ss/user/ntuser/painting.c
@@ -1613,6 +1613,7 @@ NtUserScrollWindowEx(
    HDC hDC;
    HRGN hrgnOwn = NULL, hrgnTemp;
    HWND hwndCaret;
+   DWORD dcxflags = 0;
    NTSTATUS Status = STATUS_SUCCESS;
    DECLARE_RETURN(DWORD);
    USER_REFERENCE_ENTRY Ref, CaretRef;
@@ -1669,7 +1670,25 @@ NtUserScrollWindowEx(
    else
       hrgnOwn = IntSysCreateRectRgn(0, 0, 0, 0);
 
-   hDC = UserGetDCEx(Window, 0, DCX_CACHE | DCX_USESTYLE);
+   /* ScrollWindow uses the window DC, ScrollWindowEx doesn't */
+   if (flags & SW_SCROLLWNDDCE)
+   {
+      dcxflags = DCX_USESTYLE;
+
+      if (!(Window->pcls->style & (CS_OWNDC|CS_CLASSDC)))
+         dcxflags |= DCX_CACHE; // AH??? wine~ If not Powned or with Class go Cheap! 
+
+      if (flags & SW_SCROLLCHILDREN && Window->style & WS_CLIPCHILDREN)
+         dcxflags |= DCX_CACHE|DCX_NOCLIPCHILDREN;
+   }
+   else
+   {
+       /* So in this case ScrollWindowEx uses Cache DC. */
+       dcxflags = DCX_CACHE|DCX_USESTYLE;
+       if (flags & SW_SCROLLCHILDREN) dcxflags |= DCX_NOCLIPCHILDREN;
+   }
+
+   hDC = UserGetDCEx(Window, 0, dcxflags);
    if (!hDC)
    {
       /* FIXME: SetLastError? */
diff --git a/reactos/win32ss/user/user32/windows/window.c b/reactos/win32ss/user/user32/windows/window.c
index 53ed882e6a2..a26080702c5 100644
--- a/reactos/win32ss/user/user32/windows/window.c
+++ b/reactos/win32ss/user/user32/windows/window.c
@@ -1900,9 +1900,10 @@ ScrollWindow(HWND hWnd,
                                 prcClip,
                                 0,
                                 NULL,
-                                (lpRect ? 0 : SW_SCROLLCHILDREN) | SW_INVALIDATE) != ERROR;
+                                (lpRect ? 0 : SW_SCROLLCHILDREN) | (SW_ERASE|SW_INVALIDATE|SW_SCROLLWNDDCE)) != ERROR;
 }
 
+/* ScrollWindow uses the window DC, ScrollWindowEx doesn't */
 
 /*
  * @implemented
@@ -1917,6 +1918,11 @@ ScrollWindowEx(HWND hWnd,
                LPRECT prcUpdate,
                UINT flags)
 {
+    if (flags & SW_SMOOTHSCROLL)
+    {
+       FIXME("SW_SMOOTHSCROLL not supported.");
+       // Fall through....
+    }
     return NtUserScrollWindowEx(hWnd,
                                 dx,
                                 dy,