From c93da30330d9f3c310dfe5d1e467a396942f2492 Mon Sep 17 00:00:00 2001
From: narzoul <narzoul@users.noreply.github.com>
Date: Sat, 19 Mar 2016 13:38:41 +0100
Subject: [PATCH] Added child window invalidation to scroll functions

---
 DDrawCompat/CompatGdiScrollFunctions.cpp | 16 ++++++++++++----
 DDrawCompat/CompatGdiScrollFunctions.h   |  1 +
 DDrawCompat/CompatGdiWinProc.cpp         | 13 ++++---------
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/DDrawCompat/CompatGdiScrollFunctions.cpp b/DDrawCompat/CompatGdiScrollFunctions.cpp
index e62780d..b3e1016 100644
--- a/DDrawCompat/CompatGdiScrollFunctions.cpp
+++ b/DDrawCompat/CompatGdiScrollFunctions.cpp
@@ -12,8 +12,9 @@ namespace
 		_In_ const RECT *lpRect,
 		_In_ const RECT *lpClipRect)
 	{
-		InvalidateRect(hWnd, nullptr, TRUE);
-		return CALL_ORIG_GDI(ScrollWindow)(hWnd, XAmount, YAmount, lpRect, lpClipRect);
+		BOOL result = CALL_ORIG_GDI(ScrollWindow)(hWnd, XAmount, YAmount, lpRect, lpClipRect);
+		CompatGdiScrollFunctions::updateScrolledWindow(hWnd);
+		return result;
 	}
 
 	int WINAPI scrollWindowEx(
@@ -26,8 +27,10 @@ namespace
 		_Out_       LPRECT prcUpdate,
 		_In_        UINT   flags)
 	{
-		InvalidateRect(hWnd, nullptr, TRUE);
-		return CALL_ORIG_GDI(ScrollWindowEx)(hWnd, dx, dy, prcScroll, prcClip, hrgnUpdate, prcUpdate, flags);
+		int result = CALL_ORIG_GDI(ScrollWindowEx)(
+			hWnd, dx, dy, prcScroll, prcClip, hrgnUpdate, prcUpdate, flags);
+		CompatGdiScrollFunctions::updateScrolledWindow(hWnd);
+		return result;
 	}
 }
 
@@ -40,4 +43,9 @@ namespace CompatGdiScrollFunctions
 		HOOK_GDI_FUNCTION(user32, ScrollWindowEx, scrollWindowEx);
 		DetourTransactionCommit();
 	}
+
+	void updateScrolledWindow(HWND hwnd)
+	{
+		RedrawWindow(hwnd, nullptr, nullptr, RDW_ERASE | RDW_FRAME | RDW_INVALIDATE | RDW_ALLCHILDREN);
+	}
 }
diff --git a/DDrawCompat/CompatGdiScrollFunctions.h b/DDrawCompat/CompatGdiScrollFunctions.h
index 7c8e489..3aa9260 100644
--- a/DDrawCompat/CompatGdiScrollFunctions.h
+++ b/DDrawCompat/CompatGdiScrollFunctions.h
@@ -3,4 +3,5 @@
 namespace CompatGdiScrollFunctions
 {
 	void installHooks();
+	void updateScrolledWindow(HWND hwnd);
 };
diff --git a/DDrawCompat/CompatGdiWinProc.cpp b/DDrawCompat/CompatGdiWinProc.cpp
index 57a941b..a5d1382 100644
--- a/DDrawCompat/CompatGdiWinProc.cpp
+++ b/DDrawCompat/CompatGdiWinProc.cpp
@@ -8,6 +8,7 @@
 #include "CompatGdi.h"
 #include "CompatGdiDc.h"
 #include "CompatGdiScrollBar.h"
+#include "CompatGdiScrollFunctions.h"
 #include "CompatGdiTitleBar.h"
 #include "CompatGdiWinProc.h"
 #include "DDrawLog.h"
@@ -21,7 +22,6 @@ namespace
 	void ncPaint(HWND hwnd);
 	void onWindowPosChanged(HWND hwnd);
 	void removeDropShadow(HWND hwnd);
-	void updateScrolledWindow(HWND hwnd);
 
 	LRESULT CALLBACK callWndRetProc(int nCode, WPARAM wParam, LPARAM lParam)
 	{
@@ -60,7 +60,7 @@ namespace
 			}
 			else if (WM_VSCROLL == ret->message || WM_HSCROLL == ret->message)
 			{
-				updateScrolledWindow(ret->hwnd);
+				CompatGdiScrollFunctions::updateScrolledWindow(ret->hwnd);
 			}
 			else if (WM_COMMAND == ret->message)
 			{
@@ -68,7 +68,7 @@ namespace
 				auto notifCode = HIWORD(ret->wParam);
 				if (0 != msgSource && 1 != msgSource && (EN_HSCROLL == notifCode || EN_VSCROLL == notifCode))
 				{
-					updateScrolledWindow(reinterpret_cast<HWND>(ret->lParam));
+					CompatGdiScrollFunctions::updateScrolledWindow(reinterpret_cast<HWND>(ret->lParam));
 				}
 			}
 			else if (BM_SETSTYLE == ret->message)
@@ -127,7 +127,7 @@ namespace
 			auto mhs = reinterpret_cast<MOUSEHOOKSTRUCT*>(lParam);
 			if (WM_MOUSEWHEEL == wParam || WM_MOUSEHWHEEL == wParam)
 			{
-				updateScrolledWindow(mhs->hwnd);
+				CompatGdiScrollFunctions::updateScrolledWindow(mhs->hwnd);
 			}
 		}
 
@@ -246,11 +246,6 @@ namespace
 			SetClassLongPtr(hwnd, GCL_STYLE, style ^ CS_DROPSHADOW);
 		}
 	}
-
-	void updateScrolledWindow(HWND hwnd)
-	{
-		RedrawWindow(hwnd, nullptr, nullptr, RDW_ERASE | RDW_FRAME | RDW_INVALIDATE | RDW_ALLCHILDREN);
-	}
 }
 
 namespace CompatGdiWinProc