From 23051ff7ec4e367baef0fd1ee79e976943b443c9 Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@digia.com>
Date: Fri, 22 Mar 2013 16:23:36 +0100
Subject: [PATCH] Clean up touch window registration.

Stop processing for Qt::Desktop windows (which caused
RegisterTouchWindow() to fail with access denied) and set a
flag to cleanly unregister.

Change-Id: I3d10c93ec92536d3ab1c0503f088c40b0c08a01f
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
---
 .../platforms/windows/qwindowswindow.cpp      | 20 +++++++++++++------
 .../platforms/windows/qwindowswindow.h        |  3 ++-
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 6cbe3e8cf7..9b2b67619d 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -791,13 +791,16 @@ QWindowsWindow::QWindowsWindow(QWindow *aWindow, const WindowData &data) :
     m_iconSmall(0),
     m_iconBig(0)
 {
-    if (aWindow->surfaceType() == QWindow::OpenGLSurface)
-        setFlag(OpenGLSurface);
     // Clear the creation context as the window can be found in QWindowsContext's map.
     QWindowsContext::instance()->setWindowCreationContext(QSharedPointer<QWindowCreationContext>());
     QWindowsContext::instance()->addWindow(m_data.hwnd, this);
+    const Qt::WindowType type = aWindow->type();
+    if (type == Qt::Desktop)
+        return; // No further handling for Qt::Desktop
+    if (aWindow->surfaceType() == QWindow::OpenGLSurface)
+        setFlag(OpenGLSurface);
     if (aWindow->isTopLevel()) {
-        switch (aWindow->type()) {
+        switch (type) {
         case Qt::Window:
         case Qt::Dialog:
         case Qt::Sheet:
@@ -811,8 +814,13 @@ QWindowsWindow::QWindowsWindow(QWindow *aWindow, const WindowData &data) :
         }
     }
 #ifndef Q_OS_WINCE
-    if (QWindowsContext::instance()->systemInfo() & QWindowsContext::SI_SupportsTouch)
-        QWindowsContext::user32dll.registerTouchWindow(m_data.hwnd, 0);
+    if (QWindowsContext::instance()->systemInfo() & QWindowsContext::SI_SupportsTouch) {
+        if (QWindowsContext::user32dll.registerTouchWindow(m_data.hwnd, 0)) {
+            setFlag(TouchRegistered);
+        } else {
+            qErrnoWarning("RegisterTouchWindow() failed for window '%s'.", qPrintable(aWindow->objectName()));
+        }
+    }
 #endif // !Q_OS_WINCE
     setWindowState(aWindow->windowState());
     const qreal opacity = qt_window_private(aWindow)->opacity;
@@ -824,7 +832,7 @@ QWindowsWindow::~QWindowsWindow()
 {
 #ifndef Q_OS_WINCE
     QWindowSystemInterface::flushWindowSystemEvents();
-    if (QWindowsContext::instance()->systemInfo() & QWindowsContext::SI_SupportsTouch)
+    if (testFlag(TouchRegistered))
         QWindowsContext::user32dll.unregisterTouchWindow(m_data.hwnd);
 #endif // !Q_OS_WINCE
     destroyWindow();
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index 87397f1c1d..1148440f05 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -131,7 +131,8 @@ public:
         FrameStrutEventsEnabled = 0x200,
         SynchronousGeometryChangeEvent = 0x400,
         WithinSetStyle = 0x800,
-        WithinDestroy = 0x1000
+        WithinDestroy = 0x1000,
+        TouchRegistered = 0x2000
     };
 
     struct WindowData