Fixed bug where GL widget was not fully updated on Vista.

There were cases where the QGLWidget would not be fully
updated on screen on Windows Vista and Windows 7 with Aero
disabled.

Task-number: QTBUG-7865
Reviewed-by: Prasanth

Author: Kim Motoyoshi Kalland

src/gui/kernel/qapplication_win.cpp

@@ -927,7 +927,11 @@ const QString qt_reg_winclass(QWidget *w)        // register window class
     uint style;
     bool icon;
     QString cname;
-    if (flags & Qt::MSWindowsOwnDC) {
+    if (qt_widget_private(w)->isGLWidget) {
+        cname = QLatin1String("QGLWidget");
+        style = CS_DBLCLKS;
+        icon  = true;
+    } else if (flags & Qt::MSWindowsOwnDC) {
         cname = QLatin1String("QWidgetOwnDC");
         style = CS_DBLCLKS;
 #ifndef Q_OS_WINCE
@@ -1011,7 +1015,7 @@ const QString qt_reg_winclass(QWidget *w)        // register window class
 
     ATOM atom;
 #ifndef Q_OS_WINCE
-    HBRUSH bgBrush = (HBRUSH)GetSysColorBrush(COLOR_WINDOW);
+    HBRUSH bgBrush = qt_widget_private(w)->isGLWidget ? 0 : (HBRUSH)GetSysColorBrush(COLOR_WINDOW);
     QT_WA({
         WNDCLASS wc;
         wc.style        = style;
@@ -3626,13 +3630,19 @@ bool QETWidget::translatePaintEvent(const MSG &msg)
         return true;
 
     setAttribute(Qt::WA_PendingUpdate, false);
-    const QRegion dirtyInBackingStore(qt_dirtyRegion(this));
-    // Make sure the invalidated region contains the region we're about to repaint.
-    // BeginPaint will set the clip to the invalidated region and it is impossible
-    // to enlarge it afterwards (only shrink it). Using GetDCEx is not suffient
-    // as it may return an invalid context (especially on Windows Vista).
-    if (!dirtyInBackingStore.isEmpty())
-        InvalidateRgn(internalWinId(), dirtyInBackingStore.handle(), false);
+
+    if (d_func()->isGLWidget) {
+        if (d_func()->usesDoubleBufferedGLContext)
+            InvalidateRect(internalWinId(), 0, false);
+    } else {
+        const QRegion dirtyInBackingStore(qt_dirtyRegion(this));
+        // Make sure the invalidated region contains the region we're about to repaint.
+        // BeginPaint will set the clip to the invalidated region and it is impossible
+        // to enlarge it afterwards (only shrink it). Using GetDCEx is not suffient
+        // as it may return an invalid context (especially on Windows Vista).
+        if (!dirtyInBackingStore.isEmpty())
+            InvalidateRgn(internalWinId(), dirtyInBackingStore.handle(), false);
+    }
     PAINTSTRUCT ps;
     d_func()->hd = BeginPaint(internalWinId(), &ps);
 

src/gui/kernel/qwidget.cpp

@@ -183,6 +183,7 @@ QWidgetPrivate::QWidgetPrivate(int version) :
         ,inDirtyList(0)
         ,isScrolled(0)
         ,isMoved(0)
+        , isGLWidget(0)
         ,usesDoubleBufferedGLContext(0)
 #ifdef Q_WS_WIN
         ,noPaintOnScreen(0)
@@ -194,7 +195,6 @@ QWidgetPrivate::QWidgetPrivate(int version) :
 #endif
 #ifdef Q_WS_MAC
         ,needWindowChange(0)
-        ,isGLWidget(0)
 #endif
         ,polished(0)
 

src/gui/kernel/qwidget_p.h

@@ -537,6 +537,7 @@ class Q_GUI_EXPORT QWidgetPrivate : public QObjectPrivate
     uint inDirtyList : 1;
     uint isScrolled : 1;
     uint isMoved : 1;
+    uint isGLWidget : 1;
     uint usesDoubleBufferedGLContext : 1;
 
 #ifdef Q_WS_WIN
@@ -593,7 +594,6 @@ class Q_GUI_EXPORT QWidgetPrivate : public QObjectPrivate
 
     // This is new stuff
     uint needWindowChange : 1;
-    uint isGLWidget : 1;
 #endif
 
 #if defined(Q_WS_X11) || defined (Q_WS_WIN) || defined(Q_WS_MAC)

src/opengl/qgl_mac.mm

@@ -882,8 +882,6 @@ QRegion qt_mac_get_widget_rgn(const QWidget *widget)
             break;
         current = current->parentWidget();
     }
-
-    isGLWidget = 1;
 }
 
 bool QGLWidgetPrivate::renderCxPm(QPixmap*)

src/opengl/qgl_p.h

@@ -160,7 +160,9 @@ class QGLWidgetPrivate : public QWidgetPrivate
 #if defined(Q_WS_X11) && defined(QT_OPENGL_ES)
                        , eglSurfaceWindowId(0)
 #endif
-        {}
+    {
+        isGLWidget = 1;
+    }
 
     ~QGLWidgetPrivate() {}