1 files changed, 709 insertions, 0 deletions
diff --git a/vcl/source/window/clipping.cxx b/vcl/source/window/clipping.cxx
new file mode 100644
index 000000000..f55283cff
--- /dev/null
+++ b/vcl/source/window/clipping.cxx
@@ -0,0 +1,709 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <vcl/window.hxx>
+#include <vcl/virdev.hxx>
+
+#include <tools/debug.hxx>
+
+#include <salobj.hxx>
+#include <window.h>
+
+namespace vcl {
+
+vcl::Region WindowOutputDevice::GetOutputBoundsClipRegion() const
+{
+    vcl::Region aClip(GetClipRegion());
+    aClip.Intersect(tools::Rectangle(Point(), GetOutputSize()));
+
+    return aClip;
+}
+
+void WindowOutputDevice::InitClipRegion()
+{
+    DBG_TESTSOLARMUTEX();
+
+    vcl::Region  aRegion;
+
+    if ( mxOwnerWindow->mpWindowImpl->mbInPaint )
+        aRegion = *(mxOwnerWindow->mpWindowImpl->mpPaintRegion);
+    else
+    {
+        aRegion = mxOwnerWindow->ImplGetWinChildClipRegion();
+        // only this region is in frame coordinates, so re-mirror it
+        // the mpWindowImpl->mpPaintRegion above is already correct (see ImplCallPaint()) !
+        if( ImplIsAntiparallel() )
+            ReMirror ( aRegion );
+    }
+    if ( mbClipRegion )
+        aRegion.Intersect( ImplPixelToDevicePixel( maRegion ) );
+    if ( aRegion.IsEmpty() )
+        mbOutputClipped = true;
+    else
+    {
+        mbOutputClipped = false;
+        SelectClipRegion( aRegion );
+    }
+    mbClipRegionSet = true;
+
+    mbInitClipRegion = false;
+}
+
+void Window::SetParentClipMode( ParentClipMode nMode )
+{
+    if ( mpWindowImpl->mpBorderWindow )
+        mpWindowImpl->mpBorderWindow->SetParentClipMode( nMode );
+    else
+    {
+        if ( !ImplIsOverlapWindow() )
+        {
+            mpWindowImpl->mnParentClipMode = nMode;
+            if ( nMode & ParentClipMode::Clip )
+                mpWindowImpl->mpParent->mpWindowImpl->mbClipChildren = true;
+        }
+    }
+}
+
+ParentClipMode Window::GetParentClipMode() const
+{
+    if ( mpWindowImpl->mpBorderWindow )
+        return mpWindowImpl->mpBorderWindow->GetParentClipMode();
+    else
+        return mpWindowImpl->mnParentClipMode;
+}
+
+void Window::ExpandPaintClipRegion( const vcl::Region& rRegion )
+{
+    if( !mpWindowImpl->mpPaintRegion )
+        return;
+
+    vcl::Region aPixRegion = LogicToPixel( rRegion );
+    vcl::Region aDevPixRegion = GetOutDev()->ImplPixelToDevicePixel( aPixRegion );
+
+    vcl::Region aWinChildRegion = ImplGetWinChildClipRegion();
+    // only this region is in frame coordinates, so re-mirror it
+    if( GetOutDev()->ImplIsAntiparallel() )
+    {
+        const OutputDevice *pOutDev = GetOutDev();
+        pOutDev->ReMirror( aWinChildRegion );
+    }
+
+    aDevPixRegion.Intersect( aWinChildRegion );
+    if( ! aDevPixRegion.IsEmpty() )
+    {
+        mpWindowImpl->mpPaintRegion->Union( aDevPixRegion );
+        GetOutDev()->mbInitClipRegion = true;
+    }
+}
+
+vcl::Region Window::GetWindowClipRegionPixel() const
+{
+    vcl::Region aWinClipRegion;
+
+    if ( mpWindowImpl->mbInitWinClipRegion )
+        const_cast<vcl::Window*>(this)->ImplInitWinClipRegion();
+    aWinClipRegion = mpWindowImpl->maWinClipRegion;
+
+    vcl::Region   aWinRegion( GetOutputRectPixel() );
+
+    if ( aWinRegion == aWinClipRegion )
+        aWinClipRegion.SetNull();
+
+    aWinClipRegion.Move( -GetOutDev()->mnOutOffX, -GetOutDev()->mnOutOffY );
+
+    return aWinClipRegion;
+}
+
+
+vcl::Region WindowOutputDevice::GetActiveClipRegion() const
+{
+    vcl::Region aRegion(true);
+
+    if ( mxOwnerWindow->mpWindowImpl->mbInPaint )
+    {
+        aRegion = *(mxOwnerWindow->mpWindowImpl->mpPaintRegion);
+        aRegion.Move( -mnOutOffX, -mnOutOffY );
+    }
+
+    if ( mbClipRegion )
+        aRegion.Intersect( maRegion );
+
+    return PixelToLogic( aRegion );
+}
+
+void WindowOutputDevice::ClipToPaintRegion(tools::Rectangle& rDstRect)
+{
+    const vcl::Region aPaintRgn(mxOwnerWindow->GetPaintRegion());
+
+    if (!aPaintRgn.IsNull())
+        rDstRect.Intersection(LogicToPixel(aPaintRgn.GetBoundRect()));
+}
+
+void Window::EnableClipSiblings( bool bClipSiblings )
+{
+
+    if ( mpWindowImpl->mpBorderWindow )
+        mpWindowImpl->mpBorderWindow->EnableClipSiblings( bClipSiblings );
+
+    mpWindowImpl->mbClipSiblings = bClipSiblings;
+}
+
+void Window::ImplClipBoundaries( vcl::Region& rRegion, bool bThis, bool bOverlaps )
+{
+    if ( bThis )
+        ImplIntersectWindowClipRegion( rRegion );
+    else if ( ImplIsOverlapWindow() )
+    {
+        // clip to frame if required
+        if ( !mpWindowImpl->mbFrame )
+            rRegion.Intersect( tools::Rectangle( Point( 0, 0 ), mpWindowImpl->mpFrameWindow->GetOutputSizePixel() ) );
+
+        if ( bOverlaps && !rRegion.IsEmpty() )
+        {
+            // Clip Overlap Siblings
+            vcl::Window* pStartOverlapWindow = this;
+            while ( !pStartOverlapWindow->mpWindowImpl->mbFrame )
+            {
+                vcl::Window* pOverlapWindow = pStartOverlapWindow->mpWindowImpl->mpOverlapWindow->mpWindowImpl->mpFirstOverlap;
+                while ( pOverlapWindow && (pOverlapWindow != pStartOverlapWindow) )
+                {
+                    pOverlapWindow->ImplExcludeOverlapWindows2( rRegion );
+                    pOverlapWindow = pOverlapWindow->mpWindowImpl->mpNext;
+                }
+                pStartOverlapWindow = pStartOverlapWindow->mpWindowImpl->mpOverlapWindow;
+            }
+
+            // Clip Child Overlap Windows
+            ImplExcludeOverlapWindows( rRegion );
+        }
+    }
+    else
+        ImplGetParent()->ImplIntersectWindowClipRegion( rRegion );
+}
+
+bool Window::ImplClipChildren( vcl::Region& rRegion ) const
+{
+    bool    bOtherClip = false;
+    vcl::Window* pWindow = mpWindowImpl->mpFirstChild;
+    while ( pWindow )
+    {
+        if ( pWindow->mpWindowImpl->mbReallyVisible )
+        {
+            // read-out ParentClipMode-Flags
+            ParentClipMode nClipMode = pWindow->GetParentClipMode();
+            if ( !(nClipMode & ParentClipMode::NoClip) &&
+                 ((nClipMode & ParentClipMode::Clip) || (GetStyle() & WB_CLIPCHILDREN)) )
+                pWindow->ImplExcludeWindowRegion( rRegion );
+            else
+                bOtherClip = true;
+        }
+
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+
+    return bOtherClip;
+}
+
+void Window::ImplClipAllChildren( vcl::Region& rRegion ) const
+{
+    vcl::Window* pWindow = mpWindowImpl->mpFirstChild;
+    while ( pWindow )
+    {
+        if ( pWindow->mpWindowImpl->mbReallyVisible )
+            pWindow->ImplExcludeWindowRegion( rRegion );
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void Window::ImplClipSiblings( vcl::Region& rRegion ) const
+{
+    vcl::Window* pWindow = ImplGetParent()->mpWindowImpl->mpFirstChild;
+    while ( pWindow )
+    {
+        if ( pWindow == this )
+            break;
+
+        if ( pWindow->mpWindowImpl->mbReallyVisible )
+            pWindow->ImplExcludeWindowRegion( rRegion );
+
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void Window::ImplInitWinClipRegion()
+{
+    // Build Window Region
+    mpWindowImpl->maWinClipRegion = GetOutputRectPixel();
+    if ( mpWindowImpl->mbWinRegion )
+        mpWindowImpl->maWinClipRegion.Intersect( GetOutDev()->ImplPixelToDevicePixel( mpWindowImpl->maWinRegion ) );
+
+    // ClipSiblings
+    if ( mpWindowImpl->mbClipSiblings && !ImplIsOverlapWindow() )
+        ImplClipSiblings( mpWindowImpl->maWinClipRegion );
+
+    // Clip Parent Boundaries
+    ImplClipBoundaries( mpWindowImpl->maWinClipRegion, false, true );
+
+    // Clip Children
+    if ( (GetStyle() & WB_CLIPCHILDREN) || mpWindowImpl->mbClipChildren )
+        mpWindowImpl->mbInitChildRegion = true;
+
+    mpWindowImpl->mbInitWinClipRegion = false;
+}
+
+void Window::ImplInitWinChildClipRegion()
+{
+    if ( !mpWindowImpl->mpFirstChild )
+    {
+        mpWindowImpl->mpChildClipRegion.reset();
+    }
+    else
+    {
+        if ( !mpWindowImpl->mpChildClipRegion )
+            mpWindowImpl->mpChildClipRegion.reset( new vcl::Region( mpWindowImpl->maWinClipRegion ) );
+        else
+            *mpWindowImpl->mpChildClipRegion = mpWindowImpl->maWinClipRegion;
+
+        ImplClipChildren( *mpWindowImpl->mpChildClipRegion );
+    }
+
+    mpWindowImpl->mbInitChildRegion = false;
+}
+
+Region& Window::ImplGetWinChildClipRegion()
+{
+    if ( mpWindowImpl->mbInitWinClipRegion )
+        ImplInitWinClipRegion();
+    if ( mpWindowImpl->mbInitChildRegion )
+        ImplInitWinChildClipRegion();
+    if ( mpWindowImpl->mpChildClipRegion )
+        return *mpWindowImpl->mpChildClipRegion;
+    return mpWindowImpl->maWinClipRegion;
+}
+
+bool Window::ImplSysObjClip( const vcl::Region* pOldRegion )
+{
+    bool bUpdate = true;
+
+    if ( mpWindowImpl->mpSysObj )
+    {
+        bool bVisibleState = mpWindowImpl->mbReallyVisible;
+
+        if ( bVisibleState )
+        {
+            vcl::Region& rWinChildClipRegion = ImplGetWinChildClipRegion();
+
+            if (!rWinChildClipRegion.IsEmpty())
+            {
+                if ( pOldRegion )
+                {
+                    vcl::Region aNewRegion = rWinChildClipRegion;
+                    rWinChildClipRegion.Intersect(*pOldRegion);
+                    bUpdate = aNewRegion == rWinChildClipRegion;
+                }
+
+                vcl::Region      aRegion = rWinChildClipRegion;
+                vcl::Region      aWinRectRegion( GetOutputRectPixel() );
+
+                if ( aRegion == aWinRectRegion )
+                    mpWindowImpl->mpSysObj->ResetClipRegion();
+                else
+                {
+                    aRegion.Move( -GetOutDev()->mnOutOffX, -GetOutDev()->mnOutOffY );
+
+                    // set/update clip region
+                    RectangleVector aRectangles;
+                    aRegion.GetRegionRectangles(aRectangles);
+                    mpWindowImpl->mpSysObj->BeginSetClipRegion(aRectangles.size());
+
+                    for (auto const& rectangle : aRectangles)
+                    {
+                        mpWindowImpl->mpSysObj->UnionClipRegion(
+                            rectangle.Left(),
+                            rectangle.Top(),
+                            rectangle.GetWidth(),   // orig nWidth was ((R - L) + 1), same as GetWidth does
+                            rectangle.GetHeight()); // same for height
+                    }
+
+                    mpWindowImpl->mpSysObj->EndSetClipRegion();
+                }
+            }
+            else
+                bVisibleState = false;
+        }
+
+        // update visible status
+        mpWindowImpl->mpSysObj->Show( bVisibleState );
+    }
+
+    return bUpdate;
+}
+
+void Window::ImplUpdateSysObjChildrenClip()
+{
+    if ( mpWindowImpl->mpSysObj && mpWindowImpl->mbInitWinClipRegion )
+        ImplSysObjClip( nullptr );
+
+    vcl::Window* pWindow = mpWindowImpl->mpFirstChild;
+    while ( pWindow )
+    {
+        pWindow->ImplUpdateSysObjChildrenClip();
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void Window::ImplUpdateSysObjOverlapsClip()
+{
+    ImplUpdateSysObjChildrenClip();
+
+    vcl::Window* pWindow = mpWindowImpl->mpFirstOverlap;
+    while ( pWindow )
+    {
+        pWindow->ImplUpdateSysObjOverlapsClip();
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void Window::ImplUpdateSysObjClip()
+{
+    if ( !ImplIsOverlapWindow() )
+    {
+        ImplUpdateSysObjChildrenClip();
+
+        // siblings should recalculate their clip region
+        if ( mpWindowImpl->mbClipSiblings )
+        {
+            vcl::Window* pWindow = mpWindowImpl->mpNext;
+            while ( pWindow )
+            {
+                pWindow->ImplUpdateSysObjChildrenClip();
+                pWindow = pWindow->mpWindowImpl->mpNext;
+            }
+        }
+    }
+    else
+        mpWindowImpl->mpFrameWindow->ImplUpdateSysObjOverlapsClip();
+}
+
+bool Window::ImplSetClipFlagChildren( bool bSysObjOnlySmaller )
+{
+    bool bUpdate = true;
+    if ( mpWindowImpl->mpSysObj )
+    {
+        std::unique_ptr<vcl::Region> pOldRegion;
+        if ( bSysObjOnlySmaller && !mpWindowImpl->mbInitWinClipRegion )
+            pOldRegion.reset(new vcl::Region( mpWindowImpl->maWinClipRegion ));
+
+        GetOutDev()->mbInitClipRegion = true;
+        mpWindowImpl->mbInitWinClipRegion = true;
+
+        vcl::Window* pWindow = mpWindowImpl->mpFirstChild;
+        while ( pWindow )
+        {
+            if ( !pWindow->ImplSetClipFlagChildren( bSysObjOnlySmaller ) )
+                bUpdate = false;
+            pWindow = pWindow->mpWindowImpl->mpNext;
+        }
+
+        if ( !ImplSysObjClip( pOldRegion.get() ) )
+        {
+            GetOutDev()->mbInitClipRegion = true;
+            mpWindowImpl->mbInitWinClipRegion = true;
+            bUpdate = false;
+        }
+    }
+    else
+    {
+        GetOutDev()->mbInitClipRegion = true;
+        mpWindowImpl->mbInitWinClipRegion = true;
+
+        vcl::Window* pWindow = mpWindowImpl->mpFirstChild;
+        while ( pWindow )
+        {
+            if ( !pWindow->ImplSetClipFlagChildren( bSysObjOnlySmaller ) )
+                bUpdate = false;
+            pWindow = pWindow->mpWindowImpl->mpNext;
+        }
+    }
+    return bUpdate;
+}
+
+bool Window::ImplSetClipFlagOverlapWindows( bool bSysObjOnlySmaller )
+{
+    bool bUpdate = ImplSetClipFlagChildren( bSysObjOnlySmaller );
+
+    vcl::Window* pWindow = mpWindowImpl->mpFirstOverlap;
+    while ( pWindow )
+    {
+        if ( !pWindow->ImplSetClipFlagOverlapWindows( bSysObjOnlySmaller ) )
+            bUpdate = false;
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+
+    return bUpdate;
+}
+
+bool Window::ImplSetClipFlag( bool bSysObjOnlySmaller )
+{
+    if ( !ImplIsOverlapWindow() )
+    {
+        bool bUpdate = ImplSetClipFlagChildren( bSysObjOnlySmaller );
+
+        vcl::Window* pParent = ImplGetParent();
+        if ( pParent &&
+             ((pParent->GetStyle() & WB_CLIPCHILDREN) || (mpWindowImpl->mnParentClipMode & ParentClipMode::Clip)) )
+        {
+            pParent->GetOutDev()->mbInitClipRegion = true;
+            pParent->mpWindowImpl->mbInitChildRegion = true;
+        }
+
+        // siblings should recalculate their clip region
+        if ( mpWindowImpl->mbClipSiblings )
+        {
+            vcl::Window* pWindow = mpWindowImpl->mpNext;
+            while ( pWindow )
+            {
+                if ( !pWindow->ImplSetClipFlagChildren( bSysObjOnlySmaller ) )
+                    bUpdate = false;
+                pWindow = pWindow->mpWindowImpl->mpNext;
+            }
+        }
+
+        return bUpdate;
+    }
+    else
+        return mpWindowImpl->mpFrameWindow->ImplSetClipFlagOverlapWindows( bSysObjOnlySmaller );
+}
+
+void Window::ImplIntersectWindowClipRegion( vcl::Region& rRegion )
+{
+    if ( mpWindowImpl->mbInitWinClipRegion )
+        ImplInitWinClipRegion();
+
+    rRegion.Intersect( mpWindowImpl->maWinClipRegion );
+}
+
+void Window::ImplIntersectWindowRegion( vcl::Region& rRegion )
+{
+    rRegion.Intersect( GetOutputRectPixel() );
+    if ( mpWindowImpl->mbWinRegion )
+        rRegion.Intersect( GetOutDev()->ImplPixelToDevicePixel( mpWindowImpl->maWinRegion ) );
+}
+
+void Window::ImplExcludeWindowRegion( vcl::Region& rRegion )
+{
+    if ( mpWindowImpl->mbWinRegion )
+    {
+        vcl::Region aRegion( GetOutputRectPixel() );
+        aRegion.Intersect( GetOutDev()->ImplPixelToDevicePixel( mpWindowImpl->maWinRegion ) );
+        rRegion.Exclude( aRegion );
+    }
+    else
+    {
+        rRegion.Exclude( GetOutputRectPixel() );
+    }
+}
+
+void Window::ImplExcludeOverlapWindows( vcl::Region& rRegion ) const
+{
+    vcl::Window* pWindow = mpWindowImpl->mpFirstOverlap;
+    while ( pWindow )
+    {
+        if ( pWindow->mpWindowImpl->mbReallyVisible )
+        {
+            pWindow->ImplExcludeWindowRegion( rRegion );
+            pWindow->ImplExcludeOverlapWindows( rRegion );
+        }
+
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void Window::ImplExcludeOverlapWindows2( vcl::Region& rRegion )
+{
+    if ( mpWindowImpl->mbReallyVisible )
+        ImplExcludeWindowRegion( rRegion );
+
+    ImplExcludeOverlapWindows( rRegion );
+}
+
+void Window::ImplIntersectAndUnionOverlapWindows( const vcl::Region& rInterRegion, vcl::Region& rRegion ) const
+{
+    vcl::Window* pWindow = mpWindowImpl->mpFirstOverlap;
+    while ( pWindow )
+    {
+        if ( pWindow->mpWindowImpl->mbReallyVisible )
+        {
+            vcl::Region aTempRegion( rInterRegion );
+            pWindow->ImplIntersectWindowRegion( aTempRegion );
+            rRegion.Union( aTempRegion );
+            pWindow->ImplIntersectAndUnionOverlapWindows( rInterRegion, rRegion );
+        }
+
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void Window::ImplIntersectAndUnionOverlapWindows2( const vcl::Region& rInterRegion, vcl::Region& rRegion )
+{
+    if ( mpWindowImpl->mbReallyVisible )
+    {
+        vcl::Region aTempRegion( rInterRegion );
+        ImplIntersectWindowRegion( aTempRegion );
+        rRegion.Union( aTempRegion );
+    }
+
+    ImplIntersectAndUnionOverlapWindows( rInterRegion, rRegion );
+}
+
+void Window::ImplCalcOverlapRegionOverlaps( const vcl::Region& rInterRegion, vcl::Region& rRegion ) const
+{
+    // Clip Overlap Siblings
+    vcl::Window const * pStartOverlapWindow;
+    if ( !ImplIsOverlapWindow() )
+        pStartOverlapWindow = mpWindowImpl->mpOverlapWindow;
+    else
+        pStartOverlapWindow = this;
+    while ( !pStartOverlapWindow->mpWindowImpl->mbFrame )
+    {
+        vcl::Window* pOverlapWindow = pStartOverlapWindow->mpWindowImpl->mpOverlapWindow->mpWindowImpl->mpFirstOverlap;
+        while ( pOverlapWindow && (pOverlapWindow != pStartOverlapWindow) )
+        {
+            pOverlapWindow->ImplIntersectAndUnionOverlapWindows2( rInterRegion, rRegion );
+            pOverlapWindow = pOverlapWindow->mpWindowImpl->mpNext;
+        }
+        pStartOverlapWindow = pStartOverlapWindow->mpWindowImpl->mpOverlapWindow;
+    }
+
+    // Clip Child Overlap Windows
+    if ( !ImplIsOverlapWindow() )
+        mpWindowImpl->mpOverlapWindow->ImplIntersectAndUnionOverlapWindows( rInterRegion, rRegion );
+    else
+        ImplIntersectAndUnionOverlapWindows( rInterRegion, rRegion );
+}
+
+void Window::ImplCalcOverlapRegion( const tools::Rectangle& rSourceRect, vcl::Region& rRegion,
+                                    bool bChildren, bool bSiblings )
+{
+    vcl::Region  aRegion( rSourceRect );
+    if ( mpWindowImpl->mbWinRegion )
+        rRegion.Intersect( GetOutDev()->ImplPixelToDevicePixel( mpWindowImpl->maWinRegion ) );
+    vcl::Region  aTempRegion;
+    vcl::Window* pWindow;
+
+    ImplCalcOverlapRegionOverlaps( aRegion, rRegion );
+
+    // Parent-Boundaries
+    pWindow = this;
+    if ( !ImplIsOverlapWindow() )
+    {
+        pWindow = ImplGetParent();
+        do
+        {
+            aTempRegion = aRegion;
+            pWindow->ImplExcludeWindowRegion( aTempRegion );
+            rRegion.Union( aTempRegion );
+            if ( pWindow->ImplIsOverlapWindow() )
+                break;
+            pWindow = pWindow->ImplGetParent();
+        }
+        while ( pWindow );
+    }
+    if ( pWindow && !pWindow->mpWindowImpl->mbFrame )
+    {
+        aTempRegion = aRegion;
+        aTempRegion.Exclude( tools::Rectangle( Point( 0, 0 ), mpWindowImpl->mpFrameWindow->GetOutputSizePixel() ) );
+        rRegion.Union( aTempRegion );
+    }
+
+    // Siblings
+    if ( bSiblings && !ImplIsOverlapWindow() )
+    {
+        pWindow = mpWindowImpl->mpParent->mpWindowImpl->mpFirstChild;
+        do
+        {
+            if ( pWindow->mpWindowImpl->mbReallyVisible && (pWindow != this) )
+            {
+                aTempRegion = aRegion;
+                pWindow->ImplIntersectWindowRegion( aTempRegion );
+                rRegion.Union( aTempRegion );
+            }
+            pWindow = pWindow->mpWindowImpl->mpNext;
+        }
+        while ( pWindow );
+    }
+
+    if ( !bChildren )
+        return;
+
+    pWindow = mpWindowImpl->mpFirstChild;
+    while ( pWindow )
+    {
+        if ( pWindow->mpWindowImpl->mbReallyVisible )
+        {
+            aTempRegion = aRegion;
+            pWindow->ImplIntersectWindowRegion( aTempRegion );
+            rRegion.Union( aTempRegion );
+        }
+        pWindow = pWindow->mpWindowImpl->mpNext;
+    }
+}
+
+void WindowOutputDevice::SaveBackground(VirtualDevice& rSaveDevice, const Point& rPos, const Size& rSize, const Size&) const
+{
+    MapMode aTempMap(GetMapMode());
+    aTempMap.SetOrigin(Point());
+    rSaveDevice.SetMapMode(aTempMap);
+
+    if ( mxOwnerWindow->mpWindowImpl->mpPaintRegion )
+    {
+        vcl::Region      aClip( *mxOwnerWindow->mpWindowImpl->mpPaintRegion );
+        const Point aPixPos( LogicToPixel( rPos ) );
+
+        aClip.Move( -mnOutOffX, -mnOutOffY );
+        aClip.Intersect( tools::Rectangle( aPixPos, LogicToPixel( rSize ) ) );
+
+        if ( !aClip.IsEmpty() )
+        {
+            const vcl::Region    aOldClip( rSaveDevice.GetClipRegion() );
+            const Point     aPixOffset( rSaveDevice.LogicToPixel( Point() ) );
+            const bool      bMap = rSaveDevice.IsMapModeEnabled();
+
+            // move clip region to have the same distance to DestOffset
+            aClip.Move( aPixOffset.X() - aPixPos.X(), aPixOffset.Y() - aPixPos.Y() );
+
+            // set pixel clip region
+            rSaveDevice.EnableMapMode( false );
+            rSaveDevice.SetClipRegion( aClip );
+            rSaveDevice.EnableMapMode( bMap );
+            rSaveDevice.DrawOutDev( Point(), rSize, rPos, rSize, *this );
+            rSaveDevice.SetClipRegion( aOldClip );
+        }
+    }
+    else
+    {
+        rSaveDevice.DrawOutDev( Point(), rSize, rPos, rSize, *this );
+    }
+
+    rSaveDevice.SetMapMode(MapMode());
+}
+
+} /* namespace vcl */
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */