tdf#92982 vcl rendercontext: let PaintBufferGuard also manage pixel offset

Change-Id: Ifd6a75c4312f93c815f5d137f515724f3629fa0d

include/vcl/outdev.hxx

@@ -319,7 +319,6 @@ namespace vcl {
 
 class VCL_DLLPUBLIC OutputDevice
 {
-    friend class PaintHelper;
     friend class Printer;
     friend class VirtualDevice;
     friend class vcl::Window;
@@ -500,6 +499,8 @@ public:
     long                        GetOutputHeightPixel() const { return mnOutHeight; }
     long                        GetOutOffXPixel() const { return mnOutOffX; }
     long                        GetOutOffYPixel() const { return mnOutOffY; }
+    void                        SetOutOffXPixel(long nOutOffX);
+    void                        SetOutOffYPixel(long nOutOffY);
 
     Size                        GetOutputSize() const
                                     { return PixelToLogic( GetOutputSizePixel() ); }

vcl/source/outdev/outdev.cxx

@@ -426,6 +426,16 @@ sal_uInt16 OutputDevice::GetBitCount() const
     return (sal_uInt16)mpGraphics->GetBitCount();
 }
 
+void OutputDevice::SetOutOffXPixel(long nOutOffX)
+{
+    mnOutOffX = nOutOffX;
+}
+
+void OutputDevice::SetOutOffYPixel(long nOutOffY)
+{
+    mnOutOffY = nOutOffY;
+}
+
 sal_uLong OutputDevice::GetColorCount() const
 {
 

vcl/source/window/paint.cxx

@@ -47,10 +47,14 @@ class PaintBufferGuard
     bool mbBackground;
     Wallpaper maBackground;
     AllSettings maSettings;
+    long mnOutOffX;
+    long mnOutOffY;
 public:
     PaintBufferGuard(ImplFrameData* pFrameData, vcl::Window* pWindow)
         : mpFrameData(pFrameData),
-        mbBackground(false)
+        mbBackground(false),
+        mnOutOffX(0),
+        mnOutOffY(0)
     {
         // transfer various settings
         // FIXME: this must disappear as we move to RenderContext only,
@@ -97,10 +101,18 @@ public:
         pFrameData->mpBuffer->SetRasterOp(pWindow->GetRasterOp());
         pFrameData->mpBuffer->SetLayoutMode(pWindow->GetLayoutMode());
         pFrameData->mpBuffer->SetDigitLanguage(pWindow->GetDigitLanguage());
+
+        mnOutOffX = pFrameData->mpBuffer->GetOutOffXPixel();
+        mnOutOffY = pFrameData->mpBuffer->GetOutOffYPixel();
+        pFrameData->mpBuffer->SetOutOffXPixel(pWindow->GetOutOffXPixel());
+        pFrameData->mpBuffer->SetOutOffYPixel(pWindow->GetOutOffYPixel());
     }
     ~PaintBufferGuard()
     {
         // Restore buffer state.
+        mpFrameData->mpBuffer->SetOutOffXPixel(mnOutOffX);
+        mpFrameData->mpBuffer->SetOutOffYPixel(mnOutOffY);
+
         mpFrameData->mpBuffer->Pop();
         mpFrameData->mpBuffer->SetSettings(maSettings);
         if (mbBackground)
@@ -183,16 +195,13 @@ void PaintHelper::StartBufferedPaint()
     // painting over, as VirtualDevice::ImplInitVirDev() would do.
     // The painted area is m_aPaintRect, or in case it's empty, then the whole window.
     pFrameData->mpBuffer->SetBackground(Wallpaper(Color(COL_WHITE)));
-    long nOutOffX = pFrameData->mpBuffer->GetOutOffXPixel();
-    long nOutOffY = pFrameData->mpBuffer->GetOutOffYPixel();
-    pFrameData->mpBuffer->mnOutOffX = m_pWindow->GetOutOffXPixel();
-    pFrameData->mpBuffer->mnOutOffY = m_pWindow->GetOutOffYPixel();
-    if (m_aPaintRect.IsEmpty())
-        pFrameData->mpBuffer->Erase(Rectangle(Point(0, 0), m_pWindow->GetOutputSize()));
-    else
-        pFrameData->mpBuffer->Erase(m_aPaintRect);
-    pFrameData->mpBuffer->mnOutOffX = nOutOffX;
-    pFrameData->mpBuffer->mnOutOffY = nOutOffY;
+    {
+        PaintBufferGuard g(pFrameData, m_pWindow);
+        if (m_aPaintRect.IsEmpty())
+            pFrameData->mpBuffer->Erase(Rectangle(Point(0, 0), m_pWindow->GetOutputSize()));
+        else
+            pFrameData->mpBuffer->Erase(m_aPaintRect);
+    }
 
     pFrameData->mbInBufferedPaint = true;
     m_bStartedBufferedPaint = true;
@@ -232,13 +241,8 @@ void PaintHelper::PaintBuffer()
             aPaintRectSize = m_pWindow->PixelToLogic(aRectanglePixel.GetSize());
         }
 
-        long nOutOffX = pFrameData->mpBuffer->GetOutOffXPixel();
-        long nOutOffY = pFrameData->mpBuffer->GetOutOffYPixel();
-        pFrameData->mpBuffer->mnOutOffX = m_pWindow->GetOutOffXPixel();
-        pFrameData->mpBuffer->mnOutOffY = m_pWindow->GetOutOffYPixel();
+        PaintBufferGuard g(pFrameData, m_pWindow);
         m_pWindow->DrawOutDev(m_aPaintRect.TopLeft(), aPaintRectSize, m_aPaintRect.TopLeft(), aPaintRectSize, *pFrameData->mpBuffer.get());
-        pFrameData->mpBuffer->mnOutOffX = nOutOffX;
-        pFrameData->mpBuffer->mnOutOffY = nOutOffY;
     }
 }
 
@@ -289,14 +293,8 @@ void PaintHelper::DoPaint(const vcl::Region* pRegion)
             PaintBufferGuard g(pFrameData, m_pWindow);
             m_pWindow->ApplySettings(*pFrameData->mpBuffer.get());
 
-            long nOutOffX = pFrameData->mpBuffer->mnOutOffX;
-            long nOutOffY = pFrameData->mpBuffer->mnOutOffY;
-            pFrameData->mpBuffer->mnOutOffX = m_pWindow->GetOutOffXPixel();
-            pFrameData->mpBuffer->mnOutOffY = m_pWindow->GetOutOffYPixel();
             m_pWindow->PushPaintHelper(this, *pFrameData->mpBuffer.get());
             m_pWindow->Paint(*pFrameData->mpBuffer.get(), m_aPaintRect);
-            pFrameData->mpBuffer->mnOutOffX = nOutOffX;
-            pFrameData->mpBuffer->mnOutOffY = nOutOffY;
         }
         else
         {