PATCH: [ 2005031 ] Fix location pane flickering(2)

diff --git a/Docs/Users/ChangeLog.txt b/Docs/Users/ChangeLog.txt
index 02d5274..6119e5e 100644 (file)
--- a/Docs/Users/ChangeLog.txt
+++ b/Docs/Users/ChangeLog.txt
@@ -8,6 +8,7 @@ WinMerge 2.9.1.5
   Manual: Clarify 64-bit support (#2002431)
   Reduce executable sizes (#2003203)
   BugFix: Possible crash when enabling line filter (#2004160)
+  BugFix: Location Pane flickers when scrolling (#1938177, #2005031)
 
 WinMerge 2.9.1.4 - 2008-06-24 (r5518)
   Use PCRE regular expressions in the editor (#1991259)

diff --git a/Src/LocationView.cpp b/Src/LocationView.cpp
index a621fb7..db63c91 100644 (file)
--- a/Src/LocationView.cpp
+++ b/Src/LocationView.cpp
@@ -112,9 +112,8 @@ BEGIN_MESSAGE_MAP(CLocationView, CView)
        ON_WM_CONTEXTMENU()
        ON_WM_CLOSE()
        ON_WM_SIZE()
-  ON_WM_VSCROLL()
+       ON_WM_VSCROLL()
        ON_WM_ERASEBKGND()
-       ON_WM_PAINT()
        //}}AFX_MSG_MAP
 END_MESSAGE_MAP()
 
@@ -269,22 +268,6 @@ void CLocationView::CalculateBlocks()
 }
 
 /** 
- * @brief Invalidate rect of old visible area indicator to restore background correctly
- */
-void CLocationView::OnPaint()
-{
-       if (m_visibleTop != -1 && m_visibleBottom != -1)
-       {
-               CRect rc;
-               GetClientRect(rc);
-               rc.top = m_visibleTop;
-               rc.bottom = m_visibleBottom;
-               InvalidateRect(rc);
-       }
-       CView::OnPaint();
-}
-
-/** 
  * @brief Draw maps of files.
  *
  * Draws maps of differences in files. Difference list is walked and
@@ -303,7 +286,10 @@ void CLocationView::OnDraw(CDC* pDC)
 
        if (!m_view[MERGE_VIEW_LEFT]->IsInitialized()) return;
 
-       CMemDC dc(pDC);
+       CRect rc;
+       GetClientRect(&rc);
+
+       CMemDC dc(pDC, &rc);
 
        COLORREF cr0 = CLR_NONE; // Left side color
        COLORREF cr1 = CLR_NONE; // Right side color
@@ -436,6 +422,10 @@ void CLocationView::OnDraw(CDC* pDC)
        if (m_displayMovedBlocks != DISPLAY_MOVED_NONE)
                DrawConnectLines(&dc);
 
+       if (m_pSavedBackgroundBitmap)
+               delete m_pSavedBackgroundBitmap;
+       m_pSavedBackgroundBitmap = CopyRectToBitmap(&dc, rc);
+
        // Since we have invalidated locationbar there is no previous
        // arearect to remove
        m_visibleTop = -1;
@@ -802,18 +792,6 @@ void CLocationView::DrawVisibleAreaRect(CDC *pClientDC, int nTopLine, int nBotto
                        (static_cast<double>(nBottomLine * m_lineInPix)));
        int nRightCoord = rc.Width() - INDICATOR_MARGIN;
        
-       // Visible area was not changed
-       if (m_visibleTop == nTopCoord && m_visibleBottom == nBottomCoord)
-               return;
-
-       // Clear previous visible rect
-       if (m_visibleTop != -1 && m_visibleBottom != -1 && m_pSavedBackgroundBitmap)
-       {
-               DrawBitmap(pClientDC, 2, m_visibleTop, m_pSavedBackgroundBitmap);
-               delete m_pSavedBackgroundBitmap;
-               m_pSavedBackgroundBitmap = NULL;
-       }
-
        double xbarBottom = min(nbLines / m_pixInLines + Y_OFFSET, rc.Height() - Y_OFFSET);
        int barBottom = (int)xbarBottom;
        // Make sure bottom coord is in bar range
@@ -839,9 +817,7 @@ void CLocationView::DrawVisibleAreaRect(CDC *pClientDC, int nTopLine, int nBotto
        CBitmap *pDarkenedBitmap = GetDarkenedBitmap(pClientDC, pBitmap);
        DrawBitmap(pClientDC, rcVisibleArea.left, rcVisibleArea.top, pDarkenedBitmap);
        delete pDarkenedBitmap;
-       if (m_pSavedBackgroundBitmap)
-               delete m_pSavedBackgroundBitmap;
-       m_pSavedBackgroundBitmap = pBitmap;
+       delete pBitmap;
 }
 
 /**
@@ -854,9 +830,24 @@ void CLocationView::UpdateVisiblePos(int nTopLine, int nBottomLine)
 {
        if (m_bDrawn)
        {
-               CDC *pDC = GetDC();
-               DrawVisibleAreaRect(pDC, nTopLine, nBottomLine);
-               ReleaseDC(pDC);
+               int nTopCoord = static_cast<int>(Y_OFFSET +
+                               (static_cast<double>(nTopLine * m_lineInPix)));
+               int nBottomCoord = static_cast<int>(Y_OFFSET +
+                               (static_cast<double>(nBottomLine * m_lineInPix)));
+               if (m_visibleTop != nTopCoord || m_visibleBottom != nBottomCoord)
+               {
+                       // Visible area was changed
+                       CDC *pDC = GetDC();
+                       if (m_pSavedBackgroundBitmap)
+                       {
+                               CMemDC dc(pDC);
+                               // Clear previous visible rect
+                               DrawBitmap(&dc, 0, 0, m_pSavedBackgroundBitmap);
+
+                               DrawVisibleAreaRect(&dc, nTopLine, nBottomLine);
+                       }
+                       ReleaseDC(pDC);
+               }
        }
 }