break;
        
    case SB_PAGELEFT:
        if (scrollPos > 0)
        {
            rect.left = GetFixedColumnWidth();
            int offset = -rect.Width();
            int pos = max(0, scrollPos + offset);
            SetScrollPos32(SB_HORZ, pos);
            rect.left = GetFixedColumnWidth();
            InvalidateRect(rect);
        }
        break;
        
    case SB_THUMBPOSITION:
    case SB_THUMBTRACK:
        {
            SetScrollPos32(SB_HORZ, GetScrollPos32(SB_HORZ, TRUE));
            CCellID idNewTopLeft = GetTopleftNonFixedCell();
            if (idNewTopLeft != idTopLeft)
            {
                rect.left = GetFixedColumnWidth();
                InvalidateRect(rect);
            }
        }
        break;
        
    case SB_LEFT:
        if (scrollPos > 0)
        {
            SetScrollPos32(SB_HORZ, 0);
            Invalidate();
        }
        break;
        
    case SB_RIGHT:
        if (scrollPos < m_nHScrollMax)
        {
            SetScrollPos32(SB_HORZ, m_nHScrollMax);
            Invalidate();
        }
        break;
        
        
    default: 
        break;
    }
}

// Handle vert scrollbar notifications
void CGridCtrl::OnVScroll(UINT nSBCode, UINT /*nPos*/, CScrollBar* /*pScrollBar*/)
{
    EndEditing();

#ifndef GRIDCONTROL_NO_TITLETIPS
    m_TitleTip.Hide();  // hide any titletips
#endif

    // Get the scroll position ourselves to ensure we get a 32 bit value
    int scrollPos = GetScrollPos32(SB_VERT);

    CCellID idTopLeft = GetTopleftNonFixedCell();

    CRect rect;
    GetClientRect(rect);

    switch (nSBCode)
    {
    case SB_LINEDOWN:
        if (scrollPos < m_nVScrollMax)
        {
            // may have contiguous hidden rows.  Blow by them
            while(  idTopLeft.row < (GetRowCount()-1)
                    && GetRowHeight( idTopLeft.row) < 1 )
            {
                idTopLeft.row++;
            }

            int yScroll = GetRowHeight(idTopLeft.row);
            SetScrollPos32(SB_VERT, scrollPos + yScroll);
            if (GetScrollPos32(SB_VERT) == scrollPos)
                break;          // didn't work

            rect.top = GetFixedRowHeight();
            //rect.top = GetFixedRowHeight() + yScroll;
            //ScrollWindow(0, -yScroll, rect);
            //rect.top = rect.bottom - yScroll;
            InvalidateRect(rect);
        }
        break;
        
    case SB_LINEUP:
        if (scrollPos > 0 && idTopLeft.row > GetFixedRowCount())
        {
            int iRowToUse = idTopLeft.row-1;
            // may have contiguous hidden rows.  Blow by them
            while(  iRowToUse > GetFixedRowCount()
                    && GetRowHeight( iRowToUse) < 1 )
            {
                iRowToUse--;
            }

            int yScroll = GetRowHeight( iRowToUse);
            SetScrollPos32(SB_VERT, max(0, scrollPos - yScroll));
            rect.top = GetFixedRowHeight();
            //ScrollWindow(0, yScroll, rect);
            //rect.bottom = rect.top + yScroll;
            InvalidateRect(rect);
        }
        break;
        
    case SB_PAGEDOWN:
        if (scrollPos < m_nVScrollMax)
        {
            rect.top = GetFixedRowHeight();
            scrollPos = min(m_nVScrollMax, scrollPos + rect.Height());
            SetScrollPos32(SB_VERT, scrollPos);
            rect.top = GetFixedRowHeight();
            InvalidateRect(rect);
        }
        break;
        
    case SB_PAGEUP:
        if (scrollPos > 0)
        {
            rect.top = GetFixedRowHeight();
            int offset = -rect.Height();
            int pos = max(0, scrollPos + offset);
            SetScrollPos32(SB_VERT, pos);
            rect.top = GetFixedRowHeight();
            InvalidateRect(rect);
        }
        break;
        
    case SB_THUMBPOSITION:
    case SB_THUMBTRACK:
        {
            SetScrollPos32(SB_VERT, GetScrollPos32(SB_VERT, TRUE));
            CCellID idNewTopLeft = GetTopleftNonFixedCell();
            if (idNewTopLeft != idTopLeft)
            {
                rect.top = GetFixedRowHeight();
                InvalidateRect(rect);
            }
        }
        break;
        
    case SB_TOP:
        if (scrollPos > 0)
        {
            SetScrollPos32(SB_VERT, 0);
            Invalidate();
        }
        break;
        
    case SB_BOTTOM:
        if (scrollPos < m_nVScrollMax)
        {
            SetScrollPos32(SB_VERT, m_nVScrollMax);
            Invalidate();
        }
        
    default: 
        break;
    }
}

/////////////////////////////////////////////////////////////////////////////
// CGridCtrl implementation functions

void CGridCtrl::OnDraw(CDC* pDC)
{
    if (!m_bAllowDraw)
        return;

    CRect clipRect;
    if (pDC->GetClipBox(&clipRect) == ERROR)
        return;

    EraseBkgnd(pDC);            // OnEraseBkgnd does nothing, so erase bkgnd here.
    // This necessary since we may be using a Memory DC.

    CRect rect;
    int row, col;
    CGridCellBase* pCell;


    int nFixedRowHeight = GetFixedRowHeight();
    int nFixedColWidth  = GetFixedColumnWidth();

    CCellID idTopLeft = GetTopleftNonFixedCell();
    int minVisibleRow = idTopLeft.row,
        minVisibleCol = idTopLeft.col;

    CRect VisRect;
    CCellRange VisCellRange = GetVisibleNonFixedCellRange(VisRect);
    int maxVisibleRow = VisCellRange.GetMaxRow(),
        maxVisibleCol = VisCellRange.GetMaxCol();

    // draw top-left cells 0..m_nFixedRows-1, 0..m_nFixedCols-1
    rect.bottom = -1;
    for (row = 0; row < m_nFixedRows; row++)
    {
        rect.top = rect.bottom+1;
        rect.bottom = rect.top + GetRowHeight(row)-1;
        rect.right = -1;
        for (col = 0; col < m_nFixedCols; col++)
        {
            rect.left = rect.right+1;
            rect.right = rect.left + GetColumnWidth(col)-1;

            pCell = GetCell(row, col);
            if (pCell)
                pCell->Draw(pDC, row, col, rect, FALSE);
        }
    }

    // draw fixed column cells:  m_nFixedRows..n, 0..m_nFixedCols-1
    rect.bottom = nFixedRowHeight-1;
    for (row = minVisibleRow; row <= maxVisibleRow; row++)
    {
        rect.top = rect.bottom+1;
        rect.bottom = rect.top + GetRowHeight(row)-1;

        // rect.bottom = bottom pixel of previous row
        if (rect.top > clipRect.bottom)
            break;                // Gone past cliprect
        if (rect.bottom < clipRect.top)
            continue;             // Reached cliprect yet?

        rect.right = -1;
        for (col = 0; col < m_nFixedCols; col++)
        {
            rect.left = rect.right+1;
            rect.right = rect.left + GetColumnWidth(col)-1;

            if (rect.left > clipRect.right)
                break;            // gone past cliprect
            if (rect.right < clipRect.left)
                continue;         // Reached cliprect yet?

            pCell = GetCell(row, col);
            if (pCell)
                pCell->Draw(pDC, row, col, rect, FALSE);
        }
    }

    // draw fixed row cells  0..m_nFixedRows, m_nFixedCols..n
    rect.bottom = -1;
    for (row = 0; row < m_nFixedRows; row++)
    {
        rect.top = rect.bottom+1;
        rect.bottom = rect.top + GetRowHeight(row)-1;

        // rect.bottom = bottom pixel of previous row
        if (rect.top > clipRect.bottom)
            break;                // Gone past cliprect
        if (rect.bottom < clipRect.top)
            continue;             // Reached cliprect yet?

        rect.right = nFixedColWidth-1;
        for (col = minVisibleCol; col <= maxVisibleCol; col++)
        {
            rect.left = rect.right+1;
            rect.right = rect.left + GetColumnWidth(col)-1;

            if (rect.left > clipRect.right)
                break;        // gone past cliprect
            if (rect.right < clipRect.left)
                continue;     // Reached cliprect yet?

            pCell = GetCell(row, col);
            if (pCell)
                pCell->Draw(pDC, row, col, rect, FALSE);
        }
    }

    // draw rest of non-fixed cells
    rect.bottom = nFixedRowHeight-1;
    for (row = minVisibleRow; row <= maxVisibleRow; row++)
    {
        rect.top = rect.bottom+1;
        rect.bottom = rect.top + GetRowHeight(row)-1;

        // rect.bottom = bottom pixel of previous row
        if (rect.top > clipRect.bottom)
            break;                // Gone past cliprect
        if (rect.bottom < clipRect.top)
            continue;             // Reached cliprect yet?

        rect.right = nFixedColWidth-1;
        for (col = minVisibleCol; col <= maxVisibleCol; col++)
        {
            rect.left = rect.right+1;
            rect.right = rect.left + GetColumnWidth(col)-1;

            if (rect.left > clipRect.right)
                break;        // gone past cliprect
            if (rect.right < clipRect.left)
                continue;     // Reached cliprect yet?

            pCell = GetCell(row, col);
            // TRACE(_T("Cell %d,%d type: %s\n"), row, col, pCell->GetRuntimeClass()->m_lpszClassName);
            if (pCell)
                pCell->Draw(pDC, row, col, rect, FALSE);
        }
    }


    CPen pen;
    TRY
    {
        pen.CreatePen(PS_SOLID, 0, m_crGridColour);
    }
    CATCH (CResourceException, e)
    {
        e->Delete();
        return;
    }
    END_CATCH
        pDC->SelectObject(&pen);

    // draw vertical lines (drawn at ends of cells)
    if (m_nGridLines == GVL_BOTH || m_nGridLines == GVL_VERT)
    {
        int x = nFixedColWidth;
        for (col = minVisibleCol; col <= maxVisibleCol; col++)
        {
            x += GetColumnWidth(col);
            pDC->MoveTo(x-1, nFixedRowHeight);
            pDC->LineTo(x-1, VisRect.bottom);
        }
    }

    // draw horizontal lines (drawn at bottom of each cell)
    if (m_nGridLines == GVL_BOTH || m_nGridLines == GVL_HORZ)
    {
        int y = nFixedRowHeight;
        for (row = minVisibleRow; row <= maxVisibleRow; row++)
        {
            y += GetRowHeight(row);
            pDC->MoveTo(nFixedColWidth, y-1);
            pDC->LineTo(VisRect.right,  y-1);
        }
    }

    pDC->SelectStockObject(NULL_PEN);

}

////////////////////////////////////////////////////////////////////////////////////////
// CGridCtrl Cell selection stuff

// Is a given cell designation valid (ie within the bounds of our number
// of columns/rows)?
BOOL CGridCtrl::IsValid(int nRow, int nCol) const
{
    return (nRow >= 0 && nRow < m_nRows && nCol >= 0 && nCol < m_nCols);
}

BOOL CGridCtrl::IsValid(const CCellID& cell) const
{
    return IsValid(cell.row, cell.col);
}

// Is a given cell range valid (ie within the bounds of our number
// of columns/rows)?
BOOL CGridCtrl::IsValid(const CCellRange& range) const
{
    return (range.GetMinRow() >= 0 && range.GetMinCol() >= 0 &&
        range.GetMaxRow() >= 0 && range.GetMaxCol() >= 0 &&
        range.GetMaxRow() < m_nRows && range.GetMaxCol() < m_nCols &&
        range.GetMinRow() <= range.GetMaxRow() && range.GetMinCol() <= range.GetMaxCol());
}

// Enables/Disables redraw for certain operations like columns auto-sizing etc,
// but not for user caused things such as selection changes.
void CGridCtrl::SetRedraw(BOOL bAllowDraw, BOOL bResetScrollBars /* = FALSE */)
{
//    TRACE(_T("%s: Setting redraw to %s\n"),
//             GetRuntimeClass()->m_lpszClassName, bAllowDraw? _T("TRUE") : _T("FALSE"));

    if (bAllowDraw && !m_bAllowDraw)
        Invalidate();

    m_bAllowDraw = bAllowDraw;
    if (bResetScrollBars)
        ResetScrollBars();
}

// Forces a redraw of a cell immediately (using a direct DC construction,
// or the supplied dc)
BOOL CGridCtrl::RedrawCell(const CCellID& cell, CDC* pDC /* = NULL */)
{
    return RedrawCell(cell.row, cell.col, pDC);
}

BOOL CGridCtrl::RedrawCell(int nRow, int nCol, CDC* pDC /* = NULL */)
{
    BOOL bResult = TRUE;
    BOOL bMustReleaseDC = FALSE;

    if (!m_bAllowDraw || !IsCellVisible(nRow, nCol))
        return FALSE;

    CRect rect;
    if (!GetCellRect(nRow, nCol, rect))