[wxWidgets.git] / src / generic / gridsel.cpp

///////////////////////////////////////////////////////////////////////////
// Name:        generic/gridsel.cpp
// Purpose:     wxGridSelection
// Author:      Stefan Neis
// Modified by:
// Created:     20/02/1999
// RCS-ID:      $$
// Copyright:   (c) Stefan Neis (Stefan.Neis@t-online.de)
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#ifdef __GNUG__
    #pragma implementation "gridsel.h"
#endif

// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"

#include "wx/defs.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#include "wx/generic/gridsel.h"

wxGridSelection::wxGridSelection( wxGrid * grid,
                                  wxGrid::wxGridSelectionModes sel )
{
    m_grid = grid;
    m_selectionMode = sel;
}

bool wxGridSelection::IsSelection()
{
  return ( m_cellSelection.GetCount() || m_blockSelectionTopLeft.GetCount() ||
           m_rowSelection.GetCount() || m_colSelection.GetCount() );
}

bool wxGridSelection::IsInSelection ( int row, int col )
{
  size_t count;
    if ( m_selectionMode != wxGrid::wxGridSelectRows &&
         m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        count = m_cellSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            wxGridCellCoords& coords = m_cellSelection[n];
            if ( row == coords.GetRow() && col == coords.GetCol() )
                return true;
        }
    }
    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        if ( BlockContainsCell(coords1.GetRow(), coords1.GetCol(),
                               coords2.GetRow(), coords2.GetCol(),
                               row, col ) )
            return true;
    }
    if ( m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        size_t count = m_rowSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            if ( row == m_rowSelection[n] )
              return true;
        }
    }
    if ( m_selectionMode != wxGrid::wxGridSelectRows )
    {
        size_t count = m_colSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            if ( col == m_colSelection[n] )
              return true;
        }
    }
    return false;
}

void wxGridSelection::SelectRow( int row, bool addToSelected = FALSE )
{
    if ( m_selectionMode == wxGrid::wxGridSelectColumns )
        return;
    size_t count;

    // Remove single cells contained in newly selected block.
    if ( m_selectionMode != wxGrid::wxGridSelectRows &&
         m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        count = m_cellSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            wxGridCellCoords& coords = m_cellSelection[n];
            if ( BlockContainsCell( row, 0, row, m_grid->GetNumberCols() - 1,
                                    coords.GetRow(), coords.GetCol() ) )
            {
                m_cellSelection.RemoveAt(n);
                n--; count--;
            }
        }
    }

    // If possible, merge row with existing selected block
    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        if ( coords1.GetRow() == row && row == coords2.GetRow() )
        {
            m_blockSelectionTopLeft.RemoveAt(n);
            m_blockSelectionBottomRight.RemoveAt(n);
            n--; count--;
        }
        else if ( coords1.GetCol() == 0  &&
                  coords2.GetCol() == m_grid->GetNumberCols() - 1 )
        {
            if ( coords1.GetRow() <= row && row <= coords2.GetRow() )
                return;
            else if ( coords1.GetRow() == row + 1)
            {
                coords1.SetRow(row);
                return;
            }
            else if ( coords2.GetRow() == row - 1)
            {
                coords2.SetRow(row);
                return;
            }           
        }
    }

    // Check whether row is already selected.
    count = m_rowSelection.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        if ( row == m_rowSelection[n] )
            return;
    }

    // Add row to selection
    m_rowSelection.Add(row);

    // Update View:
    wxRect r = m_grid->BlockToDeviceRect( wxGridCellCoords( row, 0 ),
                                          wxGridCellCoords( row, m_grid->GetNumberCols() - 1 ) );
    if ( !m_grid->GetBatchCount() )
        ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
}

void wxGridSelection::SelectCol( int col, bool addToSelected = FALSE )
{
    if ( m_selectionMode == wxGrid::wxGridSelectRows )
        return;
    size_t count;

    // Remove single cells contained in newly selected block.
    if ( m_selectionMode != wxGrid::wxGridSelectRows &&
         m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        count = m_cellSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            wxGridCellCoords& coords = m_cellSelection[n];
            if ( BlockContainsCell( 0, col, m_grid->GetNumberRows() - 1, col,
                                    coords.GetRow(), coords.GetCol() ) )
            {
                m_cellSelection.RemoveAt(n);
                n--; count--;
            }
        }
    }

    // If possible, merge col with existing selected block
    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        if ( coords1.GetCol() == col && col == coords2.GetCol() )
        {
            m_blockSelectionTopLeft.RemoveAt(n);
            m_blockSelectionBottomRight.RemoveAt(n);
            n--; count--;
        }
        else if ( coords1.GetRow() == 0  &&
                  coords2.GetRow() == m_grid->GetNumberRows() - 1 )
        {
            if ( coords1.GetCol() <= col && col <= coords2.GetCol() )
                return;
            else if ( coords1.GetCol() == col + 1)
            {
                coords1.SetCol(col);
                return;
            }
            else if ( coords2.GetCol() == col - 1)
            {
                coords2.SetCol(col);
                return;
            }           
        }
    }

    // Check whether col is already selected.
    count = m_colSelection.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        if ( col == m_colSelection[n] )
            return;
    }

    // Add col to selection
    m_colSelection.Add(col);

    // Update View:
    wxRect r = m_grid->BlockToDeviceRect( wxGridCellCoords( 0, col ),
                                          wxGridCellCoords( m_grid->GetNumberRows() - 1, col ) );
    if ( !m_grid->GetBatchCount() )
        ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
}

void wxGridSelection::SelectBlock( int topRow, int leftCol, int bottomRow, int rightCol )
{
    // Fix the coordinates of the block if potentially needed
    if ( m_selectionMode == wxGrid::wxGridSelectRows )
    {
        leftCol = 0;
        rightCol = m_grid->GetNumberCols() - 1;
    }
    else if ( m_selectionMode == wxGrid::wxGridSelectColumns )
    {
        topRow = 0;
        bottomRow = m_grid->GetNumberRows() - 1;
    }

    // Handle single cell selection in SelectCell.
    if ( topRow == bottomRow && leftCol == rightCol )
        SelectCell( topRow, leftCol );

    size_t count;
    // Remove single cells contained in newly selected block.
    if ( m_selectionMode != wxGrid::wxGridSelectRows &&
         m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        count = m_cellSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            wxGridCellCoords& coords = m_cellSelection[n];
            if ( BlockContainsCell( topRow, leftCol, bottomRow, rightCol,
                                    coords.GetRow(), coords.GetCol() ) )
            {
                m_cellSelection.RemoveAt(n);
                n--; count--;
            }
        }
    }

    // If a block containing the selection is already selected, return,
    // if a block contained in the selection is found, remove it.

    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        switch ( BlockContain( coords1.GetRow(), coords1.GetCol(),
                               coords2.GetRow(), coords2.GetCol(),
                               topRow, leftCol, bottomRow, rightCol ) )
        {
          case 1:
            return;
          case -1:
            m_blockSelectionTopLeft.RemoveAt(n);
            m_blockSelectionBottomRight.RemoveAt(n);
            n--; count--;
          default:
            ;
        }
    }

    // If a row containing the selection is already selected, return,
    // if a row contained in newly selected block is found, remove it.
    if ( m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        size_t count = m_rowSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            switch ( BlockContain( m_rowSelection[n], 0,
                                   m_rowSelection[n], m_grid->GetNumberCols()-1,
                                   topRow, leftCol, bottomRow, rightCol ) )
            {
              case 1:
                return;
              case -1:
                m_rowSelection.RemoveAt(n);
                n--; count--;
              default:
                ;
            }
        }
    }
    if ( m_selectionMode != wxGrid::wxGridSelectRows )
    {
        size_t count = m_colSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            switch ( BlockContain( 0, m_colSelection[n],
                                   m_grid->GetNumberRows()-1, m_colSelection[n], 
                                   topRow, leftCol, bottomRow, rightCol ) )
            {
              case 1:
                return;
              case -1:
                m_colSelection.RemoveAt(n);
                n--; count--;
              default:
                ;
            }
        }
    }
    m_blockSelectionTopLeft.Add( wxGridCellCoords( topRow, leftCol ) );
    m_blockSelectionBottomRight.Add( wxGridCellCoords( bottomRow, rightCol ) );

    // Update View:
    wxRect r = m_grid->BlockToDeviceRect( wxGridCellCoords( topRow, leftCol ),
                                          wxGridCellCoords( bottomRow, rightCol ) );
    if ( !m_grid->GetBatchCount() )
        ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
}

void wxGridSelection::SelectCell( int row, int col)
{
    if ( m_selectionMode == wxGrid::wxGridSelectRows )
        SelectBlock(row, 0, row, m_grid->GetNumberCols() - 1 );
    else if ( m_selectionMode == wxGrid::wxGridSelectColumns )
        SelectBlock(0, col, m_grid->GetNumberRows() - 1, col );
    else if ( IsInSelection ( row, col ) )
        return;
    m_cellSelection.Add( wxGridCellCoords( row, col ) );

    wxRect r = m_grid->BlockToDeviceRect( wxGridCellCoords( row, col ),
                                          wxGridCellCoords( row, col ) );
    if ( !m_grid->GetBatchCount() )
        ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
}

void wxGridSelection::ToggleCellSelection( int row, int col)
{
    if ( !IsInSelection ( row, col ) )
    {
        SelectCell( row, col );
        return;
    }
    size_t count;

    // Maybe we want to toggle a member of m_cellSelection.
    // Then it can't be contained in rows/cols/block, and we
    // just have to remove it from m_cellSelection.

    if ( m_selectionMode != wxGrid::wxGridSelectRows &&
         m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        count = m_cellSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            wxGridCellCoords& coords = m_cellSelection[n];
            if ( row == coords.GetRow() && col == coords.GetCol() )
            {
                wxRect r;
                r = m_grid->BlockToDeviceRect( m_cellSelection[n],
                                               m_cellSelection[n] );
                m_cellSelection.RemoveAt(n);
                n--; count--;
                if ( !m_grid->GetBatchCount() )
                    ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
                return;
            }
        }
    }

    // remove a cell from the middle of a block (the really ugly case)
    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
      {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        int topRow = coords1.GetRow();
        int leftCol = coords1.GetCol();
        int bottomRow = coords2.GetRow();
        int rightCol = coords2.GetCol();
        if ( BlockContainsCell( topRow, leftCol, bottomRow, rightCol,
                                row, col ) )
        {
            // remove the block
            m_blockSelectionTopLeft.RemoveAt(n);
            m_blockSelectionBottomRight.RemoveAt(n);
            n--; count--;
            // add up to 4 smaller blocks and set update region
            if ( m_selectionMode != wxGrid::wxGridSelectColumns )
            {
                if ( topRow < row )
                    SelectBlock( topRow, leftCol, row - 1, rightCol );
                if ( bottomRow > row )
                    SelectBlock( row + 1, leftCol, bottomRow, rightCol );
            }
            if ( m_selectionMode != wxGrid::wxGridSelectRows )
            {
                if ( leftCol < col )
                    SelectBlock( row, leftCol, row, col - 1 );
                if ( rightCol > col )
                    SelectBlock( row, col + 1, row, rightCol );
            }
        }
    }

    // remove a cell from a row, adding up to two new blocks
    if ( m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        size_t count = m_rowSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            if ( m_rowSelection[n] == row )
            {
                m_rowSelection.RemoveAt(n);
                n--; count--;
                if (m_selectionMode == wxGrid::wxGridSelectCells)
                {
                    if ( col > 0 )
                        SelectBlock( row, 0, row, col - 1 );
                    if ( col < m_grid->GetNumberCols() - 1 )
                        SelectBlock( row, col + 1, row, m_grid->GetNumberCols() - 1 );
                }
            }
        }
    }

    // remove a cell from a column, adding up to two new blocks
    if ( m_selectionMode != wxGrid::wxGridSelectRows )
    {
        size_t count = m_colSelection.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            if ( m_colSelection[n] == col )
            {
                m_colSelection.RemoveAt(n);
                n--; count--;
                if (m_selectionMode == wxGrid::wxGridSelectCells)
                {
                    if ( row > 0 )
                        SelectBlock( 0, col, row - 1, col );
                    if ( row < m_grid->GetNumberRows() - 1 )
                        SelectBlock( row + 1, col, m_grid->GetNumberRows() - 1, col );
                }
            }
        }
    }
    wxRect r;
    switch (m_selectionMode)
    {
      case wxGrid::wxGridSelectCells:
        r = m_grid->BlockToDeviceRect( wxGridCellCoords( row, col ),
                                       wxGridCellCoords( row, col ) );
        break;
      case wxGrid::wxGridSelectRows:
        r = m_grid->BlockToDeviceRect( wxGridCellCoords( row, 0 ),
                                       wxGridCellCoords( row, m_grid->GetNumberCols() - 1 ) );
        break;
      case wxGrid::wxGridSelectColumns:
        r = m_grid->BlockToDeviceRect( wxGridCellCoords( 0, col ),
                                       wxGridCellCoords( m_grid->GetNumberRows() - 1, col ) );
        break;
    }
    if ( !m_grid->GetBatchCount() )
        ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
}

void wxGridSelection::ClearSelection()
{
    size_t n;
    if ( m_selectionMode != wxGrid::wxGridSelectRows &&
         m_selectionMode != wxGrid::wxGridSelectColumns )
    {
      
        while( ( n = m_cellSelection.GetCount() ) > 0)
        {
            wxRect r;
            n--;
            r = m_grid->BlockToDeviceRect( m_cellSelection[n],
                                           m_cellSelection[n] );
            m_cellSelection.RemoveAt(n);
            if ( !m_grid->GetBatchCount() )
                ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );
        }
    }
    while( ( n = m_blockSelectionTopLeft.GetCount() ) > 0)
    {
        wxRect r;
        n--;
        r = m_grid->BlockToDeviceRect( m_blockSelectionTopLeft[n],
                                       m_blockSelectionBottomRight[n] );
        m_blockSelectionTopLeft.RemoveAt(n);
        m_blockSelectionBottomRight.RemoveAt(n);
        if ( !m_grid->GetBatchCount() )
            ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );   
    }
    if ( m_selectionMode != wxGrid::wxGridSelectColumns )
    {
        while( ( n = m_rowSelection.GetCount() ) > 0)
        {
            n--;
            int & row = m_rowSelection[n];
            wxRect r;
            r = m_grid->BlockToDeviceRect( wxGridCellCoords( row, 0 ),
                                           wxGridCellCoords( row, m_grid->GetNumberCols() - 1 ) );
            m_rowSelection.RemoveAt(n);
            if ( !m_grid->GetBatchCount() )
                ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );   
        }
    }
    if ( m_selectionMode != wxGrid::wxGridSelectRows )
    {
        while( ( n = m_colSelection.GetCount() ) > 0)
        {
            n--;
            int & col = m_colSelection[n];
            wxRect r;
            r = m_grid->BlockToDeviceRect( wxGridCellCoords( 0, col ),
                                           wxGridCellCoords( m_grid->GetNumberRows() - 1, col ) );
            m_colSelection.RemoveAt(n);
            if ( !m_grid->GetBatchCount() )
                ((wxWindow *)m_grid->m_gridWin)->Refresh( FALSE, &r );   
        }
    }
}


void wxGridSelection::UpdateRows( size_t pos, int numRows )
{
    size_t count = m_cellSelection.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords = m_cellSelection[n];
        wxCoord row = coords.GetRow();
        if ((size_t)row >= pos)
        {
            if (numRows > 0)
            {
                // If rows inserted, increase row counter where necessary
                coords.SetRow(row + numRows);
            }
            else if (numRows < 0)
            {
                // If rows deleted ...
                if ((size_t)row >= pos - numRows)
                {
                    // ...either decrement row counter (if row still exists)...
                    coords.SetRow(row + numRows);
                }
                else
                {
                    // ...or remove the attribute
                    m_cellSelection.RemoveAt(n);
                    n--; count--;
                }
            }
        }
    }

    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        wxCoord row1 = coords1.GetRow();
        wxCoord row2 = coords2.GetRow();
        if ((size_t)row2 >= pos)
        {
            if (numRows > 0)
            {
                // If rows inserted, increase row counter where necessary
                coords2.SetRow(row2 + numRows);
                if ( (size_t)row1 >= pos )
                    coords1.SetRow(row1 + numRows);
            }
            else if (numRows < 0)
            {
                // If rows deleted ...
                if ((size_t)row2 >= pos - numRows)
                {
                    // ...either decrement row counter (if row still exists)...
                    coords2.SetRow(row2 + numRows);
                    if ( (size_t) row1 >= pos)
                        coords1.SetRow( wxMax(row1 + numRows, (int) pos) );
                    
                }
                else
                {
                    if ( (size_t) row1 >= pos)
                    {
                        // ...or remove the attribute
                        m_blockSelectionTopLeft.RemoveAt(n);
                        m_blockSelectionBottomRight.RemoveAt(n);
                        n--; count--;
                    }
                    else
                        coords2.SetRow(pos);
                }
            }
        }
    }

    count = m_rowSelection.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        int & rowOrCol = m_rowSelection[n];
        if ( (size_t)rowOrCol >= pos )
        {
            if ( numRows > 0 )
            {
                // If rows inserted, include row counter where necessary
                rowOrCol += numRows;
            }
            else if ( numRows < 0)
            {
                // If rows deleted, either decrement row counter (if row still exists)
                if ((size_t)rowOrCol >= pos - numRows)
                    rowOrCol += numRows;
                else
                {
                    m_rowSelection.RemoveAt(n);
                    n--; count--;
                }
            }
        }
    }
}

void wxGridSelection::UpdateCols( size_t pos, int numCols )
{
    size_t count = m_cellSelection.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords = m_cellSelection[n];
        wxCoord col = coords.GetCol();
        if ((size_t)col >= pos)
        {
            if (numCols > 0)
            {
                // If rows inserted, increase row counter where necessary
                coords.SetCol(col + numCols);
            }
            else if (numCols < 0)
            {
                // If rows deleted ...
                if ((size_t)col >= pos - numCols)
                {
                    // ...either decrement row counter (if row still exists)...
                    coords.SetCol(col + numCols);
                }
                else
                {
                    // ...or remove the attribute
                    m_cellSelection.RemoveAt(n);
                    n--; count--;
                }
            }
        }
    }

    count = m_blockSelectionTopLeft.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        wxGridCellCoords& coords1 = m_blockSelectionTopLeft[n];
        wxGridCellCoords& coords2 = m_blockSelectionBottomRight[n];
        wxCoord col1 = coords1.GetCol();
        wxCoord col2 = coords2.GetCol();
        if ((size_t)col2 >= pos)
        {
            if (numCols > 0)
            {
                // If rows inserted, increase row counter where necessary
                coords2.SetCol(col2 + numCols);
                if ( (size_t)col1 >= pos )
                    coords1.SetCol(col1 + numCols);
            }
            else if (numCols < 0)
            {
                // If cols deleted ...
                if ((size_t)col2 >= pos - numCols)
                {
                    // ...either decrement col counter (if col still exists)...
                    coords2.SetCol(col2 + numCols);
                    if ( (size_t) col1 >= pos)
                        coords1.SetCol( wxMax(col1 + numCols, (int) pos) );
                    
                }
                else
                {
                    if ( (size_t) col1 >= pos)
                    {
                        // ...or remove the attribute
                        m_blockSelectionTopLeft.RemoveAt(n);
                        m_blockSelectionBottomRight.RemoveAt(n);
                        n--; count--;
                    }
                    else
                        coords2.SetCol(pos);
                }
            }
        }
    }

    count = m_colSelection.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        int & rowOrCol = m_colSelection[n];
        if ( (size_t)rowOrCol >= pos )
        {
            if ( numCols > 0 )
            {
                // If cols inserted, include col counter where necessary
                rowOrCol += numCols;
            }
            else if ( numCols < 0)
            {
                // If cols deleted, either decrement col counter (if col still exists)
                if ((size_t)rowOrCol >= pos - numCols)
                    rowOrCol += numCols;
                else
                {
                    m_colSelection.RemoveAt(n);
                    n--; count--;
                }
            }
        }
    }
}

int wxGridSelection::BlockContain( int topRow1, int leftCol1,
                                   int bottomRow1, int rightCol1,
                                   int topRow2, int leftCol2,
                                   int bottomRow2, int rightCol2 )
// returns 1, if Block1 contains Block2,
//        -1, if Block2 contains Block1,
//         0, otherwise
{
    if ( topRow1 <= topRow2 && bottomRow2 <= bottomRow1 &&
         leftCol1 <= leftCol2 && rightCol2 <= rightCol1 )
        return 1;
    else if ( topRow2 <= topRow1 && bottomRow1 <= bottomRow2 &&
              leftCol2 <= leftCol1 && rightCol1 <= rightCol2 )
        return -1;
    return 0;
}