/** <title>NSMatrix</title>

   <abstract>Matrix class for grouping controls</abstract>

   Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.

   Author: Ovidiu Predescu <ovidiu@net-community.com>
   Date: March 1997
   A completely rewritten version of the original source by Pascal Forget and
   Scott Christley.
   Modified: Felipe A. Rodriguez <far@ix.netcom.com>
   Date: August 1998
   Cell handling rewritten: Richard Frith-Macdonald <richard@brainstorm.co.uk>
   Date: November 1999
   Implementation of Editing: Nicola Pero <n.pero@mi.flashnet.it>
   Date: November 1999
   Modified: Mirko Viviani <mirko.viviani@rccr.cremona.it>
   Date: March 2001

   This file is part of the GNUstep GUI Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; see the file COPYING.LIB.
   If not, write to the Free Software Foundation,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#include <gnustep/gui/config.h>
#include <stdlib.h>

#include <Foundation/NSValue.h>
#include <Foundation/NSArray.h>
#include <Foundation/NSAutoreleasePool.h>
#include <Foundation/NSString.h>
#include <Foundation/NSZone.h>

#include <AppKit/NSColor.h>
#include <AppKit/NSCursor.h>
#include <AppKit/NSActionCell.h>
#include <AppKit/NSWindow.h>
#include <AppKit/NSApplication.h>
#include <AppKit/NSMatrix.h>

#include <math.h>

static NSNotificationCenter *nc;

#define	STRICT	0

#ifdef MIN
# undef MIN
#endif
#define MIN(A,B)  ({ typeof(A) __a = (A); \
		  typeof(B) __b = (B); \
		  __a < __b ? __a : __b; })

#ifdef MAX
# undef MAX
#endif
#define MAX(A,B)  ({ typeof(A) __a = (A); \
		  typeof(B) __b = (B); \
		  __a < __b ? __b : __a; })

#ifdef ABS
# undef ABS
#endif
#define ABS(A)	({ typeof(A) __a = (A); __a < 0 ? -__a : __a; })


#define SIGN(x) \
    ({typeof(x) _SIGN_x = (x); \
      _SIGN_x > 0 ? 1 : (_SIGN_x == 0 ? 0 : -1); })

#define POINT_FROM_INDEX(index) \
    ({MPoint point = { index % _numCols, index / _numCols }; point; })

#define INDEX_FROM_COORDS(x,y) \
    (y * _numCols + x)
#define INDEX_FROM_POINT(point) \
    (point.y * _numCols + point.x)


/* Some stuff needed to compute the selection in the list mode. */
typedef struct {
  int x;
  int y;
} MPoint;

typedef struct {
  int x;
  int y;
  int width;
  int height;
} MRect;

static inline MPoint MakePoint (int x, int y)
{
  MPoint point = { x, y };
  return point;
}

@interface NSMatrix (PrivateMethods)
- (void) _renewRows: (int)row
	    columns: (int)col
	   rowSpace: (int)rowSpace
	   colSpace: (int)colSpace;
- (void) _setState: (int)state
	 highlight: (BOOL)highlight
	startIndex: (int)start
	  endIndex: (int)end;
- (BOOL) _selectNextSelectableCellAfterRow: (int)row
				    column: (int)column;
- (BOOL) _selectPreviousSelectableCellBeforeRow: (int)row
					 column: (int)column;
@end

enum {
  DEFAULT_CELL_HEIGHT = 17,
  DEFAULT_CELL_WIDTH = 100
};

@implementation NSMatrix

/* Class variables */
static Class defaultCellClass = nil;
static int mouseDownFlags = 0;
static SEL copySel;
static SEL initSel;
static SEL allocSel;
static SEL getSel;

+ (void) initialize
{
  if (self == [NSMatrix class])
    {
      /* Set the initial version */
      [self setVersion: 1];

      copySel = @selector(copyWithZone:);
      initSel = @selector(init);
      allocSel = @selector(allocWithZone:);
      getSel = @selector(objectAtIndex:);

      /*
       * MacOS-X docs say default cell class is NSActionCell
       */
      defaultCellClass = [NSActionCell class];
      //
      nc = [NSNotificationCenter defaultCenter];
    }
}

+ (Class) cellClass
{
  return defaultCellClass;
}

+ (void) setCellClass: (Class)classId
{
  defaultCellClass = classId;
  if (defaultCellClass == nil)
    defaultCellClass = [NSActionCell class];
}

- (id) init
{
  return [self initWithFrame: NSZeroRect
		        mode: NSRadioModeMatrix
		   cellClass: [isa cellClass]
		numberOfRows: 0
	     numberOfColumns: 0];
}

- (id) initWithFrame: (NSRect)frameRect
{
  return [self initWithFrame: frameRect
		        mode: NSRadioModeMatrix
		   cellClass: [isa cellClass]
		numberOfRows: 0
	     numberOfColumns: 0];
}

- (id) _privateFrame: (NSRect)frameRect
	        mode: (int)aMode
        numberOfRows: (int)rows
     numberOfColumns: (int)cols
{
  _myZone = [self zone];
  [self _renewRows: rows columns: cols rowSpace: 0 colSpace: 0];
  _mode = aMode;
  [self setFrame: frameRect];

  if ((_numCols > 0) && (_numRows > 0))
    _cellSize = NSMakeSize (rint(frameRect.size.width/_numCols),
			    rint(frameRect.size.height/_numRows));
  else
    _cellSize = NSMakeSize (DEFAULT_CELL_WIDTH, DEFAULT_CELL_HEIGHT);

  _intercell = NSMakeSize(1, 1);
  _tabKeyTraversesCells = YES;
  [self setBackgroundColor: [NSColor controlBackgroundColor]];
  [self setDrawsBackground: YES];
  [self setCellBackgroundColor: [NSColor controlBackgroundColor]];
  [self setSelectionByRect: YES];
  [self setAutosizesCells: YES];
  _dottedRow = _dottedColumn = -1;
  if (_mode == NSRadioModeMatrix && _numRows > 0 && _numCols > 0)
    {
      [self selectCellAtRow: 0 column: 0];
    }
  else
    {
      _selectedRow = _selectedColumn = -1;
    }
  return self;
}

- (id) initWithFrame: (NSRect)frameRect
	        mode: (int)aMode
	   cellClass: (Class)class
        numberOfRows: (int)rowsHigh
     numberOfColumns: (int)colsWide
{
  self = [super initWithFrame: frameRect];

  [self setCellClass: class];
  return [self _privateFrame: frameRect
		        mode: aMode
		numberOfRows: rowsHigh
	     numberOfColumns: colsWide];
}

- (id) initWithFrame: (NSRect)frameRect
	        mode: (int)aMode
	   prototype: (NSCell*)prototype
        numberOfRows: (int)rowsHigh
     numberOfColumns: (int)colsWide
{
  self = [super initWithFrame: frameRect];

  [self setPrototype: prototype];
  return [self _privateFrame: frameRect
		        mode: aMode
		numberOfRows: rowsHigh
	     numberOfColumns: colsWide];
}

- (void) dealloc
{
  int		i;

  for (i = 0; i < _maxRows; i++)
    {
      int	j;

      for (j = 0; j < _maxCols; j++)
	{
	  [_cells[i][j] release];
	}
      NSZoneFree(_myZone, _cells[i]);
      NSZoneFree(GSAtomicMallocZone(), _selectedCells[i]);
    }
  NSZoneFree(_myZone, _cells);
  NSZoneFree(_myZone, _selectedCells);

  [_cellPrototype release];
  [_backgroundColor release];
  [_cellBackgroundColor release];
  [super dealloc];
}

- (void) addColumn
{
  [self insertColumn: _numCols withCells: nil];
}

- (void) addColumnWithCells: (NSArray*)cellArray
{
  [self insertColumn: _numCols withCells: cellArray];
}

- (void) addRow
{
  [self insertRow: _numRows withCells: nil];
}

- (void) addRowWithCells: (NSArray*)cellArray
{
  [self insertRow: _numRows withCells: cellArray];
}

- (void) insertColumn: (int)column
{
  [self insertColumn: column withCells: nil];
}

- (void) insertColumn: (int)column withCells: (NSArray*)cellArray
{
  int	count = [cellArray count];
  int	i = _numCols + 1;

  if (column < 0)
    {
      column = 0;
#if	STRICT == 0
      NSLog(@"insert negative column (%d) in matrix", column);
#else
      [NSException raise: NSRangeException
		  format: @"insert negative column (%d) in matrix", column];
#endif
    }

  if (column >= i)
    {
      i = column + 1;
    }

  /*
   * Use _renewRows:columns:rowSpace:colSpace: to grow the matrix as necessary.
   * MacOS-X docs say that if the matrix is empty, we make it have one column
   * and enough rows for all the elements.
   */
  if (count > 0 && (_numRows == 0 || _numCols == 0))
    {
      [self _renewRows: count columns: 1 rowSpace: 0 colSpace: count];
    }
  else
    {
      [self _renewRows: _numRows ? _numRows : 1
	       columns: i
	      rowSpace: 0
	      colSpace: count];
    }

  /*
   * Rotate the new column to the insertion point if necessary.
   */
  if (_numCols != column)
    {
      for (i = 0; i < _numRows; i++)
	{
	  int	j = _numCols;
	  id	old = _cells[i][j-1];

	  while (--j > column)
	    {
	      _cells[i][j] = _cells[i][j-1];
	      _selectedCells[i][j] = _selectedCells[i][j-1];
	    }
	  _cells[i][column] = old;
	  _selectedCells[i][column] = NO;
	}
      if (_selectedCell && (_selectedColumn >= column))
	{
	  _selectedColumn++;
	}
    }

  /*
   * Now put the new cells from the array into the matrix.
   */
  if (count > 0)
    {
      IMP	getImp = [cellArray methodForSelector: getSel];

      for (i = 0; i < _numRows && i < count; i++)
	{
	  ASSIGN(_cells[i][column], (*getImp)(cellArray, getSel, i));
	}
    }

  if (_mode == NSRadioModeMatrix && _allowsEmptySelection == NO
    && _selectedCell == nil)
    [self selectCellAtRow: 0 column: 0];
}

- (void) insertRow: (int)row
{
  [self insertRow: row withCells: nil];
}

- (void) insertRow: (int)row withCells: (NSArray*)cellArray
{
  int	count = [cellArray count];
  int	i = _numRows + 1;

  if (row < 0)
    {
      row = 0;
#if	STRICT == 0
      NSLog(@"insert negative row (%d) in matrix", row);
#else
      [NSException raise: NSRangeException
		  format: @"insert negative row (%d) in matrix", row];
#endif
    }

  if (row >= i)
    {
      i = row + 1;
    }

  /*
   * Grow the matrix to have the new row.
   * MacOS-X docs say that if the matrix is empty, we make it have one
   * row and enough columns for all the elements.
   */
  if (count > 0 && (_numRows == 0 || _numCols == 0))
    {
      [self _renewRows: 1 columns: count rowSpace: count colSpace: 0];
    }
  else
    {
      [self _renewRows: i
	       columns: _numCols ? _numCols : 1
	      rowSpace: count
	      colSpace: 0];
    }

  /*
   * Rotate the newly created row to the insertion point if necessary.
   */
  if (_numRows != row)
    {
      id	*oldr = _cells[_numRows - 1];
      BOOL	*olds = _selectedCells[_numRows - 1];

      for (i = _numRows - 1; i > row; i--)
	{
	  _cells[i] = _cells[i-1];
	  _selectedCells[i] = _selectedCells[i-1];
	}
      _cells[row] = oldr;
      _selectedCells[row] = olds;
      if (_selectedCell && (_selectedRow >= row))
	_selectedRow++;

      if (_dottedRow != -1 && _dottedRow >= row)
	_dottedRow++;
    }

  /*
   * Put cells from the array into the matrix.
   */
  if (count > 0)
    {
      IMP	getImp = [cellArray methodForSelector: getSel];

      for (i = 0; i < _numCols && i < count; i++)
	{
	  ASSIGN(_cells[row][i], (*getImp)(cellArray, getSel, i));
	}
    }

  if (_mode == NSRadioModeMatrix && !_allowsEmptySelection
    && _selectedCell == nil)
    {
      [self selectCellAtRow: 0 column: 0];
    }
}

- (NSCell*) makeCellAtRow: (int)row
		   column: (int)column
{
  NSCell	*aCell;

  if (_cellPrototype != nil)
    {
      aCell = (*_cellNew)(_cellPrototype, copySel, _myZone);
    }
  else
    {
      aCell = (*_cellNew)(_cellClass, allocSel, _myZone);
      if (aCell != nil)
	{
	  aCell = (*_cellInit)(aCell, initSel);
	}
    }
  /*
   * This is only ever called when we are creating a new cell - so we know
   * we can simply assign a value into the matrix without releasing an old
   * value.  If someone uses this method directly (which the documentation
   * specifically says they shouldn't) they may produce a memory leak.
   */
  _cells[row][column] = aCell;
  return aCell;
}

- (NSRect) cellFrameAtRow: (int)row
		   column: (int)column
{
  NSRect rect;

  rect.origin.x = column * (_cellSize.width + _intercell.width);
  if (_rFlags.flipped_view)
    {
      rect.origin.y = row * (_cellSize.height + _intercell.height);
    }
  else
    {
      rect.origin.y = (_numRows - row - 1)
	* (_cellSize.height + _intercell.height);
    }
  rect.size = _cellSize;
  return rect;
}

- (void) getNumberOfRows: (int*)rowCount
		 columns: (int*)columnCount
{
  *rowCount = _numRows;
  *columnCount = _numCols;
}

- (void) putCell: (NSCell*)newCell
	   atRow: (int)row
	  column: (int)column
{
  if (row < 0 || row >= _numRows || column < 0 || column >= _numCols)
    {
      [NSException raise: NSRangeException
		  format: @"attempt to put cell outside matrix bounds"];
    }

  if ((row == _selectedRow) && (column == _selectedColumn) 
    && (_selectedCell != nil))
    {
      _selectedCell = newCell;
    }
  
  ASSIGN(_cells[row][column], newCell);

  [self setNeedsDisplayInRect: [self cellFrameAtRow: row column: column]];
}

- (void) removeColumn: (int)col
{
  if (col >= 0 && col < _numCols)
    {
      int i;

      for (i = 0; i < _maxRows; i++)
	{
	  int	j;

	  AUTORELEASE(_cells[i][col]);
	  for (j = col + 1; j < _maxCols; j++)
	    {
	      _cells[i][j-1] = _cells[i][j];
	      _selectedCells[i][j-1] = _selectedCells[i][j];
	    }
	}
      _numCols--;
      _maxCols--;

      if (col == _selectedColumn)
	{
	  _selectedCell = nil;
	  [self selectCellAtRow: _selectedRow column: 0];
	}
      if (col == _dottedColumn)
	{
	  if (_numCols && [_cells[_dottedRow][0] acceptsFirstResponder])
	    _dottedColumn = 0;
	  else
	    _dottedRow = _dottedColumn = -1;
	}
    }
  else
    {
#if	STRICT == 0
      NSLog(@"remove non-existent column (%d) from matrix", col);
#else
      [NSException raise: NSRangeException
		  format: @"remove non-existent column (%d) from matrix", col];
#endif
    }
}

- (void) removeRow: (int)row
{
  if (row >= 0 && row < _numRows)
    {
      int	i;

#if	GS_WITH_GC == 0
      for (i = 0; i < _maxCols; i++)
	{
	  [_cells[row][i] autorelease];
	}
#endif
      NSZoneFree(_myZone, _cells[row]);
      NSZoneFree(GSAtomicMallocZone(), _selectedCells[row]);
      for (i = row + 1; i < _maxRows; i++)
	{
	  _cells[i-1] = _cells[i];
	  _selectedCells[i-1] = _selectedCells[i];
	}
      _maxRows--;
      _numRows--;

      if (row == _selectedRow)
	{
	  _selectedCell = nil;
	  [self selectCellAtRow: 0 column: _selectedColumn];
	}
      if (row == _dottedRow)
	{
	  if (_numRows && [_cells[0][_dottedColumn] acceptsFirstResponder])
	    _dottedRow = 0;
	  else
	    _dottedRow = _dottedColumn = -1;
	}
    }
  else
    {
#if	STRICT == 0
      NSLog(@"remove non-existent row (%d) from matrix", row);
#else
      [NSException raise: NSRangeException
		  format: @"remove non-existent row (%d) from matrix", row];
#endif
    }
}

- (void) renewRows: (int)r
	   columns: (int)c
{
  [self _renewRows: r columns: c rowSpace: 0 colSpace: 0];
}

- (void) setCellSize: (NSSize)size
{
  _cellSize = size;
  [self sizeToCells];
}

- (void) setIntercellSpacing: (NSSize)size
{
  _intercell = size;
  [self sizeToCells];
}

- (void) sortUsingFunction: (int (*)(id element1, id element2,
				   void *userData))comparator
		   context: (void*)context
{
  NSMutableArray	*sorted;
  IMP			add;
  IMP			get;
  int			i, j, index = 0;

  sorted = [NSMutableArray arrayWithCapacity: _numRows * _numCols];
  add = [sorted methodForSelector: @selector(addObject:)];
  get = [sorted methodForSelector: @selector(objectAtIndex:)];

  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  (*add)(sorted, @selector(addObject:), _cells[i][j]);
	}
    }

  [sorted sortUsingFunction: comparator context: context];

  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  _cells[i][j] = (*get)(sorted, @selector(objectAtIndex:), index++);
	}
    }
}

- (void) sortUsingSelector: (SEL)comparator
{
  NSMutableArray	*sorted;
  IMP			add;
  IMP			get;
  int			i, j, index = 0;

  sorted = [NSMutableArray arrayWithCapacity: _numRows * _numCols];
  add = [sorted methodForSelector: @selector(addObject:)];
  get = [sorted methodForSelector: @selector(objectAtIndex:)];

  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  (*add)(sorted, @selector(addObject:), _cells[i][j]);
	}
    }

  [sorted sortUsingSelector: comparator];

  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  _cells[i][j] = (*get)(sorted, @selector(objectAtIndex:), index++);
	}
    }
}

- (BOOL) getRow: (int*)row
	 column: (int*)column
       forPoint: (NSPoint)point
{
  BOOL	betweenRows;
  BOOL	betweenCols;
  BOOL	beyondRows;
  BOOL	beyondCols;
  int	approxRow = point.y / (_cellSize.height + _intercell.height);
  float	approxRowsHeight = approxRow * (_cellSize.height + _intercell.height);
  int	approxCol = point.x / (_cellSize.width + _intercell.width);
  float	approxColsWidth = approxCol * (_cellSize.width + _intercell.width);

  /* First check the limit cases - is the point outside the matrix */
  beyondCols = (point.x > _bounds.size.width  || point.x < 0);
  beyondRows = (point.y > _bounds.size.height || point.y < 0);

  /* Determine if the point is inside a cell - note: if the point lies
     on the cell boundaries, we consider it inside the cell.  to be
     outside the cell (that is, in the intercell spacing) it must be
     completely in the intercell spacing - not on the border */
  /* The following is non zero if the point lies between rows (not inside 
     a cell) */
  betweenRows = (point.y < approxRowsHeight
		 || point.y > approxRowsHeight + _cellSize.height);
  betweenCols = (point.x < approxColsWidth
		 || point.x > approxColsWidth + _cellSize.width);

  if (beyondRows || betweenRows || beyondCols || betweenCols || 
      (_numCols == 0) || (_numRows == 0))
    {
      if (row)
	{
	  *row = -1;
	}

      if (column)
	{
	  *column = -1;
	}
      
      return NO;
    }

  if (row)
    {
      if (_rFlags.flipped_view == NO)
	{
	  approxRow = _numRows - approxRow - 1;
	}
      
      if (approxRow < 0)
	{
	  approxRow = 0;
	}
      else if (approxRow >= _numRows)
	{
	  approxRow = _numRows - 1;
	}
      *row = approxRow;
    }

  if (column)
    {
      if (approxCol < 0)
	{
	  approxCol = 0;
	}
      else if (approxCol >= _numCols)
	{
	  approxCol = _numCols - 1;
	}
      *column = approxCol;
    }

  return YES;
}

- (BOOL) getRow: (int*)row
	 column: (int*)column
	 ofCell: (NSCell*)aCell
{
  int	i;

  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  if (_cells[i][j] == aCell)
	    {
	      if(row)
		*row = i;
	      if(column)
		*column = j;
	      return YES;
	    }
	}
    }

  if(row)
    *row = -1;
  if(column)
    *column = -1;

  return NO;
}

- (void) setState: (int)value
	    atRow: (int)row
	   column: (int)column
{
  NSCell	*aCell = [self cellAtRow: row column: column];

  if (!aCell)
    return;

  if (_mode == NSRadioModeMatrix)
    {
      if (value)
	{
	  if (_selectedRow > -1 && _selectedColumn > -1)
	    {
	      _selectedCells[_selectedRow][_selectedColumn] = NO;
	    }

	  _selectedCell = aCell;
	  _selectedRow = row;
	  _selectedColumn = column;

	  if ([_cells[_dottedRow][_dottedColumn] acceptsFirstResponder])
	    {
	      _dottedRow = row;
	      _dottedColumn = column;
	    }

	  [_selectedCell setState: value];
	  _selectedCells[row][column] = YES;
	}
      else if (_allowsEmptySelection)
	{
	  [self deselectSelectedCell];
	}
    }
  else
    {
      [aCell setState: value];
    }
  [self setNeedsDisplayInRect: [self cellFrameAtRow: row column: column]];
}

- (void) deselectAllCells
{
  int		i;

  if (!_allowsEmptySelection && _mode == NSRadioModeMatrix)
    return;

  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  if (_selectedCells[i][j])
	    {
	      NSCell	*aCell = _cells[i][j];
	      BOOL       isHighlighted = [aCell isHighlighted];

	      _selectedCells[i][j] = NO;

	      if ([aCell state] || isHighlighted)
		{
		  [aCell setState: NSOffState];

		  if (isHighlighted)
		    [self highlightCell: NO atRow: i column: j];
		  else
		    [self drawCellAtRow: i column: j];
		}
	    }
	}
    }
  _selectedCell = nil;
  _selectedRow = -1;
  _selectedColumn = -1;
}

- (void) deselectSelectedCell
{
  int i,j;

  if (!_selectedCell
    || (!_allowsEmptySelection && (_mode == NSRadioModeMatrix)))
    return;

  /*
   * For safety (as in macosx)
   */
  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  if (_selectedCells[i][j])
	    {
	      [_cells[i][j] setState: NSOffState];
	      _selectedCells[i][j] = NO;
	    }
	}
    }

  _selectedCell = nil;
  _selectedRow = -1;
  _selectedColumn = -1;
}

- (void) selectAll: (id)sender
{
  unsigned	i, j;

  _selectedCell = nil;
  _selectedRow = -1;
  _selectedColumn = -1;

  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  if ([_cells[i][j] isEnabled] == YES
	    && [_cells[i][j] isEditable] == NO)
	    {
	      _selectedCell = _cells[i][j];
	      [_selectedCell setState: NSOnState];
	      _selectedCells[i][j] = YES;

	      _selectedRow = i;
	      _selectedColumn = j;
	    }
	  else
	    {
	      _selectedCells[i][j] = NO;
	      [_cells[i][j] setShowsFirstResponder: NO];
	    }
	}
    }

  [self setNeedsDisplay: YES];
}

- (void) _selectCell: (NSCell *)aCell atRow: (int)row column: (int)column
{
  /*
   * We always deselect the current selection unless the new selection
   * is the same. (in NSRadioModeMatrix)
   */
  if (_mode == NSRadioModeMatrix && _selectedCell && aCell
    && _selectedCell != aCell)
    {
      _selectedCells[_selectedRow][_selectedColumn] = NO;
      [_selectedCell setState: NSOffState];
      [self setNeedsDisplayInRect: [self cellFrameAtRow: _selectedRow
					 column: _selectedColumn]];
    }

  if (aCell)
    {
      NSRect cellFrame;

      if (_selectedCell && _selectedCell != aCell)
	{
	  [_selectedCell setShowsFirstResponder: NO];
	  [self setNeedsDisplayInRect: [self cellFrameAtRow: _selectedRow
					     column: _selectedColumn]];
	}

      _selectedCell = aCell;
      _selectedRow = row;
      _selectedColumn = column;
      _selectedCells[row][column] = YES;

      cellFrame = [self cellFrameAtRow: row column: column];

      if ([_cells[row][column] acceptsFirstResponder])
	{
	  int lastRow, lastColumn;

	  lastRow = _dottedRow;
	  lastColumn = _dottedColumn;

	  _dottedRow = row;
	  _dottedColumn = column;

	  if (lastRow != -1 && lastColumn != -1
	    && (lastRow != row || lastColumn != column) 
	    && [self window] != nil)
	    {
	      [self drawCellAtRow: lastRow column: lastColumn];
	    }
	}

      [_selectedCell setState: NSOnState];

      if (_mode == NSListModeMatrix)
	[aCell setCellAttribute: NSCellHighlighted to: 1];

      if (_autoscroll)
	[self scrollRectToVisible: cellFrame];

      // Note: we select the cell iff it is 'selectable', not 'editable' 
      // as macosx says.  This looks definitely more appropriate. 
      // [This is going to start editing only if the cell is also editable,
      // otherwise the text gets selected and that's all.]
      [self selectTextAtRow: row column: column];

      [self setNeedsDisplayInRect: cellFrame];
    }
  else
    {
      _selectedCell = nil;
      _selectedRow = _selectedColumn = -1;
    }
}

- (void) selectCell: (NSCell *)aCell
{
  int row, column;

  if ([self getRow: &row column: &column ofCell: aCell] == YES)
    [self _selectCell: aCell atRow: row column: column];
}

- (void) selectCellAtRow: (int)row column: (int)column
{
  NSCell	*aCell;

  if ((row == -1) || (column == -1))
    {
      [self deselectAllCells];
      return;
    }

  aCell = [self cellAtRow: row column: column];

  if (aCell)
    [self _selectCell: aCell atRow: row column: column];
}

- (BOOL) selectCellWithTag: (int)anInt
{
  id	aCell;
  int	i = _numRows;

  while (i-- > 0)
    {
      int	j = _numCols;

      while (j-- > 0)
	{
	  aCell = _cells[i][j];
	  if ([aCell tag] == anInt)
	    {
	      [self _selectCell: aCell atRow: i column: j];
	      return YES;
	    }
	}
    }
  return NO;
}

- (NSArray*) selectedCells
{
  NSMutableArray	*array = [NSMutableArray array];
  int	i;

  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  if (_selectedCells[i][j] == YES)
	    {
	      [array addObject: _cells[i][j]];
	    }
	}
    }
  return array;
}

- (void) setSelectionFrom: (int)startPos
		       to: (int)endPos
		   anchor: (int)anchorPos
	        highlight: (BOOL)flag
{
  BOOL	 doSelect = NO;
  BOOL	 doUnselect = NO;
  BOOL   drawLast = NO;
  int	 selectx = 0;
  int	 selecty = 0;
  int	 unselectx = 0;
  int	 unselecty = 0;
  int	 dca = endPos - anchorPos;
  int	 dla = startPos - anchorPos;
  int	 dca_dla = SIGN(dca) / (SIGN(dla) ? SIGN(dla) : 1);
  int    lastDottedRow, lastDottedColumn;
  MPoint end = POINT_FROM_INDEX(endPos);

  if (dca_dla >= 0)
    {
      if (ABS(dca) >= ABS(dla))
	{
	  doSelect = YES;
	  selectx = MIN(startPos, endPos);
	  selecty = MAX(startPos, endPos);
	}
      else
	{
	  doUnselect = YES;
	  drawLast = YES;
	  if (endPos < startPos)
	    {
	      unselectx = endPos + 1;
	      unselecty = startPos;
	    }
	  else
	    {
	      unselectx = startPos;
	      unselecty = endPos - 1;
	    }
	}
    }
  else
    {
      doSelect = YES;
      if (anchorPos < endPos)
	{
	  selectx = anchorPos;
	  selecty = endPos;
	}
      else
	{
	  selectx = endPos;
	  selecty = anchorPos;
	}

      doUnselect = YES;
      if (anchorPos < startPos)
	{
	  unselectx = anchorPos;
	  unselecty = startPos - 1;
	}
      else
	{
	  unselectx = startPos;
	  unselecty = anchorPos - 1;
	}
    }

  if (_dottedRow != -1 && _dottedColumn != -1
      && (_dottedRow != end.y || _dottedColumn != end.x))
    {
      lastDottedRow = _dottedRow;
      lastDottedColumn = _dottedColumn;

      [self drawCellAtRow: lastDottedRow column: lastDottedColumn];
    }

  _selectedRow = _dottedRow = end.y;
  _selectedColumn = _dottedColumn = end.x;
  _selectedCells[_selectedRow][_selectedColumn] = YES;
  _selectedCell = _cells[_selectedRow][_selectedColumn];

  if (doUnselect)
    {
      [self _setState: flag ? NSOffState : NSOnState
	    highlight: flag ? NO : YES
	    startIndex: unselectx
	    endIndex: unselecty];
    }
  if (doSelect)
    {
      [self _setState: flag ? NSOnState : NSOffState
	    highlight: flag ? YES : NO
	    startIndex: selectx
	    endIndex: selecty];
    }

  if (drawLast)
    [self drawCellAtRow: _dottedRow column: _dottedColumn];
}

- (id) cellAtRow: (int)row
	  column: (int)column
{
  if (row < 0 || row >= _numRows || column < 0 || column >= _numCols)
    return nil;
  return _cells[row][column];
}

- (id) cellWithTag: (int)anInt
{
  int	i = _numRows;

  while (i-- > 0)
    {
      int	j = _numCols;

      while (j-- > 0)
	{
	  id	aCell = _cells[i][j];

	  if ([aCell tag] == anInt)
	    {
	      return aCell;
	    }
	}
    }
  return nil;
}

- (NSArray*) cells
{
  NSMutableArray	*c;
  IMP			add;
  int			i;

  c = [NSMutableArray arrayWithCapacity: _numRows * _numCols];
  add = [c methodForSelector: @selector(addObject:)];
  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  (*add)(c, @selector(addObject:), _cells[i][j]);
	}
    }
  return c;
}

- (void) selectText: (id)sender
{
  // Attention, we are *not* doing what MacOS-X does.
  // But they are *not* doing what the OpenStep specification says.
  // This is a compromise -- and fully OpenStep compliant.
  NSSelectionDirection s =  NSDirectSelection;

  if (_window)
    s = [_window keyViewSelectionDirection];

  switch (s)
    {
      // _window selecting backwards
    case NSSelectingPrevious:
      [self _selectPreviousSelectableCellBeforeRow: _numRows
	    column: _numCols];
      break;
      // _Window selecting forward
    case NSSelectingNext:
      [self _selectNextSelectableCellAfterRow: -1
	    column: -1];
      break;
    case NSDirectSelection:
      // Someone else -- we have some freedom here
      if ([_selectedCell isSelectable])
	{
	  [self selectTextAtRow: _selectedRow
			 column: _selectedColumn];
	}
      else
	{
	  if (_keyCell != nil)
	    {
	      BOOL isValid;
	      int row, column;
	      
	      isValid = [self getRow: &row  column: &column  
			      ofCell: _keyCell];
	      if (isValid == YES)
		{
		  [self selectTextAtRow: row  column: column];
		}
	    }
	}
      break;
    }
}

- (id) selectTextAtRow: (int)row column: (int)column
{
  if (row < 0 || row >= _numRows || column < 0 || column >= _numCols)
    return self;

  // macosx doesn't select the cell if it isn't 'editable'; instead,
  // we select the cell if and only if it is 'selectable', which looks
  // more appropriate.  This is going to start editing if and only if
  // the cell is also 'editable'.
  if ([_cells[row][column] isSelectable] == NO)
    return nil;

  if (_textObject)
    {
      if (_selectedCell == _cells[row][column])
	{
	  [_textObject selectAll: self];
	  return _selectedCell;
	}
      else
	{
	  [self validateEditing];
	  [self abortEditing];
	}
    }

  // Now _textObject == nil
  {
    NSText *t = [_window fieldEditor: YES
			forObject: self];
    int length;

    if ([t superview] != nil)
      if ([t resignFirstResponder] == NO)
	return nil;

    if (_selectedCell && _selectedCell != _cells[row][column])
      {
	[_selectedCell setShowsFirstResponder: NO];
	[self setNeedsDisplayInRect: [self cellFrameAtRow: _selectedRow
					   column: _selectedColumn]];
      }

    _selectedCell = _cells[row][column];
    _selectedRow = row;
    _selectedColumn = column;

    if ([_cells[row][column] acceptsFirstResponder])
      {
	_dottedRow = row;
	_dottedColumn = column;
      }

    /* See comment in NSTextField */
    length = [[_selectedCell stringValue] length];
    _textObject = [_selectedCell setUpFieldEditorAttributes: t];
    [_selectedCell selectWithFrame: [self cellFrameAtRow: _selectedRow
					  column: _selectedColumn]
		   inView: self
		   editor: _textObject
		   delegate: self
		   start: 0
		   length: length];
    return _selectedCell;
  }
}

- (id) keyCell
{
  return _keyCell;
}

- (void) setKeyCell: (NSCell *)aCell 
{
  BOOL isValid;
  int row, column;

  isValid = [self getRow: &row  column: &column  ofCell: aCell];

  if (isValid == YES)
    {
      ASSIGN (_keyCell, aCell);
    }
}

- (id) nextText
{
  return _nextKeyView;
}

- (id) previousText
{
  return _previousKeyView;
}

- (void) textDidBeginEditing: (NSNotification *)aNotification
{
  NSMutableDictionary *d;

  d = [[NSMutableDictionary alloc] initWithDictionary: 
				     [aNotification userInfo]];
  AUTORELEASE (d);
  [d setObject: [aNotification object] forKey: @"NSFieldEditor"];
  [nc postNotificationName: NSControlTextDidBeginEditingNotification
      object: self
      userInfo: d];
}

- (void) textDidChange: (NSNotification *)aNotification
{
  NSMutableDictionary *d;
  NSFormatter *formatter;

  // MacOS-X asks us to inform the cell if possible.
  if ((_selectedCell != nil) && [_selectedCell respondsToSelector: 
						 @selector(textDidChange:)])
    [_selectedCell textDidChange: aNotification];

  d = [[NSMutableDictionary alloc] initWithDictionary: 
				     [aNotification userInfo]];
  AUTORELEASE (d);
  [d setObject: [aNotification object] forKey: @"NSFieldEditor"];

  [nc postNotificationName: NSControlTextDidChangeNotification
      object: self
      userInfo: d];

  formatter = [_cell formatter];
  if (formatter != nil)
    {
      /*
       * FIXME: This part needs heavy interaction with the yet to finish 
       * text system.
       *
       */
      NSString *partialString;
      NSString *newString = nil;
      NSString *error = nil;
      BOOL wasAccepted;
      
      partialString = [_textObject string];
      wasAccepted = [formatter isPartialStringValid: partialString 
			       newEditingString: &newString 
			       errorDescription: &error];

      if (wasAccepted == NO)
	{
	  [_delegate control:self 
		     didFailToValidatePartialString: partialString 
		     errorDescription: error];
	}

      if (newString != nil)
	{
	  NSLog (@"Unimplemented: should set string to %@", newString);
	  // FIXME ! This would reset editing !
	  //[_textObject setString: newString];
	}
      else
	{
	  if (wasAccepted == NO)
	    {
	      // FIXME: Need to delete last typed character (?!)
	      NSLog (@"Unimplemented: should delete last typed character");
	    }
	}
      
    }
}

- (void) textDidEndEditing: (NSNotification *)aNotification
{
  NSMutableDictionary *d;
  id textMovement;

  [self validateEditing];

  d = [[NSMutableDictionary alloc] initWithDictionary: 
				     [aNotification userInfo]];
  AUTORELEASE (d);
  [d setObject: [aNotification object] forKey: @"NSFieldEditor"];
  [nc postNotificationName: NSControlTextDidEndEditingNotification
      object: self
      userInfo: d];

  [_selectedCell endEditing: [aNotification object]];
  _textObject = nil;

  textMovement = [[aNotification userInfo] objectForKey: @"NSTextMovement"];
  if (textMovement)
    {
      switch ([(NSNumber *)textMovement intValue])
	{
	case NSReturnTextMovement:
	  if ([self sendAction] == NO)
	    {
	      NSEvent *event = [_window currentEvent];

	      if ([self performKeyEquivalent: event] == NO
		  && [_window performKeyEquivalent: event] == NO)
		[self selectText: self];
	    }
	  break;
	case NSTabTextMovement:
	  if (_tabKeyTraversesCells)
	    {
	      if([self _selectNextSelectableCellAfterRow: _selectedRow
		       column: _selectedColumn])
		break;
	    }
	  [_window selectKeyViewFollowingView: self];

	  if ([_window firstResponder] == _window)
	    {
	      if (_tabKeyTraversesCells)
		{
		  if([self _selectNextSelectableCellAfterRow: -1
			   column: -1])
		    break;
		}
	      [self selectText: self];
	    }
	  break;
	case NSBacktabTextMovement:
	  if (_tabKeyTraversesCells)
	    {
	      if([self _selectPreviousSelectableCellBeforeRow: _selectedRow
		       column: _selectedColumn])
		break;
	    }
	  [_window selectKeyViewPrecedingView: self];

	  if ([_window firstResponder] == _window)
	    {
	      if (_tabKeyTraversesCells)
		{
		  if([self _selectPreviousSelectableCellBeforeRow: _numRows
			   column: _numCols])
		    break;
		}
	      [self selectText: self];
	    }
	  break;
	}
    }
}

- (BOOL) textShouldBeginEditing: (NSText *)textObject
{
  if (_delegate && [_delegate respondsToSelector:
				@selector(control:textShouldBeginEditing:)])
    return [_delegate control: self
		      textShouldBeginEditing: textObject];
  else
    return YES;
}

- (BOOL) textShouldEndEditing: (NSText *)aTextObject
{
  if ([_selectedCell isEntryAcceptable: [aTextObject text]] == NO)
    {
      [self sendAction: _errorAction to: _target];
      return NO;
    }

  if ([_delegate respondsToSelector:
		   @selector(control:textShouldEndEditing:)])
    {
      if ([_delegate control: self
		     textShouldEndEditing: aTextObject] == NO)
	{
	  NSBeep ();
	  return NO;
	}
    }

  if ([_delegate respondsToSelector: 
		   @selector(control:isValidObject:)] == YES)
    {
      NSFormatter *formatter;
      id newObjectValue;
      
      formatter = [_cell formatter];
      
      if ([formatter getObjectValue: &newObjectValue 
		     forString: [_textObject text] 
		     errorDescription: NULL] == YES)
	{
	  if ([_delegate control: self
			 isValidObject: newObjectValue] == NO)
	    return NO;
	}
    }

  // In all other cases
  return YES;
}

- (BOOL) tabKeyTraversesCells
{
  return _tabKeyTraversesCells;
}

- (void) setTabKeyTraversesCells: (BOOL)flag
{
  _tabKeyTraversesCells = flag;
}

- (void) setNextText: (id)anObject
{
  [self setNextKeyView: anObject];
}

- (void) setPreviousText: (id)anObject
{
  [self setPreviousKeyView: anObject];
}

- (void) setValidateSize: (BOOL)flag
{
  // TODO
}

- (void) sizeToCells
{
  NSSize newSize;
  int nc = _numCols;
  int nr = _numRows;

  if (!nc)
    nc = 1;
  if (!nr)
    nr = 1;
  newSize.width = nc * (_cellSize.width + _intercell.width) - _intercell.width;
  newSize.height = nr * (_cellSize.height + _intercell.height) - _intercell.height;
  [self setFrameSize: newSize];
}
  
- (void) sizeToFit
{
  /*
   * A simple explanation of the logic behind this method.
   *
   * Example of when you would like to use this method:
   * you have a matrix containing radio buttons.  Say that you have the 
   * following radio buttons - 
   *
   * * First option
   * * Second option
   * * Third option
   * * No thanks, no option for me
   *
   * this method should size the matrix so that it can comfortably
   * show all the cells it contains.  To do it, we must consider that
   * all the cells should be given the same size, yet some cells need
   * more space than the others to show their contents, so we need to
   * choose the cell size as to be enough to display every cell.  We
   * loop on all cells, call cellSize on each (which returns the
   * *minimum* comfortable size to display that cell), and choose a
   * final cellSize which is enough big to be bigger than all these
   * cellSizes.  We resize the matrix to have that cellSize, and
   * that's it.  */
  NSSize newSize = NSZeroSize;

  int i, j;

  for (i = 0; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  NSSize tempSize = [_cells[i][j] cellSize];
	  tempSize.height = ceil(tempSize.height);
	  tempSize.width = ceil(tempSize.width);
	  if (tempSize.width > newSize.width)
	    {
	      newSize.width = tempSize.width;
	    }
	  if (tempSize.height > newSize.height)
	    {
	      newSize.height = tempSize.height;
	    }
	}
    }
  
  [self setCellSize: newSize];
}

- (void) scrollCellToVisibleAtRow: (int)row
			   column: (int)column
{
  [self scrollRectToVisible: [self cellFrameAtRow: row column: column]];
}

- (void) setAutoscroll: (BOOL)flag
{
  _autoscroll = flag;
}

- (void) setScrollable: (BOOL)flag
{
  int	i;

  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  [_cells[i][j] setScrollable: flag];
	}
    }
  [_cellPrototype setScrollable: flag];
}

- (void) drawRect: (NSRect)rect
{
  int i, j;
  int row1, col1;	// The cell at the upper left corner
  int row2, col2;	// The cell at the lower right corner

  if (_drawsBackground)
    {
      [_backgroundColor set];
      NSRectFill(rect);
    }

  if (!_numRows || !_numCols)
    return;

  row1 = rect.origin.y / (_cellSize.height + _intercell.height);
  col1 = rect.origin.x / (_cellSize.width + _intercell.width);
  row2 = NSMaxY(rect) / (_cellSize.height + _intercell.height);
  col2 = NSMaxX(rect) / (_cellSize.width + _intercell.width);

  if (_rFlags.flipped_view == NO)
    {
      row1 = _numRows - row1 - 1;
      row2 = _numRows - row2 - 1;
    }

  if (row1 < 0)
    row1 = 0;
  else if (row1 >= _numRows)
    row1 = _numRows - 1;

  if (col1 < 0)
    col1 = 0;
  else if (col1 >= _numCols)
    col1 = _numCols - 1;

  if (row2 < 0)
    row2 = 0;
  else if (row1 >= _numRows)
    row2 = _numRows - 1;

  if (col2 < 0)
    col2 = 0;
  else if (col2 >= _numCols)
    col2 = _numCols - 1;

  /* Draw the cells within the drawing rectangle. */
  for (i = row1; i <= row2 && i < _numRows; i++)
    for (j = col1; j <= col2 && j < _numCols; j++)
      {
	[self drawCellAtRow: i column: j];
      }
}

- (BOOL) isOpaque
{
  return _drawsBackground;
}

- (void) drawCell: (NSCell *)aCell
{
  int row, column;

  if ([self getRow: &row  column: &column  ofCell: aCell] == YES)
    {
      [self drawCellAtRow: row  column: column];
    }
}

- (void) drawCellAtRow: (int)row column: (int)column
{
  NSCell *aCell = [self cellAtRow: row column: column];

  if (aCell)
    {
      NSRect cellFrame = [self cellFrameAtRow: row column: column];

      if (_drawsCellBackground)
	{
	  [self lockFocus];
	  [_cellBackgroundColor set];
	  NSRectFill(cellFrame);
	  [self unlockFocus];
	}

      if (_dottedRow == row && _dottedColumn == column
	  && [aCell acceptsFirstResponder])
	{
	  [aCell
	    setShowsFirstResponder: ([_window isKeyWindow]
				     && [_window firstResponder] == self)];
	}
      else
	[aCell setShowsFirstResponder: NO];

      [aCell drawWithFrame: cellFrame inView: self];
      [aCell setShowsFirstResponder: NO];
    }
}

- (void) highlightCell: (BOOL)flag atRow: (int)row column: (int)column
{
  NSCell	*aCell = [self cellAtRow: row column: column];

  if (aCell)
    {
      NSRect cellFrame = [self cellFrameAtRow: row column: column];

      if (_drawsCellBackground)
	{
	  [self lockFocus];
	  [_cellBackgroundColor set];
	  NSRectFill(cellFrame);
	  [self unlockFocus];
	}

      if (_dottedRow != -1 && _dottedColumn != -1
	  && _cells[_dottedRow][_dottedColumn] == aCell
	  && [_cells[_dottedRow][_dottedColumn] acceptsFirstResponder])
	{
	  [_cells[_dottedRow][_dottedColumn]
		 setShowsFirstResponder:
		   ([_window isKeyWindow]
		    && [_window firstResponder] == self)];
	}

      [aCell highlight: flag
             withFrame: cellFrame
                inView: self];

      if (_dottedRow != -1 && _dottedColumn != -1)
	[_cells[_dottedRow][_dottedColumn] setShowsFirstResponder: NO];
    }
}

- (BOOL) sendAction
{
  if (_selectedCell)
    {
      if ([_selectedCell isEnabled] == NO)
	return NO;

      return [self sendAction: [_selectedCell action] 
		   to:         [_selectedCell target]]; 
    }

  // _selectedCell == nil
  return [super sendAction: _action to: _target];
}

- (BOOL) sendAction: (SEL)theAction
		 to: (id)theTarget
{
  if (theAction)
    {
      if (theTarget)
	{
	  return [super sendAction: theAction to: theTarget];
	}
      else
	{
	  return [super sendAction: theAction to: _target];
	}
    }
  else
    {
      return [super sendAction: _action to: _target];
    }
}

- (void) sendAction: (SEL)aSelector
		 to: (id)anObject
        forAllCells: (BOOL)flag
{
  int	i;

  if (flag)
    {
      for (i = 0; i < _numRows; i++)
	{
	  int	j;

	  for (j = 0; j < _numCols; j++)
	    {
	      if (![anObject performSelector: aSelector
				  withObject: _cells[i][j]])
		{
		  return;
		}
	    }
	}
    }
  else
    {
      for (i = 0; i < _numRows; i++)
	{
	  int	j;

	  for (j = 0; j < _numCols; j++)
	    {
	      if (_selectedCells[i][j])
		{
		  if (![anObject performSelector: aSelector
				      withObject: _cells[i][j]])
		    {
		      return;
		    }
		}
	    }
	}
    }
}

- (void) sendDoubleAction
{
  if ([_selectedCell isEnabled] == NO)
    return;

  if (_doubleAction)
    [self sendAction: _doubleAction to: _target];
  else
    [self sendAction];
}

- (BOOL) acceptsFirstMouse: (NSEvent*)theEvent
{
  if (_mode == NSListModeMatrix)
    return NO;
  else
    return YES;
}

- (void) _mouseDownNonListMode: (NSEvent *)theEvent
{
  BOOL mouseUpInCell = NO, onCell, scrolling = NO;
  NSCell *highlightedCell = nil;
  int highlightedRow = 0;
  int highlightedColumn = 0;
  NSCell *mouseCell;
  int mouseRow;
  int mouseColumn;
  NSPoint mouseLocation;
  NSRect mouseCellFrame;
  NSEvent *currentEvent = nil;
  unsigned eventMask = NSLeftMouseUpMask | NSLeftMouseDownMask
                     | NSMouseMovedMask  | NSLeftMouseDraggedMask;

  while (!mouseUpInCell && ([theEvent type] != NSLeftMouseUp))
    {
      mouseLocation = [self convertPoint: [theEvent locationInWindow]
                                fromView: nil];

      onCell = [self getRow: &mouseRow
		     column: &mouseColumn
		     forPoint: mouseLocation];

      if (!onCell)
	scrolling = NO;

      if (onCell)
	{
	  mouseCellFrame = [self cellFrameAtRow: mouseRow column: mouseColumn];
	  mouseCell = [self cellAtRow: mouseRow column: mouseColumn];

	  if (_autoscroll)
	    scrolling = [self scrollRectToVisible: mouseCellFrame];

	  if ([mouseCell isEnabled])
	    {
	      if ([mouseCell acceptsFirstResponder])
		{
		  NSCell *aCell = [self cellAtRow: _dottedRow
					column: _dottedColumn];

		  _dottedRow = mouseRow;
		  _dottedColumn = mouseColumn;

		  if (aCell && aCell != mouseCell)
		    [self drawCell: aCell];
		}

	      if (_selectedCell)
		{
		  if (_mode == NSRadioModeMatrix)
		    {
		      [_selectedCell setState: NSOffState];
		      [self drawCell: _selectedCell];
		    }

		  _selectedCells[_selectedRow][_selectedColumn] = NO;
		}

	      _selectedCell = mouseCell;
	      _selectedRow = mouseRow;
	      _selectedColumn = mouseColumn;
	      _selectedCells[_selectedRow][_selectedColumn] = YES;

	      if (_mode != NSTrackModeMatrix && highlightedCell != mouseCell)
		{
		  highlightedCell = mouseCell;
		  highlightedRow = mouseRow;
		  highlightedColumn = mouseColumn;

		  [self highlightCell: YES
			atRow: highlightedRow
			column: highlightedColumn];
		  [_window flushWindow];
		}

	      if (_mode == NSRadioModeMatrix)
		[mouseCell setState: NSOffState];

	      mouseUpInCell = [mouseCell trackMouse: theEvent
                                         inRect: mouseCellFrame
                                         ofView: self
					 untilMouseUp:
					   [[mouseCell class]
					     prefersTrackingUntilMouseUp]];

	      if (_mode != NSTrackModeMatrix)
		{
		  if(_mode == NSRadioModeMatrix)
		    {
		      if (!mouseUpInCell)
			[mouseCell setState: NSOnState];
		    }

		  highlightedCell = nil;

		  [self highlightCell: NO
			atRow: highlightedRow
			column: highlightedColumn];
		  [_window flushWindow];
		}

	      if (!mouseUpInCell)
		{
		  ASSIGN(currentEvent, [NSApp currentEvent]);

		  if (currentEvent && currentEvent != theEvent
		      && [currentEvent type] != NSPeriodic)
		    {
		      if (!scrolling)
			{
			  theEvent = currentEvent;
			  continue;
			}
		    }
		  else
		    DESTROY(currentEvent);
		}
	    }
	}
      else if (_mode != NSRadioModeMatrix)
        {
          // mouse is not over a Cell
	  if (_selectedCell != nil)
	    {
	      if ([_selectedCell state])
		{
		  [_selectedCell setState: NSOffState];
		  [self drawCell: _selectedCell];
		}

	      _selectedCells[_selectedRow][_selectedColumn] = NO;
	      _selectedCell = nil;
	      _selectedRow = _selectedColumn = -1;
	    }
        }

      // if mouse didn't go up, take next event
      if (!mouseUpInCell)
	{
	  theEvent = [NSApp nextEventMatchingMask: eventMask
			    untilDate: !scrolling || !currentEvent
			    ? [NSDate distantFuture]
			    : [NSDate dateWithTimeIntervalSinceNow: 0.05]
			    inMode: NSEventTrackingRunLoopMode
			    dequeue: YES];

	  if (scrolling && !theEvent)
	    theEvent = currentEvent;
	  else
	    DESTROY(currentEvent);
	}
    }

  RELEASE(currentEvent);

  // the mouse went up.
  // if it was inside a cell, the cell has already sent the action.
  // if not, _selectedCell is the last cell that had the mouse, and
  // it's state is Off. It must be set into a consistent state.
  // anyway, the action has to be sent
  if (!mouseUpInCell)
    {
      if (_mode != NSRadioModeMatrix)
	{
	  if (_selectedCell != nil)
	    {
	      _selectedCells[_selectedRow][_selectedColumn] = NO;
	      _selectedCell = nil;
	      _selectedRow = _selectedColumn = -1;
	    }
	}
      [self sendAction];
    }
}


- (void) mouseDown: (NSEvent*)theEvent
{
  BOOL onCell;
  int row, column;
  unsigned eventMask = NSLeftMouseUpMask | NSLeftMouseDownMask
			| NSMouseMovedMask | NSLeftMouseDraggedMask
			| NSPeriodicMask;
  NSPoint lastLocation = [theEvent locationInWindow];
  NSEvent* lastEvent = nil;
  BOOL done = NO;
  NSRect rect;
  id aCell, previousCell = nil;
  NSRect previousRect;
  NSApplication *app = [NSApplication sharedApplication];
  static MPoint anchor = {0, 0};
  int clickCount;

  /*
   * Pathological case -- ignore mouse down
   */
  if ((_numRows == 0) || (_numCols == 0))
    {
      [super mouseDown: theEvent];
      return; 
    }

  // Manage multi-click events
  clickCount = [theEvent clickCount];

  if (clickCount > 2)
    return;

  if (clickCount == 2 && (_ignoresMultiClick == NO))
    {
      [self sendDoubleAction];
      return;
    }

  // From now on, code to manage simple-click events

  lastLocation = [self convertPoint: lastLocation
		       fromView: nil];

  // If mouse down was on a selectable cell, start editing/selecting.
  if ([self getRow: &row
	    column: &column
	    forPoint: lastLocation])
    {
      if ([_cells[row][column] isEnabled])
	{
	  if ((_mode == NSRadioModeMatrix) && _selectedCell != nil)
	    {
	      [_selectedCell setState: NSOffState];
	      [self drawCellAtRow: _selectedRow column: _selectedColumn];
	      [_window flushWindow];
	      _selectedCells[_selectedRow][_selectedColumn] = NO;
	      _selectedCell = nil;
	      _selectedRow = _selectedColumn = -1;
	    }

	  if ([_cells[row][column] isSelectable])
	    {
	      NSText* t = [_window fieldEditor: YES forObject: self];

	      if ([t superview] != nil)
		{
		  if ([t resignFirstResponder] == NO)
		    {
		      if ([_window makeFirstResponder: _window] == NO)
			return;
		    }
		}
	      // During editing, the selected cell is the cell being edited
	      _selectedCell = _cells[row][column];
	      _selectedRow = row;
	      _selectedColumn = column;
	      if ([_cells[row][column] acceptsFirstResponder])
		{
		  _dottedRow = row;
		  _dottedColumn = column;
		}
	      _textObject = [_selectedCell setUpFieldEditorAttributes: t];
	      [_selectedCell editWithFrame: [self cellFrameAtRow: row
						  column: column]
			     inView: self
			     editor: _textObject
			     delegate: self
			     event: theEvent];
	      return;
	    }
	}
    }

  // Paranoia check -- _textObject should already be nil, since we
  // accept first responder, so NSWindow should have already given
  // us first responder status (thus already ending editing with _textObject).
  if (_textObject)
    {
      NSLog (@"Hi, I am a bug.");
      [self validateEditing];
      [self abortEditing];
    }

  mouseDownFlags = [theEvent modifierFlags];

  if (_mode != NSListModeMatrix)
    {
      [self _mouseDownNonListMode: theEvent];
      return;
    }

  [NSEvent startPeriodicEventsAfterDelay: 0.05
	   withPeriod: 0.05];
  ASSIGN(lastEvent, theEvent);

  // selection involves two steps, first
  // a loop that continues until the left mouse goes up; then a series of
  // steps which send actions and display the cell as it should appear after
  // the selection process is complete
  while (!done)
    {
      BOOL shouldProceedEvent = NO;

      onCell = [self getRow: &row
		     column: &column
		     forPoint: lastLocation];

      if (onCell)
	{
	  aCell = [self cellAtRow: row column: column];
	  rect = [self cellFrameAtRow: row column: column];

	  if (_autoscroll)
	    [self scrollRectToVisible: rect];

	  if (aCell != previousCell && [aCell isEnabled] == YES)
	    {
	      unsigned modifiers = [lastEvent modifierFlags];

	      // List mode allows multiple cells to be selected

	      // When the user first clicks on a cell
	      // we clear the existing selection
	      // unless the Alternate or Shift keys have been pressed.

	      if (!previousCell)
		{
		  if (!(modifiers & NSShiftKeyMask)
		      && !(modifiers & NSAlternateKeyMask))
		    {
		      [self deselectAllCells];
		      anchor = MakePoint (column, row);
		    }

		  // Consider the selected cell as the
		  // anchor from which to extend the
		  // selection to the current cell
		  if (!(modifiers & NSAlternateKeyMask))
		    [self _selectCell: aCell atRow: row column: column];
		}
	      else
		{
		  [self setSelectionFrom:
			  INDEX_FROM_COORDS(_selectedColumn, _selectedRow)
			to: INDEX_FROM_COORDS(column, row)
			anchor: INDEX_FROM_POINT(anchor)
			highlight: YES];
		}

	      [_window flushWindow];

	      previousCell = aCell;
	      previousRect = rect;
	    }
	}

      // if done break out of selection loop
      if (done)
	break;

      while (!shouldProceedEvent)
	{
	  theEvent = [app nextEventMatchingMask: eventMask
				      untilDate: [NSDate distantFuture]
					 inMode: NSEventTrackingRunLoopMode
				        dequeue: YES];
	  switch ([theEvent type])
	    {
	    case NSPeriodic:
	      NSDebugLog(@"NSMatrix: got NSPeriodic event\n");
	      shouldProceedEvent = YES;
	      break;

	    case NSLeftMouseUp:
	      done = YES;
	    case NSLeftMouseDown:
	    default:
	      shouldProceedEvent = YES;
	      NSDebugLog(@"NSMatrix: got event of type: %d\n",
			 [theEvent type]);
	      ASSIGN(lastEvent, theEvent);
	      continue;
	    }
	}
      lastLocation = [lastEvent locationInWindow];
      lastLocation = [self convertPoint: lastLocation fromView: nil];
    }

  [self setNeedsDisplayInRect: rect];
  [_window flushWindow];

  [NSEvent stopPeriodicEvents];

  [self sendAction];
  
  RELEASE(lastEvent);
}

- (void) updateCell: (NSCell*)aCell
{
  int		row, col;
  NSRect	rect;

  if ([self getRow: &row column: &col ofCell: aCell] == NO)
    return;	// Not a cell in this matrix - we can't update it.

  rect = [self cellFrameAtRow: row column: col];
  [self setNeedsDisplayInRect: rect];
}

- (BOOL) performKeyEquivalent: (NSEvent*)theEvent
{
  NSString	*key = [theEvent charactersIgnoringModifiers];
  int		i;

  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  NSCell	*aCell = _cells[i][j];;

	  if ([aCell isEnabled]
	    && [[aCell keyEquivalent] isEqualToString: key])
	    {
	      NSCell *oldSelectedCell = _selectedCell;
	      int     oldSelectedRow = _selectedRow; 
	      int     oldSelectedColumn = _selectedColumn;

	      _selectedCell = aCell;
	      [self highlightCell: YES atRow: i column: j];
	      [aCell setNextState];
	      [self sendAction];
	      [self highlightCell: NO atRow: i column: j];
	      _selectedCell = oldSelectedCell;
	      _selectedRow = oldSelectedRow;
	      _selectedColumn = oldSelectedColumn;

	      return YES;
	    }
	}
    }

  return NO;
}

- (void) resetCursorRects
{
  int	i;

  for (i = 0; i < _numRows; i++)
    {
      int	j;

      for (j = 0; j < _numCols; j++)
	{
	  NSCell	*aCell = _cells[i][j];

	  [aCell resetCursorRect: [self cellFrameAtRow: i column: j]
		 inView: self];
	}
    }
}

- (void) encodeWithCoder: (NSCoder*)aCoder
{
  [super encodeWithCoder: aCoder];

  [aCoder encodeValueOfObjCType: @encode (int) at: &_mode];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_allowsEmptySelection];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_selectionByRect];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_autosizesCells];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_autoscroll];
  [aCoder encodeSize: _cellSize];
  [aCoder encodeSize: _intercell];
  [aCoder encodeObject: _backgroundColor];
  [aCoder encodeObject: _cellBackgroundColor];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_drawsBackground];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_drawsCellBackground];
  [aCoder encodeObject: NSStringFromClass (_cellClass)];
  [aCoder encodeObject: _cellPrototype];
  [aCoder encodeValueOfObjCType: @encode (int) at: &_numRows];
  [aCoder encodeValueOfObjCType: @encode (int) at: &_numCols];
  
  /* This is slower, but does not expose NSMatrix internals and will work 
     with subclasses */
  [aCoder encodeObject: [self cells]];
  
  [aCoder encodeConditionalObject: _delegate];
  [aCoder encodeConditionalObject: _target];
  [aCoder encodeValueOfObjCType: @encode (SEL) at: &_action];
  [aCoder encodeValueOfObjCType: @encode (SEL) at: &_doubleAction];
  [aCoder encodeValueOfObjCType: @encode (SEL) at: &_errorAction];
  [aCoder encodeValueOfObjCType: @encode (BOOL) at: &_tabKeyTraversesCells];
  [aCoder encodeObject: _keyCell];
  /* We do not encode information on selected cells, because this is saved 
     with the cells themselves */
}

- (id) initWithCoder: (NSCoder*)aDecoder
{
  Class class;
  id cell;
  int rows, columns;
  NSArray *array;
  int i, count;

  [super initWithCoder: aDecoder];

  _myZone = [self zone];
  [aDecoder decodeValueOfObjCType: @encode (int) at: &_mode];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_allowsEmptySelection];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_selectionByRect];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_autosizesCells];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_autoscroll];
  _cellSize = [aDecoder decodeSize];
  _intercell = [aDecoder decodeSize];
  [aDecoder decodeValueOfObjCType: @encode (id) at: &_backgroundColor];
  [aDecoder decodeValueOfObjCType: @encode (id) at: &_cellBackgroundColor];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_drawsBackground];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_drawsCellBackground];

  class = NSClassFromString ((NSString *)[aDecoder decodeObject]);
  if (class != Nil)
    {
      [self setCellClass: class]; 
    }

  cell = [aDecoder decodeObject];
  if (cell != nil)
    {
      [self setPrototype: cell];
    }

  if (_cellPrototype == nil)
    {
      [self setCellClass: [isa cellClass]];
    }

  [aDecoder decodeValueOfObjCType: @encode (int) at: &rows];
  [aDecoder decodeValueOfObjCType: @encode (int) at: &columns];

  /* NB: This works without changes for NSForm */
  array = [aDecoder decodeObject];
  [self renewRows: rows  columns: columns];
  count = [array count];
  if (count != rows * columns)
    {
      NSLog (@"Trying to decode an invalid NSMatrix: cell number does not fit matrix dimension");
      // Quick fix to do what we can
      if (count > rows * columns)
	{
	  count = rows * columns;
	}
    }

  _selectedRow = _selectedColumn = 0;

  for (i = 0; i < count; i++)
    {
      int row, column;
      cell = [array objectAtIndex: i];

      row = i / columns;
      column = i % columns;
      
      [self putCell:cell   atRow: row   column: column];
      if ([cell state])
	 {
	   [self selectCellAtRow: row   column: column];
	 }
     }

  [aDecoder decodeValueOfObjCType: @encode (id) at: &_delegate];
  [aDecoder decodeValueOfObjCType: @encode (id) at: &_target];
  [aDecoder decodeValueOfObjCType: @encode (SEL) at: &_action];
  [aDecoder decodeValueOfObjCType: @encode (SEL) at: &_doubleAction];
  [aDecoder decodeValueOfObjCType: @encode (SEL) at: &_errorAction];
  [aDecoder decodeValueOfObjCType: @encode (BOOL) at: &_tabKeyTraversesCells];
  [self setKeyCell: [aDecoder decodeObject]];
  
  return self;
}

- (void) setMode: (NSMatrixMode)aMode
{
  _mode = aMode;
}

- (NSMatrixMode) mode
{
  return _mode;
}

- (void) setCellClass: (Class)class
{
  _cellClass = class;
  if (_cellClass == nil)
    {
      _cellClass = defaultCellClass;
    }
  _cellNew = [_cellClass methodForSelector: allocSel];
  _cellInit = [_cellClass instanceMethodForSelector: initSel];
  DESTROY(_cellPrototype);
}

- (Class) cellClass
{
  return _cellClass;
}

- (void) setPrototype: (NSCell*)aCell
{
  ASSIGN(_cellPrototype, aCell);
  if (_cellPrototype == nil)
    {
      [self setCellClass: defaultCellClass];
    }
  else
    {
      _cellNew = [_cellPrototype methodForSelector: copySel];
      _cellInit = 0;
      _cellClass = [aCell class];
    }
}

- (id) prototype
{
  return _cellPrototype;
}

- (NSSize) cellSize
{
  return _cellSize;
}

- (NSSize) intercellSpacing
{
  return _intercell;
}

- (void) setBackgroundColor: (NSColor*)c
{
  ASSIGN(_backgroundColor, c);
}

- (NSColor*) backgroundColor
{
  return _backgroundColor;
}

- (void) setCellBackgroundColor: (NSColor*)c
{
  ASSIGN(_cellBackgroundColor, c);
}

- (NSColor*) cellBackgroundColor
{
  return _cellBackgroundColor;
}

- (void) setDelegate: (id)object
{
  if (_delegate)
    [nc removeObserver: _delegate name: nil object: self];
  _delegate = object;

#define SET_DELEGATE_NOTIFICATION(notif_name) \
  if ([_delegate respondsToSelector: @selector(controlText##notif_name:)]) \
    [nc addObserver: _delegate \
      selector: @selector(controlText##notif_name:) \
      name: NSControlText##notif_name##Notification object: self]

  if (_delegate)
    {
      SET_DELEGATE_NOTIFICATION(DidBeginEditing);
      SET_DELEGATE_NOTIFICATION(DidEndEditing);
      SET_DELEGATE_NOTIFICATION(DidChange);
    }
}

- (id) delegate
{
  return _delegate;
}

- (void) setTarget: anObject
{
  _target = anObject;
}

- (id) target
{
  return _target;
}

- (void) setAction: (SEL)sel
{
  _action = sel;
}

- (SEL) action
{
  return _action;
}

// NB: In GNUstep the following method does *not* set 
// ignoresMultiClick to NO as in the MacOS-X spec. 
// It simply sets the doubleAction, as in OpenStep spec.
- (void) setDoubleAction: (SEL)sel
{
  _doubleAction = sel;
}

- (SEL) doubleAction
{
  return _doubleAction;
}

- (void) setErrorAction: (SEL)sel
{
  _errorAction = sel;
}

- (SEL) errorAction
{
  return _errorAction;
}

- (void) setAllowsEmptySelection: (BOOL)f
{
  _allowsEmptySelection = f;
}

- (BOOL) allowsEmptySelection
{
  return _allowsEmptySelection;
}

- (void) setSelectionByRect: (BOOL)flag
{
  _selectionByRect = flag;
}

- (BOOL) isSelectionByRect
{
  return _selectionByRect;
}

- (void) setDrawsBackground: (BOOL)flag
{
  _drawsBackground = flag;
}

- (BOOL) drawsBackground
{
  return _drawsBackground;
}

- (void) setDrawsCellBackground: (BOOL)f
{
  _drawsCellBackground = f;
}

- (BOOL) drawsCellBackground
{
  return _drawsCellBackground;
}

- (void) setAutosizesCells: (BOOL)flag
{
  _autosizesCells = flag;
}

- (BOOL) autosizesCells
{
  return _autosizesCells;
}

- (BOOL) isAutoscroll
{
  return _autoscroll;
}

- (int) numberOfRows
{
  return _numRows;
}

- (int) numberOfColumns
{
  return _numCols;
}

- (id) selectedCell
{
  return _selectedCell;
}

- (int) selectedColumn
{
  return _selectedColumn;
}

- (int) selectedRow
{
  return _selectedRow;
}

- (int) mouseDownFlags
{
  return mouseDownFlags;
}

- (BOOL) isFlipped
{
  return YES;
}

- (void) resizeWithOldSuperviewSize: (NSSize)oldSize
{
  NSSize oldBoundsSize = _bounds.size;
  NSSize newBoundsSize;
  NSSize change;
  int nc = _numCols;
  int nr = _numRows;

  [super resizeWithOldSuperviewSize: oldSize];

  newBoundsSize = _bounds.size;

  change.height = newBoundsSize.height - oldBoundsSize.height;
  change.width = newBoundsSize.width - oldBoundsSize.width;

  if (_autosizesCells)
    {
      if (change.height != 0)
	{
	  if (nr <= 0) nr = 1;
	  if (_cellSize.height == 0)
	    {
	      _cellSize.height = oldBoundsSize.height
		- ((nr - 1) * _intercell.height);
	      _cellSize.height = _cellSize.height / nr;
	    }
	  change.height = change.height / nr;
	  _cellSize.height += change.height;
	  _cellSize.height = rint(_cellSize.height);
	  if (_cellSize.height < 0)
	    _cellSize.height = 0;
	}
      if (change.width != 0)
	{
	  if (nc <= 0) nc = 1;
	  if (_cellSize.width == 0)
	    {
	      _cellSize.width = oldBoundsSize.width
		- ((nc - 1) * _intercell.width);
	      _cellSize.width = _cellSize.width / nc;
	    }
	  change.width = change.width / nc;
	  _cellSize.width += change.width;
	  _cellSize.width = rint(_cellSize.width);
	  if (_cellSize.width < 0)
	    _cellSize.width = 0;
	}
    }
  else // !autosizesCells
    {
      if (change.height != 0)
	{
	  if (nr > 1)
	    {
	      if (_intercell.height == 0)
		{
		  _intercell.height = oldBoundsSize.height - (nr * _cellSize.height);
		  _intercell.height = _intercell.height / (nr - 1);
		}
	      change.height = change.height / (nr - 1);
	      _intercell.height += change.height;
	      if (_intercell.height < 0)
		_intercell.height = 0;
	    }
	}
      if (change.width != 0)
	{
	  if (nc > 1)
	    {
	      if (_intercell.width == 0)
		{
		  _intercell.width = oldBoundsSize.width - (nc * _cellSize.width);
		  _intercell.width = _intercell.width / (nc - 1);
		}
	      change.width = change.width / (nc - 1);
	      _intercell.width += change.width;
	      if (_intercell.width < 0)
		_intercell.width = 0;
	    }
	}
    }
  [self setNeedsDisplay: YES];
}

- (void)_move:(unichar)pos
{
  BOOL selectCell = NO;
  int h, i, lastDottedRow, lastDottedColumn;

  if (_mode == NSRadioModeMatrix || _mode == NSListModeMatrix)
    selectCell = YES;

  if (_dottedRow == -1 || _dottedColumn == -1)
    {
      if (pos == NSUpArrowFunctionKey || pos == NSDownArrowFunctionKey)
	{
	  for (h = 0; h < _numCols; h++)
	    {
	      for (i = 0; i < _numRows; i++)
		{
		  if ([_cells[i][h] acceptsFirstResponder])
		    {
		      _dottedRow = i;
		      _dottedColumn = h;
		      break;
		    }
		}

	      if (i == _dottedRow)
		break;
	    }
	}
      else
	{
	  for (i = 0; i < _numRows; i++)
	    {
	      for (h = 0; h < _numCols; h++)
		{
		  if ([_cells[i][h] acceptsFirstResponder])
		    {
		      _dottedRow = i;
		      _dottedColumn = h;
		      break;
		    }
		}

	      if (h == _dottedColumn)
		break;
	    }
	}

      if (_dottedRow == -1 || _dottedColumn == -1)
	return;

      if (selectCell)
	{
	  if (_selectedCell)
	    {
	      if (_mode == NSRadioModeMatrix)
		{
		  NSCell *aCell = _selectedCell;

		  [aCell setState: NSOffState];
		  _selectedCells[_selectedRow][_selectedColumn] = NO;
		  _selectedRow = _selectedColumn = -1;
		  _selectedCell = nil;

		  [self drawCell: aCell];
		}
	      else
		[self deselectAllCells];
	    }

	  [self selectCellAtRow: _dottedRow column: _dottedColumn];
	}
      else
	[self drawCellAtRow: _dottedRow column: _dottedColumn];
    }
  else
    {
      lastDottedRow = _dottedRow;
      lastDottedColumn = _dottedColumn;

      if (pos == NSUpArrowFunctionKey)
	{
	  if (_dottedRow <= 0)
	    return;

	  for (i = _dottedRow-1; i >= 0; i--)
	    {
	      if ([_cells[i][_dottedColumn] acceptsFirstResponder])
		{
		  _dottedRow = i;
		  break;
		}
	    }
	}
      else if (pos == NSDownArrowFunctionKey)
	{
	  if (_dottedRow >= _numRows-1)
	    return;

	  for (i = _dottedRow+1; i < _numRows; i++)
	    {
	      if ([_cells[i][_dottedColumn] acceptsFirstResponder])
		{
		  _dottedRow = i;
		  break;
		}
	    }
	}
      else if (pos == NSLeftArrowFunctionKey)
	{
	  if (_dottedColumn <= 0)
	    return;

	  for (i = _dottedColumn-1; i >= 0; i--)
	    {
	      if ([_cells[_dottedRow][i] acceptsFirstResponder])
		{
		  _dottedColumn = i;
		  break;
		}
	    }
	}
      else
	{
	  if (_dottedColumn >= _numCols-1)
	    return;

	  for (i = _dottedColumn+1; i < _numCols; i++)
	    {
	      if ([_cells[_dottedRow][i] acceptsFirstResponder])
		{
		  _dottedColumn = i;
		  break;
		}
	    }
	}

      if ((pos == NSUpArrowFunctionKey || pos == NSDownArrowFunctionKey)
	  && _dottedRow != i)
	return;

      if ((pos == NSLeftArrowFunctionKey || pos == NSRightArrowFunctionKey)
	  && _dottedColumn != i)
	return;

      if (selectCell)
	{
	  if (_mode == NSRadioModeMatrix)
	    {
	      NSCell *aCell = _cells[lastDottedRow][lastDottedColumn];
	      BOOL    isHighlighted = [aCell isHighlighted];

	      if ([aCell state] || isHighlighted)
		{
		  [aCell setState: NSOffState];
		  _selectedCells[lastDottedRow][lastDottedColumn] = NO;
		  _selectedRow = _selectedColumn = -1;
		  _selectedCell = nil;

		  if (isHighlighted)
		    [self highlightCell: NO
			  atRow: lastDottedRow
			  column: lastDottedColumn];
		  else
		    [self drawCell: aCell];
		}
	    }
	  else
	    [self deselectAllCells];

	  [self selectCellAtRow: _dottedRow column: _dottedColumn];
	}
      else
	{
	  [self drawCell: _cells[lastDottedRow][lastDottedColumn]];
	  [self drawCell: _cells[_dottedRow][_dottedColumn]];
	}
    }

  [_window flushWindow];

  if (selectCell)
    {
      [self performClick: self];
      [_window flushWindow];
    }
}

- (void)moveUp:(id)sender
{
  [self _move: NSUpArrowFunctionKey];
}

- (void)moveDown:(id)sender
{
  [self _move: NSDownArrowFunctionKey];
}

- (void)moveLeft:(id)sender
{
  [self _move: NSLeftArrowFunctionKey];
}

- (void)moveRight:(id)sender
{
  [self _move: NSRightArrowFunctionKey];
}

- (void) _shiftModifier:(unichar)character
{
  int i, lastDottedRow, lastDottedColumn;

  lastDottedRow = _dottedRow;
  lastDottedColumn = _dottedColumn;

  if (character == NSUpArrowFunctionKey)
    {
      if (_dottedRow <= 0)
	return;

      for (i = _dottedRow-1; i >= 0; i--)
	{
	  if ([_cells[i][_dottedColumn] acceptsFirstResponder])
	    {
	      _dottedRow = i;
	      break;
	    }
	}

      if (_dottedRow != i)
	return;
    }
  else if (character == NSDownArrowFunctionKey)
    {
      if (_dottedRow < 0 || _dottedRow >= _numRows-1)
	return;

      for (i = _dottedRow+1; i < _numRows; i++)
	{
	  if ([_cells[i][_dottedColumn] acceptsFirstResponder])
	    {
	      _dottedRow = i;
	      break;
	    }
	}
    }
  else if (character == NSLeftArrowFunctionKey)
    {
      if (_dottedColumn <= 0)
	return;

      for (i = _dottedColumn-1; i >= 0; i--)
	{
	  if ([_cells[_dottedRow][i] acceptsFirstResponder])
	    {
	      _dottedColumn = i;
	      break;
	    }
	}
    }
  else
    {
      if (_dottedColumn < 0 || _dottedColumn >= _numCols-1)
	return;

      for (i = _dottedColumn+1; i < _numCols; i++)
	{
	  if ([_cells[_dottedRow][i] acceptsFirstResponder])
	    {
	      _dottedColumn = i;
	      break;
	    }
	}
    }

  [self drawCell: _cells[lastDottedRow][_dottedColumn]];
  [self drawCell: _cells[_dottedRow][_dottedColumn]];
  [_window flushWindow];

  [self performClick: self];
}

- (void) _altModifier:(unichar)character
{
  switch (character)
    {
    case NSUpArrowFunctionKey:
      if (_dottedRow <= 0)
	return;

      _dottedRow--;
      break;

    case NSDownArrowFunctionKey:
      if (_dottedRow < 0 || _dottedRow >= _numRows-1)
	return;

      _dottedRow++;
      break;

    case NSLeftArrowFunctionKey:
      if (_dottedColumn <= 0)
	return;

      _dottedColumn--;
      break;

    case NSRightArrowFunctionKey:
      if (_dottedColumn < 0 || _dottedColumn >= _numCols-1)
	return;

      _dottedColumn++;
      break;
    }

  [self setSelectionFrom:
	  INDEX_FROM_COORDS(_selectedRow, _selectedColumn)
	to: INDEX_FROM_COORDS(_dottedRow, _dottedColumn)
	anchor: INDEX_FROM_COORDS(_selectedRow, _selectedColumn)
	highlight: YES];

  [self performClick: self];
}

- (void) keyDown: (NSEvent *)theEvent
{
  NSString *characters = [theEvent characters];
  unsigned modifiers = [theEvent modifierFlags];
  unichar  character = 0;

  if ([characters length] > 0)
    {
      character = [characters characterAtIndex: 0];
    }

  switch (character)
    {
    case NSCarriageReturnCharacter:
    case NSNewlineCharacter:
    case NSEnterCharacter: 
      [self selectText: self];
      break;

    case ' ':
      if (_dottedRow != -1 && _dottedColumn != -1)
	{
	  if (modifiers & NSAlternateKeyMask)
	    [self _altModifier: character];
	  else
	    {
	      NSCell *cell;

	      switch (_mode)
		{
		case NSTrackModeMatrix:
		case NSHighlightModeMatrix:
		  cell = _cells[_dottedRow][_dottedColumn];

		  [cell setNextState];
		  [self drawCell: cell];
		  break;

		case NSListModeMatrix:
		  if (!(modifiers & NSShiftKeyMask))
		    [self deselectAllCells];

		case NSRadioModeMatrix:
		  [self selectCellAtRow: _dottedRow column: _dottedColumn];
		  break;
		}

	      [_window flushWindow];
	      [self performClick: self];
	    }
	  return;
	}
      break;

    case NSLeftArrowFunctionKey:
    case NSRightArrowFunctionKey:
      if (_numCols <= 1)
	break;

    case NSUpArrowFunctionKey:
    case NSDownArrowFunctionKey:
      if (modifiers & NSShiftKeyMask)
	[self _shiftModifier: character];
      else if (modifiers & NSAlternateKeyMask)
	[self _altModifier: character];
      else
	{
	  if (character == NSUpArrowFunctionKey)
	    [self moveUp: self];
	  else if (character == NSDownArrowFunctionKey)
	    [self moveDown: self];
	  else if (character == NSLeftArrowFunctionKey)
	    [self moveLeft: self];
	  else
	    [self moveRight: self];
	}
      return;

    case NSTabCharacter:
      if (_tabKeyTraversesCells)
	{
	  if ([theEvent modifierFlags] & NSShiftKeyMask)
	    {
	      if([self _selectNextSelectableCellAfterRow: _selectedRow
		       column: _selectedColumn])
		return;
	    }
	  else
	    {
	      if([self _selectPreviousSelectableCellBeforeRow: _selectedRow
		       column: _selectedColumn])
		return;
	    }
	}
      break;

    default:
      break;
    }

  [super keyDown: theEvent];
}

- (void) performClick: (id)sender
{
  [super sendAction: _action to: _target];
}

- (BOOL) acceptsFirstResponder
{
  // We gratefully accept keyboard events.
  return YES;
}

- (void) _setNeedsDisplayDottedCell
{
  if (_dottedRow != -1 && _dottedColumn != -1)
    {
      [self setNeedsDisplayInRect: [self cellFrameAtRow: _dottedRow
					 column: _dottedColumn]];
    }
}

- (BOOL) becomeFirstResponder
{
  [self _setNeedsDisplayDottedCell];

  return YES;
}

- (BOOL) resignFirstResponder
{
  [self _setNeedsDisplayDottedCell];

  return YES;
}

- (void) becomeKeyWindow
{
  [self _setNeedsDisplayDottedCell];
}

- (void) resignKeyWindow
{
  [self _setNeedsDisplayDottedCell];
}

- (BOOL) abortEditing
{
  if (_textObject)
    {
      [_textObject setString: @""];
      [_selectedCell endEditing: _textObject];
      _textObject = nil;
      return YES;
    }
  else
    return NO;
}

- (NSText *) currentEditor
{
  if (_textObject && ([_window firstResponder] == _textObject))
    return _textObject;
  else
    return nil;
}

- (void) validateEditing
{
  if (_textObject)
    {
      NSFormatter *formatter;
      NSString *string;

      formatter = [_selectedCell formatter];
      string = AUTORELEASE ([[_textObject text] copy]);

      if (formatter == nil)
	{
	  [_selectedCell setStringValue: string];
	}
      else
	{
	  id newObjectValue;
	  NSString *error;
 
	  if ([formatter getObjectValue: &newObjectValue 
			 forString: string 
			 errorDescription: &error] == YES)
	    {
	      [_selectedCell setObjectValue: newObjectValue];
	    }
	  else
	    {
	      if ([_delegate control: self 
			     didFailToFormatString: string 
			     errorDescription: error] == YES)
		{
		  [_selectedCell setStringValue: string];
		}
	      
	    }
	}
    }
}

@end


@implementation NSMatrix (PrivateMethods)

/*
 * Renew rows and columns, but when expanding the matrix, refrain from
 * creating rowSpace  items in the last row and colSpace items in the
 * last column.  When inserting the contents of an array into the matrix,
 * this avoids creation of new cless which would immediately be replaced
 * by those from the array.
 * NB. new spaces in the matrix are pre-initialised with nil values so
 * that replacing them doesn't cause attempts to release random memory.
 */
- (void) _renewRows: (int)row
	    columns: (int)col
	   rowSpace: (int)rowSpace
	   colSpace: (int)colSpace
{
  int		i, j;
  int		oldMaxC;
  int		oldMaxR;
  SEL		mkSel = @selector(makeCellAtRow:column:);
  IMP		mkImp = [self methodForSelector: mkSel];

//NSLog(@"%x - mr: %d mc:%d nr:%d nc:%d r:%d c:%d", (unsigned)self, _maxRows, _maxCols, _numRows, _numCols, row, col);
  if (row < 0)
    {
#if	STRICT == 0
      NSLog(@"renew negative row (%d) in matrix", row);
#else
      [NSException raise: NSRangeException
		  format: @"renew negative row (%d) in matrix", row];
#endif
      row = 0;
    }
  if (col < 0)
    {
#if	STRICT == 0
      NSLog(@"renew negative column (%d) in matrix", col);
#else
      [NSException raise: NSRangeException
		  format: @"renew negative column (%d) in matrix", col];
#endif
      col = 0;
    }

  /*
   * Update matrix dimension before we actually change it - so that
   * makeCellAtRow:column: diesn't think we are trying to make a cell
   * outside the array bounds.
   * Our implementation doesn't care, but a subclass might use
   * putCell:atRow:column: to implement it, and that checks bounds.
   */
  oldMaxC = _maxCols;
  _numCols = col;
  if (col > _maxCols)
    _maxCols = col;
  oldMaxR = _maxRows;
  _numRows = row;
  if (row > _maxRows)
    _maxRows = row;

  if (col > oldMaxC)
    {
      int	end = col - 1;

      for (i = 0; i < oldMaxR; i++)
	{
	  _cells[i] = NSZoneRealloc(_myZone, _cells[i], col * sizeof(id));
	  _selectedCells[i] = NSZoneRealloc(GSAtomicMallocZone(),
	    _selectedCells[i], col * sizeof(BOOL));

	  for (j = oldMaxC; j < col; j++)
	    {
	      _cells[i][j] = nil;
	      _selectedCells[i][j] = NO;
	      if (j == end && colSpace > 0)
		{
		  colSpace--;
		}
	      else
		{
		  (*mkImp)(self, mkSel, i, j);
		}
	    }
	}
    }

  if (row > oldMaxR)
    {
      int	end = row - 1;

      _cells = NSZoneRealloc(_myZone, _cells, row * sizeof(id*));
      _selectedCells = NSZoneRealloc(_myZone, _selectedCells, row * sizeof(BOOL*));

      /* Allocate the new rows and fill them */
      for (i = oldMaxR; i < row; i++)
	{
	  _cells[i] = NSZoneMalloc(_myZone, col * sizeof(id));
	  _selectedCells[i] = NSZoneMalloc(GSAtomicMallocZone(),
	    col * sizeof(BOOL));

	  if (i == end)
	    {
	      for (j = 0; j < col; j++)
		{
		  _cells[i][j] = nil;
		  _selectedCells[i][j] = NO;
		  if (rowSpace > 0)
		    {
		      rowSpace--;
		    }
		  else
		    {
		      (*mkImp)(self, mkSel, i, j);
		    }
		}
	    }
	  else
	    {
	      for (j = 0; j < col; j++)
		{
		  _cells[i][j] = nil;
		  _selectedCells[i][j] = NO;
		  (*mkImp)(self, mkSel, i, j);
		}
	    }
	}
    }

  [self deselectAllCells];
//NSLog(@"%x - end mr: %d mc:%d nr:%d nc:%d r:%d c:%d", (unsigned)self, _maxRows, _maxCols, _numRows, _numCols, row, col);
}

- (void) _setState: (int)state
	 highlight: (BOOL)highlight
	startIndex: (int)start
	  endIndex: (int)end
{
  int		i;
  MPoint	startPoint = POINT_FROM_INDEX(start);
  MPoint	endPoint = POINT_FROM_INDEX(end);

  for (i = startPoint.y; i <= endPoint.y; i++)
    {
      int	j;
      int	colLimit;

      if (i == startPoint.y)
	{
	  j = startPoint.x;
	}
      else
	{
	  j = 0;
	}

      if (_selectionByRect || i == endPoint.y)
	colLimit = endPoint.x;
      else
	colLimit = _numCols - 1;

      for (; j <= colLimit; j++)
	{
	  NSCell	*aCell = _cells[i][j];

	  [aCell setState: state];

	  if (state == NSOffState)
	    _selectedCells[i][j] = NO;
	  else
	    _selectedCells[i][j] = YES;

	  [aCell setCellAttribute: NSCellHighlighted to: highlight];
	  [self drawCell: aCell];
	}
    }

  [_window flushWindow];
}

// Return YES on success; NO if no selectable cell found.
-(BOOL) _selectNextSelectableCellAfterRow: (int)row
				   column: (int)column
{
  int i,j;

  if (row > -1)
    {
      // First look for cells in the same row
      for (j = column + 1; j < _numCols; j++)
	{
	  if ([_cells[row][j] isEnabled] && [_cells[row][j] isSelectable])
	    {
	      _selectedCell = [self selectTextAtRow: row
				    column: j];
	      _selectedRow = row;
	      _selectedColumn = j;
	      return YES;
	    }
	}
    }
  // Otherwise, make the big cycle.
  for (i = row + 1; i < _numRows; i++)
    {
      for (j = 0; j < _numCols; j++)
	{
	  if ([_cells[i][j] isEnabled] && [_cells[i][j] isSelectable])
	    {
	      _selectedCell = [self selectTextAtRow: i
				    column: j];
	      _selectedRow = i;
	      _selectedColumn = j;
	      return YES;
	    }
	}
    }
  return NO;
}

-(BOOL) _selectPreviousSelectableCellBeforeRow: (int)row
					column: (int)column
{
  int i,j;

  if (row < _numRows)
    {
      // First look for cells in the same row
      for (j = column - 1; j > -1; j--)
	{
	  if ([_cells[row][j] isEnabled] && [_cells[row][j] isSelectable])
	    {
	      _selectedCell = [self selectTextAtRow: row column: j];
	      _selectedRow = row;
	      _selectedColumn = j;
	      return YES;
	    }
	}
    }
  // Otherwise, make the big cycle.
  for (i = row - 1; i > -1; i--)
    {
      for (j = _numCols - 1; j > -1; j--)
	{
	  if ([_cells[i][j] isEnabled] && [_cells[i][j] isSelectable])
	    {
	      _selectedCell = [self selectTextAtRow: i column: j];
	      _selectedRow = i;
	      _selectedColumn = j;
	      return YES;
	    }
	}
    }
  return NO;
}
@end