/* This file is part of the KDE project
   Copyright 2006-2007 Stefan Nikolaus <stefan.nikolaus@kdemail.net>

   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, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#ifndef KSPREAD_RECALC_MANAGER
#define KSPREAD_RECALC_MANAGER

#include <Region.h>

namespace KSpread
{
class Cell;
class Map;
class Sheet;

/**
 * \class RecalcManager
 * \brief Manages the recalculations of cells containing a formula.
 *
 * The recalculations of a cell region, a sheet or the map are based
 * on the following principle:
 *
 * A cell could refer to other cells, which need to be recalculated
 * before. The order of recalculation is determined by the depth of
 * references, i.e. first the cells, which do not refer to other cells,
 * are recalculated. Cells referring to those are next. Then cells, which
 * refer to the ones in the last step follow and so on until all cells
 * have been updated.
 *
 * Cell value changes are blocked while doing this, i.e. they do not
 * trigger a new recalculation event.
 */
class KSPREAD_EXPORT RecalcManager
{
public:
  /**
   * Creates a RecalcManager. It is used for a whole map.
   *
   * \param map The Map which this RecalcManager belongs to.
   */
  explicit RecalcManager( const Map* map );

  /**
   * Destructor.
   */
  ~RecalcManager();

  /**
   * Recalculates the cells referring to cells in \p region .
   * The cells are recalculated sorted by the reference depth in ascending order.
   *
   * \see recalc()
   */
  void regionChanged(const Region& region);

  /**
   * Recalculates the sheet \p sheet .
   * The cells are recalculated sorted by the reference depth in ascending order.
   *
   * \see recalc()
   */
  void recalcSheet(Sheet* const sheet);

  /**
   * Recalculates the whole map.
   * The cells are recalculated sorted by the reference depth in ascending order.
   *
   * \see recalc()
   */
  void recalcMap();

  /**
   * Returns the recalculation state.
   * \return \c true, if recalculations are in progress
   */
  bool isActive() const;

  /**
   * Prints out the cell depths in the current recalculation event.
   */
  void dump() const;

protected:
  /**
   * Iterates over the map of cell with their reference depths
   * and calls recalcCell().
   *
   * \see recalcCell()
   */
  void recalc();

private:
    Q_DISABLE_COPY( RecalcManager )

    class Private;
    Private * const d;
};

} // namespace KSpread

#endif // KSPREAD_RECALC_MANAGER
