ReferenceOperation.java :  » ERP-CRM-Financial » csheets » csheets » core » formula » lang » Java Open Source

/*
 * Copyright (c) 2005 Einar Pehrson <einar@pehrson.nu>.
 *
 * This file is part of
 * CleanSheets - a spreadsheet application for the Java platform.
 *
 * CleanSheets is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * CleanSheets 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with CleanSheets; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package csheets.core.formula.lang;

import java.util.SortedSet;
import java.util.TreeSet;

import csheets.core.Cell;
import csheets.core.Value;
import csheets.core.formula.BinaryOperation;
import csheets.core.formula.Reference;
import csheets.core.formula.util.ExpressionVisitor;
import csheets.core.formula.util.ExpressionVisitorException;

/**
 * A binary reference operation in a formula.
 * @author Einar Pehrson
 */
public class ReferenceOperation extends BinaryOperation implements Reference {

  /** The unique version identifier used for serialization */
  private static final long serialVersionUID = 1767227655524985408L;

  /** The cells that constitute the range */
  private SortedSet<Cell> cells;

  /**
   * Creates a new reference operation.
   * @param leftOperand the left(first) operand
   * @param operator the reference operator
   * @param rightOperand the right(second) operand
   */
  public ReferenceOperation(Reference leftOperand, RangeReference operator, Reference rightOperand) {
    super(leftOperand, operator, rightOperand);
  }

  public SortedSet<Cell> getCells() {
    if (cells == null) {
      cells = new TreeSet<Cell>();
      Cell[][] range = getOperator().getCells(getLeftOperand(), getRightOperand());
      for (int row = 0; row < range.length; row++)
        for (int column = 0; column < range[row].length; column++)
          cells.add(range[row][column]);
    }
    return cells;
  }

  public RangeReference getOperator() {
    return (RangeReference)operator;
  }

  public Reference getLeftOperand() {
    return (Reference)super.getLeftOperand();
  }

  public Reference getRightOperand() {
    return (Reference)super.getRightOperand();
  }

  public Value evaluate() {
    return getOperator().applyTo(getLeftOperand(), getRightOperand());
  }

  public Object accept(ExpressionVisitor visitor) throws ExpressionVisitorException {
    return visitor.visitReference(this);
  }

  public int compareTo(Reference reference) {
    Cell otherCell = reference.getCells().first();
    int firstDiff = getCells().first().compareTo(otherCell);
    if (firstDiff != 0)
      return firstDiff;
    else
      if (reference instanceof CellReference)
        return 1;
      else
        return getCells().last().compareTo(reference.getCells().last());
  }
}