001    /*
002     * Copyright (c) 2005 Einar Pehrson <einar@pehrson.nu>.
003     *
004     * This file is part of
005     * CleanSheets - a spreadsheet application for the Java platform.
006     *
007     * CleanSheets is free software; you can redistribute it and/or modify
008     * it under the terms of the GNU General Public License as published by
009     * the Free Software Foundation; either version 2 of the License, or
010     * (at your option) any later version.
011     *
012     * CleanSheets is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
015     * GNU General Public License for more details.
016     *
017     * You should have received a copy of the GNU General Public License
018     * along with CleanSheets; if not, write to the Free Software
019     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
020     */
021    package csheets.core.formula.lang;
022    
023    import java.util.SortedSet;
024    import java.util.TreeSet;
025    
026    import csheets.core.Cell;
027    import csheets.core.Value;
028    import csheets.core.formula.BinaryOperation;
029    import csheets.core.formula.Reference;
030    import csheets.core.formula.util.ExpressionVisitor;
031    import csheets.core.formula.util.ExpressionVisitorException;
032    
033    /**
034     * A binary reference operation in a formula.
035     * @author Einar Pehrson
036     */
037    public class ReferenceOperation extends BinaryOperation implements Reference {
038    
039            /** The unique version identifier used for serialization */
040            private static final long serialVersionUID = 1767227655524985408L;
041    
042            /** The cells that constitute the range */
043            private SortedSet<Cell> cells;
044    
045            /**
046             * Creates a new reference operation.
047             * @param leftOperand the left(first) operand
048             * @param operator the reference operator
049             * @param rightOperand the right(second) operand
050             */
051            public ReferenceOperation(Reference leftOperand, RangeReference operator, Reference rightOperand) {
052                    super(leftOperand, operator, rightOperand);
053            }
054    
055            public SortedSet<Cell> getCells() {
056                    if (cells == null) {
057                            cells = new TreeSet<Cell>();
058                            Cell[][] range = getOperator().getCells(getLeftOperand(), getRightOperand());
059                            for (int row = 0; row < range.length; row++)
060                                    for (int column = 0; column < range[row].length; column++)
061                                            cells.add(range[row][column]);
062                    }
063                    return cells;
064            }
065    
066            public RangeReference getOperator() {
067                    return (RangeReference)operator;
068            }
069    
070            public Reference getLeftOperand() {
071                    return (Reference)super.getLeftOperand();
072            }
073    
074            public Reference getRightOperand() {
075                    return (Reference)super.getRightOperand();
076            }
077    
078            public Value evaluate() {
079                    return getOperator().applyTo(getLeftOperand(), getRightOperand());
080            }
081    
082            public Object accept(ExpressionVisitor visitor) throws ExpressionVisitorException {
083                    return visitor.visitReference(this);
084            }
085    
086            public int compareTo(Reference reference) {
087                    Cell otherCell = reference.getCells().first();
088                    int firstDiff = getCells().first().compareTo(otherCell);
089                    if (firstDiff != 0)
090                            return firstDiff;
091                    else
092                            if (reference instanceof CellReference)
093                                    return 1;
094                            else
095                                    return getCells().last().compareTo(reference.getCells().last());
096            }
097    }