001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it 
010     * under the terms of the GNU Lesser General Public License as published by 
011     * the Free Software Foundation; either version 2.1 of the License, or 
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but 
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022     * USA.  
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * ----------------
028     * Arrangement.java
029     * ----------------
030     * (C) Copyright 2004, 2005, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: Arrangement.java,v 1.5.2.1 2005/10/25 20:39:38 mungady Exp $
036     *
037     * Changes:
038     * --------
039     * 22-Oct-2004 : Version 1 (DG);
040     * 11-Feb-2005 : Modified arrange() method to return Size2D (DG);
041     * 22-Apr-2005 : Reordered arguments in arrange() method (DG);
042     * 
043     */
044    
045    package org.jfree.chart.block;
046    
047    import java.awt.Graphics2D;
048    
049    import org.jfree.ui.Size2D;
050    
051    /**
052     * An object that is responsible for arranging a collection of {@link Block}s
053     * within a {@link BlockContainer}.
054     */
055    public interface Arrangement {
056        
057        /**
058         * Adds a block and a key which can be used to determine the position of 
059         * the block in the arrangement.  This method is called by the container 
060         * (you don't need to call this method directly) and gives the arrangement
061         * an opportunity to record the details if they are required.
062         * 
063         * @param block  the block.
064         * @param key  the key (<code>null</code> permitted).
065         */
066        public void add(Block block, Object key);
067        
068        /**
069         * Arranges the blocks within the specified container, subject to the given
070         * constraint.
071         * 
072         * @param container  the container.
073         * @param g2  the graphics device.
074         * @param constraint  the constraint.
075         * 
076         * @return The container size after the arrangement.
077         */
078        public Size2D arrange(BlockContainer container, 
079                              Graphics2D g2,
080                              RectangleConstraint constraint);
081    
082        /**
083         * Clears any cached layout information retained by the arrangement.
084         */
085        public void clear();
086        
087    }