001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 2004-2007, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes:
036 * --------
037 * 22-Oct-2004 : Version 1 (DG);
038 * 11-Feb-2005 : Modified arrange() method to return Size2D (DG);
039 * 22-Apr-2005 : Reordered arguments in arrange() method (DG);
040 * 
041 */
042
043package org.jfree.chart.block;
044
045import java.awt.Graphics2D;
046
047import org.jfree.ui.Size2D;
048
049/**
050 * An object that is responsible for arranging a collection of {@link Block}s
051 * within a {@link BlockContainer}.
052 */
053public interface Arrangement {
054    
055    /**
056     * Adds a block and a key which can be used to determine the position of 
057     * the block in the arrangement.  This method is called by the container 
058     * (you don't need to call this method directly) and gives the arrangement
059     * an opportunity to record the details if they are required.
060     * 
061     * @param block  the block.
062     * @param key  the key (<code>null</code> permitted).
063     */
064    public void add(Block block, Object key);
065    
066    /**
067     * Arranges the blocks within the specified container, subject to the given
068     * constraint.
069     * 
070     * @param container  the container.
071     * @param g2  the graphics device.
072     * @param constraint  the constraint.
073     * 
074     * @return The container size after the arrangement.
075     */
076    public Size2D arrange(BlockContainer container, 
077                          Graphics2D g2,
078                          RectangleConstraint constraint);
079
080    /**
081     * Clears any cached layout information retained by the arrangement.
082     */
083    public void clear();
084    
085}