/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 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 Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ----------------
 * Arrangement.java
 * ----------------
 * (C) Copyright 2004-2007, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes:
 * --------
 * 22-Oct-2004 : Version 1 (DG);
 * 11-Feb-2005 : Modified arrange() method to return Size2D (DG);
 * 22-Apr-2005 : Reordered arguments in arrange() method (DG);
 * 
 */

package org.jfree.chart.block;

import java.awt.Graphics2D;

import org.jfree.ui.Size2D;

/**
 * An object that is responsible for arranging a collection of {@link Block}s
 * within a {@link BlockContainer}.
 */
public interface Arrangement {
    
    /**
     * Adds a block and a key which can be used to determine the position of 
     * the block in the arrangement.  This method is called by the container 
     * (you don't need to call this method directly) and gives the arrangement
     * an opportunity to record the details if they are required.
     * 
     * @param block  the block.
     * @param key  the key (<code>null</code> permitted).
     */
    public void add(Block block, Object key);
    
    /**
     * Arranges the blocks within the specified container, subject to the given
     * constraint.
     * 
     * @param container  the container.
     * @param g2  the graphics device.
     * @param constraint  the constraint.
     * 
     * @return The container size after the arrangement.
     */
    public Size2D arrange(BlockContainer container, 
                          Graphics2D g2,
                          RectangleConstraint constraint);

    /**
     * Clears any cached layout information retained by the arrangement.
     */
    public void clear();
    
}
