001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ----------------
028 * Arrangement.java
029 * ----------------
030 * (C) Copyright 2004-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.block;
038
039import java.awt.Graphics2D;
040import org.jfree.chart.ui.Size2D;
041
042/**
043 * An object that is responsible for arranging a collection of {@link Block}s
044 * within a {@link BlockContainer}.
045 */
046public interface Arrangement {
047
048    /**
049     * Adds a block and a key which can be used to determine the position of
050     * the block in the arrangement.  This method is called by the container
051     * (you don't need to call this method directly) and gives the arrangement
052     * an opportunity to record the details if they are required.
053     *
054     * @param block  the block.
055     * @param key  the key ({@code null} permitted).
056     */
057    void add(Block block, Object key);
058
059    /**
060     * Arranges the blocks within the specified container, subject to the given
061     * constraint.
062     *
063     * @param container  the container ({@code null} not permitted).
064     * @param g2  the graphics device.
065     * @param constraint  the constraint.
066     *
067     * @return The container size after the arrangement.
068     */
069    Size2D arrange(BlockContainer container,
070                   Graphics2D g2,
071                   RectangleConstraint constraint);
072
073    /**
074     * Clears any cached layout information retained by the arrangement.
075     */
076    void clear();
077
078}