title.java

java图形利器

/* ===========================================================
 * 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.]
 * 
 * ----------
 * Title.java
 * ----------
 * (C) Copyright 2000-2007, by David Berry and Contributors.
 *
 * Original Author:  David Berry;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *                   Nicolas Brodu;
 *
 * $Id: Title.java,v 1.10.2.2 2007/01/24 11:07:07 mungady Exp $
 *
 * Changes (from 21-Aug-2001)
 * --------------------------
 * 21-Aug-2001 : Added standard header (DG);
 * 18-Sep-2001 : Updated header (DG);
 * 14-Nov-2001 : Package com.jrefinery.common.ui.* changed to 
 *               com.jrefinery.ui.* (DG);
 * 07-Feb-2002 : Changed blank space around title from Insets --> Spacer, to 
 *               allow for relative or absolute spacing (DG);
 * 25-Jun-2002 : Removed unnecessary imports (DG);
 * 01-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 14-Oct-2002 : Changed the event listener storage structure (DG);
 * 11-Sep-2003 : Took care of listeners while cloning (NB);
 * 22-Sep-2003 : Spacer cannot be null. Added nullpointer checks for this (TM);
 * 08-Jan-2003 : Renamed AbstractTitle --> Title and moved to separate 
 *               package (DG);
 * 26-Oct-2004 : Refactored to implement Block interface, and removed redundant 
 *               constants (DG);
 * 11-Jan-2005 : Removed deprecated code in preparation for the 1.0.0 
 *               release (DG);
 * 02-Feb-2005 : Changed Spacer --> RectangleInsets for padding (DG);
 * 03-May-2005 : Fixed problem in equals() method (DG);
 * 
 */

package org.jfree.chart.title;

import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import javax.swing.event.EventListenerList;

import org.jfree.chart.block.AbstractBlock;
import org.jfree.chart.block.Block;
import org.jfree.chart.event.TitleChangeEvent;
import org.jfree.chart.event.TitleChangeListener;
import org.jfree.ui.HorizontalAlignment;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.RectangleInsets;
import org.jfree.ui.VerticalAlignment;
import org.jfree.util.ObjectUtilities;

/**
 * The base class for all chart titles.  A chart can have multiple titles, 
 * appearing at the top, bottom, left or right of the chart.
 * <P>
 * Concrete implementations of this class will render text and images, and 
 * hence do the actual work of drawing titles.
 */
public abstract class Title extends AbstractBlock 
                            implements Block, Cloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -6675162505277817221L;
    
    /** The default title position. */
    public static final RectangleEdge DEFAULT_POSITION = RectangleEdge.TOP;

    /** The default horizontal alignment. */
    public static final HorizontalAlignment 
            DEFAULT_HORIZONTAL_ALIGNMENT = HorizontalAlignment.CENTER;

    /** The default vertical alignment. */
    public static final VerticalAlignment 
            DEFAULT_VERTICAL_ALIGNMENT = VerticalAlignment.CENTER;

    /** Default title padding. */
    public static final RectangleInsets DEFAULT_PADDING = new RectangleInsets(
            1, 1, 1, 1);

    /** The title position. */
    private RectangleEdge position;

    /** The horizontal alignment of the title content. */
    private HorizontalAlignment horizontalAlignment;

    /** The vertical alignment of the title content. */
    private VerticalAlignment verticalAlignment;

    /** Storage for registered change listeners. */
    private transient EventListenerList listenerList;

    /** 
     * A flag that can be used to temporarily disable the listener mechanism. 
     */
    private boolean notify;

    /**
     * Creates a new title, using default attributes where necessary.
     */
    protected Title() {
        this(Title.DEFAULT_POSITION,
                Title.DEFAULT_HORIZONTAL_ALIGNMENT,
                Title.DEFAULT_VERTICAL_ALIGNMENT, Title.DEFAULT_PADDING);
    }

    /**
     * Creates a new title, using default attributes where necessary.
     *
     * @param position  the position of the title (<code>null</code> not 
     *                  permitted).
     * @param horizontalAlignment  the horizontal alignment of the title 
     *                             (<code>null</code> not permitted).
     * @param verticalAlignment  the vertical alignment of the title 
     *                           (<code>null</code> not permitted).
     */
    protected Title(RectangleEdge position, 
                    HorizontalAlignment horizontalAlignment, 
                    VerticalAlignment verticalAlignment) {

        this(position, horizontalAlignment, verticalAlignment,
                Title.DEFAULT_PADDING);

    }

    /**
     * Creates a new title.
     *
     * @param position  the position of the title (<code>null</code> not 
     *                  permitted).
     * @param horizontalAlignment  the horizontal alignment of the title (LEFT,
     *                             CENTER or RIGHT, <code>null</code> not 
     *                             permitted).
     * @param verticalAlignment  the vertical alignment of the title (TOP, 
     *                           MIDDLE or BOTTOM, <code>null</code> not 
     *                           permitted).
     * @param padding  the amount of space to leave around the outside of the 
     *                 title (<code>null</code> not permitted).
     */
    protected Title(RectangleEdge position,
                    HorizontalAlignment horizontalAlignment, 
                    VerticalAlignment verticalAlignment,
                    RectangleInsets padding) {

        // check arguments...
        if (position == null) {
            throw new IllegalArgumentException("Null 'position' argument.");
        }
        if (horizontalAlignment == null) {
            throw new IllegalArgumentException(
                    "Null 'horizontalAlignment' argument.");
        }

        if (verticalAlignment == null) {
            throw new IllegalArgumentException(
                    "Null 'verticalAlignment' argument.");
        }
        if (padding == null) {
            throw new IllegalArgumentException("Null 'spacer' argument.");
        }

        this.position = position;
        this.horizontalAlignment = horizontalAlignment;
        this.verticalAlignment = verticalAlignment;
        setPadding(padding);
        this.listenerList = new EventListenerList();
        this.notify = true;

    }

    /**
     * Returns the position of the title.
     *
     * @return The title position (never <code>null</code>).
     */
    public RectangleEdge getPosition() {
        return this.position;
    }

    /**
     * Sets the position for the title and sends a {@link TitleChangeEvent} to 
     * all registered listeners.
     *
     * @param position  the position (<code>null</code> not permitted).
     */
    public void setPosition(RectangleEdge position) {
        if (position == null) {
            throw new IllegalArgumentException("Null 'position' argument.");
        }
        if (this.position != position) {
            this.position = position;