jfreechart example source code file (EmptyBlock.java)

This example jfreechart source code file (EmptyBlock.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

abstractblock, awt, block, clonenotsupportedexception, emptyblock, emptyblock, geometry, io, object, object, publiccloneable, rectangle2d, rectangle2d, rectangleconstraint, serializable, size2d, size2d

The jfreechart EmptyBlock.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.]
 *
 * ---------------
 * EmptyBlock.java
 * ---------------
 * (C) Copyright 2004-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes:
 * --------
 * 22-Oct-2004 : Version 1 (DG);
 * 04-Feb-2005 : Now cloneable and serializable (DG);
 * 20-Apr-2005 : Added new draw() method (DG);
 * 08-Apr-2008 : Added support for margin and border (DG);
 * 08-May-2008 : Updated arrange() method to recognise
 *               incoming constraint (DG);
 *
 */

package org.jfree.chart.block;

import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.ui.Size2D;
import org.jfree.util.PublicCloneable;

/**
 * An empty block with a fixed size.
 */
public class EmptyBlock extends AbstractBlock
        implements Block, Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -4083197869412648579L;

    /**
     * Creates a new block with the specified width and height.
     *
     * @param width  the width.
     * @param height  the height.
     */
    public EmptyBlock(double width, double height) {
        setWidth(width);
        setHeight(height);
    }

    /**
     * Arranges the contents of the block, within the given constraints, and
     * returns the block size.
     *
     * @param g2  the graphics device.
     * @param constraint  the constraint (<code>null not permitted).
     *
     * @return The block size (in Java2D units, never <code>null).
     */
    public Size2D arrange(Graphics2D g2, RectangleConstraint constraint) {
        Size2D base = new Size2D(calculateTotalWidth(getWidth()),
                calculateTotalHeight(getHeight()));
        return constraint.calculateConstrainedSize(base);
    }

    /**
     * Draws the block.  Since the block is empty, there is nothing to draw
     * except the optional border.
     *
     * @param g2  the graphics device.
     * @param area  the area.
     */
    public void draw(Graphics2D g2, Rectangle2D area) {
        draw(g2, area, null);
    }

    /**
     * Draws the block within the specified area.  Since the block is empty,
     * there is nothing to draw except the optional border.
     *
     * @param g2  the graphics device.
     * @param area  the area.
     * @param params  ignored (<code>null permitted).
     *
     * @return Always <code>null.
     */
    public Object draw(Graphics2D g2, Rectangle2D area, Object params) {
        area = trimMargin(area);
        drawBorder(g2, area);
        return null;
    }

    /**
     * Returns a clone of the block.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException if there is a problem cloning.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

}