content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jcommon/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.]
   *
   * -------------------------
   * WaitingImageObserver.java
   * -------------------------
   * (C)opyright 2000-2004, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner
   * Contributor(s):   Stefan Prange;
   *
   * $Id: WaitingImageObserver.java,v 1.8 2008/09/10 09:24:41 mungady Exp $
   *
   * Changes (from 8-Feb-2002)
   * -------------------------
   * 15-Apr-2002 : first version used by ImageElement.
   * 16-May-2002 : Line delimiters adjusted
   * 04-Jun-2002 : Documentation and added a NullPointerCheck for the constructor.
   * 14-Jul-2002 : BugFixed: WaitingImageObserver dead-locked (bugfix by Stefan
   *               Prange)
   * 18-Mar-2003 : Updated header and made minor Javadoc changes (DG);
   * 21-Sep-2003 : Moved from JFreeReport.
   */
  
  package org.jfree.util;
  
  import java.awt.Graphics;
  import java.awt.Image;
  import java.awt.image.BufferedImage;
  import java.awt.image.ImageObserver;
  import java.io.Serializable;
  
  /**
   * This image observer blocks until the image is completely loaded. AWT
   * defers the loading of images until they are painted on a graphic.
   *
   * While printing reports it is not very nice, not to know whether a image
   * was completely loaded, so this observer forces the loading of the image
   * until a final state (either ALLBITS, ABORT or ERROR) is reached.
   *
   * @author Thomas Morgner
   */
  public class WaitingImageObserver implements ImageObserver, Serializable,
                                               Cloneable
  {
    /** For serialization. */
    static final long serialVersionUID = -807204410581383550L;
  
    /** The lock. */
    private boolean lock;
  
    /** The image. */
    private Image image;
  
    /** A flag that signals an error. */
    private boolean error;
  
    /**
     * Creates a new <code>ImageObserver<code> for the given <code>Image<code>.
     * The observer has to be started by an external thread.
     *
     * @param image  the image to observe (<code>null</code> not permitted).
     */
    public WaitingImageObserver(final Image image) {
      if (image == null) {
        throw new NullPointerException();
      }
      this.image = image;
      this.lock = true;
    }
  
    /**
     * Callback function used by AWT to inform that more data is available. The
     * observer waits until either all data is loaded or AWT signals that the
     * image cannot be loaded.
     *
     * @param     img   the image being observed.
     * @param     infoflags   the bitwise inclusive OR of the following
     *               flags:  <code>WIDTH</code>, <code>HEIGHT</code>,
     *               <code>PROPERTIES</code>, <code>SOMEBITS</code>,
     *               <code>FRAMEBITS</code>, <code>ALLBITS</code>,
     *               <code>ERROR</code>, <code>ABORT</code>.
     * @param     x   the <i>x</i> coordinate.
     * @param     y   the <i>y</i> coordinate.
     * @param     width    the width.
     * @param     height   the height.
     *
     * @return    <code>false</code> if the infoflags indicate that the
     *            image is completely loaded; <code>true</code> otherwise.
     */
    public synchronized boolean imageUpdate(
        final Image img,
        final int infoflags,
        final int x,
        final int y,
        final int width,
        final int height) {
      if ((infoflags & ImageObserver.ALLBITS) == ImageObserver.ALLBITS) {
          this.lock = false;
          this.error = false;
          notifyAll();
          return false;
      }
      else if ((infoflags & ImageObserver.ABORT) == ImageObserver.ABORT
          || (infoflags & ImageObserver.ERROR) == ImageObserver.ERROR) {
          this.lock = false;
          this.error = true;
          notifyAll();
          return false;
      }
      //notifyAll();
      return true;
    }
  
    /**
     * The workerthread. Simply draws the image to a BufferedImage's
     * Graphics-Object and waits for the AWT to load the image.
     */
    public synchronized void waitImageLoaded() {
  
      if (this.lock == false)
      {
        return;
      }
  
      final BufferedImage img = new BufferedImage(
          1, 1, BufferedImage.TYPE_INT_RGB
      );
      final Graphics g = img.getGraphics();
  
      while (this.lock) {
        if (g.drawImage(this.image, 0, 0, img.getWidth(this),
              img.getHeight(this), this)) {
          return;
        }
  
        try {
          wait(500);
        }
        catch (InterruptedException e) {
          Log.info(
            "WaitingImageObserver.waitImageLoaded(): InterruptedException thrown",
            e
          );
        }
      }
    }
  
    /**
     * Clones this WaitingImageObserver.
     *
     * @return a clone.
     *
     * @throws CloneNotSupportedException this should never happen.
     * @deprecated cloning may lock down the observer
     */
    public Object clone() throws CloneNotSupportedException {
      return (WaitingImageObserver) super.clone();
    }
  
    /**
     * Returns <code>true</code> if loading is complete, and <code>false</code>
     * otherwise.
     *
     * @return A boolean.
     */
    public boolean isLoadingComplete() {
      return this.lock == false;
    }
  
    /**
     * Returns true if there is an error condition, and false otherwise.
     *
     * @return A boolean.
     */
    public boolean isError() {
      return this.error;
    }
  }
  