gt:         this.paint = SerialUtilities.readPaint(stream);
context: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,
   * Boston, MA 02111-1307, USA.
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
   * in the United States and other countries.]
   *
   * ---------------------
   * XYLineAnnotation.java
   * ---------------------
   * (C) Copyright 2003, 2004, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * $Id: XYLineAnnotation.java,v 1.1 2004/08/31 14:28:00 mungady Exp $
   *
   * Changes:
   * --------
   * 02-Apr-2003 : Version 1 (DG);
   * 19-Aug-2003 : Added equals method, implemented Cloneable, and applied serialization fixes (DG);
   * 21-Jan-2004 : Update for renamed method in ValueAxis (DG);
   * 14-Apr-2004 : Fixed draw() method to handle plot orientation correctly (DG);
   *
   */
  
  package org.jfree.chart.annotations;
  
  import java.awt.BasicStroke;
  import java.awt.Color;
  import java.awt.Graphics2D;
  import java.awt.Paint;
  import java.awt.Stroke;
  import java.awt.geom.Line2D;
  import java.awt.geom.Rectangle2D;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.io.Serializable;
  
  import org.jfree.chart.axis.ValueAxis;
  import org.jfree.chart.plot.Plot;
  import org.jfree.chart.plot.PlotOrientation;
  import org.jfree.chart.plot.XYPlot;
  import org.jfree.io.SerialUtilities;
  import org.jfree.ui.RectangleEdge;
  import org.jfree.util.ObjectUtils;
  
  /**
   * A simple line annotation that can be placed on an {@link XYPlot}.
   */
  public class XYLineAnnotation implements XYAnnotation, Cloneable, Serializable {
  
      /** The x-coordinate. */
      private double x1;
  
      /** The y-coordinate. */
      private double y1;
  
      /** The x-coordinate. */
      private double x2;
  
      /** The y-coordinate. */
      private double y2;
  
      /** The line stroke. */
      private transient Stroke stroke;
  
      /** The line color. */
      private transient Paint paint;
  
      /**
       * Creates a new annotation that draws a line from (x1, y1) to (x2, y2) where 
       * the coordinates are measured in data space (that is, against the plot's axes).
       * 
       * @param x1  the x-coordinate for the start of the line.
       * @param y1  the y-coordinate for the start of the line.
       * @param x2  the x-coordinate for the end of the line.
       * @param y2  the y-coordinate for the end of the line.
       */
      public XYLineAnnotation(double x1, double y1, double x2, double y2) {
          this(x1, y1, x2, y2, new BasicStroke(1.0f), Color.black);
      }
      
      /**
       * Creates a new annotation that draws a line from (x1, y1) to (x2, y2) where 
       * the coordinates are measured in data space (that is, against the plot's axes).
       *
       * @param x1  the x-coordinate for the start of the line.
       * @param y1  the y-coordinate for the start of the line.
       * @param x2  the x-coordinate for the end of the line.
       * @param y2  the y-coordinate for the end of the line.
       * @param stroke  the line stroke (<code>null</code> not permitted).
       * @param paint  the line color (<code>null</code> not permitted).
       */
      public XYLineAnnotation(double x1, double y1, double x2, double y2,
                              Stroke stroke, Paint paint) {
  
          if (stroke == null) {
              throw new IllegalArgumentException("Null 'stroke' argument.");   
          }
          if (paint == null) {
              throw new IllegalArgumentException("Null 'paint' argument.");   
          }
          this.x1 = x1;
          this.y1 = y1;
          this.x2 = x2;
          this.y2 = y2;
          this.stroke = stroke;
          this.paint = paint;
  
      }
  
      /**
       * Draws the annotation.  This method is called by the {@link XYPlot} class, you 
       * won't normally need to call it yourself.
       *
       * @param g2  the graphics device.
       * @param plot  the plot.
       * @param dataArea  the data area.
       * @param domainAxis  the domain axis.
       * @param rangeAxis  the range axis.
       */
      public void draw(Graphics2D g2, XYPlot plot, Rectangle2D dataArea,
                       ValueAxis domainAxis, ValueAxis rangeAxis) {
  
          PlotOrientation orientation = plot.getOrientation();
          RectangleEdge domainEdge = Plot.resolveDomainAxisLocation(
              plot.getDomainAxisLocation(), orientation
          );
          RectangleEdge rangeEdge = Plot.resolveRangeAxisLocation(
              plot.getRangeAxisLocation(), orientation
          );
          float j2DX1 = 0.0f;
          float j2DX2 = 0.0f;
          float j2DY1 = 0.0f;
          float j2DY2 = 0.0f;
          if (orientation == PlotOrientation.VERTICAL) {
              j2DX1 = (float) domainAxis.valueToJava2D(this.x1, dataArea, domainEdge);
              j2DY1 = (float) rangeAxis.valueToJava2D(this.y1, dataArea, rangeEdge);
              j2DX2 = (float) domainAxis.valueToJava2D(this.x2, dataArea, domainEdge);
              j2DY2 = (float) rangeAxis.valueToJava2D(this.y2, dataArea, rangeEdge);
          }
          else if (orientation == PlotOrientation.HORIZONTAL) {
              j2DY1 = (float) domainAxis.valueToJava2D(this.x1, dataArea, domainEdge);
              j2DX1 = (float) rangeAxis.valueToJava2D(this.y1, dataArea, rangeEdge);
              j2DY2 = (float) domainAxis.valueToJava2D(this.x2, dataArea, domainEdge);
              j2DX2 = (float) rangeAxis.valueToJava2D(this.y2, dataArea, rangeEdge);                
          }
          g2.setPaint(this.paint);
          g2.setStroke(this.stroke);
          Line2D line = new Line2D.Float(j2DX1, j2DY1, j2DX2, j2DY2);
          g2.draw(line);
  
      }
  
      /**
       * Tests this object for equality with an arbitrary object.
       * 
       * @param object  the object to test against (<code>null</code> permitted).
       * 
       * @return <code>true</code> or <code>false</code>.
       */
      public boolean equals(Object object) {
          
          if (object == null) {
              return false;
          }
          
          if (object == this) {
              return true;
          }
          
          if (object instanceof XYLineAnnotation) {
          
              XYLineAnnotation a = (XYLineAnnotation) object;
              boolean b0 = (this.x1 == a.x1);
              boolean b1 = (this.y1 == a.y1);
              boolean b2 = (this.x2 == a.x2);
              boolean b3 = (this.y2 == a.y2);
              boolean b4 = ObjectUtils.equal(this.paint, a.paint);
              boolean b5 = ObjectUtils.equal(this.stroke, a.stroke);
              return b0 && b1 && b2 && b3 && b4 && b5;
          }
          
          return false;
          
      }
      
      /**
       * Returns a clone of the annotation.
       * 
       * @return A clone.
       * 
       * @throws CloneNotSupportedException  if the annotation can't be cloned.
       */
      public Object clone() throws CloneNotSupportedException {
          return super.clone();
      }
      
      /**
       * Provides serialization support.
       *
       * @param stream  the output stream.
       *
       * @throws IOException  if there is an I/O error.
       */
      private void writeObject(ObjectOutputStream stream) throws IOException {
  
          stream.defaultWriteObject();
          SerialUtilities.writePaint(this.paint, stream);
          SerialUtilities.writeStroke(this.stroke, stream);
  
      }
  
      /**
       * Provides serialization support.
       *
       * @param stream  the input stream.
       *
       * @throws IOException  if there is an I/O error.
       * @throws ClassNotFoundException  if there is a classpath problem.
       */
      private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
  
          stream.defaultReadObject();
  