Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2013, 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. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * --------------- * PlotEntity.java * --------------- * (C) Copyright 2009-2013, by Object Refinery Limited and Contributors. * * Original Author: Peter Kolb; * Contributor(s): ; * * Changes: * -------- * 15-Feb-2009 : Version 1 (PK); * 02-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.chart.entity; import java.awt.Shape; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import org.jfree.chart.plot.Plot; import org.jfree.chart.HashUtilities; import org.jfree.chart.util.ParamChecks; import org.jfree.io.SerialUtilities; import org.jfree.util.ObjectUtilities; /** * A class that captures information about a plot. * * @since 1.0.13 */ public class PlotEntity extends ChartEntity { /** For serialization. */ private static final long serialVersionUID = -4445994133561919083L; //same as for ChartEntity! /** The plot. */ private Plot plot; /** * Creates a new plot entity. * * @param area the area (<code>null</code> not permitted). * @param plot the plot (<code>null</code> not permitted). */ public PlotEntity(Shape area, Plot plot) { // defer argument checks... this(area, plot, null); } /** * Creates a new plot entity. * * @param area the area (<code>null</code> not permitted). * @param plot the plot (<code>null</code> not permitted). * @param toolTipText the tool tip text (<code>null</code> permitted). */ public PlotEntity(Shape area, Plot plot, String toolTipText) { // defer argument checks... this(area, plot, toolTipText, null); } /** * Creates a new plot entity. * * @param area the area (<code>null</code> not permitted). * @param plot the plot (<code>null</code> not permitted). * @param toolTipText the tool tip text (<code>null</code> permitted). * @param urlText the URL text for HTML image maps (<code>null</code> * permitted). */ public PlotEntity(Shape area, Plot plot, String toolTipText, String urlText) { super(area, toolTipText, urlText); ParamChecks.nullNotPermitted(plot, "plot"); this.plot = plot; } /** * Returns the plot that occupies the entity area. * * @return The plot (never <code>null</code>). */ public Plot getPlot() { return this.plot; } /** * Returns a string representation of the plot entity, useful for * debugging. * * @return A string. */ @Override public String toString() { StringBuilder sb = new StringBuilder("PlotEntity: "); sb.append("tooltip = "); sb.append(getToolTipText()); return sb.toString(); } /** * Tests the entity for equality with an arbitrary object. * * @param obj the object to test against (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof PlotEntity)) { return false; } PlotEntity that = (PlotEntity) obj; if (!getArea().equals(that.getArea())) { return false; } if (!ObjectUtilities.equal(getToolTipText(), that.getToolTipText())) { return false; } if (!ObjectUtilities.equal(getURLText(), that.getURLText())) { return false; } if (!(this.plot.equals(that.plot))) { return false; } return true; } /** * Returns a hash code for this instance. * * @return A hash code. */ @Override public int hashCode() { int result = 39; result = HashUtilities.hashCode(result, getToolTipText()); result = HashUtilities.hashCode(result, getURLText()); return result; } /** * Returns a clone of the entity. * * @return A clone. * * @throws CloneNotSupportedException if there is a problem cloning the * entity. */ @Override 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.writeShape(getArea(), 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(); setArea(SerialUtilities.readShape(stream)); } }