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.] * * ----------------------------- * StandardEntityCollection.java * ----------------------------- * (C) Copyright 2001-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 23-May-2002 : Version 1 (DG); * 26-Jun-2002 : Added iterator() method (DG); * 03-Oct-2002 : Fixed errors reported by Checkstyle (DG); * 19-May-2004 : Implemented Serializable (DG); * 29-Sep-2004 : Renamed addEntity() --> add() and addEntities() * --> addAll() (DG); * 19-Jan-2005 : Changed storage from Collection --> List (DG); * 20-May-2005 : Fixed bug 1113521 - inefficiency in getEntity() method (DG); * ------------- JFREECHART 1.0.x --------------------------------------------- * 01-Dec-2006 : Implemented PublicCloneable and fixed clone() method (DG); * 02-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.chart.entity; import java.io.Serializable; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.List; import org.jfree.chart.util.ParamChecks; import org.jfree.util.ObjectUtilities; import org.jfree.util.PublicCloneable; /** * A standard implementation of the {@link EntityCollection} interface. */ public class StandardEntityCollection implements EntityCollection, Cloneable, PublicCloneable, Serializable { /** For serialization. */ private static final long serialVersionUID = 5384773031184897047L; /** Storage for the entities. */ private List entities; /** * Constructs a new entity collection (initially empty). */ public StandardEntityCollection() { this.entities = new java.util.ArrayList(); } /** * Returns the number of entities in the collection. * * @return The entity count. */ @Override public int getEntityCount() { return this.entities.size(); } /** * Returns a chart entity from the collection. * * @param index the entity index. * * @return The entity. * * @see #add(ChartEntity) */ @Override public ChartEntity getEntity(int index) { return (ChartEntity) this.entities.get(index); } /** * Clears all the entities from the collection. */ @Override public void clear() { this.entities.clear(); } /** * Adds an entity to the collection. * * @param entity the entity (<code>null</code> not permitted). */ @Override public void add(ChartEntity entity) { ParamChecks.nullNotPermitted(entity, "entity"); this.entities.add(entity); } /** * Adds all the entities from the specified collection. * * @param collection the collection of entities (<code>null</code> not * permitted). */ @Override public void addAll(EntityCollection collection) { this.entities.addAll(collection.getEntities()); } /** * Returns the last entity in the list with an area that encloses the * specified coordinates, or <code>null</code> if there is no such entity. * * @param x the x coordinate. * @param y the y coordinate. * * @return The entity (possibly <code>null</code>). */ @Override public ChartEntity getEntity(double x, double y) { int entityCount = this.entities.size(); for (int i = entityCount - 1; i >= 0; i--) { ChartEntity entity = (ChartEntity) this.entities.get(i); if (entity.getArea().contains(x, y)) { return entity; } } return null; } /** * Returns the entities in an unmodifiable collection. * * @return The entities. */ @Override public Collection getEntities() { return Collections.unmodifiableCollection(this.entities); } /** * Returns an iterator for the entities in the collection. * * @return An iterator. */ @Override public Iterator iterator() { return this.entities.iterator(); } /** * Tests this object 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 StandardEntityCollection) { StandardEntityCollection that = (StandardEntityCollection) obj; return ObjectUtilities.equal(this.entities, that.entities); } return false; } /** * Returns a clone of this entity collection. * * @return A clone. * * @throws CloneNotSupportedException if the object cannot be cloned. */ @Override public Object clone() throws CloneNotSupportedException { StandardEntityCollection clone = (StandardEntityCollection) super.clone(); clone.entities = new java.util.ArrayList(this.entities.size()); for (int i = 0; i < this.entities.size(); i++) { ChartEntity entity = (ChartEntity) this.entities.get(i); clone.entities.add(entity.clone()); } return clone; } }