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.] * * --------- * Task.java * --------- * (C) Copyright 2003-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 10-Jan-2003 : Version 1 (DG); * 16-Sep-2003 : Added percentage complete (DG); * 30-Jul-2004 : Added clone() and equals() methods and implemented * Serializable (DG); * 03-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.data.gantt; import java.io.Serializable; import java.util.Date; import java.util.List; import org.jfree.chart.util.ParamChecks; import org.jfree.data.time.SimpleTimePeriod; import org.jfree.data.time.TimePeriod; import org.jfree.util.ObjectUtilities; import org.jfree.util.PublicCloneable; /** * A simple representation of a task. The task has a description and a * duration. You can add sub-tasks to the task. */ public class Task implements Cloneable, PublicCloneable, Serializable { /** For serialization. */ private static final long serialVersionUID = 1094303785346988894L; /** The task description. */ private String description; /** The time period for the task (estimated or actual). */ private TimePeriod duration; /** The percent complete (<code>null</code> is permitted). */ private Double percentComplete; /** Storage for the sub-tasks (if any). */ private List subtasks; /** * Creates a new task. * * @param description the task description (<code>null</code> not * permitted). * @param duration the task duration (<code>null</code> permitted). */ public Task(String description, TimePeriod duration) { ParamChecks.nullNotPermitted(description, "description"); this.description = description; this.duration = duration; this.percentComplete = null; this.subtasks = new java.util.ArrayList(); } /** * Creates a new task. * * @param description the task description (<code>null</code> not * permitted). * @param start the start date (<code>null</code> not permitted). * @param end the end date (<code>null</code> not permitted). */ public Task(String description, Date start, Date end) { this(description, new SimpleTimePeriod(start, end)); } /** * Returns the task description. * * @return The task description (never <code>null</code>). */ public String getDescription() { return this.description; } /** * Sets the task description. * * @param description the description (<code>null</code> not permitted). */ public void setDescription(String description) { ParamChecks.nullNotPermitted(description, "description"); this.description = description; } /** * Returns the duration (actual or estimated) of the task. * * @return The task duration (possibly <code>null</code>). */ public TimePeriod getDuration() { return this.duration; } /** * Sets the task duration (actual or estimated). * * @param duration the duration (<code>null</code> permitted). */ public void setDuration(TimePeriod duration) { this.duration = duration; } /** * Returns the percentage complete for this task. * * @return The percentage complete (possibly <code>null</code>). */ public Double getPercentComplete() { return this.percentComplete; } /** * Sets the percentage complete for the task. * * @param percent the percentage (<code>null</code> permitted). */ public void setPercentComplete(Double percent) { this.percentComplete = percent; } /** * Sets the percentage complete for the task. * * @param percent the percentage. */ public void setPercentComplete(double percent) { setPercentComplete(new Double(percent)); } /** * Adds a sub-task to the task. * * @param subtask the subtask (<code>null</code> not permitted). */ public void addSubtask(Task subtask) { ParamChecks.nullNotPermitted(subtask, "subtask"); this.subtasks.add(subtask); } /** * Removes a sub-task from the task. * * @param subtask the subtask. */ public void removeSubtask(Task subtask) { this.subtasks.remove(subtask); } /** * Returns the sub-task count. * * @return The sub-task count. */ public int getSubtaskCount() { return this.subtasks.size(); } /** * Returns a sub-task. * * @param index the index. * * @return The sub-task. */ public Task getSubtask(int index) { return (Task) this.subtasks.get(index); } /** * Tests this object for equality with an arbitrary object. * * @param object the other object (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object object) { if (object == this) { return true; } if (!(object instanceof Task)) { return false; } Task that = (Task) object; if (!ObjectUtilities.equal(this.description, that.description)) { return false; } if (!ObjectUtilities.equal(this.duration, that.duration)) { return false; } if (!ObjectUtilities.equal(this.percentComplete, that.percentComplete)) { return false; } if (!ObjectUtilities.equal(this.subtasks, that.subtasks)) { return false; } return true; } /** * Returns a clone of the task. * * @return A clone. * * @throws CloneNotSupportedException never thrown by this class, but * subclasses may not support cloning. */ @Override public Object clone() throws CloneNotSupportedException { Task clone = (Task) super.clone(); return clone; } }