/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2012, 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.]
*
* -----------------------
* AbstractAnnotation.java
* -----------------------
* (C) Copyright 2009, by Object Refinery Limited and Contributors.
*
* Original Author: Peter Kolb (see patch 2809117);
* Contributor(s): ;
*
* Changes:
* --------
* 20-Jun-2009 : Version 1 (PK);
*
*/
package org.jfree.chart.annotations;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;
import java.util.EventListener;
import java.util.List;
import javax.swing.event.EventListenerList;
import org.jfree.chart.event.AnnotationChangeEvent;
import org.jfree.chart.event.AnnotationChangeListener;
/**
* An abstract implementation of the {@link Annotation} interface, containing a
* mechanism for registering change listeners.
*
* @since 1.0.14
*/
public abstract class AbstractAnnotation implements Annotation, Cloneable,
Serializable {
/** Storage for registered change listeners. */
private transient EventListenerList listenerList;
/**
* A flag that indicates whether listeners should be notified
* about changes of the annotation.
*/
private boolean notify = true;
/**
* Constructs an annotation.
*/
protected AbstractAnnotation() {
this.listenerList = new EventListenerList();
}
/**
* Registers an object to receive notification of changes to the
* annotation.
*
* @param listener the object to register.
*
* @see #removeChangeListener(AnnotationChangeListener)
*/
@Override
public void addChangeListener(AnnotationChangeListener listener) {
this.listenerList.add(AnnotationChangeListener.class, listener);
}
/**
* Deregisters an object so that it no longer receives notification of
* changes to the annotation.
*
* @param listener the object to deregister.
*
* @see #addChangeListener(AnnotationChangeListener)
*/
@Override
public void removeChangeListener(AnnotationChangeListener listener) {
this.listenerList.remove(AnnotationChangeListener.class, listener);
}
/**
* Returns <code>true</code> if the specified object is registered with
* the annotation as a listener. Most applications won't need to call this
* method, it exists mainly for use by unit testing code.
*
* @param listener the listener.
*
* @return A boolean.
*
* @see #addChangeListener(AnnotationChangeListener)
* @see #removeChangeListener(AnnotationChangeListener)
*/
public boolean hasListener(EventListener listener) {
List<Object> list = Arrays.asList(this.listenerList.getListenerList());
return list.contains(listener);
}
/**
* Notifies all registered listeners that the annotation has changed.
*
* @see #addChangeListener(AnnotationChangeListener)
*/
protected void fireAnnotationChanged() {
if (notify) {
notifyListeners(new AnnotationChangeEvent(this, this));
}
}
/**
* Notifies all registered listeners that the annotation has changed.
*
* @param event contains information about the event that triggered the
* notification.
*
* @see #addChangeListener(AnnotationChangeListener)
* @see #removeChangeListener(AnnotationChangeListener)
*/
protected void notifyListeners(AnnotationChangeEvent event) {
Object[] listeners = this.listenerList.getListenerList();
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == AnnotationChangeListener.class) {
((AnnotationChangeListener) listeners[i + 1]).annotationChanged(
event);
}
}
}
/**
* Returns a flag that indicates whether listeners should be
* notified about changes to the annotation.
*
* @return the flag.
*
* @see #setNotify(boolean)
*/
public boolean getNotify(){
return this.notify;
}
/**
* Sets a flag that indicates whether listeners should be notified about
* changes of an annotation.
*
* @param flag the flag
*
* @see #getNotify()
*/
public void setNotify(boolean flag){
this.notify = flag;
if (notify) {
fireAnnotationChanged();
}
}
/**
* Returns a clone of the annotation. The cloned annotation will NOT
* include the {@link AnnotationChangeListener} references that have been
* registered with this annotation.
*
* @return A clone.
*
* @throws CloneNotSupportedException if the annotation does not support
* cloning.
*/
@Override
public Object clone() throws CloneNotSupportedException {
AbstractAnnotation clone = (AbstractAnnotation) super.clone();
clone.listenerList = new EventListenerList();
return clone;
}
/**
* Handles serialization.
*
* @param stream the output stream.
*
* @throws IOException if there is an I/O problem.
*/
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
}
/**
* Restores a serialized object.
*
* @param stream the input stream.
*
* @throws IOException if there is an I/O problem.
* @throws ClassNotFoundException if there is a problem loading a class.
*/
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
this.listenerList = new EventListenerList();
}
}