/* ===========================================================
 
* JFreeChart : a free chart library for the Java(tm) platform
 
* ===========================================================
 
*
 
* (C) Copyright 2000-2016, 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 2009-2016, 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} 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 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
     
*
     
*
 

     
*/

    
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();
    
}

}