AbstractBean.java

/*
 * @(#)AbstractBean.java
 *
 * Copyright (c) 1996-2010 The authors and contributors of JHotDraw.
 * You may not use, copy or modify this file, except in compliance with the 
 * accompanying license terms.
 */
package org.jhotdraw.beans;

import edu.umd.cs.findbugs.annotations.Nullable;
import java.beans.*;

/**
 * This abstract class can be extended to implement a JavaBean. <p> Implements
 * the methods required for adding and removing property change listeners.
 *
 * @author Werner Randelshofer
 * @version $Id$
 */
public class AbstractBean extends Object implements java.io.Serializable, Cloneable {

    private static final long serialVersionUID = 1L;
    
    protected PropertyChangeSupport propertySupport = new PropertyChangeSupport(this);

    /**
     * Adds a {@code PropertyChangeListener} which can optionally be wrapped
     * into a {@code WeakPropertyChangeListener}.
     *
     * @param listener the listener
     */
    public void addPropertyChangeListener(PropertyChangeListener listener) {
        propertySupport.addPropertyChangeListener(listener);
    }

    /**
     * Adds a {@code PropertyChangeListener} which can optionally be wrapped
     * into a {@code WeakPropertyChangeListener}.
     *
     * @param propertyName the property name
     * @param listener the listener
     */
    public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
        propertySupport.addPropertyChangeListener(propertyName, listener);
    }

    /**
     * Removes a {@code PropertyChangeListener}. If the listener was added
     * wrapped into a {@code WeakPropertyChangeListener}, the
     * {@code WeakPropertyChangeListener} is removed.
     *
     * @param listener the listener
     */
    public void removePropertyChangeListener(PropertyChangeListener listener) {
        // Removes a property change listener from our list.
        // We need a somewhat complex procedure here in case a listener
        // has been registered using addPropertyChangeListener(new WeakPropertyChangeListener(listener));
        for (PropertyChangeListener l : propertySupport.getPropertyChangeListeners()) {
            if (l == listener) {
                propertySupport.removePropertyChangeListener(l);
                break;
            }
            if (l instanceof WeakPropertyChangeListener) {
                WeakPropertyChangeListener wl = (WeakPropertyChangeListener) l;
                PropertyChangeListener target = wl.getTarget();
                if (target == listener) {
                    propertySupport.removePropertyChangeListener(l);
                    break;
                }
            }
        }
    }

    /**
     * Removes a {@code PropertyChangeListener}. If the listener was added
     * wrapped into a {@code WeakPropertyChangeListener}, the
     * {@code WeakPropertyChangeListener} is removed.
     *
     * @param propertyName the property name
     * @param listener the listener
     */
    public void removePropertyChangeListener(String propertyName, PropertyChangeListener listener) {
        // Removes a property change listener from our list.
        // We need a somewhat complex procedure here in case a listener
        // has been registered using addPropertyChangeListener(propertyName, new WeakPropertyChangeListener(listener));
        for (PropertyChangeListener l : propertySupport.getPropertyChangeListeners(propertyName)) {
            if (l == listener) {
                propertySupport.removePropertyChangeListener(propertyName, l);
                break;
            }
            if (l instanceof WeakPropertyChangeListener) {
                WeakPropertyChangeListener wl = (WeakPropertyChangeListener) l;
                PropertyChangeListener target = wl.getTarget();
                if (target == listener) {
                    propertySupport.removePropertyChangeListener(propertyName, l);
                    break;
                }
            }
        }
    }

    protected void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) {
        propertySupport.firePropertyChange(propertyName, oldValue, newValue);
    }

    protected void firePropertyChange(String propertyName, int oldValue, int newValue) {
        propertySupport.firePropertyChange(propertyName, oldValue, newValue);
    }

    protected void firePropertyChange(String propertyName, @Nullable Object oldValue, @Nullable Object newValue) {
        propertySupport.firePropertyChange(propertyName, oldValue, newValue);
    }

    @Override
    public AbstractBean clone() {
        AbstractBean that;
        try {
            that = (AbstractBean) super.clone();
        } catch (CloneNotSupportedException ex) {
            InternalError error = new InternalError("Clone failed");
            error.initCause(ex);
            throw error;
        }
        that.propertySupport = new PropertyChangeSupport(that);
        return that;
    }

    public PropertyChangeListener[] getPropertyChangeListeners() {
        return propertySupport.getPropertyChangeListeners();
    }
}