/*
 * JBoss, Home of Professional Open Source.
 *
 * See the LEGAL.txt file distributed with this work for information regarding copyright ownership and licensing.
 *
 * See the AUTHORS.txt file distributed with this work for a full listing of individual contributors.
 */
package org.teiid.designer.extension;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.ArrayList;
import java.util.List;

/**
 * 
 */
public final class Listener implements PropertyChangeListener {

    private List<PropertyChangeEvent> events = new ArrayList<PropertyChangeEvent>();

    /**
     * Clears the stored events.
     */
    public void clear() {
        this.events.clear();
    }

    /**
     * @return the number of events received
     */
    public int getCount() {
        return this.events.size();
    }

    /**
     * @return the first event received or <code>null</code>
     */
    public PropertyChangeEvent getEvent() {
        if (this.events.isEmpty()) {
            return null;
        }

        return this.events.get(0);
    }

    public Object getNewValue() {
        if (this.events.isEmpty()) {
            return null;
        }

        return getEvent().getNewValue();
    }

    public Object getOldValue() {
        if (this.events.isEmpty()) {
            return false;
        }

        return getEvent().getOldValue();
    }

    public String getPropertyName() {
        if (this.events.isEmpty()) {
            return null;
        }

        return getEvent().getPropertyName();
    }

    /**
     * {@inheritDoc}
     * 
     * @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent)
     */
    @Override
    public void propertyChange( PropertyChangeEvent e ) {
        this.events.add(e);
    }

}