/*******************************************************************************
 * Copyright (c) 2005, 2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/

module dwtx.jface.action.AbstractAction;

import dwtx.jface.action.IAction;

import dwtx.core.commands.common.EventManager;
import dwtx.jface.util.IPropertyChangeListener;
import dwtx.jface.util.PropertyChangeEvent;

import dwt.dwthelper.utils;

/**
 * <p>
 * Some common functionality to share between implementations of
 * <code>IAction</code>. This functionality deals with the property change
 * event mechanism.
 * </p>
 * <p>
 * Clients may neither instantiate nor extend this class.
 * </p>
 *
 * @since 3.2
 */
public abstract class AbstractAction : EventManager, IAction {

    public void addPropertyChangeListener(IPropertyChangeListener listener) {
        addListenerObject(cast(Object)listener);
    }

    /**
     * Notifies any property change listeners that a property has changed. Only
     * listeners registered at the time this method is called are notified.
     *
     * @param event
     *            the property change event
     *
     * @see dwtx.jface.util.IPropertyChangeListener#propertyChange(PropertyChangeEvent)
     */
    protected final void firePropertyChange(PropertyChangeEvent event) {
        final Object[] list = getListeners();
        for (int i = 0; i < list.length; ++i) {
            (cast(IPropertyChangeListener) list[i]).propertyChange(event);
        }
    }

    /**
     * Notifies any property change listeners that a property has changed. Only
     * listeners registered at the time this method is called are notified. This
     * method avoids creating an event object if there are no listeners
     * registered, but calls
     * <code>firePropertyChange(PropertyChangeEvent)</code> if there are.
     *
     * @param propertyName
     *            the name of the property that has changed
     * @param oldValue
     *            the old value of the property, or <code>null</code> if none
     * @param newValue
     *            the new value of the property, or <code>null</code> if none
     *
     * @see dwtx.jface.util.IPropertyChangeListener#propertyChange(PropertyChangeEvent)
     */
    protected final void firePropertyChange(String propertyName,
            Object oldValue, Object newValue) {
        if (isListenerAttached()) {
            firePropertyChange(new PropertyChangeEvent(this, propertyName,
                    oldValue, newValue));
        }
    }

    public void removePropertyChangeListener(
            IPropertyChangeListener listener) {
        removeListenerObject(cast(Object)listener);
    }

}