jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/model/listener/CommandChangeListener.java

/*******************************************************************************
 * Copyright (c) 2009 Oracle. 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:
 *     Oracle - initial API and implementation
 ******************************************************************************/
package org.eclipse.jpt.utility.model.listener;

import org.eclipse.jpt.utility.Command;
import org.eclipse.jpt.utility.model.event.ChangeEvent;
import org.eclipse.jpt.utility.model.event.CollectionAddEvent;
import org.eclipse.jpt.utility.model.event.CollectionChangeEvent;
import org.eclipse.jpt.utility.model.event.CollectionClearEvent;
import org.eclipse.jpt.utility.model.event.CollectionRemoveEvent;
import org.eclipse.jpt.utility.model.event.ListAddEvent;
import org.eclipse.jpt.utility.model.event.ListChangeEvent;
import org.eclipse.jpt.utility.model.event.ListClearEvent;
import org.eclipse.jpt.utility.model.event.ListMoveEvent;
import org.eclipse.jpt.utility.model.event.ListRemoveEvent;
import org.eclipse.jpt.utility.model.event.ListReplaceEvent;
import org.eclipse.jpt.utility.model.event.PropertyChangeEvent;
import org.eclipse.jpt.utility.model.event.StateChangeEvent;
import org.eclipse.jpt.utility.model.event.TreeAddEvent;
import org.eclipse.jpt.utility.model.event.TreeChangeEvent;
import org.eclipse.jpt.utility.model.event.TreeClearEvent;
import org.eclipse.jpt.utility.model.event.TreeRemoveEvent;

/**
 * Convenience implementation of ChangeListener.
 * All change notifications are funneled through a single command (or method).
 * This class can be used by either passing a command to its constructor or by
 * subclassing it and overriding either the #modelChanged(ChangeEvent) method
 * (if access to the event is required) or the #modelChanged() method (if access
 * to the event is not required).
 * 
 * Provisional API: This class is part of an interim API that is still
 * under development and expected to change significantly before reaching
 * stability. It is available at this early stage to solicit feedback from
 * pioneering adopters on the understanding that any code that uses this API
 * will almost certainly be broken (repeatedly) as the API evolves.
 */
public class CommandChangeListener implements ChangeListener {
	protected final Command command;

	/**
	 * Construct a change listener with a null command.
	 * Use this constructor if you want to override the
	 * <code>modelChanged(ChangeEvent)</code> or <code>modelChanged()</code>
	 * method instead of building a <code>Command</code>.
	 */
	public CommandChangeListener() {
		this(Command.Null.instance());
	}

	/**
	 * Construct a change listener that executes the specified command whenever
	 * it receives any change notification from the model to which it is added
	 * to as a listener.
	 */
	public CommandChangeListener(Command command) {
		super();
		this.command = command;
	}

	public void stateChanged(StateChangeEvent event) {
		this.modelChanged(event);
	}

	public void propertyChanged(PropertyChangeEvent event) {
		this.modelChanged(event);
	}

	public void collectionChanged(CollectionChangeEvent event) {
		this.modelChanged(event);
	}

	public void collectionCleared(CollectionClearEvent event) {
		this.modelChanged(event);
	}

	public void itemsAdded(CollectionAddEvent event) {
		this.modelChanged(event);
	}

	public void itemsRemoved(CollectionRemoveEvent event) {
		this.modelChanged(event);
	}

	public void itemsAdded(ListAddEvent event) {
		this.modelChanged(event);
	}

	public void itemsMoved(ListMoveEvent event) {
		this.modelChanged(event);
	}

	public void itemsRemoved(ListRemoveEvent event) {
		this.modelChanged(event);
	}

	public void itemsReplaced(ListReplaceEvent event) {
		this.modelChanged(event);
	}

	public void listChanged(ListChangeEvent event) {
		this.modelChanged(event);
	}

	public void listCleared(ListClearEvent event) {
		this.modelChanged(event);
	}

	public void nodeAdded(TreeAddEvent event) {
		this.modelChanged(event);
	}

	public void nodeRemoved(TreeRemoveEvent event) {
		this.modelChanged(event);
	}

	public void treeChanged(TreeChangeEvent event) {
		this.modelChanged(event);
	}

	public void treeCleared(TreeClearEvent event) {
		this.modelChanged(event);
	}

	/**
	 * The model has notified the listener of the change described by the
	 * specified change event. By default the listener executes its command.
	 */
	protected void modelChanged(@SuppressWarnings("unused") ChangeEvent event) {
		this.modelChanged();
	}

	/**
	 * The model has notified the listener of a change.
	 * By default the listener executes its command.
	 */
	protected void modelChanged() {
		this.command.execute();
	}

}