/*******************************************************************************

 * Copyright (c) 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

 *******************************************************************************/

package org.eclipse.gef.handles;

import org.eclipse.core.runtime.Assert;

import org.eclipse.draw2d.ConnectionLocator;

import org.eclipse.gef.ConnectionEditPart;

import org.eclipse.gef.DragTracker;

import org.eclipse.gef.RequestConstants;

import org.eclipse.gef.tools.ConnectionEndpointTracker;

/**

 * A handle used at the start or end of the

 * {@link org.eclipse.draw2d.Connection}. A ConnectionEndpointHandle may be

 * extended rather than using the final {@link ConnectionStartHandle} or

 * {@link ConnectionEndHandle}

 * 

 * @author Anthony Hunter

 * @since 3.4

 */

public class ConnectionEndpointHandle extends ConnectionHandle {

	/**

	 * Caches whether the handle is for the source or target endpoint. endPoint

	 * is either {@link ConnectionLocator#SOURCE} or

	 * {@link ConnectionLocator#TARGET}.

	 */

	private int endPoint;

	/**

	 * Creates a new ConnectionStartHandle, sets its owner to <code>owner</code>,

	 * and sets its locator to a {@link ConnectionLocator}.

	 * 

	 * @param owner

	 *            the ConnectionEditPart owner

	 * @param endPoint

	 *            one of {@link ConnectionLocator#SOURCE} or

	 *            {@link ConnectionLocator#TARGET}.

	 */

	public ConnectionEndpointHandle(ConnectionEditPart owner, int endPoint) {

		setOwner(owner);

		Assert.isTrue(endPoint == ConnectionLocator.SOURCE

				|| endPoint == ConnectionLocator.TARGET);

		this.endPoint = endPoint;

		setLocator(new ConnectionLocator(getConnection(), endPoint));

	}

	/**

	 * Creates a new ConnectionStartHandle and sets its owner to

	 * <code>owner</code>. If the handle is fixed, it cannot be dragged.

	 * 

	 * @param owner

	 *            the ConnectionEditPart owner

	 * @param fixed

	 *            if true, handle cannot be dragged.

	 * @param endPoint

	 *            one of {@link ConnectionLocator#SOURCE} or

	 *            {@link ConnectionLocator#TARGET}.

	 */

	public ConnectionEndpointHandle(ConnectionEditPart owner, boolean fixed,

			int endPoint) {

		super(fixed);

		setOwner(owner);

		Assert.isTrue(endPoint == ConnectionLocator.SOURCE

				|| endPoint == ConnectionLocator.TARGET);

		this.endPoint = endPoint;

		setLocator(new ConnectionLocator(getConnection(), endPoint));

	}

	/**

	 * Creates a new ConnectionStartHandle.

	 * 

	 * @param endPoint

	 *            one of {@link ConnectionLocator#SOURCE} or

	 *            {@link ConnectionLocator#TARGET}.

	 */

	public ConnectionEndpointHandle(int endPoint) {

		Assert.isTrue(endPoint == ConnectionLocator.SOURCE

				|| endPoint == ConnectionLocator.TARGET);

		this.endPoint = endPoint;

	}

	/**

	 * Creates and returns a new {@link ConnectionEndpointTracker}.

	 * 

	 * @return the new ConnectionEndpointTracker

	 */

	protected DragTracker createDragTracker() {

		if (isFixed())

			return null;

		ConnectionEndpointTracker tracker;

		tracker = new ConnectionEndpointTracker((ConnectionEditPart) getOwner());

		if (endPoint == ConnectionLocator.SOURCE) {

			tracker.setCommandName(RequestConstants.REQ_RECONNECT_SOURCE);

		} else {

			tracker.setCommandName(RequestConstants.REQ_RECONNECT_TARGET);

		}

		tracker.setDefaultCursor(getCursor());

		return tracker;

	}

}