/*******************************************************************************
 * Copyright (c) 2000, 2005 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.examples.flow.model.commands;

import java.util.List;

import org.eclipse.gef.commands.Command;

import org.eclipse.gef.examples.flow.model.Activity;
import org.eclipse.gef.examples.flow.model.Transition;

/**
 * Command that handles the reconnection of target Activities.
 * @author Daniel Lee
 */
public class ReconnectTargetCommand extends Command {

/** Source Activity **/
protected Activity source;
/** Target Activity **/
protected Activity target;
/** Transition between source and target **/
protected Transition transition;
/** Previous target prior to command execution **/
protected Activity oldTarget;

/**
 * @see org.eclipse.gef.commands.Command#canExecute()
 */
public boolean canExecute() {
	if (transition.source.equals(target))
		return false;
	
	List transitions = source.getOutgoingTransitions();	
	for (int i = 0; i < transitions.size(); i++) {
		Transition trans = ((Transition)(transitions.get(i)));
		if (trans.target.equals(target) && !trans.target.equals(oldTarget))
			return false;
	}
	return true;	
}

/**
 * @see org.eclipse.gef.commands.Command#execute()
 */
public void execute() {
	if (target != null) {
		oldTarget.removeInput(transition);
		transition.target = target;
		target.addInput(transition);
	}
}

/**
 * Returns the source Activity associated with this command
 * @return the source Activity
 */
public Activity getSource() {
	return source;
}

/**
 * Returns the target Activity associated with this command
 * @return the target Activity
 */
public Activity getTarget() {
	return target;
}

/**
 * Returns the Transition associated with this command
 * @return the Transition
 */
public Transition getTransition() {
	return transition;
}

/**
 * Sets the source Activity associated with this command
 * @param activity the source Activity
 */
public void setSource(Activity activity) {
	source = activity;
}

/**
 * Sets the target Activity assoicated with this command
 * @param activity the target Activity
 */
public void setTarget(Activity activity) {
	target = activity;
}

/**
 * Sets the transition associated with this 
 * @param trans the transition
 */
public void setTransition(Transition trans) {
	transition = trans;
	source = trans.source;
	oldTarget = trans.target;
}

/**
 * @see org.eclipse.gef.commands.Command#undo()
 */
public void undo() {
	target.removeInput(transition);
	transition.target = oldTarget;
	oldTarget.addInput(transition);
}

}