/*******************************************************************************
 * 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.policies;

import org.eclipse.draw2d.PolylineConnection;

import org.eclipse.gef.EditPart;
import org.eclipse.gef.Request;
import org.eclipse.gef.commands.Command;
import org.eclipse.gef.editpolicies.ConnectionEditPolicy;
import org.eclipse.gef.requests.CreateRequest;
import org.eclipse.gef.requests.GroupRequest;

import org.eclipse.gef.examples.flow.model.Activity;
import org.eclipse.gef.examples.flow.model.StructuredActivity;
import org.eclipse.gef.examples.flow.model.Transition;
import org.eclipse.gef.examples.flow.model.commands.DeleteConnectionCommand;
import org.eclipse.gef.examples.flow.model.commands.SplitTransitionCommand;
import org.eclipse.gef.examples.flow.parts.TransitionPart;

/**
 * EditPolicy for Transitions. Supports deletion and "splitting", i.e. adding an
 * Activity that splits the transition into an incoming and outgoing connection to
 * the new Activity. 
 * 
 * @author Daniel Lee
 */
public class TransitionEditPolicy extends ConnectionEditPolicy {

/**
 * @see org.eclipse.gef.editpolicies.ConnectionEditPolicy#getCommand(org.eclipse.gef.Request)
 */
public Command getCommand(Request request) {
	if (REQ_CREATE.equals(request.getType()))
		return getSplitTransitionCommand(request);
	return super.getCommand(request);
}

private PolylineConnection getConnectionFigure() {
	return ((PolylineConnection)((TransitionPart)getHost()).getFigure());
}

/**
 * @see ConnectionEditPolicy#getDeleteCommand(org.eclipse.gef.requests.GroupRequest)
 */
protected Command getDeleteCommand(GroupRequest request) {
	DeleteConnectionCommand cmd = new DeleteConnectionCommand();
	Transition t = (Transition)getHost().getModel();
	cmd.setTransition(t);
	cmd.setSource(t.source);
	cmd.setTarget(t.target);
	return cmd;
}

protected Command getSplitTransitionCommand(Request request){
	SplitTransitionCommand cmd = new SplitTransitionCommand();
	cmd.setTransition(((Transition)getHost().getModel()));
	cmd.setParent(
		((StructuredActivity) ((TransitionPart) getHost())
			.getSource()
			.getParent()
			.getModel()));
	cmd.setNewActivity(((Activity)((CreateRequest)request).getNewObject()));		
	return cmd;
}
/**
 * @see org.eclipse.gef.editpolicies.AbstractEditPolicy#getTargetEditPart(org.eclipse.gef.Request)
 */
public EditPart getTargetEditPart(Request request) {
	if (REQ_CREATE.equals(request.getType()))
		return getHost();
	return null;	
}
/**
 * @see org.eclipse.gef.editpolicies.AbstractEditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
 */
public void eraseTargetFeedback(Request request) {
	if (REQ_CREATE.equals(request.getType()))
		getConnectionFigure().setLineWidth(1);
}

/**
 * @see org.eclipse.gef.editpolicies.AbstractEditPolicy#showTargetFeedback(org.eclipse.gef.Request)
 */
public void showTargetFeedback(Request request) {
	if (REQ_CREATE.equals(request.getType()))
		getConnectionFigure().setLineWidth(2);
}

}