path: root/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.sequence/custom-src/org/eclipse/papyrus/uml/diagram/sequence/edit/policies/SequenceDiagramLayoutEditPolicy.java

/*****************************************************************************
 * Copyright (c) 2017 CEA LIST 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:
 *   CEA LIST - Initial API and implementation
 *
 *****************************************************************************/

package org.eclipse.papyrus.uml.diagram.sequence.edit.policies;

import org.eclipse.draw2d.geometry.Point;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.Request;
import org.eclipse.gef.commands.Command;
import org.eclipse.gef.commands.UnexecutableCommand;
import org.eclipse.gef.requests.ChangeBoundsRequest;
import org.eclipse.papyrus.infra.gmfdiag.common.editpolicies.XYLayoutWithConstrainedResizedEditPolicy;
import org.eclipse.papyrus.uml.diagram.sequence.edit.parts.LifelineEditPart;

/**
 * this class has been customized to prevent the strange feedback of lifeline during the move
 * @since 3.0
 */
public class SequenceDiagramLayoutEditPolicy extends XYLayoutWithConstrainedResizedEditPolicy {
	/**
	 * @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#createAddCommand(org.eclipse.gef.requests.ChangeBoundsRequest, org.eclipse.gef.EditPart, java.lang.Object)
	 *
	 * @param request
	 * @param child
	 * @param constraint
	 * @return
	 */
	@Override
	protected Command createAddCommand(ChangeBoundsRequest request, EditPart child, Object constraint) {
		if( child instanceof LifelineEditPart) {
			return UnexecutableCommand.INSTANCE;
		}
		return super.createAddCommand(request, child, constraint);
	}


	/**
	 * @see org.eclipse.gef.editpolicies.LayoutEditPolicy#showTargetFeedback(org.eclipse.gef.Request)
	 *
	 * @param request
	 */
	@Override
	public void showTargetFeedback(Request request) {
		if(request instanceof ChangeBoundsRequest){
			ChangeBoundsRequest changeBoundsRequest= (ChangeBoundsRequest)request;

			if( changeBoundsRequest.getEditParts().get(0) instanceof LifelineEditPart) {
				changeBoundsRequest.setMoveDelta(new Point(changeBoundsRequest.getMoveDelta().x,0));
			}
		}
		super.showTargetFeedback(request);
	}
}