org.eclipse.gmf.runtime.diagram.ui/src/org/eclipse/gmf/runtime/diagram/ui/editpolicies/XYLayoutEditPolicy.java - gmf-runtime/org.eclipse.gmf-runtime - Git at Google

 /******************************************************************************
  * Copyright (c) 2002, 2010, 2012 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.gmf.runtime.diagram.ui.editpolicies;

 import java.util.Iterator;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.draw2d.IFigure;
 import org.eclipse.draw2d.PositionConstants;
 import org.eclipse.draw2d.geometry.Dimension;
 import org.eclipse.draw2d.geometry.Point;
 import org.eclipse.draw2d.geometry.Rectangle;
 import org.eclipse.emf.transaction.TransactionalEditingDomain;
 import org.eclipse.gef.EditPart;
 import org.eclipse.gef.EditPartViewer;
 import org.eclipse.gef.EditPolicy;
 import org.eclipse.gef.GraphicalEditPart;
 import org.eclipse.gef.Request;
 import org.eclipse.gef.SnapToGuides;
 import org.eclipse.gef.commands.Command;
 import org.eclipse.gef.requests.ChangeBoundsRequest;
 import org.eclipse.gef.requests.CreateRequest;
 import org.eclipse.gef.rulers.RulerProvider;
 import org.eclipse.gmf.runtime.common.core.command.ICommand;
 import org.eclipse.gmf.runtime.diagram.ui.commands.ICommandProxy;
 import org.eclipse.gmf.runtime.diagram.ui.commands.SetBoundsCommand;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.ShapeEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.figures.LayoutHelper;
 import org.eclipse.gmf.runtime.diagram.ui.internal.ruler.DiagramGuide;
 import org.eclipse.gmf.runtime.diagram.ui.internal.ruler.commands.ChangeGuideCommand;
 import org.eclipse.gmf.runtime.diagram.ui.l10n.DiagramUIMessages;
 import org.eclipse.gmf.runtime.diagram.ui.requests.CreateViewRequest;
 import org.eclipse.gmf.runtime.diagram.ui.requests.RequestConstants;
 import org.eclipse.gmf.runtime.draw2d.ui.mapmode.IMapMode;
 import org.eclipse.gmf.runtime.draw2d.ui.mapmode.MapModeUtil;
 import org.eclipse.gmf.runtime.emf.commands.core.command.CompositeTransactionalCommand;
 import org.eclipse.gmf.runtime.emf.core.util.EObjectAdapter;
 import org.eclipse.gmf.runtime.notation.Guide;
 import org.eclipse.gmf.runtime.notation.View;

 /**
  * the xy layout edit policy
  * @see org.eclipse.gef.editpolicies.XYLayoutEditPolicy
  * @author sshaw
  *
  */
 public class XYLayoutEditPolicy
 	extends org.eclipse.gef.editpolicies.XYLayoutEditPolicy {


 	/**
 	 * Called in response to a <tt>REQ_ADD</tt> (reparent) request.
 	 * Returns a <tt>SetPropertyCommand</tt> to set the <tt>child<tt>'s bounds
 	 * to the supplied constraint.
 	 *
 	 * @param child element being reparented.
 	 * @param constraint - rectangle containing the child's bounds (location)
 	 * @return a new command or null if the compound command is empty
 	 *
 	 */
 	protected Command createAddCommand(EditPart child, Object constraint) {
 		if ( child instanceof ShapeEditPart && constraint instanceof Rectangle) {
 			Rectangle rect = (Rectangle) constraint;

 	 		ICommand boundsCommand =
 	 			new SetBoundsCommand(((ShapeEditPart) child).getEditingDomain(),
 	 				DiagramUIMessages.SetLocationCommand_Label_Resize,
 	 				new EObjectAdapter((View) child.getModel()),
 					rect.getTopLeft());
 			return new ICommandProxy(boundsCommand);
 		}
 		return null;
 	}


 	/* (non-Javadoc)
 	 * @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#createChangeConstraintCommand(org.eclipse.gef.requests.ChangeBoundsRequest, org.eclipse.gef.EditPart, java.lang.Object)
 	 */
 	protected Command createChangeConstraintCommand(
 			ChangeBoundsRequest request, EditPart child, Object constraint) {


         TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
             .getEditingDomain();

 		Command cmd = createChangeConstraintCommand(child, constraint);
 		View view = (View)child.getModel();
 		if ((request.getResizeDirection() & PositionConstants.NORTH_SOUTH) != 0) {
 			Integer guidePos = (Integer)request.getExtendedData()
 					.get(SnapToGuides.KEY_HORIZONTAL_GUIDE);
 			if (guidePos != null) {
 				int hAlignment = ((Integer)request.getExtendedData()
 						.get(SnapToGuides.KEY_HORIZONTAL_ANCHOR)).intValue();
 				ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, true);
 				cgm.setNewGuide(findGuideAt(guidePos.intValue(), true), hAlignment);
 				cmd = cmd.chain(new ICommandProxy(cgm));
 			} else if (DiagramGuide.getInstance().getHorizontalGuide(view) != null) {
 				// SnapToGuides didn't provide a horizontal guide, but this part is attached
 				// to a horizontal guide.  Now we check to see if the part is attached to
 				// the guide along the edge being resized.  If that is the case, we need to
 				// detach the part from the guide; otherwise, we leave it alone.
 				int alignment = DiagramGuide.getInstance().getHorizontalAlignment(view);
 				int edgeBeingResized = 0;
 				if ((request.getResizeDirection() & PositionConstants.NORTH) != 0)
 					edgeBeingResized = -1;
 				else
 					edgeBeingResized = 1;
 				if (alignment == edgeBeingResized) {
 					ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, true);
 					cmd = cmd.chain(new ICommandProxy(cgm));
 				}
 			}
 		}

 		if ((request.getResizeDirection() & PositionConstants.EAST_WEST) != 0) {
 			Integer guidePos = (Integer)request.getExtendedData()
 					.get(SnapToGuides.KEY_VERTICAL_GUIDE);
 			if (guidePos != null) {
 				int vAlignment = ((Integer)request.getExtendedData()
 						.get(SnapToGuides.KEY_VERTICAL_ANCHOR)).intValue();
 				ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, false);
 				cgm.setNewGuide(findGuideAt(guidePos.intValue(), false), vAlignment);
 				cmd = cmd.chain(new ICommandProxy(cgm));
 			} else if (DiagramGuide.getInstance().getVerticalGuide(view) != null) {
 				int alignment = DiagramGuide.getInstance().getVerticalAlignment(view);
 				int edgeBeingResized = 0;
 				if ((request.getResizeDirection() & PositionConstants.WEST) != 0)
 					edgeBeingResized = -1;
 				else
 					edgeBeingResized = 1;
 				if (alignment == edgeBeingResized) {
 					ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, false);
 					cmd = cmd.chain(new ICommandProxy(cgm));
 				}
 			}
 		}

         if (request.getType().equals(REQ_MOVE_CHILDREN)
                 || request.getType().equals(REQ_ALIGN_CHILDREN)) {
             Integer guidePos = (Integer)request.getExtendedData()
                     .get(SnapToGuides.KEY_HORIZONTAL_GUIDE);
             ChangeGuideCommand cgm = null;
             if (guidePos != null) {
                 cgm = new ChangeGuideCommand(editingDomain,view, true);;
                 int hAlignment = ((Integer)request.getExtendedData()
                         .get(SnapToGuides.KEY_HORIZONTAL_ANCHOR)).intValue();
                 cgm.setNewGuide(findGuideAt(guidePos.intValue(), true), hAlignment);
             }else {
                 Guide theOldGuide = DiagramGuide.getInstance().getHorizontalGuide(view);
                 if (theOldGuide!=null)
                     cgm = new ChangeGuideCommand(editingDomain,view, true);
             }
             // If know this creates a lot of extra commands.  They are currently
             // required for attaching/detaching shapes to guides
             if (cgm!=null)
                 cmd = cmd.chain(new ICommandProxy(cgm));

             guidePos = (Integer)request.getExtendedData()
                     .get(SnapToGuides.KEY_VERTICAL_GUIDE);
             cgm = null;
             if (guidePos != null) {
                 cgm = new ChangeGuideCommand(editingDomain, view, false);
                 int vAlignment = ((Integer)request.getExtendedData()
                         .get(SnapToGuides.KEY_VERTICAL_ANCHOR)).intValue();
                 cgm.setNewGuide(findGuideAt(guidePos.intValue(), false), vAlignment);
             }else {
                  Guide theOldGuide = DiagramGuide.getInstance().getVerticalGuide(view);
                     if (theOldGuide!=null)
                         cgm = new ChangeGuideCommand(editingDomain, view, true);
             }
             // If know this creates a lot of extra commands.  They are currently
             // required for attaching/detaching shapes to guides
             if (cgm!=null)
                 cmd = cmd.chain(new ICommandProxy(cgm));
         }


 		return cmd;
 	}

 	/**
 	 * Called in response to a <tt>REQ_RESIZE_CHILDREN</tt> request.
 	 *
 	 * This implementation creates a <tt>SetPropertyCommand</i> and sets
 	 * the <tt>ID_BOUNDS</tt> property value to the supplied constraints.
 	 *
 	 * @param child the element being resized.
 	 * @param constraint the elements new bounds.
 	 * @return {@link SetBoundsCommand}
 	 */
 	protected Command createChangeConstraintCommand(
 		EditPart child,
 		Object constraint) {
 		Rectangle newBounds = (Rectangle) constraint;
 		View shapeView = (View) child.getModel();

         TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
             .getEditingDomain();

  		ICommand boundsCommand =
  			new SetBoundsCommand(editingDomain,
  				DiagramUIMessages.SetLocationCommand_Label_Resize,
  				new EObjectAdapter(shapeView),
 				newBounds);
 		return new ICommandProxy(boundsCommand);
 	}

 	/**
 	 * @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#getConstraintFor(org.eclipse.gef.requests.ChangeBoundsRequest, org.eclipse.gef.GraphicalEditPart)
 	 */
 	protected Object getConstraintFor(
 		ChangeBoundsRequest request,
 		GraphicalEditPart child) {
 		Rectangle rect = (Rectangle) super.getConstraintFor(request, child);
 		Rectangle cons = getCurrentConstraintFor(child);
 		Dimension requestSizeDelta = request.getSizeDelta();
 		if (requestSizeDelta.width == 0 && cons != null){
 			rect.width = cons.width;
 		}
 		if (requestSizeDelta.height == 0 && cons != null){
 			rect.height = cons.height;
 		}
 		return rect;
 	}

 	/**
 	 * Called in response to a <tt>REQ_CREATE</tt> request. Returns a command
 	 * to set each created element bounds and autosize properties.
 	 *
 	 * @param request a create request (understands instances of {@link CreateViewRequest}).
 	 * @return a command to satify the request; <tt>null</tt> if the request is not
 	 * understood.
 	 */
 	protected Command getCreateCommand(CreateRequest request) {
 		CreateViewRequest req = (CreateViewRequest) request;


         TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
             .getEditingDomain();

 		CompositeTransactionalCommand cc = new CompositeTransactionalCommand(
             editingDomain, DiagramUIMessages.AddCommand_Label);
         Iterator iter = req.getViewDescriptors().iterator();

 		final Rectangle BOUNDS = (Rectangle) getConstraintFor(request);


 		while (iter.hasNext()) {
 			CreateViewRequest.ViewDescriptor viewDescriptor = (CreateViewRequest.ViewDescriptor)iter.next();
 			Rectangle rect = getBoundsOffest(req, BOUNDS,viewDescriptor);
 			cc.compose(new SetBoundsCommand(editingDomain,
 				DiagramUIMessages.SetLocationCommand_Label_Resize,
 				viewDescriptor,
 				rect));
 		}

 		if( cc.reduce() == null )
 			return null;

 		return chainGuideAttachmentCommands( request,
 			new ICommandProxy(cc.reduce()));
 	}

 	/**
 	 * Return bounds offset by some predefined amount.
 	 * @param request the request
 	 * @param bounds	the rectangle bounds
 	 * @param viewDescriptor the view descriptor
 	 * @return rectangle
 	 */
 	protected Rectangle getBoundsOffest( CreateViewRequest request, Rectangle bounds, CreateViewRequest.ViewDescriptor viewDescriptor ) {
 		int translate = request.getViewDescriptors().indexOf(viewDescriptor) * 10;
 		return bounds.getCopy().translate( translate, translate );
 	}

 	/**
 	 * <tt>null</tt> implementation: request not handled.
 	 */
 	protected Command getDeleteDependantCommand(Request request) {
 		return null;
 	}

 	/**
 	 * <tt>null</tt> implementation: request not handled.
 	 */
 	protected Command getOrphanChildrenCommand(Request request) {
 		return null;
 	}

 	protected EditPolicy createChildEditPolicy(EditPart child) {
 		if ( child instanceof ShapeEditPart ) {
 			return ((ShapeEditPart)child).getPrimaryDragEditPolicy();
 		}

 		return null;
 	}

 	/**
 	 * Creates command for <tt>REQ_CREATE</tt>
 	 * requests only; all others requests are forwarded to the parent class.
 	 *
 	 * @see #getCommand(Request)
 	 */
 	public Command getCommand(Request request) {

 		if (REQ_CREATE.equals(request.getType())) {

 			if (request instanceof CreateViewRequest) {
 				return getCreateCommand((CreateViewRequest) request);
 			} else {
 				return null;
 			}

 		}
 		return super.getCommand(request);
 	}

 	/* Override to use to deal with causes where the point is UNDERFINED
 	 * we will ask the layout helper to find a location for us
 	 * @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#getConstraintFor(org.eclipse.gef.requests.CreateRequest)
 	 */
 	protected Object getConstraintFor(CreateRequest request) {

 		Object constraint = super.getConstraintFor(request);

 		if ( LayoutHelper.UNDEFINED.getLocation().equals(request.getLocation()) ){
 			Rectangle rect = (Rectangle)constraint;
 			rect.setLocation(getLayoutHelper().getReferencePosition(getHostFigure()));
 			Point point = getLayoutHelper().validatePosition(getHostFigure(),rect);
 			rect.setLocation(point);
 			return rect;
 		}
 		return constraint;
 	}

 	/**
 	 * Return the host's figure.
 	 * The super calls getFigure().  This is a problem when used with shapecompartments.  Instead,
 	 * return getContextPane().  In shape comaprtments this will return the correct containing figure.
 	 */
 	protected IFigure getHostFigure() {
 		return ((GraphicalEditPart)getHost()).getContentPane();
 	}

 	// layout helper used to help locate shape created with undefined points
 	LayoutHelper layoutHelper = null;

 	/** Return this layout helper. */
 	private LayoutHelper getLayoutHelper() {
 		if (layoutHelper == null) {
 			layoutHelper = new LayoutHelper();
 		}
 		return layoutHelper;
 	}

 	/**
 	 * @param request
 	 * @param cmd
 	 * @return command
 	 */
 	protected Command chainGuideAttachmentCommands(
 			Request request, Command cmd) {
 		Assert.isNotNull(request);
 		Assert.isNotNull(cmd);

 		EditPartViewer editPartViewer = getHost().getRoot().getViewer();
 		Command result = cmd;

 		CreateViewRequest req = (CreateViewRequest) request;

         TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
             .getEditingDomain();

 		// Attach to horizontal guide, if one is given
 		Integer guidePos = (Integer)request.getExtendedData()
 				.get(SnapToGuides.KEY_HORIZONTAL_GUIDE);
 		if (guidePos != null) {
 			int hAlignment = ((Integer)request.getExtendedData()
 					.get(SnapToGuides.KEY_HORIZONTAL_ANCHOR)).intValue();

 			Guide guide = findGuideAt(guidePos.intValue(), true);

 			Iterator iter = req.getViewDescriptors().iterator();

 			while (iter.hasNext()) {
 				IAdaptable desc = (IAdaptable)iter.next();
 				ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain,
                     editPartViewer, desc, true);
 				cgm.setNewGuide(guide, hAlignment);
 				result = result.chain(new ICommandProxy(cgm));
 			}
 		}

 		// Attach to vertical guide, if one is given
 		guidePos = (Integer)request.getExtendedData()
 				.get(SnapToGuides.KEY_VERTICAL_GUIDE);
 		if (guidePos != null) {
 			int vAlignment = ((Integer)request.getExtendedData()
 					.get(SnapToGuides.KEY_VERTICAL_ANCHOR)).intValue();

 			Guide guide = findGuideAt(guidePos.intValue(), false);

 			Iterator iter = req.getViewDescriptors().iterator();

 			while (iter.hasNext()) {
 				IAdaptable desc = (IAdaptable)iter.next();

 				ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain,
                     editPartViewer, desc, false);
 				cgm.setNewGuide(guide, vAlignment);
 				result = result.chain(new ICommandProxy(cgm));
 			}
 		}

 		return result;
 	}

 	/**
 	 * gets the guid at a specific pos
 	 * @param pos	the position
 	 * @param horizontal the horizontal flag
 	 * @return the guid
 	 */
 	protected Guide findGuideAt(int pos, boolean horizontal) {
 		RulerProvider provider = ((RulerProvider)getHost().getViewer().getProperty(
 				horizontal ? RulerProvider.PROPERTY_VERTICAL_RULER
 				: RulerProvider.PROPERTY_HORIZONTAL_RULER));
 		IMapMode mm = MapModeUtil.getMapMode(((GraphicalEditPart)getHost()).getFigure());

 		return (Guide)provider.getGuideAt(mm.LPtoDP(pos));
 	}

 	/*
 	 * Override to erase in case of GMF drop request, see https://bugs.eclipse.org/bugs/show_bug.cgi?id=276033
 	 * (non-Javadoc)
 	 * @see org.eclipse.gef.editpolicies.LayoutEditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
 	 */
 	@Override
 	public void eraseTargetFeedback(Request request) {
 		super.eraseTargetFeedback(request);
 		if (RequestConstants.REQ_DROP.equals(request.getType()))
 				eraseLayoutTargetFeedback(request);
 	}
 }
	/******************************************************************************
	* Copyright (c) 2002, 2010, 2012 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.gmf.runtime.diagram.ui.editpolicies;

	import java.util.Iterator;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.draw2d.IFigure;
	import org.eclipse.draw2d.PositionConstants;
	import org.eclipse.draw2d.geometry.Dimension;
	import org.eclipse.draw2d.geometry.Point;
	import org.eclipse.draw2d.geometry.Rectangle;
	import org.eclipse.emf.transaction.TransactionalEditingDomain;
	import org.eclipse.gef.EditPart;
	import org.eclipse.gef.EditPartViewer;
	import org.eclipse.gef.EditPolicy;
	import org.eclipse.gef.GraphicalEditPart;
	import org.eclipse.gef.Request;
	import org.eclipse.gef.SnapToGuides;
	import org.eclipse.gef.commands.Command;
	import org.eclipse.gef.requests.ChangeBoundsRequest;
	import org.eclipse.gef.requests.CreateRequest;
	import org.eclipse.gef.rulers.RulerProvider;
	import org.eclipse.gmf.runtime.common.core.command.ICommand;
	import org.eclipse.gmf.runtime.diagram.ui.commands.ICommandProxy;
	import org.eclipse.gmf.runtime.diagram.ui.commands.SetBoundsCommand;
	import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
	import org.eclipse.gmf.runtime.diagram.ui.editparts.ShapeEditPart;
	import org.eclipse.gmf.runtime.diagram.ui.figures.LayoutHelper;
	import org.eclipse.gmf.runtime.diagram.ui.internal.ruler.DiagramGuide;
	import org.eclipse.gmf.runtime.diagram.ui.internal.ruler.commands.ChangeGuideCommand;
	import org.eclipse.gmf.runtime.diagram.ui.l10n.DiagramUIMessages;
	import org.eclipse.gmf.runtime.diagram.ui.requests.CreateViewRequest;
	import org.eclipse.gmf.runtime.diagram.ui.requests.RequestConstants;
	import org.eclipse.gmf.runtime.draw2d.ui.mapmode.IMapMode;
	import org.eclipse.gmf.runtime.draw2d.ui.mapmode.MapModeUtil;
	import org.eclipse.gmf.runtime.emf.commands.core.command.CompositeTransactionalCommand;
	import org.eclipse.gmf.runtime.emf.core.util.EObjectAdapter;
	import org.eclipse.gmf.runtime.notation.Guide;
	import org.eclipse.gmf.runtime.notation.View;

	/**
	* the xy layout edit policy
	* @see org.eclipse.gef.editpolicies.XYLayoutEditPolicy
	* @author sshaw
	*
	*/
	public class XYLayoutEditPolicy
	extends org.eclipse.gef.editpolicies.XYLayoutEditPolicy {


	/**
	* Called in response to a <tt>REQ_ADD</tt> (reparent) request.
	* Returns a <tt>SetPropertyCommand</tt> to set the <tt>child<tt>'s bounds
	* to the supplied constraint.
	*
	* @param child element being reparented.
	* @param constraint - rectangle containing the child's bounds (location)
	* @return a new command or null if the compound command is empty
	*
	*/
	protected Command createAddCommand(EditPart child, Object constraint) {
	if ( child instanceof ShapeEditPart && constraint instanceof Rectangle) {
	Rectangle rect = (Rectangle) constraint;

	ICommand boundsCommand =
	new SetBoundsCommand(((ShapeEditPart) child).getEditingDomain(),
	DiagramUIMessages.SetLocationCommand_Label_Resize,
	new EObjectAdapter((View) child.getModel()),
	rect.getTopLeft());
	return new ICommandProxy(boundsCommand);
	}
	return null;
	}




	/* (non-Javadoc)
	* @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#createChangeConstraintCommand(org.eclipse.gef.requests.ChangeBoundsRequest, org.eclipse.gef.EditPart, java.lang.Object)
	*/
	protected Command createChangeConstraintCommand(
	ChangeBoundsRequest request, EditPart child, Object constraint) {


	TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
	.getEditingDomain();

	Command cmd = createChangeConstraintCommand(child, constraint);
	View view = (View)child.getModel();
	if ((request.getResizeDirection() & PositionConstants.NORTH_SOUTH) != 0) {
	Integer guidePos = (Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_HORIZONTAL_GUIDE);
	if (guidePos != null) {
	int hAlignment = ((Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_HORIZONTAL_ANCHOR)).intValue();
	ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, true);
	cgm.setNewGuide(findGuideAt(guidePos.intValue(), true), hAlignment);
	cmd = cmd.chain(new ICommandProxy(cgm));
	} else if (DiagramGuide.getInstance().getHorizontalGuide(view) != null) {
	// SnapToGuides didn't provide a horizontal guide, but this part is attached
	// to a horizontal guide. Now we check to see if the part is attached to
	// the guide along the edge being resized. If that is the case, we need to
	// detach the part from the guide; otherwise, we leave it alone.
	int alignment = DiagramGuide.getInstance().getHorizontalAlignment(view);
	int edgeBeingResized = 0;
	if ((request.getResizeDirection() & PositionConstants.NORTH) != 0)
	edgeBeingResized = -1;
	else
	edgeBeingResized = 1;
	if (alignment == edgeBeingResized) {
	ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, true);
	cmd = cmd.chain(new ICommandProxy(cgm));
	}
	}
	}

	if ((request.getResizeDirection() & PositionConstants.EAST_WEST) != 0) {
	Integer guidePos = (Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_VERTICAL_GUIDE);
	if (guidePos != null) {
	int vAlignment = ((Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_VERTICAL_ANCHOR)).intValue();
	ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, false);
	cgm.setNewGuide(findGuideAt(guidePos.intValue(), false), vAlignment);
	cmd = cmd.chain(new ICommandProxy(cgm));
	} else if (DiagramGuide.getInstance().getVerticalGuide(view) != null) {
	int alignment = DiagramGuide.getInstance().getVerticalAlignment(view);
	int edgeBeingResized = 0;
	if ((request.getResizeDirection() & PositionConstants.WEST) != 0)
	edgeBeingResized = -1;
	else
	edgeBeingResized = 1;
	if (alignment == edgeBeingResized) {
	ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain, view, false);
	cmd = cmd.chain(new ICommandProxy(cgm));
	}
	}
	}

	if (request.getType().equals(REQ_MOVE_CHILDREN)
	\|\| request.getType().equals(REQ_ALIGN_CHILDREN)) {
	Integer guidePos = (Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_HORIZONTAL_GUIDE);
	ChangeGuideCommand cgm = null;
	if (guidePos != null) {
	cgm = new ChangeGuideCommand(editingDomain,view, true);;
	int hAlignment = ((Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_HORIZONTAL_ANCHOR)).intValue();
	cgm.setNewGuide(findGuideAt(guidePos.intValue(), true), hAlignment);
	}else {
	Guide theOldGuide = DiagramGuide.getInstance().getHorizontalGuide(view);
	if (theOldGuide!=null)
	cgm = new ChangeGuideCommand(editingDomain,view, true);
	}
	// If know this creates a lot of extra commands. They are currently
	// required for attaching/detaching shapes to guides
	if (cgm!=null)
	cmd = cmd.chain(new ICommandProxy(cgm));

	guidePos = (Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_VERTICAL_GUIDE);
	cgm = null;
	if (guidePos != null) {
	cgm = new ChangeGuideCommand(editingDomain, view, false);
	int vAlignment = ((Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_VERTICAL_ANCHOR)).intValue();
	cgm.setNewGuide(findGuideAt(guidePos.intValue(), false), vAlignment);
	}else {
	Guide theOldGuide = DiagramGuide.getInstance().getVerticalGuide(view);
	if (theOldGuide!=null)
	cgm = new ChangeGuideCommand(editingDomain, view, true);
	}
	// If know this creates a lot of extra commands. They are currently
	// required for attaching/detaching shapes to guides
	if (cgm!=null)
	cmd = cmd.chain(new ICommandProxy(cgm));
	}


	return cmd;
	}

	/**
	* Called in response to a <tt>REQ_RESIZE_CHILDREN</tt> request.
	*
	* This implementation creates a <tt>SetPropertyCommand</i> and sets
	* the <tt>ID_BOUNDS</tt> property value to the supplied constraints.
	*
	* @param child the element being resized.
	* @param constraint the elements new bounds.
	* @return {@link SetBoundsCommand}
	*/
	protected Command createChangeConstraintCommand(
	EditPart child,
	Object constraint) {
	Rectangle newBounds = (Rectangle) constraint;
	View shapeView = (View) child.getModel();

	TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
	.getEditingDomain();

	ICommand boundsCommand =
	new SetBoundsCommand(editingDomain,
	DiagramUIMessages.SetLocationCommand_Label_Resize,
	new EObjectAdapter(shapeView),
	newBounds);
	return new ICommandProxy(boundsCommand);
	}

	/**
	* @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#getConstraintFor(org.eclipse.gef.requests.ChangeBoundsRequest, org.eclipse.gef.GraphicalEditPart)
	*/
	protected Object getConstraintFor(
	ChangeBoundsRequest request,
	GraphicalEditPart child) {
	Rectangle rect = (Rectangle) super.getConstraintFor(request, child);
	Rectangle cons = getCurrentConstraintFor(child);
	Dimension requestSizeDelta = request.getSizeDelta();
	if (requestSizeDelta.width == 0 && cons != null){
	rect.width = cons.width;
	}
	if (requestSizeDelta.height == 0 && cons != null){
	rect.height = cons.height;
	}
	return rect;
	}

	/**
	* Called in response to a <tt>REQ_CREATE</tt> request. Returns a command
	* to set each created element bounds and autosize properties.
	*
	* @param request a create request (understands instances of {@link CreateViewRequest}).
	* @return a command to satify the request; <tt>null</tt> if the request is not
	* understood.
	*/
	protected Command getCreateCommand(CreateRequest request) {
	CreateViewRequest req = (CreateViewRequest) request;


	TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
	.getEditingDomain();

	CompositeTransactionalCommand cc = new CompositeTransactionalCommand(
	editingDomain, DiagramUIMessages.AddCommand_Label);
	Iterator iter = req.getViewDescriptors().iterator();

	final Rectangle BOUNDS = (Rectangle) getConstraintFor(request);



	while (iter.hasNext()) {
	CreateViewRequest.ViewDescriptor viewDescriptor = (CreateViewRequest.ViewDescriptor)iter.next();
	Rectangle rect = getBoundsOffest(req, BOUNDS,viewDescriptor);
	cc.compose(new SetBoundsCommand(editingDomain,
	DiagramUIMessages.SetLocationCommand_Label_Resize,
	viewDescriptor,
	rect));
	}

	if( cc.reduce() == null )
	return null;

	return chainGuideAttachmentCommands( request,
	new ICommandProxy(cc.reduce()));
	}

	/**
	* Return bounds offset by some predefined amount.
	* @param request the request
	* @param bounds the rectangle bounds
	* @param viewDescriptor the view descriptor
	* @return rectangle
	*/
	protected Rectangle getBoundsOffest( CreateViewRequest request, Rectangle bounds, CreateViewRequest.ViewDescriptor viewDescriptor ) {
	int translate = request.getViewDescriptors().indexOf(viewDescriptor) * 10;
	return bounds.getCopy().translate( translate, translate );
	}

	/**
	* <tt>null</tt> implementation: request not handled.
	*/
	protected Command getDeleteDependantCommand(Request request) {
	return null;
	}

	/**
	* <tt>null</tt> implementation: request not handled.
	*/
	protected Command getOrphanChildrenCommand(Request request) {
	return null;
	}

	protected EditPolicy createChildEditPolicy(EditPart child) {
	if ( child instanceof ShapeEditPart ) {
	return ((ShapeEditPart)child).getPrimaryDragEditPolicy();
	}

	return null;
	}

	/**
	* Creates command for <tt>REQ_CREATE</tt>
	* requests only; all others requests are forwarded to the parent class.
	*
	* @see #getCommand(Request)
	*/
	public Command getCommand(Request request) {

	if (REQ_CREATE.equals(request.getType())) {

	if (request instanceof CreateViewRequest) {
	return getCreateCommand((CreateViewRequest) request);
	} else {
	return null;
	}

	}
	return super.getCommand(request);
	}

	/* Override to use to deal with causes where the point is UNDERFINED
	* we will ask the layout helper to find a location for us
	* @see org.eclipse.gef.editpolicies.ConstrainedLayoutEditPolicy#getConstraintFor(org.eclipse.gef.requests.CreateRequest)
	*/
	protected Object getConstraintFor(CreateRequest request) {

	Object constraint = super.getConstraintFor(request);

	if ( LayoutHelper.UNDEFINED.getLocation().equals(request.getLocation()) ){
	Rectangle rect = (Rectangle)constraint;
	rect.setLocation(getLayoutHelper().getReferencePosition(getHostFigure()));
	Point point = getLayoutHelper().validatePosition(getHostFigure(),rect);
	rect.setLocation(point);
	return rect;
	}
	return constraint;
	}

	/**
	* Return the host's figure.
	* The super calls getFigure(). This is a problem when used with shapecompartments. Instead,
	* return getContextPane(). In shape comaprtments this will return the correct containing figure.
	*/
	protected IFigure getHostFigure() {
	return ((GraphicalEditPart)getHost()).getContentPane();
	}

	// layout helper used to help locate shape created with undefined points
	LayoutHelper layoutHelper = null;

	/** Return this layout helper. */
	private LayoutHelper getLayoutHelper() {
	if (layoutHelper == null) {
	layoutHelper = new LayoutHelper();
	}
	return layoutHelper;
	}

	/**
	* @param request
	* @param cmd
	* @return command
	*/
	protected Command chainGuideAttachmentCommands(
	Request request, Command cmd) {
	Assert.isNotNull(request);
	Assert.isNotNull(cmd);

	EditPartViewer editPartViewer = getHost().getRoot().getViewer();
	Command result = cmd;

	CreateViewRequest req = (CreateViewRequest) request;

	TransactionalEditingDomain editingDomain = ((IGraphicalEditPart) getHost())
	.getEditingDomain();

	// Attach to horizontal guide, if one is given
	Integer guidePos = (Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_HORIZONTAL_GUIDE);
	if (guidePos != null) {
	int hAlignment = ((Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_HORIZONTAL_ANCHOR)).intValue();

	Guide guide = findGuideAt(guidePos.intValue(), true);

	Iterator iter = req.getViewDescriptors().iterator();

	while (iter.hasNext()) {
	IAdaptable desc = (IAdaptable)iter.next();
	ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain,
	editPartViewer, desc, true);
	cgm.setNewGuide(guide, hAlignment);
	result = result.chain(new ICommandProxy(cgm));
	}
	}

	// Attach to vertical guide, if one is given
	guidePos = (Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_VERTICAL_GUIDE);
	if (guidePos != null) {
	int vAlignment = ((Integer)request.getExtendedData()
	.get(SnapToGuides.KEY_VERTICAL_ANCHOR)).intValue();

	Guide guide = findGuideAt(guidePos.intValue(), false);

	Iterator iter = req.getViewDescriptors().iterator();

	while (iter.hasNext()) {
	IAdaptable desc = (IAdaptable)iter.next();

	ChangeGuideCommand cgm = new ChangeGuideCommand(editingDomain,
	editPartViewer, desc, false);
	cgm.setNewGuide(guide, vAlignment);
	result = result.chain(new ICommandProxy(cgm));
	}
	}

	return result;
	}

	/**
	* gets the guid at a specific pos
	* @param pos the position
	* @param horizontal the horizontal flag
	* @return the guid
	*/
	protected Guide findGuideAt(int pos, boolean horizontal) {
	RulerProvider provider = ((RulerProvider)getHost().getViewer().getProperty(
	horizontal ? RulerProvider.PROPERTY_VERTICAL_RULER
	: RulerProvider.PROPERTY_HORIZONTAL_RULER));
	IMapMode mm = MapModeUtil.getMapMode(((GraphicalEditPart)getHost()).getFigure());

	return (Guide)provider.getGuideAt(mm.LPtoDP(pos));
	}

	/*
	* Override to erase in case of GMF drop request, see https://bugs.eclipse.org/bugs/show_bug.cgi?id=276033
	* (non-Javadoc)
	* @see org.eclipse.gef.editpolicies.LayoutEditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
	*/
	@Override
	public void eraseTargetFeedback(Request request) {
	super.eraseTargetFeedback(request);
	if (RequestConstants.REQ_DROP.equals(request.getType()))
	eraseLayoutTargetFeedback(request);
	}
	}