plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/internal/policy/DefaultConnectionEditPolicy.java - graphiti/org.eclipse.graphiti - Git at Google

 /*******************************************************************************
  * <copyright>
  *
  * Copyright (c) 2005, 2018 SAP AG, Redhat.
  * 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:
  *    SAP AG - initial API, implementation and documentation
  *    Aurelien Pupier - Bug 499720 - DefaultConnectionEditPolicy doesn't support scroll
  *    mwenz - Bug 541020 - IndexOutOfBoundsException below DefaultConnectionEditPolicy.getAddCommand
  *
  * </copyright>
  *
  *******************************************************************************/
 package org.eclipse.graphiti.ui.internal.policy;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.draw2d.FigureCanvas;
 import org.eclipse.draw2d.Graphics;
 import org.eclipse.draw2d.IFigure;
 import org.eclipse.draw2d.Shape;
 import org.eclipse.draw2d.Viewport;
 import org.eclipse.draw2d.geometry.Point;
 import org.eclipse.draw2d.geometry.Rectangle;
 import org.eclipse.gef.EditPart;
 import org.eclipse.gef.GraphicalEditPart;
 import org.eclipse.gef.GraphicalViewer;
 import org.eclipse.gef.Request;
 import org.eclipse.gef.RootEditPart;
 import org.eclipse.gef.commands.Command;
 import org.eclipse.gef.commands.UnexecutableCommand;
 import org.eclipse.gef.editpolicies.ConnectionEditPolicy;
 import org.eclipse.gef.requests.ChangeBoundsRequest;
 import org.eclipse.gef.requests.CreateRequest;
 import org.eclipse.gef.requests.GroupRequest;
 import org.eclipse.graphiti.features.ICreateFeature;
 import org.eclipse.graphiti.features.IFeature;
 import org.eclipse.graphiti.features.IFeatureProvider;
 import org.eclipse.graphiti.features.IMoveShapeFeature;
 import org.eclipse.graphiti.features.context.ICreateContext;
 import org.eclipse.graphiti.features.context.IDeleteContext;
 import org.eclipse.graphiti.features.context.IMoveShapeContext;
 import org.eclipse.graphiti.features.context.impl.CreateContext;
 import org.eclipse.graphiti.features.context.impl.DeleteContext;
 import org.eclipse.graphiti.features.context.impl.MoveShapeContext;
 import org.eclipse.graphiti.internal.command.GenericFeatureCommandWithContext;
 import org.eclipse.graphiti.internal.command.MoveShapeFeatureCommandWithContext;
 import org.eclipse.graphiti.mm.algorithms.GraphicsAlgorithm;
 import org.eclipse.graphiti.mm.pictograms.Connection;
 import org.eclipse.graphiti.mm.pictograms.ContainerShape;
 import org.eclipse.graphiti.mm.pictograms.PictogramElement;
 import org.eclipse.graphiti.ui.internal.command.AddModelObjectCommand;
 import org.eclipse.graphiti.ui.internal.command.CreateModelObjectCommand;
 import org.eclipse.graphiti.ui.internal.command.GefCommandWrapper;
 import org.eclipse.graphiti.ui.internal.figures.GFPolylineConnection;
 import org.eclipse.graphiti.ui.internal.parts.ConnectionEditPart;
 import org.eclipse.graphiti.ui.internal.services.GraphitiUiInternal;
 import org.eclipse.graphiti.ui.internal.util.draw2d.GFColorConstants;
 import org.eclipse.graphiti.ui.platform.IConfigurationProvider;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.widgets.Control;

 /**
  * @noinstantiate This class is not intended to be instantiated by clients.
  * @noextend This class is not intended to be subclassed by clients.
  */
 public class DefaultConnectionEditPolicy extends ConnectionEditPolicy {

 	private IConfigurationProvider _configurationProvider;

 	public DefaultConnectionEditPolicy(IConfigurationProvider configurationProvider) {
 		_configurationProvider = configurationProvider;
 	}

 	protected final IConfigurationProvider getConfigurationProvider() {
 		return _configurationProvider;
 	}

 	@Override
 	public Command getCommand(Request request) {
 		if (request.getType().equals(REQ_ADD))
 			return getAddCommand((ChangeBoundsRequest) request);
 		if (request.getType().equals(REQ_CREATE))
 			return getCreateCommand((CreateRequest) request);
 		return super.getCommand(request);
 	}

 	protected Command getAddCommand(ChangeBoundsRequest request) {
 		Command result = null;

 		Object hostModel = getHost().getModel();

 		Connection connection = (Connection) hostModel;

 		List editParts = request.getEditParts();
 		if (editParts != null && editParts.size() > 0) {
 			Object model = ((EditPart) editParts.get(0)).getModel();
 			if (model instanceof org.eclipse.graphiti.mm.pictograms.Shape) {
 				org.eclipse.graphiti.mm.pictograms.Shape shape = (org.eclipse.graphiti.mm.pictograms.Shape) model;
 				IFeatureProvider featureProvider = getConfigurationProvider().getDiagramTypeProvider()
 						.getFeatureProvider();

 				ContainerShape oldContainer = shape.getContainer();

 				ContainerShape targetContainerShape = null;

 				Point location = request.getLocation();

 				GraphicalViewer graphicalViewer = getConfigurationProvider().getDiagramContainer().getGraphicalViewer();
 				Point searchLocation = getAbsolutePosition(request.getLocation(), graphicalViewer);
 				EditPart findEditPartAt = GraphitiUiInternal.getGefService().findEditPartAt(graphicalViewer,
 						searchLocation, false);
 				if (findEditPartAt != null && findEditPartAt.getModel() instanceof ContainerShape) {
 					targetContainerShape = (ContainerShape) findEditPartAt.getModel();
 					location = createRealLocation(request.getLocation(), findEditPartAt);
 				} else {
 					targetContainerShape = getCommonContainerShape();
 				}

 				IMoveShapeContext context = createMoveShapeContext(shape, oldContainer, targetContainerShape, location,
 						connection);
 				IMoveShapeFeature layoutShapeFeature = featureProvider.getMoveShapeFeature(context);
 				if (layoutShapeFeature != null) {
 					result = new GefCommandWrapper(new MoveShapeFeatureCommandWithContext(layoutShapeFeature, context),
 							getConfigurationProvider().getDiagramBehavior().getEditingDomain());
 				}
 			}
 		}

 		return result;

 	}

 	private Point getAbsolutePosition(Point requestLocation, GraphicalViewer graphicalViewer) {
 		Control control = graphicalViewer.getControl();
 		Point searchLocation = requestLocation.getCopy();
 		if (control instanceof FigureCanvas) {
 			Viewport viewport = ((FigureCanvas) control).getViewport();
 			Point viewPortLocation = viewport.getViewLocation();
 			searchLocation.translate(viewPortLocation);
 		}
 		return searchLocation;
 	}

 	protected IMoveShapeContext createMoveShapeContext(org.eclipse.graphiti.mm.pictograms.Shape shape, ContainerShape source,
 			ContainerShape target, Object constraint, Connection connection) {
 		MoveShapeContext ret = new MoveShapeContext(shape);

 		ret.setSourceContainer(source);
 		ret.setTargetContainer(target);
 		ret.setTargetConnection(connection);

 		Point loc = null;
 		if (constraint instanceof Rectangle) {
 			Rectangle rect = (Rectangle) constraint;
 			loc = rect.getLocation();
 		} else if (constraint instanceof Point) {
 			loc = (Point) constraint;
 		}
 		if (loc != null) {
 			ret.setX(loc.x);
 			ret.setY(loc.y);

 			// calculate and store deltas
 			if (shape != null) {
 				GraphicsAlgorithm graphicsAlgorithm = shape.getGraphicsAlgorithm();
 				if (graphicsAlgorithm != null) {
 					ret.setDeltaX(loc.x - graphicsAlgorithm.getX());
 					ret.setDeltaY(loc.y - graphicsAlgorithm.getY());
 				}
 			}
 		}

 		return ret;
 	}

 	protected Command getCreateCommand(CreateRequest request) {
 		Command cmd = UnexecutableCommand.INSTANCE;
 		ContainerShape targetContainerShape;

 		GraphicalViewer graphicalViewer = getConfigurationProvider().getDiagramContainer().getGraphicalViewer();
 		Point searchLocation = getAbsolutePosition(request.getLocation(), graphicalViewer);
 		EditPart findEditPartAt = GraphitiUiInternal.getGefService().findEditPartAt(graphicalViewer, searchLocation,
 				false);
 		if (findEditPartAt != null && findEditPartAt.getModel() instanceof ContainerShape) {
 			targetContainerShape = (ContainerShape) findEditPartAt.getModel();
 		} else {
 			targetContainerShape = getCommonContainerShape();
 		}

 		Object createdObject = request.getNewObject();

 		// determine constraint

 		Rectangle rectangle = new Rectangle();

 		if (findEditPartAt != null) {
 			Point where = createRealLocation(request.getLocation(), findEditPartAt);
 			rectangle.setLocation(where);
 		} else {
 			rectangle.setLocation(request.getLocation());
 		}

 		if (request.getSize() != null) {
 			rectangle.setSize(request.getSize());
 		}

 		Connection connection = (Connection) getHost().getModel();

 		if (request.getNewObjectType() == ICreateFeature.class) {
 			ICreateContext context = ShapeXYLayoutEditPolicy.createCreateContext(targetContainerShape, rectangle);
 			((CreateContext) context).setTargetConnection(connection);
 			ICreateFeature createFeature = (ICreateFeature) createdObject;
 			cmd = new CreateModelObjectCommand(getConfigurationProvider(), createFeature, context);
 			cmd.setLabel(createFeature.getDescription());
 		} else if (request.getNewObjectType() == ISelection.class) {
 			cmd = new AddModelObjectCommand(getConfigurationProvider(), targetContainerShape, (ISelection) createdObject, rectangle,
 					connection);

 		}

 		return cmd;
 	}

 	private Point createRealLocation(Point location, EditPart findEditPartAt) {
 		IFigure layoutContainer = ((GraphicalEditPart) findEditPartAt).getContentPane();
 		Point where = location.getCopy();
 		layoutContainer.translateToRelative(where);
 		layoutContainer.translateFromParent(where);
 		Point layoutOrigin = layoutContainer.getClientArea().getLocation();
 		where.translate(layoutOrigin.getNegated());
 		return where;
 	}

 	@Override
 	public EditPart getTargetEditPart(Request request) {
 		return getHost();
 	}

 	@Override
 	protected Command getDeleteCommand(GroupRequest request) {
 		if (getHost().getParent() == null) // do not allow to delete the
 			// root-object itself
 			return null;

 		IFeatureProvider featureProvider = getConfigurationProvider().getDiagramTypeProvider().getFeatureProvider();

 		EditPart modelObjectEditPart = getHost();

 		Object model = modelObjectEditPart.getModel();

 		if (!(model instanceof PictogramElement))
 			return null;

 		IDeleteContext context = new DeleteContext((PictogramElement) model);
 		IFeature feature = featureProvider.getDeleteFeature(context);

 		if (feature == null)
 			return null;

 		GenericFeatureCommandWithContext command = new GenericFeatureCommandWithContext(feature, context);

 		return new GefCommandWrapper(command, getConfigurationProvider().getDiagramBehavior().getEditingDomain());
 	}

 	/**
 	 * ********************************* FEEDBACK
 	 * *************************************************
 	 */
 	private Color originalColor;

 	private int originalLineStyle;

 	private Map<IFigure, Color> decorationColor = new HashMap<IFigure, Color>();

 	private Map<IFigure, Integer> decorationLineStyle = new HashMap<IFigure, Integer>();

 	/**
 	 * @see org.eclipse.gef.editpolicies.AbstractEditPolicy#showTargetFeedback(org.eclipse.gef.Request)
 	 */
 	@Override
 	public void showTargetFeedback(Request request) {
 		if (REQ_CREATE.equals(request.getType()) || REQ_ADD.equals(request.getType())) {

 			// show feedback only if a valid command(feature) is available
 			Command command = getHost().getCommand(request);
 			boolean commandExistsForRequest = command != null && command.canExecute();
 			if (!commandExistsForRequest) {
 				return;
 			}

 			ConnectionEditPart connectionEditPart = (ConnectionEditPart) getHost();
 			GFPolylineConnection connection = (GFPolylineConnection) connectionEditPart.getFigure();

 			if (originalColor == null) {

 				originalColor = connection.getForegroundColor();
 				originalLineStyle = connection.getLineStyle();

 				connection.setForegroundColor(GFColorConstants.HANDLE_BG);
 				connection.setLineStyle(Graphics.LINE_DASH);

 				List<IFigure> allDecorations = connection.getAllDecorations();
 				for (IFigure decoration : allDecorations) {
 					if (decoration != null) {
 						Color currentColor = decoration.getForegroundColor();
 						decorationColor.put(decoration, currentColor);
 						decoration.setForegroundColor(GFColorConstants.HANDLE_BG);
 						if (decoration instanceof Shape) {
 							Shape decorationShape = (Shape) decoration;
 							int currentLineStyle = decorationShape.getLineStyle();
 							decorationLineStyle.put(decorationShape, new Integer(currentLineStyle));
 							decorationShape.setLineStyle(Graphics.LINE_DASH);
 						}
 					}
 				}
 			}

 		}
 	}

 	/**
 	 * @see org.eclipse.gef.editpolicies.AbstractEditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
 	 */
 	@Override
 	public void eraseTargetFeedback(Request request) {
 		if (REQ_CREATE.equals(request.getType()) || REQ_ADD.equals(request.getType())) {

 			if (originalColor == null) {
 				return;
 			}

 			ConnectionEditPart connectionEditPart = (ConnectionEditPart) getHost();

 			GFPolylineConnection connection = (GFPolylineConnection) connectionEditPart.getFigure();

 			connection.setForegroundColor(originalColor);
 			connection.setLineStyle(originalLineStyle);

 			List<IFigure> allDecorations = connection.getAllDecorations();
 			for (IFigure decoration : allDecorations) {
 				if (decoration != null) {
 					Color previousColor = decorationColor.get(decoration);
 					decoration.setForegroundColor(previousColor);
 					if (decoration instanceof Shape) {
 						Shape decorationShape = (Shape) decoration;
 						Integer previousLineStyle = decorationLineStyle.get(decoration);
 						if (previousLineStyle != null)
 							decorationShape.setLineStyle(previousLineStyle);
 					}
 				}
 			}

 			originalColor = null;
 			decorationColor.clear();
 			decorationLineStyle.clear();
 		}
 	}

 	/**
 	 * @return the most specific container that source and target of this
 	 *         connection have in common
 	 */
 	private ContainerShape getCommonContainerShape() {

 		ConnectionEditPart connectionEditPart = (ConnectionEditPart) getHost();

 		EditPart sourceEditPart = connectionEditPart.getSource();
 		EditPart targetEditPart = connectionEditPart.getTarget();
 		EditPart parent = getCommonEditPart(sourceEditPart, targetEditPart);

 		return (ContainerShape) parent.getModel();
 	}

 	/**
 	 * investigates the common parent of both editparts. the least common parent
 	 * is the diagram editpart
 	 */
 	private static EditPart getCommonEditPart(EditPart source, EditPart target) {

 		// create two lists with editparts to the root

 		List<EditPart> list1 = new ArrayList<EditPart>();
 		List<EditPart> list2 = new ArrayList<EditPart>();

 		EditPart editPart = source;

 		while (!(editPart instanceof RootEditPart)) {
 			list1.add(0, editPart);
 			editPart = editPart.getParent();
 		}

 		editPart = target;

 		while (!(editPart instanceof RootEditPart)) {
 			list2.add(0, editPart);
 			editPart = editPart.getParent();
 		}

 		// compare the lists until that position where editparts differ
 		int index = 0;
 		while (true) {
 			if (index == list1.size())
 				return list1.get(index - 1);

 			if (index == list2.size())
 				return list1.get(index - 1);

 			if (list1.get(index) != list2.get(index))
 				return list1.get(index - 1);

 			index++;
 		}
 	}
 }
	/*******************************************************************************
	* <copyright>
	*
	* Copyright (c) 2005, 2018 SAP AG, Redhat.
	* 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:
	* SAP AG - initial API, implementation and documentation
	* Aurelien Pupier - Bug 499720 - DefaultConnectionEditPolicy doesn't support scroll
	* mwenz - Bug 541020 - IndexOutOfBoundsException below DefaultConnectionEditPolicy.getAddCommand
	*
	* </copyright>
	*
	*******************************************************************************/
	package org.eclipse.graphiti.ui.internal.policy;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.draw2d.FigureCanvas;
	import org.eclipse.draw2d.Graphics;
	import org.eclipse.draw2d.IFigure;
	import org.eclipse.draw2d.Shape;
	import org.eclipse.draw2d.Viewport;
	import org.eclipse.draw2d.geometry.Point;
	import org.eclipse.draw2d.geometry.Rectangle;
	import org.eclipse.gef.EditPart;
	import org.eclipse.gef.GraphicalEditPart;
	import org.eclipse.gef.GraphicalViewer;
	import org.eclipse.gef.Request;
	import org.eclipse.gef.RootEditPart;
	import org.eclipse.gef.commands.Command;
	import org.eclipse.gef.commands.UnexecutableCommand;
	import org.eclipse.gef.editpolicies.ConnectionEditPolicy;
	import org.eclipse.gef.requests.ChangeBoundsRequest;
	import org.eclipse.gef.requests.CreateRequest;
	import org.eclipse.gef.requests.GroupRequest;
	import org.eclipse.graphiti.features.ICreateFeature;
	import org.eclipse.graphiti.features.IFeature;
	import org.eclipse.graphiti.features.IFeatureProvider;
	import org.eclipse.graphiti.features.IMoveShapeFeature;
	import org.eclipse.graphiti.features.context.ICreateContext;
	import org.eclipse.graphiti.features.context.IDeleteContext;
	import org.eclipse.graphiti.features.context.IMoveShapeContext;
	import org.eclipse.graphiti.features.context.impl.CreateContext;
	import org.eclipse.graphiti.features.context.impl.DeleteContext;
	import org.eclipse.graphiti.features.context.impl.MoveShapeContext;
	import org.eclipse.graphiti.internal.command.GenericFeatureCommandWithContext;
	import org.eclipse.graphiti.internal.command.MoveShapeFeatureCommandWithContext;
	import org.eclipse.graphiti.mm.algorithms.GraphicsAlgorithm;
	import org.eclipse.graphiti.mm.pictograms.Connection;
	import org.eclipse.graphiti.mm.pictograms.ContainerShape;
	import org.eclipse.graphiti.mm.pictograms.PictogramElement;
	import org.eclipse.graphiti.ui.internal.command.AddModelObjectCommand;
	import org.eclipse.graphiti.ui.internal.command.CreateModelObjectCommand;
	import org.eclipse.graphiti.ui.internal.command.GefCommandWrapper;
	import org.eclipse.graphiti.ui.internal.figures.GFPolylineConnection;
	import org.eclipse.graphiti.ui.internal.parts.ConnectionEditPart;
	import org.eclipse.graphiti.ui.internal.services.GraphitiUiInternal;
	import org.eclipse.graphiti.ui.internal.util.draw2d.GFColorConstants;
	import org.eclipse.graphiti.ui.platform.IConfigurationProvider;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.widgets.Control;

	/**
	* @noinstantiate This class is not intended to be instantiated by clients.
	* @noextend This class is not intended to be subclassed by clients.
	*/
	public class DefaultConnectionEditPolicy extends ConnectionEditPolicy {

	private IConfigurationProvider _configurationProvider;

	public DefaultConnectionEditPolicy(IConfigurationProvider configurationProvider) {
	_configurationProvider = configurationProvider;
	}

	protected final IConfigurationProvider getConfigurationProvider() {
	return _configurationProvider;
	}

	@Override
	public Command getCommand(Request request) {
	if (request.getType().equals(REQ_ADD))
	return getAddCommand((ChangeBoundsRequest) request);
	if (request.getType().equals(REQ_CREATE))
	return getCreateCommand((CreateRequest) request);
	return super.getCommand(request);
	}

	protected Command getAddCommand(ChangeBoundsRequest request) {
	Command result = null;

	Object hostModel = getHost().getModel();

	Connection connection = (Connection) hostModel;

	List editParts = request.getEditParts();
	if (editParts != null && editParts.size() > 0) {
	Object model = ((EditPart) editParts.get(0)).getModel();
	if (model instanceof org.eclipse.graphiti.mm.pictograms.Shape) {
	org.eclipse.graphiti.mm.pictograms.Shape shape = (org.eclipse.graphiti.mm.pictograms.Shape) model;
	IFeatureProvider featureProvider = getConfigurationProvider().getDiagramTypeProvider()
	.getFeatureProvider();

	ContainerShape oldContainer = shape.getContainer();

	ContainerShape targetContainerShape = null;

	Point location = request.getLocation();

	GraphicalViewer graphicalViewer = getConfigurationProvider().getDiagramContainer().getGraphicalViewer();
	Point searchLocation = getAbsolutePosition(request.getLocation(), graphicalViewer);
	EditPart findEditPartAt = GraphitiUiInternal.getGefService().findEditPartAt(graphicalViewer,
	searchLocation, false);
	if (findEditPartAt != null && findEditPartAt.getModel() instanceof ContainerShape) {
	targetContainerShape = (ContainerShape) findEditPartAt.getModel();
	location = createRealLocation(request.getLocation(), findEditPartAt);
	} else {
	targetContainerShape = getCommonContainerShape();
	}

	IMoveShapeContext context = createMoveShapeContext(shape, oldContainer, targetContainerShape, location,
	connection);
	IMoveShapeFeature layoutShapeFeature = featureProvider.getMoveShapeFeature(context);
	if (layoutShapeFeature != null) {
	result = new GefCommandWrapper(new MoveShapeFeatureCommandWithContext(layoutShapeFeature, context),
	getConfigurationProvider().getDiagramBehavior().getEditingDomain());
	}
	}
	}

	return result;

	}

	private Point getAbsolutePosition(Point requestLocation, GraphicalViewer graphicalViewer) {
	Control control = graphicalViewer.getControl();
	Point searchLocation = requestLocation.getCopy();
	if (control instanceof FigureCanvas) {
	Viewport viewport = ((FigureCanvas) control).getViewport();
	Point viewPortLocation = viewport.getViewLocation();
	searchLocation.translate(viewPortLocation);
	}
	return searchLocation;
	}

	protected IMoveShapeContext createMoveShapeContext(org.eclipse.graphiti.mm.pictograms.Shape shape, ContainerShape source,
	ContainerShape target, Object constraint, Connection connection) {
	MoveShapeContext ret = new MoveShapeContext(shape);

	ret.setSourceContainer(source);
	ret.setTargetContainer(target);
	ret.setTargetConnection(connection);

	Point loc = null;
	if (constraint instanceof Rectangle) {
	Rectangle rect = (Rectangle) constraint;
	loc = rect.getLocation();
	} else if (constraint instanceof Point) {
	loc = (Point) constraint;
	}
	if (loc != null) {
	ret.setX(loc.x);
	ret.setY(loc.y);

	// calculate and store deltas
	if (shape != null) {
	GraphicsAlgorithm graphicsAlgorithm = shape.getGraphicsAlgorithm();
	if (graphicsAlgorithm != null) {
	ret.setDeltaX(loc.x - graphicsAlgorithm.getX());
	ret.setDeltaY(loc.y - graphicsAlgorithm.getY());
	}
	}
	}

	return ret;
	}

	protected Command getCreateCommand(CreateRequest request) {
	Command cmd = UnexecutableCommand.INSTANCE;
	ContainerShape targetContainerShape;

	GraphicalViewer graphicalViewer = getConfigurationProvider().getDiagramContainer().getGraphicalViewer();
	Point searchLocation = getAbsolutePosition(request.getLocation(), graphicalViewer);
	EditPart findEditPartAt = GraphitiUiInternal.getGefService().findEditPartAt(graphicalViewer, searchLocation,
	false);
	if (findEditPartAt != null && findEditPartAt.getModel() instanceof ContainerShape) {
	targetContainerShape = (ContainerShape) findEditPartAt.getModel();
	} else {
	targetContainerShape = getCommonContainerShape();
	}

	Object createdObject = request.getNewObject();

	// determine constraint

	Rectangle rectangle = new Rectangle();

	if (findEditPartAt != null) {
	Point where = createRealLocation(request.getLocation(), findEditPartAt);
	rectangle.setLocation(where);
	} else {
	rectangle.setLocation(request.getLocation());
	}

	if (request.getSize() != null) {
	rectangle.setSize(request.getSize());
	}

	Connection connection = (Connection) getHost().getModel();

	if (request.getNewObjectType() == ICreateFeature.class) {
	ICreateContext context = ShapeXYLayoutEditPolicy.createCreateContext(targetContainerShape, rectangle);
	((CreateContext) context).setTargetConnection(connection);
	ICreateFeature createFeature = (ICreateFeature) createdObject;
	cmd = new CreateModelObjectCommand(getConfigurationProvider(), createFeature, context);
	cmd.setLabel(createFeature.getDescription());
	} else if (request.getNewObjectType() == ISelection.class) {
	cmd = new AddModelObjectCommand(getConfigurationProvider(), targetContainerShape, (ISelection) createdObject, rectangle,
	connection);

	}

	return cmd;
	}

	private Point createRealLocation(Point location, EditPart findEditPartAt) {
	IFigure layoutContainer = ((GraphicalEditPart) findEditPartAt).getContentPane();
	Point where = location.getCopy();
	layoutContainer.translateToRelative(where);
	layoutContainer.translateFromParent(where);
	Point layoutOrigin = layoutContainer.getClientArea().getLocation();
	where.translate(layoutOrigin.getNegated());
	return where;
	}

	@Override
	public EditPart getTargetEditPart(Request request) {
	return getHost();
	}

	@Override
	protected Command getDeleteCommand(GroupRequest request) {
	if (getHost().getParent() == null) // do not allow to delete the
	// root-object itself
	return null;

	IFeatureProvider featureProvider = getConfigurationProvider().getDiagramTypeProvider().getFeatureProvider();

	EditPart modelObjectEditPart = getHost();

	Object model = modelObjectEditPart.getModel();

	if (!(model instanceof PictogramElement))
	return null;

	IDeleteContext context = new DeleteContext((PictogramElement) model);
	IFeature feature = featureProvider.getDeleteFeature(context);

	if (feature == null)
	return null;

	GenericFeatureCommandWithContext command = new GenericFeatureCommandWithContext(feature, context);

	return new GefCommandWrapper(command, getConfigurationProvider().getDiagramBehavior().getEditingDomain());
	}

	/**
	* ********************************* FEEDBACK
	* *************************************************
	*/
	private Color originalColor;

	private int originalLineStyle;

	private Map<IFigure, Color> decorationColor = new HashMap<IFigure, Color>();

	private Map<IFigure, Integer> decorationLineStyle = new HashMap<IFigure, Integer>();

	/**
	* @see org.eclipse.gef.editpolicies.AbstractEditPolicy#showTargetFeedback(org.eclipse.gef.Request)
	*/
	@Override
	public void showTargetFeedback(Request request) {
	if (REQ_CREATE.equals(request.getType()) \|\| REQ_ADD.equals(request.getType())) {

	// show feedback only if a valid command(feature) is available
	Command command = getHost().getCommand(request);
	boolean commandExistsForRequest = command != null && command.canExecute();
	if (!commandExistsForRequest) {
	return;
	}

	ConnectionEditPart connectionEditPart = (ConnectionEditPart) getHost();
	GFPolylineConnection connection = (GFPolylineConnection) connectionEditPart.getFigure();

	if (originalColor == null) {

	originalColor = connection.getForegroundColor();
	originalLineStyle = connection.getLineStyle();

	connection.setForegroundColor(GFColorConstants.HANDLE_BG);
	connection.setLineStyle(Graphics.LINE_DASH);

	List<IFigure> allDecorations = connection.getAllDecorations();
	for (IFigure decoration : allDecorations) {
	if (decoration != null) {
	Color currentColor = decoration.getForegroundColor();
	decorationColor.put(decoration, currentColor);
	decoration.setForegroundColor(GFColorConstants.HANDLE_BG);
	if (decoration instanceof Shape) {
	Shape decorationShape = (Shape) decoration;
	int currentLineStyle = decorationShape.getLineStyle();
	decorationLineStyle.put(decorationShape, new Integer(currentLineStyle));
	decorationShape.setLineStyle(Graphics.LINE_DASH);
	}
	}
	}
	}

	}
	}

	/**
	* @see org.eclipse.gef.editpolicies.AbstractEditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
	*/
	@Override
	public void eraseTargetFeedback(Request request) {
	if (REQ_CREATE.equals(request.getType()) \|\| REQ_ADD.equals(request.getType())) {

	if (originalColor == null) {
	return;
	}

	ConnectionEditPart connectionEditPart = (ConnectionEditPart) getHost();

	GFPolylineConnection connection = (GFPolylineConnection) connectionEditPart.getFigure();

	connection.setForegroundColor(originalColor);
	connection.setLineStyle(originalLineStyle);

	List<IFigure> allDecorations = connection.getAllDecorations();
	for (IFigure decoration : allDecorations) {
	if (decoration != null) {
	Color previousColor = decorationColor.get(decoration);
	decoration.setForegroundColor(previousColor);
	if (decoration instanceof Shape) {
	Shape decorationShape = (Shape) decoration;
	Integer previousLineStyle = decorationLineStyle.get(decoration);
	if (previousLineStyle != null)
	decorationShape.setLineStyle(previousLineStyle);
	}
	}
	}

	originalColor = null;
	decorationColor.clear();
	decorationLineStyle.clear();
	}
	}

	/**
	* @return the most specific container that source and target of this
	* connection have in common
	*/
	private ContainerShape getCommonContainerShape() {

	ConnectionEditPart connectionEditPart = (ConnectionEditPart) getHost();

	EditPart sourceEditPart = connectionEditPart.getSource();
	EditPart targetEditPart = connectionEditPart.getTarget();
	EditPart parent = getCommonEditPart(sourceEditPart, targetEditPart);

	return (ContainerShape) parent.getModel();
	}

	/**
	* investigates the common parent of both editparts. the least common parent
	* is the diagram editpart
	*/
	private static EditPart getCommonEditPart(EditPart source, EditPart target) {

	// create two lists with editparts to the root

	List<EditPart> list1 = new ArrayList<EditPart>();
	List<EditPart> list2 = new ArrayList<EditPart>();

	EditPart editPart = source;

	while (!(editPart instanceof RootEditPart)) {
	list1.add(0, editPart);
	editPart = editPart.getParent();
	}

	editPart = target;

	while (!(editPart instanceof RootEditPart)) {
	list2.add(0, editPart);
	editPart = editPart.getParent();
	}

	// compare the lists until that position where editparts differ
	int index = 0;
	while (true) {
	if (index == list1.size())
	return list1.get(index - 1);

	if (index == list2.size())
	return list1.get(index - 1);

	if (list1.get(index) != list2.get(index))
	return list1.get(index - 1);

	index++;
	}
	}
	}