plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/api/layout/provider/AbstractLayoutProvider.java - sirius/org.eclipse.sirius - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007, 2019 THALES GLOBAL SERVICES and others.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
 package org.eclipse.sirius.diagram.ui.tools.api.layout.provider;

 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 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.Rectangle;
 import org.eclipse.gef.EditPart;
 import org.eclipse.gef.GraphicalEditPart;
 import org.eclipse.gef.Request;
 import org.eclipse.gef.commands.Command;
 import org.eclipse.gef.commands.CompoundCommand;
 import org.eclipse.gef.commands.UnexecutableCommand;
 import org.eclipse.gef.requests.ChangeBoundsRequest;
 import org.eclipse.gmf.runtime.common.core.service.IOperation;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.DiagramEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.services.layout.AbstractLayoutEditPartProvider;
 import org.eclipse.gmf.runtime.notation.View;
 import org.eclipse.sirius.common.tools.DslCommonPlugin;
 import org.eclipse.sirius.common.tools.api.profiler.ProfilerTask;
 import org.eclipse.sirius.common.ui.SiriusTransPlugin;
 import org.eclipse.sirius.diagram.DDiagramElement;
 import org.eclipse.sirius.diagram.tools.api.layout.PinHelper;
 import org.eclipse.sirius.diagram.ui.provider.Messages;
 import org.eclipse.sirius.diagram.ui.tools.internal.layout.provider.LayoutService;

 import com.google.common.collect.Iterables;

 /**
  * An abstract layout provider.
  *
  * @author ymortier
  */
 public abstract class AbstractLayoutProvider extends AbstractLayoutEditPartProvider {

     /**
      * Modeler Category.
      */
     public static final String GENERIC_MODELER_CAT = Messages.AbstractLayoutProvider_arrangeAllProfilerTaskCategory;

     /**
      * Arrange all.
      */
     public static final ProfilerTask ARRANGE_ALL = new ProfilerTask(GENERIC_MODELER_CAT, Messages.AbstractLayoutProvider_arrangeAllProfilerTaskName);

     /** Map all views with a its associated {@link ChangeBoundsRequest}. */
     protected Map<View, List<Request>> viewsToChangeBoundsRequest;

     /**
      * Create a new {@link AbstractLayoutProvider}.
      *
      */
     public AbstractLayoutProvider() {
         this.viewsToChangeBoundsRequest = new HashMap<View, List<Request>>();
     }

     /**
      * Set the map that maps all views with a its associated
      * {@link ChangeBoundsRequest}.
      *
      * @param viewsToChangeBoundsRequest
      *            Map all views with a its associated
      *            {@link ChangeBoundsRequest}.
      */
     public void setViewsToChangeBoundsRequest(final Map<View, List<Request>> viewsToChangeBoundsRequest) {
         this.viewsToChangeBoundsRequest = viewsToChangeBoundsRequest;
     }

     /**
      * Return the map that maps all views with a its associated
      * {@link ChangeBoundsRequest}.
      *
      * @return the map that maps all views with a its associated
      *         {@link ChangeBoundsRequest}.
      */
     public Map<View, List<Request>> getViewsToChangeBoundsRequest() {
         return viewsToChangeBoundsRequest;
     }

     @Override
     public final Command layoutEditParts(final GraphicalEditPart containerEditPart, final IAdaptable layoutHint) {
         DslCommonPlugin.PROFILER.startWork(ARRANGE_ALL);

         this.getViewsToChangeBoundsRequest().clear();

         /*
          * If we are asked to layout a whole diagram, check if a specific
          * provider has been registered for it (through the
          * org.eclipse.sirius.common.ui.airLayoutProvider extension point), and
          * use that provider if there is.
          */
         if (containerEditPart instanceof DiagramEditPart) {
             final DiagramEditPart diagramEditPart = (DiagramEditPart) containerEditPart;
             final LayoutProvider diagramLayoutProvider = getDiagramLayoutProvider(diagramEditPart, layoutHint);
             if (diagramLayoutProvider != null) {
                 final Command command = getCommandFromDiagramLayoutProvider(diagramLayoutProvider, diagramEditPart, layoutHint);
                 command.setLabel(Messages.AbstractLayoutProvider_arrangeAllCommandLabel);
                 DslCommonPlugin.PROFILER.stopWork(ARRANGE_ALL);
                 return command;
             }
         }

         final Command command = buildCommand(containerEditPart, layoutHint);
         command.setLabel(Messages.AbstractLayoutProvider_arrangeAllCommandLabel);
         this.getViewsToChangeBoundsRequest().clear();
         AbstractLayoutProvider.resetWrappedCommand(command);
         DslCommonPlugin.PROFILER.stopWork(ARRANGE_ALL);
         return command;
     }

     /**
      * Get the the diagram layout provider if there is one.
      *
      * @param diagramEditPart
      *            the diagram edit part
      * @param layoutHint
      *            the layout hint
      * @return the diagram layout provider if there is one, <code>null</code>
      *         otherwise
      */
     public LayoutProvider getDiagramLayoutProvider(final DiagramEditPart diagramEditPart, final IAdaptable layoutHint) {
         final LayoutProvider candidate = LayoutService.getProvider(diagramEditPart);
         if (candidate != null && candidate.isDiagramLayoutProvider()) {
             return candidate;
         } else {
             return null;
         }
     }

     private Command getCommandFromDiagramLayoutProvider(final LayoutProvider diagramLayoutProvider, final DiagramEditPart diagramEditPart, final IAdaptable layoutHint) {
         Command command = null;
         final AbstractLayoutEditPartProvider layoutProvider = diagramLayoutProvider.getLayoutNodeProvider(diagramEditPart);
         try {
             final Method method = layoutProvider.getClass().getMethod("layoutEditParts", new Class[] { GraphicalEditPart.class, IAdaptable.class }); //$NON-NLS-1$
             Assert.isNotNull(method);
             /* this code seems to avoid an infinite loop */
             if (method.getDeclaringClass() != AbstractLayoutProvider.class) {
                 command = layoutProvider.layoutEditParts(diagramEditPart, layoutHint);
             }
         } catch (final SecurityException e) {
             SiriusTransPlugin.getPlugin().error(Messages.AbstractLayoutProvider_layoutError, e);
         } catch (final NoSuchMethodException e) {
             SiriusTransPlugin.getPlugin().error(Messages.AbstractLayoutProvider_layoutError, e);
         }
         if (command == null) {
             final List<?> children = diagramEditPart.getChildren();
             command = layoutProvider.layoutEditParts(children, layoutHint);
         }
         return command;
     }

     /**
      * Build the command which performs the layout of all the edit parts in the
      * specified container.
      * <p>
      * The resulting command is a compound command built recursively by calling
      * {@link #layoutEditParts(List, IAdaptable)} on all the descendants of the
      * specified container and then on the container itself.
      *
      * @param containerEditPart
      *            the container to layout.
      * @param layoutHint
      *            the hint to use.
      * @return a command to execute to perform the layout of the container and
      *         all its descendants.
      */
     private Command buildCommand(final GraphicalEditPart containerEditPart, final IAdaptable layoutHint) {
         final CompoundCommand cc = new CompoundCommand();
         // Depth-first recursion.
         for (final IGraphicalEditPart graphicalEditPart : Iterables.filter(containerEditPart.getChildren(), IGraphicalEditPart.class)) {
             final Command command = buildCommand(graphicalEditPart, layoutHint);
             if (command.canExecute()) {
                 cc.add(command);
             }
         }
         // Base case: layout the container's direct children.
         final Command command = this.layoutEditParts(containerEditPart.getChildren(), layoutHint);
         if (command.canExecute()) {
             cc.add(command);
         }
         return cc;
     }

     /**
      * {@inheritDoc}
      *
      * @see org.eclipse.gmf.runtime.common.core.service.IProvider#provides(org.eclipse.gmf.runtime.common.core.service.IOperation)
      */
     @Override
     public boolean provides(final IOperation operation) {
         return false;
     }

     /**
      * Search a request for the specified edit part and of the specified type.
      *
      * @param editPart
      *            the edit part.
      * @param requestType
      *            the type of the request.
      * @return the found request.
      */
     protected Request findRequest(final IGraphicalEditPart editPart, final Object requestType) {
         if (editPart != null) {
             return findRequest(editPart.getNotationView(), requestType);
         }
         return null;
     }

     /**
      * Search a request for the specified view and of the specified type.
      *
      * @param notationView
      *            the view.
      * @param requestType
      *            the type of the request.
      * @return the found request.
      */
     protected Request findRequest(final View notationView, final Object requestType) {
         final List<Request> requests = this.getViewsToChangeBoundsRequest().get(notationView);
         Request result = null;
         if (requests != null) {
             final Iterator<Request> iterRequests = requests.iterator();
             while (iterRequests.hasNext() && result == null) {
                 final Request currentRequest = iterRequests.next();
                 if (currentRequest.getType() != null && currentRequest.getType().equals(requestType)) {
                     result = currentRequest;
                 }
             }
         }
         return result;
     }

     /**
      * Create a command with the specified request.
      *
      * @param request
      *            the request.
      * @param editPart
      *            the edit part.
      * @return an executable command.
      */
     protected Command buildCommandWrapper(final Request request, final EditPart editPart) {
         if (editPart instanceof IGraphicalEditPart) {
             List<Request> requests = this.getViewsToChangeBoundsRequest().get(((IGraphicalEditPart) editPart).getNotationView());
             if (requests == null) {
                 requests = new LinkedList<Request>();
                 this.getViewsToChangeBoundsRequest().put(((IGraphicalEditPart) editPart).getNotationView(), requests);
             }
             requests.add(request);
         }
         return new CommandWrapper(request, editPart);
     }

     /**
      * Tests whether an edit part should be considered as pinned (fixed size and
      * location) during the layout.
      *
      * @param part
      *            the edit part.
      * @return <code>true</code> if the edit part should be considered as
      *         pinned.
      */
     protected boolean isPinned(final IGraphicalEditPart part) {
         boolean isPinned = false;
         if (part.resolveSemanticElement() instanceof DDiagramElement) {
             DDiagramElement dDiagramElement = (DDiagramElement) part.resolveSemanticElement();
             isPinned = new PinHelper().isPinned(dDiagramElement);
         }
         return isPinned;
     }

     /**
      * Wraps a GMF Command.
      *
      * @author ymortier
      */
     protected static class CommandWrapper extends Command {

         /**
          * The wrapped command, initialized at the first call to
          * {@link #getWrappedCommand()}.
          */
         private Command wrappedCommand;

         /** The request. */
         private final Request request;

         /** The edit part. */
         private final EditPart editPart;

         /**
          * Create a new Command wrapper.
          *
          * @param request
          *            the request.
          * @param editPart
          *            the edit part.
          */
         public CommandWrapper(final Request request, final EditPart editPart) {
             this.request = request;
             this.editPart = editPart;
         }

         @Override
         public void execute() {
             this.getWrappedCommand().execute();
         }

         @Override
         public boolean canExecute() {
             return this.getWrappedCommand().canExecute();
         }

         @Override
         public boolean canUndo() {
             return this.getWrappedCommand().canUndo();
         }

         @Override
         public void undo() {
             this.getWrappedCommand().undo();
         }

         @Override
         public void redo() {
             this.getWrappedCommand().redo();
         }

         private Command getWrappedCommand() {
             if (wrappedCommand == null) {
                 final Command cmd = editPart.getCommand(request);
                 if (cmd == null) {
                     wrappedCommand = UnexecutableCommand.INSTANCE;
                 } else {
                     wrappedCommand = cmd;
                 }
             }
             return wrappedCommand;
         }

         /**
          * {@inheritDoc}
          */
         @Override
         public String getLabel() {
             return getWrappedCommand().getLabel();
         }

         /**
          * Returns the request that is causing the command.
          *
          * @return the request
          */
         public Request getRequest() {
             return request;
         }

         /**
          * Return the associated edit part.
          *
          * @return the editPart
          */
         public EditPart getEditPart() {
             return editPart;
         }
     }

     /**
      * Return the relative bounds of the specified edit part.
      *
      * @param graphicalEditPart
      *            the edit part.
      * @return the bounds of the specified edit part.
      */
     protected Rectangle getBounds(final IGraphicalEditPart graphicalEditPart) {
         Object existingRequest = this.findRequest(graphicalEditPart, org.eclipse.gef.RequestConstants.REQ_RESIZE);
         final Rectangle figureBounds = new Rectangle(graphicalEditPart.getFigure().getBounds());
         if (existingRequest instanceof ChangeBoundsRequest) {
             final ChangeBoundsRequest changeBoundsRequest = (ChangeBoundsRequest) existingRequest;
             if (changeBoundsRequest.getSizeDelta() != null) {
                 adjustBounds(figureBounds, changeBoundsRequest);
             }
         }
         existingRequest = this.findRequest(graphicalEditPart, org.eclipse.gef.RequestConstants.REQ_MOVE);
         if (existingRequest instanceof ChangeBoundsRequest) {
             final ChangeBoundsRequest changeBoundsRequest = (ChangeBoundsRequest) existingRequest;
             if (changeBoundsRequest.getMoveDelta() != null) {
                 figureBounds.x += changeBoundsRequest.getMoveDelta().x;
                 figureBounds.y += changeBoundsRequest.getMoveDelta().y;
             }
         }
         return figureBounds;
     }

     private void adjustBounds(final Rectangle figureBounds, final ChangeBoundsRequest changeBoundsRequest) {
         switch (changeBoundsRequest.getResizeDirection()) {
         case PositionConstants.NORTH:
             figureBounds.height += changeBoundsRequest.getSizeDelta().height;
             figureBounds.y -= changeBoundsRequest.getSizeDelta().height;
             break;
         case PositionConstants.SOUTH:
             figureBounds.height += changeBoundsRequest.getSizeDelta().height;
             break;
         case PositionConstants.EAST:
             figureBounds.width += changeBoundsRequest.getSizeDelta().width;
             break;
         case PositionConstants.WEST:
             figureBounds.width += changeBoundsRequest.getSizeDelta().width;
             figureBounds.x -= changeBoundsRequest.getSizeDelta().width;
             break;
         case PositionConstants.NORTH_EAST:
             figureBounds.height += changeBoundsRequest.getSizeDelta().height;
             figureBounds.y -= changeBoundsRequest.getSizeDelta().height;
             figureBounds.width += changeBoundsRequest.getSizeDelta().width;
             break;
         case PositionConstants.NORTH_WEST:
             figureBounds.height += changeBoundsRequest.getSizeDelta().height;
             figureBounds.y -= changeBoundsRequest.getSizeDelta().height;
             figureBounds.width += changeBoundsRequest.getSizeDelta().width;
             figureBounds.x -= changeBoundsRequest.getSizeDelta().width;
             break;
         case PositionConstants.SOUTH_WEST:
             figureBounds.height += changeBoundsRequest.getSizeDelta().height;
             figureBounds.width += changeBoundsRequest.getSizeDelta().width;
             figureBounds.x -= changeBoundsRequest.getSizeDelta().width;
             break;
         default:
             figureBounds.height += changeBoundsRequest.getSizeDelta().height;
             figureBounds.width += changeBoundsRequest.getSizeDelta().width;
         }
     }

     /**
      * Return the first figure of type <code>type</code> that is the figure
      * <code>searchRoot</code> or a child of <code>searchRoot</code>.
      *
      * @param searchRoot
      *            the root figure to start the search.
      * @param type
      *            the type of the figure to return.
      * @return Return the first figure of type <code>type</code> that is the
      *         figure <code>searchRoot</code> or a child of
      *         <code>searchRoot</code>.
      */
     protected IFigure findChild(final IFigure searchRoot, final Class<?> type) {
         IFigure result = null;
         if (type.isInstance(searchRoot)) {
             result = searchRoot;
         }
         final Iterator<?> iterChildren = searchRoot.getChildren().iterator();
         while (iterChildren.hasNext() && result == null) {
             final IFigure child = (IFigure) iterChildren.next();
             result = findChild(child, type);
         }
         return result;
     }

     /**
      * Return all edit parts contained in root + root.
      *
      * @param root
      *            the root edit part
      * @return all edit parts contained in root + root.
      */
     public List<EditPart> getAllEditParts(final EditPart root) {
         final Set<EditPart> editParts = new HashSet<EditPart>();
         editParts.add(root);
         if (root instanceof GraphicalEditPart) {
             editParts.addAll(((GraphicalEditPart) root).getSourceConnections());
             editParts.addAll(((GraphicalEditPart) root).getTargetConnections());
         }
         final Iterator<EditPart> iterChildren = root.getChildren().iterator();
         while (iterChildren.hasNext()) {
             final EditPart next = iterChildren.next();
             editParts.addAll(getAllEditParts(next));
         }
         return new ArrayList<EditPart>(editParts);
     }

     private static void resetWrappedCommand(final Command command) {
         if (command instanceof CommandWrapper) {
             ((CommandWrapper) command).wrappedCommand = null;
         } else if (command instanceof CompoundCommand) {
             final Object[] children = ((CompoundCommand) command).getChildren();
             for (Object element : children) {
                 if (element instanceof Command) {
                     AbstractLayoutProvider.resetWrappedCommand((Command) element);
                 }
             }
         }
     }
 }
	/*******************************************************************************
	* Copyright (c) 2007, 2019 THALES GLOBAL SERVICES and others.
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* Obeo - initial API and implementation
	*******************************************************************************/
	package org.eclipse.sirius.diagram.ui.tools.api.layout.provider;

	import java.lang.reflect.Method;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	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.Rectangle;
	import org.eclipse.gef.EditPart;
	import org.eclipse.gef.GraphicalEditPart;
	import org.eclipse.gef.Request;
	import org.eclipse.gef.commands.Command;
	import org.eclipse.gef.commands.CompoundCommand;
	import org.eclipse.gef.commands.UnexecutableCommand;
	import org.eclipse.gef.requests.ChangeBoundsRequest;
	import org.eclipse.gmf.runtime.common.core.service.IOperation;
	import org.eclipse.gmf.runtime.diagram.ui.editparts.DiagramEditPart;
	import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
	import org.eclipse.gmf.runtime.diagram.ui.services.layout.AbstractLayoutEditPartProvider;
	import org.eclipse.gmf.runtime.notation.View;
	import org.eclipse.sirius.common.tools.DslCommonPlugin;
	import org.eclipse.sirius.common.tools.api.profiler.ProfilerTask;
	import org.eclipse.sirius.common.ui.SiriusTransPlugin;
	import org.eclipse.sirius.diagram.DDiagramElement;
	import org.eclipse.sirius.diagram.tools.api.layout.PinHelper;
	import org.eclipse.sirius.diagram.ui.provider.Messages;
	import org.eclipse.sirius.diagram.ui.tools.internal.layout.provider.LayoutService;

	import com.google.common.collect.Iterables;

	/**
	* An abstract layout provider.
	*
	* @author ymortier
	*/
	public abstract class AbstractLayoutProvider extends AbstractLayoutEditPartProvider {

	/**
	* Modeler Category.
	*/
	public static final String GENERIC_MODELER_CAT = Messages.AbstractLayoutProvider_arrangeAllProfilerTaskCategory;

	/**
	* Arrange all.
	*/
	public static final ProfilerTask ARRANGE_ALL = new ProfilerTask(GENERIC_MODELER_CAT, Messages.AbstractLayoutProvider_arrangeAllProfilerTaskName);

	/** Map all views with a its associated {@link ChangeBoundsRequest}. */
	protected Map<View, List<Request>> viewsToChangeBoundsRequest;

	/**
	* Create a new {@link AbstractLayoutProvider}.
	*
	*/
	public AbstractLayoutProvider() {
	this.viewsToChangeBoundsRequest = new HashMap<View, List<Request>>();
	}

	/**
	* Set the map that maps all views with a its associated
	* {@link ChangeBoundsRequest}.
	*
	* @param viewsToChangeBoundsRequest
	* Map all views with a its associated
	* {@link ChangeBoundsRequest}.
	*/
	public void setViewsToChangeBoundsRequest(final Map<View, List<Request>> viewsToChangeBoundsRequest) {
	this.viewsToChangeBoundsRequest = viewsToChangeBoundsRequest;
	}

	/**
	* Return the map that maps all views with a its associated
	* {@link ChangeBoundsRequest}.
	*
	* @return the map that maps all views with a its associated
	* {@link ChangeBoundsRequest}.
	*/
	public Map<View, List<Request>> getViewsToChangeBoundsRequest() {
	return viewsToChangeBoundsRequest;
	}

	@Override
	public final Command layoutEditParts(final GraphicalEditPart containerEditPart, final IAdaptable layoutHint) {
	DslCommonPlugin.PROFILER.startWork(ARRANGE_ALL);

	this.getViewsToChangeBoundsRequest().clear();

	/*
	* If we are asked to layout a whole diagram, check if a specific
	* provider has been registered for it (through the
	* org.eclipse.sirius.common.ui.airLayoutProvider extension point), and
	* use that provider if there is.
	*/
	if (containerEditPart instanceof DiagramEditPart) {
	final DiagramEditPart diagramEditPart = (DiagramEditPart) containerEditPart;
	final LayoutProvider diagramLayoutProvider = getDiagramLayoutProvider(diagramEditPart, layoutHint);
	if (diagramLayoutProvider != null) {
	final Command command = getCommandFromDiagramLayoutProvider(diagramLayoutProvider, diagramEditPart, layoutHint);
	command.setLabel(Messages.AbstractLayoutProvider_arrangeAllCommandLabel);
	DslCommonPlugin.PROFILER.stopWork(ARRANGE_ALL);
	return command;
	}
	}

	final Command command = buildCommand(containerEditPart, layoutHint);
	command.setLabel(Messages.AbstractLayoutProvider_arrangeAllCommandLabel);
	this.getViewsToChangeBoundsRequest().clear();
	AbstractLayoutProvider.resetWrappedCommand(command);
	DslCommonPlugin.PROFILER.stopWork(ARRANGE_ALL);
	return command;
	}

	/**
	* Get the the diagram layout provider if there is one.
	*
	* @param diagramEditPart
	* the diagram edit part
	* @param layoutHint
	* the layout hint
	* @return the diagram layout provider if there is one, <code>null</code>
	* otherwise
	*/
	public LayoutProvider getDiagramLayoutProvider(final DiagramEditPart diagramEditPart, final IAdaptable layoutHint) {
	final LayoutProvider candidate = LayoutService.getProvider(diagramEditPart);
	if (candidate != null && candidate.isDiagramLayoutProvider()) {
	return candidate;
	} else {
	return null;
	}
	}

	private Command getCommandFromDiagramLayoutProvider(final LayoutProvider diagramLayoutProvider, final DiagramEditPart diagramEditPart, final IAdaptable layoutHint) {
	Command command = null;
	final AbstractLayoutEditPartProvider layoutProvider = diagramLayoutProvider.getLayoutNodeProvider(diagramEditPart);
	try {
	final Method method = layoutProvider.getClass().getMethod("layoutEditParts", new Class[] { GraphicalEditPart.class, IAdaptable.class }); //$NON-NLS-1$
	Assert.isNotNull(method);
	/* this code seems to avoid an infinite loop */
	if (method.getDeclaringClass() != AbstractLayoutProvider.class) {
	command = layoutProvider.layoutEditParts(diagramEditPart, layoutHint);
	}
	} catch (final SecurityException e) {
	SiriusTransPlugin.getPlugin().error(Messages.AbstractLayoutProvider_layoutError, e);
	} catch (final NoSuchMethodException e) {
	SiriusTransPlugin.getPlugin().error(Messages.AbstractLayoutProvider_layoutError, e);
	}
	if (command == null) {
	final List<?> children = diagramEditPart.getChildren();
	command = layoutProvider.layoutEditParts(children, layoutHint);
	}
	return command;
	}

	/**
	* Build the command which performs the layout of all the edit parts in the
	* specified container.
	* <p>
	* The resulting command is a compound command built recursively by calling
	* {@link #layoutEditParts(List, IAdaptable)} on all the descendants of the
	* specified container and then on the container itself.
	*
	* @param containerEditPart
	* the container to layout.
	* @param layoutHint
	* the hint to use.
	* @return a command to execute to perform the layout of the container and
	* all its descendants.
	*/
	private Command buildCommand(final GraphicalEditPart containerEditPart, final IAdaptable layoutHint) {
	final CompoundCommand cc = new CompoundCommand();
	// Depth-first recursion.
	for (final IGraphicalEditPart graphicalEditPart : Iterables.filter(containerEditPart.getChildren(), IGraphicalEditPart.class)) {
	final Command command = buildCommand(graphicalEditPart, layoutHint);
	if (command.canExecute()) {
	cc.add(command);
	}
	}
	// Base case: layout the container's direct children.
	final Command command = this.layoutEditParts(containerEditPart.getChildren(), layoutHint);
	if (command.canExecute()) {
	cc.add(command);
	}
	return cc;
	}

	/**
	* {@inheritDoc}
	*
	* @see org.eclipse.gmf.runtime.common.core.service.IProvider#provides(org.eclipse.gmf.runtime.common.core.service.IOperation)
	*/
	@Override
	public boolean provides(final IOperation operation) {
	return false;
	}

	/**
	* Search a request for the specified edit part and of the specified type.
	*
	* @param editPart
	* the edit part.
	* @param requestType
	* the type of the request.
	* @return the found request.
	*/
	protected Request findRequest(final IGraphicalEditPart editPart, final Object requestType) {
	if (editPart != null) {
	return findRequest(editPart.getNotationView(), requestType);
	}
	return null;
	}

	/**
	* Search a request for the specified view and of the specified type.
	*
	* @param notationView
	* the view.
	* @param requestType
	* the type of the request.
	* @return the found request.
	*/
	protected Request findRequest(final View notationView, final Object requestType) {
	final List<Request> requests = this.getViewsToChangeBoundsRequest().get(notationView);
	Request result = null;
	if (requests != null) {
	final Iterator<Request> iterRequests = requests.iterator();
	while (iterRequests.hasNext() && result == null) {
	final Request currentRequest = iterRequests.next();
	if (currentRequest.getType() != null && currentRequest.getType().equals(requestType)) {
	result = currentRequest;
	}
	}
	}
	return result;
	}

	/**
	* Create a command with the specified request.
	*
	* @param request
	* the request.
	* @param editPart
	* the edit part.
	* @return an executable command.
	*/
	protected Command buildCommandWrapper(final Request request, final EditPart editPart) {
	if (editPart instanceof IGraphicalEditPart) {
	List<Request> requests = this.getViewsToChangeBoundsRequest().get(((IGraphicalEditPart) editPart).getNotationView());
	if (requests == null) {
	requests = new LinkedList<Request>();
	this.getViewsToChangeBoundsRequest().put(((IGraphicalEditPart) editPart).getNotationView(), requests);
	}
	requests.add(request);
	}
	return new CommandWrapper(request, editPart);
	}

	/**
	* Tests whether an edit part should be considered as pinned (fixed size and
	* location) during the layout.
	*
	* @param part
	* the edit part.
	* @return <code>true</code> if the edit part should be considered as
	* pinned.
	*/
	protected boolean isPinned(final IGraphicalEditPart part) {
	boolean isPinned = false;
	if (part.resolveSemanticElement() instanceof DDiagramElement) {
	DDiagramElement dDiagramElement = (DDiagramElement) part.resolveSemanticElement();
	isPinned = new PinHelper().isPinned(dDiagramElement);
	}
	return isPinned;
	}

	/**
	* Wraps a GMF Command.
	*
	* @author ymortier
	*/
	protected static class CommandWrapper extends Command {

	/**
	* The wrapped command, initialized at the first call to
	* {@link #getWrappedCommand()}.
	*/
	private Command wrappedCommand;

	/** The request. */
	private final Request request;

	/** The edit part. */
	private final EditPart editPart;

	/**
	* Create a new Command wrapper.
	*
	* @param request
	* the request.
	* @param editPart
	* the edit part.
	*/
	public CommandWrapper(final Request request, final EditPart editPart) {
	this.request = request;
	this.editPart = editPart;
	}

	@Override
	public void execute() {
	this.getWrappedCommand().execute();
	}

	@Override
	public boolean canExecute() {
	return this.getWrappedCommand().canExecute();
	}

	@Override
	public boolean canUndo() {
	return this.getWrappedCommand().canUndo();
	}

	@Override
	public void undo() {
	this.getWrappedCommand().undo();
	}

	@Override
	public void redo() {
	this.getWrappedCommand().redo();
	}

	private Command getWrappedCommand() {
	if (wrappedCommand == null) {
	final Command cmd = editPart.getCommand(request);
	if (cmd == null) {
	wrappedCommand = UnexecutableCommand.INSTANCE;
	} else {
	wrappedCommand = cmd;
	}
	}
	return wrappedCommand;
	}

	/**
	* {@inheritDoc}
	*/
	@Override
	public String getLabel() {
	return getWrappedCommand().getLabel();
	}

	/**
	* Returns the request that is causing the command.
	*
	* @return the request
	*/
	public Request getRequest() {
	return request;
	}

	/**
	* Return the associated edit part.
	*
	* @return the editPart
	*/
	public EditPart getEditPart() {
	return editPart;
	}
	}

	/**
	* Return the relative bounds of the specified edit part.
	*
	* @param graphicalEditPart
	* the edit part.
	* @return the bounds of the specified edit part.
	*/
	protected Rectangle getBounds(final IGraphicalEditPart graphicalEditPart) {
	Object existingRequest = this.findRequest(graphicalEditPart, org.eclipse.gef.RequestConstants.REQ_RESIZE);
	final Rectangle figureBounds = new Rectangle(graphicalEditPart.getFigure().getBounds());
	if (existingRequest instanceof ChangeBoundsRequest) {
	final ChangeBoundsRequest changeBoundsRequest = (ChangeBoundsRequest) existingRequest;
	if (changeBoundsRequest.getSizeDelta() != null) {
	adjustBounds(figureBounds, changeBoundsRequest);
	}
	}
	existingRequest = this.findRequest(graphicalEditPart, org.eclipse.gef.RequestConstants.REQ_MOVE);
	if (existingRequest instanceof ChangeBoundsRequest) {
	final ChangeBoundsRequest changeBoundsRequest = (ChangeBoundsRequest) existingRequest;
	if (changeBoundsRequest.getMoveDelta() != null) {
	figureBounds.x += changeBoundsRequest.getMoveDelta().x;
	figureBounds.y += changeBoundsRequest.getMoveDelta().y;
	}
	}
	return figureBounds;
	}

	private void adjustBounds(final Rectangle figureBounds, final ChangeBoundsRequest changeBoundsRequest) {
	switch (changeBoundsRequest.getResizeDirection()) {
	case PositionConstants.NORTH:
	figureBounds.height += changeBoundsRequest.getSizeDelta().height;
	figureBounds.y -= changeBoundsRequest.getSizeDelta().height;
	break;
	case PositionConstants.SOUTH:
	figureBounds.height += changeBoundsRequest.getSizeDelta().height;
	break;
	case PositionConstants.EAST:
	figureBounds.width += changeBoundsRequest.getSizeDelta().width;
	break;
	case PositionConstants.WEST:
	figureBounds.width += changeBoundsRequest.getSizeDelta().width;
	figureBounds.x -= changeBoundsRequest.getSizeDelta().width;
	break;
	case PositionConstants.NORTH_EAST:
	figureBounds.height += changeBoundsRequest.getSizeDelta().height;
	figureBounds.y -= changeBoundsRequest.getSizeDelta().height;
	figureBounds.width += changeBoundsRequest.getSizeDelta().width;
	break;
	case PositionConstants.NORTH_WEST:
	figureBounds.height += changeBoundsRequest.getSizeDelta().height;
	figureBounds.y -= changeBoundsRequest.getSizeDelta().height;
	figureBounds.width += changeBoundsRequest.getSizeDelta().width;
	figureBounds.x -= changeBoundsRequest.getSizeDelta().width;
	break;
	case PositionConstants.SOUTH_WEST:
	figureBounds.height += changeBoundsRequest.getSizeDelta().height;
	figureBounds.width += changeBoundsRequest.getSizeDelta().width;
	figureBounds.x -= changeBoundsRequest.getSizeDelta().width;
	break;
	default:
	figureBounds.height += changeBoundsRequest.getSizeDelta().height;
	figureBounds.width += changeBoundsRequest.getSizeDelta().width;
	}
	}

	/**
	* Return the first figure of type <code>type</code> that is the figure
	* <code>searchRoot</code> or a child of <code>searchRoot</code>.
	*
	* @param searchRoot
	* the root figure to start the search.
	* @param type
	* the type of the figure to return.
	* @return Return the first figure of type <code>type</code> that is the
	* figure <code>searchRoot</code> or a child of
	* <code>searchRoot</code>.
	*/
	protected IFigure findChild(final IFigure searchRoot, final Class<?> type) {
	IFigure result = null;
	if (type.isInstance(searchRoot)) {
	result = searchRoot;
	}
	final Iterator<?> iterChildren = searchRoot.getChildren().iterator();
	while (iterChildren.hasNext() && result == null) {
	final IFigure child = (IFigure) iterChildren.next();
	result = findChild(child, type);
	}
	return result;
	}

	/**
	* Return all edit parts contained in root + root.
	*
	* @param root
	* the root edit part
	* @return all edit parts contained in root + root.
	*/
	public List<EditPart> getAllEditParts(final EditPart root) {
	final Set<EditPart> editParts = new HashSet<EditPart>();
	editParts.add(root);
	if (root instanceof GraphicalEditPart) {
	editParts.addAll(((GraphicalEditPart) root).getSourceConnections());
	editParts.addAll(((GraphicalEditPart) root).getTargetConnections());
	}
	final Iterator<EditPart> iterChildren = root.getChildren().iterator();
	while (iterChildren.hasNext()) {
	final EditPart next = iterChildren.next();
	editParts.addAll(getAllEditParts(next));
	}
	return new ArrayList<EditPart>(editParts);
	}

	private static void resetWrappedCommand(final Command command) {
	if (command instanceof CommandWrapper) {
	((CommandWrapper) command).wrappedCommand = null;
	} else if (command instanceof CompoundCommand) {
	final Object[] children = ((CompoundCommand) command).getChildren();
	for (Object element : children) {
	if (element instanceof Command) {
	AbstractLayoutProvider.resetWrappedCommand((Command) element);
	}
	}
	}
	}
	}