| /****************************************************************************** |
| * Copyright (c) 2006 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 org.eclipse.gef.Request; |
| import org.eclipse.gef.commands.Command; |
| import org.eclipse.gef.editpolicies.AbstractEditPolicy; |
| import org.eclipse.gef.requests.ReconnectRequest; |
| import org.eclipse.gmf.runtime.diagram.ui.internal.editpolicies.NoteAttachmentReorientEditPolicy; |
| |
| /** |
| * By default, reorienting of connections that do not have any semantic meaning |
| * (e.g. note attachments) will be supported between any two nodes by a |
| * <code>GraphicalNodeEditPolicy</code>. The intention of this editpolicy is |
| * to provide a place where this can be disabled. To disable reorienting of a |
| * connection between two nodes, return an unexecutable command. For an example |
| * implementation, see {@link NoteAttachmentReorientEditPolicy}. |
| * |
| * @author Cherie Revells |
| */ |
| abstract public class NotationConnectionReorientEditPolicy |
| extends AbstractEditPolicy { |
| |
| public Command getCommand(Request request) { |
| if (REQ_RECONNECT_SOURCE.equals(request.getType()) |
| && connectionSourceHasChanged((ReconnectRequest) request)) { |
| return getReorientConnectionSourceCommand((ReconnectRequest) request); |
| } else if (REQ_RECONNECT_TARGET.equals(request.getType()) |
| && connectionTargetHasChanged((ReconnectRequest) request)) { |
| return getReorientConnectionTargetCommand((ReconnectRequest) request); |
| } |
| |
| return super.getCommand(request); |
| } |
| |
| /** |
| * Subclasses may override to return an unexecutable command if reorienting |
| * the connection to the new source should be disabled. Otherwise, this |
| * command should return null so as not to interfere. |
| * |
| * @param request |
| * the request to change the source of a connection |
| * @return an unexecutable command if this gesture should be disabled; null |
| * otherwise |
| */ |
| protected Command getReorientConnectionSourceCommand( |
| ReconnectRequest request) { |
| return null; |
| } |
| |
| /** |
| * Subclasses may override to return an unexecutable command if reorienting |
| * the connection to the new target should be disabled. Otherwise, this |
| * command should return null so as not to interfere. |
| * |
| * @param request |
| * the request to change the target of a connection |
| * @return an unexecutable command if this gesture should be disabled; null |
| * otherwise |
| */ |
| protected Command getReorientConnectionTargetCommand( |
| ReconnectRequest request) { |
| return null; |
| } |
| |
| /** |
| * Has the connection source changed? If not, then it is not necessary to |
| * return a command that will change the connection's source. |
| * |
| * @param request |
| * the request to reconnect the source of a connection |
| * @return true if the source has changed; false otherwise |
| */ |
| private boolean connectionSourceHasChanged(ReconnectRequest request) { |
| return !request.getConnectionEditPart().getSource().equals( |
| request.getTarget()); |
| } |
| |
| /** |
| * Has the connection target changed? If not, then it is not necessary to |
| * return a command that will change the connection's target. |
| * |
| * @param request |
| * the request to reconnect the target of a connection |
| * @return true if the target has changed; false otherwise |
| */ |
| private boolean connectionTargetHasChanged(ReconnectRequest request) { |
| return !request.getConnectionEditPart().getTarget().equals( |
| request.getTarget()); |
| } |
| |
| public boolean understandsRequest(Request request) { |
| if ((REQ_RECONNECT_SOURCE.equals(request.getType()) || REQ_RECONNECT_TARGET |
| .equals(request.getType()))) { |
| return true; |
| } |
| return false; |
| } |
| |
| } |