/******************************************************************************* | |
* Copyright (c) 2005, 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 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: | |
* IBM Corporation - initial API and implementation | |
*******************************************************************************/ | |
package org.eclipse.bpel.ui.palette; | |
import org.eclipse.bpel.ui.BPELEditor; | |
import org.eclipse.gef.DefaultEditDomain; | |
import org.eclipse.gef.tools.SelectionTool; | |
public class BPELSelectionTool extends SelectionTool { | |
public BPELSelectionTool() { | |
super(); | |
} | |
/** | |
* The following method is a workaround for a problem between | |
* the GEF SelectionTool and how AbstractTextEditor is created. The | |
* problem can be reproduced (without this workaround) as follows: | |
* Select an edit part on the canvas that has a property tab with | |
* a Text editor in it (e.g. Receive - Documentation). Select the tab | |
* as well to make sure the editor is created. Now select an edit part | |
* that does not have the same tab (so, no text editor - e.g. a Variable). | |
* Select back the first edit part. Check your log or console for a NPE. | |
* | |
* What happens underneath is: When you select the edit part (mouse down), | |
* the selection tool handles the MouseDown event activating its drag tracker | |
* and setting its current viewer. That selection causes a selection changed | |
* event to be triggered that ends up setting a new input for the properties view. | |
* The particular tab on the properties view needs a text editor and creates | |
* one. When creating the text editor, AbstractTextEditor (temporarily) sets the | |
* focus to the editor's parent composite. When that happens the edit part | |
* loses focus and the SelectionTool handles the FocusOut event by deactivating | |
* the drag tracker and setting its current viewer to null. When you release | |
* the mouse (mouse up) the selection tool tries to calculate the selection but | |
* it does not have a viewer anymore which causes the NPE. | |
* | |
* The following workaround tests if we are notifying the properties view for | |
* a selection change and ignores the FocusOut event in that case. | |
*/ | |
@Override | |
protected boolean handleFocusLost() { | |
if (isSelectionChangeBeingBroadcasted()) return true; | |
return super.handleFocusLost(); | |
} | |
protected boolean isSelectionChangeBeingBroadcasted() { | |
BPELEditor editor = (BPELEditor) ((DefaultEditDomain)getDomain()).getEditorPart(); | |
return editor.getAdaptingSelectionProvider().isBroadcastingSelectionChange(); | |
} | |
/** | |
* This workaround is similar to the one in handleFocusLost(). In this particular case | |
* there was also a timing issue related to when we received the button up event. | |
*/ | |
@Override | |
protected boolean handleButtonUp(int button) { | |
if (isSelectionChangeBeingBroadcasted()) return true; | |
return super.handleButtonUp(button); | |
} | |
/** | |
* This workaround is similar to the one in handleFocusLost(). In this particular case | |
* there was also a timing issue related to when we received the button exit event. | |
*/ | |
@Override | |
protected boolean handleViewerExited() { | |
if (isSelectionChangeBeingBroadcasted()) return true; | |
return super.handleViewerExited(); | |
} | |
} |