Bug 260892 [CellEditors] NPE from ColumnViewerEditor caused by showing a dialog during modify
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColumnViewerEditor.java
/*******************************************************************************
 * Copyright (c) 2006, 2008 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
 *     Tom Schindl <tom.schindl@bestsolution.at> - refactoring (bug 153993)
 *     											   fix in bug: 151295,178946,166500,195908,201906,207676,180504,216706,218336
 *******************************************************************************/
package org.eclipse.jface.viewers;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;