Bug 166383 [Viewers] Provide Tabing from Editor to Editor
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractViewerEditor.java
* @param viewer
	 *            the column viewer
	 */
	public AbstractViewerEditor(ColumnViewer viewer) {
		this.viewer = viewer;
		initCellEditorListener();
	}
	private void initCellEditorListener() {
		cellEditorListener = new ICellEditorListener() {
			public void editorValueChanged(boolean oldValidState,
					boolean newValidState) {
				
			}
			public void cancelEditor() {
				AbstractViewerEditor.this.cancelEditing();
			}
			public void applyEditorValue() {
				AbstractViewerEditor.this.applyEditorValue();
			}
		};
	}
	void activateCellEditor() {
		ViewerColumn part = viewer.getViewerColumn(columnNumber);
		Object element = item.getData();
		if (part != null && part.getEditingSupport() != null
				&& part.getEditingSupport().canEdit(element)) {
			cellEditor = part.getEditingSupport().getCellEditor(element);
			if (cellEditor != null) {
				cellEditor.addListener(cellEditorListener);
				Object value = part.getEditingSupport().getValue(element);