Bug 126527 [Field Assist] - API - Field Decoration alignment issues are different for cell editors
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/DecoratedTextCellEditor.java
*/
	private ModifyListener getModifyListener() {
		if (modifyListener == null) {
			modifyListener = new ModifyListener() {
				public void modifyText(ModifyEvent e) {
					editOccured(e);
				}
			};
		}
		return modifyListener;
	}
	/**
	 * Handles a default selection event from the text control by applying the
	 * editor value and deactivating this cell editor.
	 * 
	 * @param event
	 *            the selection event
	 * 
	 * @since 3.0
	 */
	protected void handleDefaultSelection(SelectionEvent event) {
		
		fireApplyEditorValue();
		deactivate();
	}
	/**
	 * The <code>TextCellEditor</code> implementation of this
	 * <code>CellEditor</code> method returns <code>true</code> if the
	 * current selection is not empty.
	 */