Bug 12329 [Cell Editors] Request:ComboBoxCellEditor READ_ONLY style
Although CCombo accepts SWT.READ_ONLY style, there is no way to specify style when it is used in ComboBoxCellEditor. How about adding createControl(Composite parent, int style) method to ComboBoxCellEditor class?
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/DialogCellEditor.java
*		value has changed</li>
 * </ul>
 * </p>
 */
public abstract class DialogCellEditor extends CellEditor {
	/**
	 * Image registry key for three dot image (value <code>"cell_editor_dots_button_image"</code>).
	 */
	public static final String CELL_EDITOR_IMG_DOTS_BUTTON = "cell_editor_dots_button_image";
	/**
	 * The editor control.
	 */
	private Composite editor;
	/**
	 * The current contents.
	 */
	private Control contents;
	/**
	 * The label that gets reused by <code>updateLabel</code>.
	 */
	private Label defaultLabel;
	/**
	 * The button.
	 */
	private Button button;
	/**
	 * The value of this cell editor; initially <code>null</code>.
	 */
	private Object value = null;