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/ComboBoxCellEditor.java
* The list of items to present in the combo box.
	 */
	private String[] items;
	/**
	 * The zero-based index of the selected item.
	 */
	private int selection;
	/**
	 * The custom combo box control.
	 */
	private CCombo comboBox;
/**
 * Creates a new cell editor with a combo containing the given 
 * list of choices and parented under the given control. The cell
 * editor value is the zero-based index of the selected item.
 * Initially, the cell editor has no cell validator and
 * the first item in the list is selected. 
 *
 * @param parent the parent control
 * @param items the list of strings for the combo box
 */
public ComboBoxCellEditor(Composite parent, String[] items) {
	super(parent);
	Assert.isNotNull(items);
	this.items = items;
	selection = 0;
	populateComboBoxItems();
}
/* (non-Javadoc)
 * Method declared on CellEditor.