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/CellEditor.java
/**
	 * Indicates whether this cell editor's current value is valid.
	 */
	private boolean valid = false;
	
	/**
	 * Optional cell editor validator; <code>null</code> if none.
	 */
	private ICellEditorValidator validator = null;
	/**
	 * The error message string to display for invalid values;
	 * <code>null</code> if none (that is, the value is valid).
	 */
	private String errorMessage = null;
	
	/**
	 * Indicates whether this cell editor has been changed recently.
	 */
	private boolean dirty = false;
	/**
	 * This cell editor's control, or <code>null</code>
	 * if not created yet.
	 */
	private Control control = null;
	/** 
	 * Struct-like layout data for cell editors, with reasonable defaults
	 * for all fields.
	 */	
	public static class LayoutData {