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
/**
 * Notifies all registered cell editor listeners of an apply event.
 * Only listeners registered at the time this method is called are notified.
 *
 * @see ICellEditorListener#applyEditorValue
 */
protected void fireApplyEditorValue() {
	Object[] listeners = this.listeners.getListeners();
	for (int i = 0; i < listeners.length; ++i) {
		((ICellEditorListener) listeners[i]).applyEditorValue();
	}
}
/**
 * Notifies all registered cell editor listeners that editing has been
 * canceled.
 *
 * @see ICellEditorListener#cancelEditor
 */
protected void fireCancelEditor() {
	Object[] listeners = this.listeners.getListeners();
	for (int i = 0; i < listeners.length; ++i) {
		((ICellEditorListener) listeners[i]).cancelEditor();
	}
}
/**
 * Notifies all registered cell editor listeners of a value change.
 *
 * @param oldValidState the valid state before the end user changed the value
 * @param newValidState the current valid state
 * @see ICellEditorListener#editorValueChanged