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
* Sets or clears the current error message for this cell editor.
 * 
 * @param message the error message, or <code>null</code> to clear
 */
protected void setErrorMessage(String message) {
	errorMessage = message;
}
/**
 * Sets the focus to the cell editor's control.
 */
public void setFocus() {
	doSetFocus();
}
/**
 * Sets the input validator for this cell editor.
 *
 * @param validator the input validator, or <code>null</code> if none
 */
public void setValidator(ICellEditorValidator validator) {
	this.validator = validator;
}
/**
 * Sets this cell editor's value.
 *
 * @param value the value of this cell editor
 */
public final void setValue(Object value) {
	valid = isCorrect(value);
	dirty = false;
	doSetValue(value);