Bug 38247 [Viewers] [Javadoc] Incomplete javadoc for DialogCellEditor
The javadoc for #openDialogBox() does not say how to indicate that the dialog box was canceled. The de-facto behaviour is that if null is returned, it is considered as "cancel".
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/DialogCellEditor.java
* @param cellEditorWindow the parent control cell editor's window
 *   so that a subclass can adjust the dialog box accordingly
 * @return the selected value
 */
protected abstract Object openDialogBox(Control cellEditorWindow);
/**
 * Updates the controls showing the value of this cell editor.
 * <p>
 * The default implementation of this framework method just converts
 * the passed object to a string using <code>toString</code> and
 * sets this as the text of the label widget.
 * </p>
 * <p>
 * Subclasses may reimplement.  If you reimplement this method, you
 * should also reimplement <code>createContents</code>.
 * </p>
 *
 * @param value the new value of this cell editor
 */
protected void updateContents(Object value) {
	if (defaultLabel == null)
		return;
		
	String text = "";
	if (value != null)
		text = value.toString(); 
	defaultLabel.setText(text);
}
}