Bug 232048 [Viewers] binary incompatibility (adding public fields) reported against jface.viewers
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CellEditor.java
* @param oldValidState
	 *            the valid state before the end user changed the value
	 * @param newValidState
	 *            the current valid state
	 * @see ICellEditorListener#editorValueChanged
	 */
	protected void valueChanged(boolean oldValidState, boolean newValidState) {
		valid = newValidState;
		dirty = true;
		fireEditorValueChanged(oldValidState, newValidState);
	}
	/**
	 * Activate the editor but also inform the editor which event triggered its
	 * activation. <b>The default implementation simply calls
	 * {@link #activate()}</b>
	 *
	 * @param activationEvent
	 *            the editor activation event
	 * @since 3.3
	 */
	public void activate(ColumnViewerEditorActivationEvent activationEvent) {
		activate();
	}
	/**
	 * The default implementation of this method returns true. Subclasses that
	 * hook their own focus listener should override this method and return
	 * false. See also bug 58777.
	 *
	 * @return <code>true</code> to indicate that a focus listener has to be
	 *         attached