Bug 120168 [Field Assist] - should be able to specify character activation subset when auto-activating
ControlContentAdapter (initial release) When there is no triggering keystroke set on a ControlContentAdapter, auto-activation is assumed, and alpha-numerics trigger the auto-activation. It is useful to be able to specify a subset of characters that trigger auto-activation. This is done, for example, by the find/replace dialog RexExProcessor, so that only those characters involving regular expressions will auto-activate the content assist.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
* are notified when content proposals are chosen.
	 * </p>
	 * 
	 * @param listener
	 *            the IContentProposalListener to be added as a listener. Must
	 *            not be <code>null</code>. If an attempt is made to register
	 *            an instance which is already registered with this instance,
	 *            this method has no effect.
	 * 
	 * @see org.eclipse.jface.fieldassist.IContentProposalListener
	 */
	public void addContentProposalListener(IContentProposalListener listener) {
		proposalListeners.add(listener);
	}
	/*
	 * Add our listener to the control. Debug information to be left in until
	 * this support is stable on all platforms.
	 */
	private void addControlListener(Control control) {
		if (DEBUG)
			System.out
					.println("ContentProposalListener#installControlListener()"); 
		if (controlListener != null)
			return;
		controlListener = new Listener() {
			public void handleEvent(Event e) {
				if (!isEnabled) 
					return;
				
				switch (e.type) {