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
* The object that provides content proposals.
	 */
	private IContentProposalProvider proposalProvider;
	/*
	 * A label provider used to display proposals in the popup, and to extract
	 * Strings from non-String proposals.
	 */
	private ILabelProvider labelProvider;
	/*
	 * The control for which content proposals are provided.
	 */
	private Control control;
	/*
	 * The adapter used to extract the String contents from an arbitrary
	 * control.
	 */
	private IControlContentAdapter controlContentAdapter;
	/*
	 * The popup used to show proposals.
	 */
	private ContentProposalPopup popup;
	/*
	 * The keystroke that signifies content proposals should be shown.
	 */
	private KeyStroke triggerKeyStroke;
	/*
	 * A flag indicating how an accepted proposal should affect the control. One
	 * of PROPOSAL_IGNORE, PROPOSAL_INSERT, or PROPOSAL_REPLACE.
	 */
	private int acceptance;