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
* from the adapter's control. This method is used when a client, such as a
	 * content proposal listener, needs to update the control's contents
	 * manually.
	 * 
	 * @return the {@link IControlContentAdapter} which can update the control
	 *         text.
	 */
	public IControlContentAdapter getControlContentAdapter() {
		return controlContentAdapter;
	}
	/**
	 * Set the boolean flag that determines whether the adapter is enabled.
	 * 
	 * @param enabled
	 *            <code>true</code> if the adapter is enabled and responding
	 *            to user input, <code>false</code> if it is ignoring user
	 *            input.
	 * 
	 */
	public void setEnabled(boolean enabled) {
		
		
		if (isEnabled && !enabled) {
			if (popup != null)
				popup.close();
		}
		isEnabled = enabled;
	}
	/**
	 * Add the specified listener to the list of content proposal listeners that