Bug 132101 [Field Assist] does not work for characters that need AltGr, Ctrl+Alt or Strg+Alt
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
private Listener targetControlListener;
		/*
		 * The listener installed in order to close the popup.
		 */
		private PopupCloserListener popupCloser;
		/*
		 * The table used to show the list of proposals.
		 */
		private Table proposalTable;
		/*
		 * The proposals to be shown (cached to avoid repeated requests).
		 */
		private IContentProposal[] proposals;
		/*
		 * Secondary popup used to show detailed information about the selected
		 * proposal..
		 */
		private InfoPopupDialog infoPopup;
		/*
		 * Filter text - tracked while popup is open, only if we are told to
		 * filter
		 */
		private String filterText = EMPTY;
		/**
		 * Constructs a new instance of this popup, specifying the control for
		 * which this popup is showing content, and how the proposals should be
		 * obtained and displayed.
		 * 
		 * @param infoText
		 *            Text to be shown in a lower info area, or