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
Runnable runnable = new Runnable() {
					public void run() {
						try {
							Thread.sleep(POPUP_DELAY);
						} catch (InterruptedException e) {
						}
						if (!isValid()) {
							return;
						}
						getShell().getDisplay().syncExec(new Runnable() {
							public void run() {
								
								
								IContentProposal p = getSelectedProposal();
								if (p != null) {
									if (infoPopup == null) {
										infoPopup = new InfoPopupDialog(
												getShell());
										infoPopup.open();
									}
									infoPopup.setContents(p.getDescription());
									infoPopup.getShell().addDisposeListener(
											new DisposeListener() {
												public void widgetDisposed(
														DisposeEvent event) {
													infoPopup = null;
												}
											});
								}