Bug 127655 [api] Must have a way to query quick assist context from source viewer
I20060214-0010 [api] Must have a way to query quick assist context from text viewer. In addition, quick assistant install must specify that besides ITextViewer also ITextViewerExtension7 must be present in order to get the invocation context. ==> assertion failure if this is not met.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/correction/PropertiesFileCorrectionProcessor.java
if (proposals.isEmpty()) {
				proposals.add(new ChangeCorrectionProposal(CorrectionMessages.NoCorrectionProposal_description, null, 0, null));
			}
			ICompletionProposal[] res= (ICompletionProposal[]) proposals.toArray(new ICompletionProposal[proposals.size()]);
			Arrays.sort(res, new CompletionProposalComparator());
			return res;
		} finally {
			try {
				manager.disconnect(path, null);
			} catch (CoreException e) {
				JavaPlugin.log(e.getStatus());
			}
		}
	}
	private boolean isAtPosition(int offset, Position pos) {
		return (pos != null) && (offset >= pos.getOffset() && offset <= (pos.getOffset() +  pos.getLength()));
	}
	private void processAnnotations(IInvocationContext context, IAnnotationModel model, ArrayList proposals) {
		int offset= context.getSelectionOffset();
		ArrayList problems= new ArrayList();
		Iterator iter= model.getAnnotationIterator();
		while (iter.hasNext()) {
			Annotation annotation= (Annotation) iter.next();
			if (isQuickFixableType(annotation)) {
				Position pos= model.getPosition(annotation);
				if (isAtPosition(offset, pos)) {
					processAnnotation(annotation, pos, problems, proposals);
				}
			}
		}