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/JavaCorrectionProcessor.java
public void assistSessionEnded(ContentAssistEvent event) {
				fAssistant.setStatusLineVisible(false);
			}
		
			public void assistSessionStarted(ContentAssistEvent event) {
				fAssistant.setStatusLineVisible(true);
			}
			public void selectionChanged(ICompletionProposal proposal, boolean smartToggle) {
				if (proposal instanceof IStatusLineProposal) {
					IStatusLineProposal statusLineProposal= (IStatusLineProposal)proposal;
					String message= statusLineProposal.getStatusMessage();
					if (message != null) {
						fAssistant.setStatusMessage(message);
					} else {
						fAssistant.setStatusMessage(""); 
					}
				} else {
					fAssistant.setStatusMessage(""); 
				}
			}
		});
	}
	/*
	 * @see IContentAssistProcessor#computeCompletionProposals(ITextViewer, int)
	 */
	public ICompletionProposal[] computeQuickAssistProposals(IQuickAssistInvocationContext quickAssistContext) {
		ITextViewer viewer= quickAssistContext.getTextViewer();
		int documentOffset= quickAssistContext.getOffset();