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 SafeHasCorrections(ICompilationUnit cu, int problemId) {
			fCu= cu;
			fProblemId= problemId;
			fHasCorrections= false;
		}
		public boolean hasCorrections() {
			return fHasCorrections;
		}
		public void safeRun(ContributedProcessorDescriptor desc) throws Exception {
			IQuickFixProcessor processor= (IQuickFixProcessor) desc.getProcessor(fCu);
			if (processor != null && processor.hasCorrections(fCu, fProblemId)) {
				fHasCorrections= true;
			}
		}
	}
	public static IStatus collectCorrections(IInvocationContext context, IProblemLocation[] locations, Collection proposals) {
		ContributedProcessorDescriptor[] processors= getCorrectionProcessors();
		SafeCorrectionCollector collector= new SafeCorrectionCollector(context, proposals);
		for (int i= 0; i < processors.length; i++) {
			ContributedProcessorDescriptor curr= processors[i];
			IProblemLocation[] handled= getHandledProblems(locations, curr);
			if (handled != null) {
				collector.setProblemLocations(handled);
				collector.process(curr);
			}
		}
		return collector.getStatus();
	}
	private static IProblemLocation[] getHandledProblems(IProblemLocation[] locations, ContributedProcessorDescriptor processor) {