EDIT

    protected void doSetInput(IEditorInput input) throws CoreException {

        AnnotatedLineDocumentProvider provider = new AnnotatedLineDocumentProvider(input);

        provider.setLineDisplayStrategy(lineDisplayStrategy, input);

        setDocumentProvider(provider);

    public LineAnnotation createAnnotatedLine(Object entity) {

        IEditorInput input = getEditorInput();

        AnnotatedLineDocumentProvider provider = (AnnotatedLineDocumentProvider) getDocumentProvider();

        LineAnnotation annotation = null;