viewer.setContentProvider(new EvaluationContentProvider(type));
viewer.setLabelProvider(new EvaluationLabelProvider(this));
int ops = DND.DROP_COPY | DND.DROP_MOVE;
Transfer[] transfers = new Transfer[] { TextTransfer.getInstance() };
viewer.addDragSupport(ops, transfers, new AnnotationTreeViewDragListener(viewer));
getSite().setSelectionProvider(viewer);
getSite().getPage().addSelectionListener(this);
document.addChangeListener(this);