int style = SWT.SINGLE | SWT.V_SCROLL | SWT.H_SCROLL;
final TreeViewer viewer = new TreeViewer(parent, style);
ColumnViewerToolTipSupport.enableFor(viewer, ToolTip.NO_RECREATE);
viewer.setContentProvider(new PageDescriptorContentProvider());
viewer.setComparator(new ViewerComparator());
viewer.setLabelProvider(new PageDescriptorLabelProvider());
viewer.getTree().addListener(SWT.MeasureItem, new Listener() {
@Override
public void handleEvent(Event event) {
event.height = (event.height < 20) ? 20 : event.height;