WritableSet selectedSet = new WritableSet(SWTObservables.getRealm(RedMobileControl.getDisplay()));

ComboViewer selectedViewer = new ComboViewer(this, SWT.READ_ONLY | SWT.DROP_DOWN);
selectedViewer.setContentProvider(new ObservableSetContentProvider());
selectedViewer.setInput(selectedSet);
selectedViewer.setLabelProvider(new LabelProvider(){
	@Override public String getText(Object element) {
		//Some irrelevant code here.
	}
});