@Override public void selectionChanged(SelectionChangedEvent event) { IStructuredSelection selection = event.getStructuredSelection(); if (!selection.isEmpty()) { ISourceContainerType type = (ISourceContainerType) selection.getFirstElement(); setMessage(type.getDescription()); getButton(IDialogConstants.OK_ID).setEnabled(true); } else { getButton(IDialogConstants.OK_ID).setEnabled(false); setMessage(SourceLookupUIMessages.AddSourceContainerDialog_select_source_container); } } });