categoryTree.setWidth(250);
categoryTree.setHeight(224);
categoryTree.setDataSource(supplyCategoryXmlDS);
categoryTree.setLoadDataOnDemand(true);
categoryTree.setAutoFetchData(true);
categoryTree.addRecordDoubleClickHandler(new RecordDoubleClickHandler() {
@Override
public void onRecordDoubleClick(RecordDoubleClickEvent event) {
final String categoryName = event.getRecord().getAttribute("categoryName");
Criteria criteria = new Criteria("category", categoryName);
itemListGrid.filterData(criteria);