listGrid.setDataSource(dataSource);
listGrid.setAutoFetchData(true);
listGrid.setCanEdit(true);
listGrid.setCanRemoveRecords(true);
Button button = new Button("Add a New Record");
button.setAutoFit(true);
button.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
listGrid.startEditingNew();
}
});