ListGrid: Filter and sort in 1 step (without fetching data 2 times)?

I have a ListGrid with a filter like the Showcase Sample

(Grids -> Filtering -> Filter http://www.smartclient.com/smartgwt/showcase/#grid_sortfilter_filter)

If i'd like to filter eg. Continents 'Asia' and sort the Capitals ascending, I have to do this in 2 steps:

1) Choose the Filter and click on the filter icon.

2) Click on the 'Captial' column header for sort.

So data is also fetched 2 times.

How do I have to modify the example that I can sort and filter without loading the data twice?

Is it somehow possible that the filter is evaluated on sorting, without before hitting the filter-icon?

Thanks