The example program alternatively displays two File Requesters.
The first one is himself alternatively used as a normal File Requester and as a Directory requester: this is why it will rescan its directory every time it is displayed. It is not draggable, as a pattern that matches all files, and accepts double-click selection.
The second one is moveable and looks for files ending with ".c" only. Note that as no critical parameter is changed between two succesive displays, it will remember the last scanned list, the display position and the selection.
