gdk-selection-convert (requestor selection target time)

requestor -- a gdk-window object
selection -- a gdk-atom as a string identifying the selection to get the contents of
target -- a gdk-atom as a string with the form in which to retrieve the selection
time -- an unsigned integer with the timestamp to use when retrieving the selection

Retrieves the contents of a selection in a given form. The selection owner may refuse the request if it did not own the selection at the time indicated by the timestamp.