When using gtk_window_begin_move_drag(), how to know when the move drag has been finished?

["Zhe Su" <james su gmail com>]

Hi,
  I use gtk_window_begin_move_drag() to initiate the window drag action when
user drag a specific area of the window. And I want to know when the user
releases the mouse button, so that I can do some extra tasks after the
window move. However, it seems that after calling
gtk_window_begin_move_drag() the next mouse up event won't be sent to the
application. So is there any other way to detect when the drag action has
been finished?

Regards
James Su