gtk-drag-dest-set-proxy (widget window protocol coordinates)

widget -- a gtk-widget object
window -- a gdk-window object to which to forward drag events
protocol -- the drag protocol of type gdk-drag-protocol which window accepts, you can use the gdk-drag-context-protocol function to determine this
coordinates -- if true, send the same coordinates to the destination, because it is an embedded subwindow

Sets the widget as a proxy for drops to another window. The function gtk-drag-dest-set-proxy has been deprecated since version 3.22 and should not be used in newly written code.