Claim ownership of a given selection for a particular widget, or, if widget is null, release ownership of the selection.
the #GdkDisplay where the selection is set
new selection owner (a #GtkWidget), or null.
an interned atom representing the selection to claim.
timestamp with which to claim the selection
TRUE if the operation succeeded
Claim ownership of a given selection for a particular widget, or, if widget is null, release ownership of the selection.