Generated when the owner of a selection changes. On X11, this information is only available if the X server supports the XFIXES extension.
the new owner of the selection, or NULL if there is none
the reason for the ownership change as a GdkOwnerChange value
the atom identifying the selection
the time at which the selection ownership was taken over
TRUE if the event was sent explicitly.
the timestamp of the event
the type of the event (GDK_OWNER_CHANGE).
the window which received the event