OOUI is smart enough to handle this automatically: https://doc.wikimedia.org/oojs-ui/master/js/#!/api/OO.ui.PopupWidget-cfg-position https://doc.wikimedia.org/oojs-ui/master/js/#!/api/OO.ui.PopupWidget-cfg-autoFlip Change-Id: Ib8e4ea0e900b3ea0904b34d82c874227462e342e