def setVisible(self, visible):
"""
Called when list widget is shown/hidden.
Arguments:
visible (bool): True if widget is being shown,
False otherwise.
"""
if visible:
self._list.setFocus()
self._list.scrollToItem(self._list.item(0),
QListWidget.PositionAtTop)
self._setSelected(0)
QMenu.setVisible(self, visible)
