message: Combine visible and contains checks
  If the control is not visible, then there should be no highlight.
diff: @@ -176,9 +176,7 @@ void ListBox::onMouseDown(EventHandler::MouseButton /*button*/, int x, int y)
  void ListBox::onMouseMove(int x, int y, int /*relX*/, int /*relY*/)
  {
  - if (!visible()) { return; }
  -
  - if (!mScrollArea.contains({x, y}))
  + if (!visible() || !mScrollArea.contains({x, y}))
  {
  mHighlightIndex = constants::NO_SELECTION;
  return;
  