Using GridView.count to create a grid that's two tiles wide in portrait mode and three tiles wide in landscape mode

Flexible(
  child: GridView.count(
    crossAxisCount: (orientation == Orientaation.portrait) ? 2 : 3,
    mainAxisSpacing: 4.0,
    crossAxisSpacing: 4.0,
    padding: const EdgeInsets.all(4.0),
    childAspectRatio: (orientation == Orientaation.portrait) ? 1.0 : 1.3,
    children: someList.map(
      (catData) => aListItemWidget(catData)
    ).toList()
  )
);