Case

PreviewLayout.device

Center the preview in a container the size of the device on which the preview is running. プレビューを、それの上でプレビューが動作しているデバイスの大きさのコンテナの中心に置きます。

Declaration 宣言 

case device

See Also 参照

Getting a Layout

case fixed(width: CGFloat, height: CGFloat)
Center the preview in a fixed size container with the given dimensions.
case sizeThatFits
Fit the container to the size of the preview when offered the size of the device that the preview is running on.