DisplayResolutionUnit.cs

using System;

namespace Xamarin.Forms
{
	public class DisplayResolutionUnit
	{
		public static DisplayResolutionUnit Pixel(bool useDeviceScale = false)
		{
			return new DisplayResolutionUnit()
			{
				UseDP = false,
				UseDeviceScale = useDeviceScale
			};
		}

		public static DisplayResolutionUnit DP(bool useDeviceScale = false)
		{
			return new DisplayResolutionUnit()
			{
				UseDP = true,
				UseDeviceScale = useDeviceScale
			};
		}

		public static DisplayResolutionUnit VP(double width)
		{
			if (width <= 0)
				throw new ArgumentException("width must be bigger than 0", "width");

			return new DisplayResolutionUnit()
			{
				UseVP = true,
				UseDeviceScale = false,
				ViewportWidth = width
			};
		}

		internal static DisplayResolutionUnit FromInit(bool useDP)
		{
			return useDP ? DP() : Pixel();
		}

		DisplayResolutionUnit() { }

		public bool UseDP { get; private set; }

		public bool UseDeviceScale { get; private set; }

		public bool UseVP { get; private set; }

		public double ViewportWidth { get; private set; } = -1;
	}
}