Vertical TextView for Xamarin.Android

VerticalTextView.cs

using System;
using Android.Content;
using Android.Runtime;
using Android.Util;
using Android.Views;

namespace TNUtils.Droid
{
	[Register("tnutils.droid.VerticalTextView")]
	public class VerticalTextView : Android.Support.V7.Widget.AppCompatTextView
	{
		private bool _isTopDown;
		public VerticalTextView(Context context) : base(context)
		{
			Initialize();
		}

		public VerticalTextView(Context context, IAttributeSet attrs) : base(context, attrs)
		{
			Initialize();
		}

		public VerticalTextView(Context context, IAttributeSet attrs, int defStyleAttr) : base(context, attrs, defStyleAttr)
		{
			Initialize();
		}

		private void Initialize()
		{
			GravityFlags gravity = Gravity;
			if (Android.Views.Gravity.IsVertical(gravity) && (gravity & GravityFlags.VerticalGravityMask) == GravityFlags.Bottom)
			{
				Gravity = (gravity & GravityFlags.HorizontalGravityMask) | GravityFlags.Top;
				_isTopDown = false;
			}
			else
			{
				_isTopDown = true;
			}
		}

		protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
		{
			base.OnMeasure(heightMeasureSpec, widthMeasureSpec);
			SetMeasuredDimension(MeasuredHeight, MeasuredWidth);
		}

		protected override void OnDraw(Android.Graphics.Canvas canvas)
		{
			if (_isTopDown)
			{
				canvas.Translate(Width, 0);
				canvas.Rotate(90);
			}
			else
			{
				canvas.Translate(0, Height);
				canvas.Rotate(-90);
			}

			canvas.Translate(CompoundPaddingLeft, ExtendedPaddingTop);

			Layout.Draw(canvas);
		}
	}
}