Custom image button based on an Eto.Forms.Drawable

CustomButton.cs

using System;
using Eto.Forms;
using Eto.Drawing;

namespace Pablo.Controls
{
	public class CustomButton : Drawable
	{
		bool pressed;
		bool hover;
		bool mouseDown;
		public static Color DisabledColor = Color.FromGrayscale(0.4f, 0.3f);
		public static Color EnabledColor = Colors.Black;

		public override bool Enabled
		{
			get
			{
				return base.Enabled;
			}
			set
			{
				if (base.Enabled != value)
				{
					base.Enabled = value;
					if (Loaded)
						Invalidate();
				}
			}
		}

		public bool Pressed
		{
			get { return pressed; }
			set
			{ 
				if (pressed != value)
				{
					pressed = value;
					mouseDown = false;
					if (Loaded)
						Invalidate();
				}
			}
		}

		public Color DrawColor
		{
			get { return Enabled ? EnabledColor : DisabledColor; }
		}

		public bool Toggle { get; set; }

		public bool Persistent { get; set; }

		public event EventHandler<EventArgs> Click;

		protected virtual void OnClick(EventArgs e)
		{
			if (Click != null)
				Click(this, e);
		}

		public CustomButton()
		{
			Enabled = true;
		}

		protected override void OnSizeChanged(EventArgs e)
		{
			base.OnSizeChanged(e);
			if (Loaded)
				Invalidate();
		}

		protected override void OnMouseDown(MouseEventArgs e)
		{
			base.OnMouseDown(e);
			if (Enabled)
			{
				mouseDown = true;
				Invalidate();
			}
		}

		protected override void OnMouseEnter(MouseEventArgs e)
		{
			base.OnMouseEnter(e);
			hover = true;
			Invalidate();
		}

		protected override void OnMouseLeave(MouseEventArgs e)
		{
			base.OnMouseLeave(e);
			hover = false;
			Invalidate();
		}

		protected override void OnMouseUp(MouseEventArgs e)
		{
			base.OnMouseUp(e);
			var rect = new Rectangle(this.Size);
			if (mouseDown && rect.Contains((Point)e.Location))
			{
				if (Toggle)
					pressed = !pressed;
				else if (Persistent)
					pressed = true;
				else
					pressed = false;
				mouseDown = false;

				this.Invalidate();
				if (Enabled)
					OnClick(EventArgs.Empty);
			}
			else
			{
				mouseDown = false;
				this.Invalidate();
			}
		}

		protected override void OnPaint(PaintEventArgs pe)
		{
			var rect = new Rectangle(this.Size);
			var col = Color.FromGrayscale(hover && Enabled ? 0.95f : 0.8f);
			if (Enabled && (pressed || mouseDown))
			{
				pe.Graphics.FillRectangle(col, rect);
				pe.Graphics.DrawInsetRectangle(Colors.Gray, Colors.White, rect);
			}
			else if (hover && Enabled)
			{
				pe.Graphics.FillRectangle(col, rect);
				pe.Graphics.DrawInsetRectangle(Colors.White, Colors.Gray, rect);
			}
			
			base.OnPaint(pe);
		}
	}
}

ImageButton.cs

using System;
using Eto.Drawing;

namespace Pablo.Controls
{
	public class ImageButton : CustomButton
	{
		bool sizeSet;
		public Image Image { get; set; }

		public Image DisabledImage { get; set; }
		
		public override Size Size {
			get {
				return base.Size;
			}
			set {
				base.Size = value;
				sizeSet = true;
			}
		}
		
		public ImageButton ()
		{
		}
		
		protected override void OnLoad (EventArgs e)
		{
			base.OnLoad (e);
			if (Image != null) {
				if (!sizeSet)
					this.Size = Image.Size + 4;
			}
		}
		
		protected override void OnLoadComplete (EventArgs e)
		{
			base.OnLoadComplete (e);
			
			if (DisabledImage == null) {
				var image = Image;
				if (image != null) {
					var disabledImage = new Bitmap (image.Size.Width, image.Size.Height, PixelFormat.Format32bppRgba);
					using (var graphics = new Graphics(disabledImage)) {
						graphics.DrawImage (image, 0, 0);
					}
					using (var bd = disabledImage.Lock())
					{
						unsafe
						{
							var data = (int*)bd.Data;
							for (int i = 0; i < bd.ScanWidth * disabledImage.Size.Height; i++)
							{
								var col = Color.FromArgb(bd.TranslateDataToArgb(*data));
								var gray = (col.R + col.G + col.B) / 3;
								*data = bd.TranslateArgbToData(Color.FromGrayscale(gray, 0.8f).ToArgb());
							}
						}
					}
				}
			}
		}
		
		protected override void OnPaint (Eto.Forms.PaintEventArgs pe)
		{
			base.OnPaint (pe);
			
			var image = this.Enabled ? Image : DisabledImage;
			var size = image.Size.FitTo (this.Size - 2);
			var xoffset = (this.Size.Width - size.Width) / 2;
			var yoffset = (this.Size.Height - size.Height) / 2;
			pe.Graphics.DrawImage (image, xoffset, yoffset, size.Width, size.Height);
		}
	}
}