Custom drawable template for Eto

MyDrawable.cs

using Eto.Forms;
using Eto.Drawing;

namespace CustomDrawable
{

	public class MyDrawable : Drawable
	{
		bool mouseDragging;
		
		public MyDrawable()
		{
			Size = new Size(100, 20); // set preferred size of ruler
		}

		protected override void OnPaint(PaintEventArgs e)
		{
			base.OnPaint(e);
			// do your painting of the ruler using e.Graphics
		}

		protected override void OnMouseDown(MouseEventArgs e)
		{
			base.OnMouseDown(e);
			if (e.Buttons == MouseButtons.Primary)
			{
				// check the position of the mouse (e.Location) to detect if it is over a margin indicator
				mouseDragging = true;
			}
		}

		protected override void OnMouseMove(MouseEventArgs e)
		{
			base.OnMouseMove(e);
			if (mouseDragging)
			{
				// move the margin
			}
		}

		protected override void OnMouseUp(MouseEventArgs e)
		{
			base.OnMouseUp(e);
			if (e.Buttons == MouseButtons.Primary && mouseDragging)
			{
				// finished dragging operation
				mouseDragging = false;
			}
		}
	}
}