public override void Layout()
        {
            base.Layout();

            var width = this.Bounds.Size.Width;

            var padding = new CGSize(10, 10);
            var p       = new CGPoint(width - padding.Width, 0);

            cancelButton.SizeToFit();
            p = p.Move(-cancelButton.Frame.Size.Width, padding.Height);
            cancelButton.SetFrameOrigin(p);

            chooseButton.SizeToFit();
            p = p.Move(-chooseButton.Frame.Size.Width, 0);
            chooseButton.SetFrameOrigin(p);

            p.X = padding.Width;
            systemFontButton.SizeToFit();
            systemFontButton.SetFrameOrigin(p);

            line.Frame = new CGRect(0, Bounds.Size.Height - 1, width, 1);
        }