void CreateDot()
        {
            var dot = new ShapeView
            {
                ShapeType     = ShapeType.Circle,
                HeightRequest = DotSize,
                WidthRequest  = DotSize,
                BorderWidth   = 1,
                BorderColor   = DotBorderColor,
                FillColor     = DotColor,
            };

            Children.Add(dot);
        }
 void SelectDot(ShapeView dot)
 {
     dot.FillColor   = SelectedDotColor;
     dot.BorderColor = SelectedDotBorderColor;
 }
 void UnselectDot(ShapeView dot)
 {
     dot.FillColor   = DotColor;
     dot.BorderColor = DotBorderColor;
 }