C# Custom ToolTip with Adjustable Font, Background Image, and Border

CustomToolTip.cs

public class CustomToolTip : ToolTip
    {
        private readonly float[] _GradientPositions;
        private readonly ColorBlend gradientBlender;
        private Color _gradientEndColor = Color.DeepSkyBlue;
        private Color _gradientMiddleColor = Color.LightSkyBlue;
        private Color _gradientStartColor = Color.LightSkyBlue;
        public CustomToolTip()
        {
            Font = new Font("Arial Narrow", 9.75F, FontStyle.Bold, GraphicsUnit.Point, 0);
            _GradientPositions = new float[3];
            _GradientPositions[0] = 0f;
            _GradientPositions[1] = .3f;
            _GradientPositions[2] = 1f;
            gradientBlender = new ColorBlend(3) {Positions = _GradientPositions};
            gradientBlender.Colors[0] = _gradientStartColor;
            gradientBlender.Colors[1] = _gradientMiddleColor;
            gradientBlender.Colors[2] = _gradientEndColor;
            OwnerDraw = true;
            Popup += OnPopup;
            Draw += OnDraw;
        }
        /// <summary>
        ///     The font used in the drawing of the text.
        /// </summary>
        [Description("The font used in the drawing of the text.")]
        public Font Font { get; set; }
        /// <summary>
        ///     The background image used in the control.
        /// </summary>
        [Description("The background image used in the control.")]
        public Image BackgroundImage { get; set; }
        /// <summary>
        ///     Sets the color of the border
        /// </summary>
        [Description("Sets the color of the border")]
        public Color BorderColor { get; set; } = Color.DodgerBlue;
        /// <summary>
        ///     Enables or disables the drawing of the border
        /// </summary>
        [Description("Enables or disables the drawing of the border")]
        public bool EnableBorder { get; set; } = true;
        /// <summary>
        ///     Enables or disables the drawing of the Gradient Background
        /// </summary>
        [Description("Enables or disables the drawing of the Gradient Background")]
        public bool EnableGradientBackground { get; set; } = false;
        public string Text { get; set; } = "";
        /// <summary>
        ///     Sets the direction of the gradient
        /// </summary>
        [Description("Sets the direction of the gradient")]
        public LinearGradientMode GradientMode { get; set; } = LinearGradientMode.Vertical;
        /// <summary>
        ///     Sets the color of the start of the gradient
        /// </summary>
        [Description("Sets the color of the start of the gradient")]
        public Color GradientStartColor
        {
            get => _gradientStartColor;
            set
            {
                _gradientStartColor = value;
                gradientBlender.Colors[0] = _gradientStartColor;
            }
        }
        /// <summary>
        ///     Sets the color of the middle of the gradient
        /// </summary>
        [Description("Sets the color of the middle of the gradient")]
        public Color GradientMiddleColor
        {
            get => _gradientMiddleColor;
            set
            {
                _gradientMiddleColor = value;
                gradientBlender.Colors[1] = _gradientMiddleColor;
            }
        }
        /// <summary>
        ///     Sets the color of the end of the gradient
        /// </summary>
        [Description("Sets the color of the end of the gradient")]
        public Color GradientEndColor
        {
            get => _gradientEndColor;
            set
            {
                _gradientEndColor = value;
                gradientBlender.Colors[2] = _gradientEndColor;
            }
        }
        /// <summary>
        ///     Set or Get the lower,center,upper bounds for the gradient brush
        /// </summary>
        [Category("Behavior")]
        [Description("Set or Get the lower,center,upper bounds for the gradient brush")]
        public float[] GradientPositions
        {
            get => _GradientPositions;
            set
            {
                _GradientPositions[0] = value[0];
                _GradientPositions[1] = value[1];
                _GradientPositions[2] = value[2];
                gradientBlender.Positions = _GradientPositions;
            }
        }
        private void OnPopup(object sender, PopupEventArgs e)
        {
            var tt = GetToolTip(e.AssociatedControl);
            var newstr = tt.Replace(@"\n", Environment.NewLine);
            e.ToolTipSize = newstr.MeasureText(Font, 1, 1);
        }
        private void OnDraw(object sender, DrawToolTipEventArgs e)
        {
            var fs = Font.GetFontSize();
            var g = e.Graphics;
            g.CompositingQuality = CompositingQuality.HighQuality;
            g.InterpolationMode = InterpolationMode.High;
            Text = e.ToolTipText;
            var newstr = e.ToolTipText.Replace(@"\n", Environment.NewLine);
            if (BackgroundImage == null)
                if (EnableGradientBackground)
                {
                    var b = new LinearGradientBrush(e.Bounds, Color.Black, Color.Black, GradientMode)
                        {InterpolationColors = gradientBlender};
                    g.FillRectangle(b, e.Bounds);
                }
                else
                {
                    g.FillRectangle(new SolidBrush(BackColor), new Rectangle(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height));
                }
            else
                g.DrawImage(new Bitmap(BackgroundImage, e.Bounds.Width, e.Bounds.Height), new Rectangle(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height));

            g.DrawString(newstr, Font, new SolidBrush(ForeColor), new PointF(e.Bounds.X + fs.Width / 2, e.Bounds.Y + fs.Height / 2));
            if (EnableBorder)
                g.DrawRectangle(new Pen(new SolidBrush(BorderColor), 1), new Rectangle(e.Bounds.X, e.Bounds.Y, e.Bounds.Width - 1, e.Bounds.Height - 1));
        }
    }