/// <inheritdoc />
        public override void Disable()
        {
            base.Disable();

            if (this.observer != null)
            {
                this.observer.ValueChanged -= this.OnObserverValueChanged;
                this.observer = null;
            }
        }
        /// <inheritdoc />
        public override void Enable()
        {
            base.Enable();

            var target = this.Target;

            if (target != null)
            {
                this.observer = new SliderValueObserver {
                    Target = target
                };
                this.observer.ValueChanged += this.OnObserverValueChanged;
            }
        }