My Personal Commander Variant

using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace Lobster.MVVM
{
    /// <summary>
    /// Interaction logic for UserControl1.xaml
    /// </summary>
    public partial class MiniColorComponentCtrl : UserControl, INotifyPropertyChanged
    {
        public MiniColorComponentCtrl()
        {
            InitializeComponent();
        }


        public object InnerBackground
        {
            get { return (object)GetValue(InnerBackgroundProperty); }
            set { SetValue(InnerBackgroundProperty, value); }
        }

        // Using a DependencyProperty as the backing store for InnerBackground.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty InnerBackgroundProperty =
            DependencyProperty.Register("InnerBackground", typeof(object), typeof(MiniColorComponentCtrl), new UIPropertyMetadata());

        
        private double ConvertVPosToColorComponent(double pos)
        {
            if (Box.ActualHeight == 0) return 0;

            return ((1.0 - (double)pos / (double)Box.ActualHeight));
        }
        
        private double doubleValue;

        public double DoubleValue
        {
            get
            {
                return doubleValue;
            }
            private set
            {
                var d = value;
                d = Math.Max(Math.Min(d, 1), 0);
                if (doubleValue!= d)
                {
                    doubleValue = d; 
                    this.OnPropertyChanged("ByteValue");
                    this.OnPropertyChanged("DoubleValue");
                }
            }
        }

        public byte ByteValue
        {
            get
            {
                return (byte)(doubleValue * 255);
            }

            set
            {
                DoubleValue = (double) value / 255.0;
            }
        }
        

        #region ChangeNotifier
        public event PropertyChangedEventHandler PropertyChanged;

        public void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = this.PropertyChanged;
            if (handler != null)
            {
                var e = new PropertyChangedEventArgs(propertyName);
                handler(this, e);
            }
        }
        #endregion ChangeNotifier

        private void Box_MouseDown(object sender, MouseButtonEventArgs e)
        {
            DoubleValue = this.ConvertVPosToColorComponent(e.GetPosition( (IInputElement) sender).Y);   
        }

        private void Box_MouseMove(object sender, MouseEventArgs e)
        {
            var i = (UIElement)sender;
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                DoubleValue = this.ConvertVPosToColorComponent((int)e.GetPosition(i).Y);
                i.CaptureMouse();
            }
            else
            {
                i.ReleaseMouseCapture();
            }
        }
    }
}