using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace TIProDevExtension.ValueEditor
{
    /// <summary>
    /// Often one editor window will feed into the next.  This class represents the
    /// output of an editor window.  If you want to know what the user selected in
    /// a window, get the window's ValueBroadcaster object and subscribe to it.
    /// 
    /// Note that some windows will continue to transmit updates after the window
    /// has been closed.  Imaging that you're editing a column, so you bring up a
    /// viewer editor to describe the column.  Then in the viewer editor you bring
    /// up a color editor to set the foreground color.  Then you close the viewer
    /// editor window.  You still have the color editor and the column editor open.
    /// Changes in the color edtior will flow through the viewer editor to the
    /// column editor, even though the viewer editor was closed.
    /// 
    /// You listen to a ValueBroadcaster rather than a window because the
    /// ValueBroadcaster may outlive the window.
    /// </summary>
    public class ValueBroadcaster
    {
        public event Action<object> ValueChanged;
        private object _value;
        public object Value
        {
            get { return _value; }
            set
            {
                if (value != _value)
                {
                    _value = value;
                    ValueChanged?.Invoke(_value);
                }
            }
        }
    }
}