using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Threading;

namespace Piston
{
    public class MTObservableCollection<T> : ObservableCollection<T>
    {
        public override event NotifyCollectionChangedEventHandler CollectionChanged;
        protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
        {
            NotifyCollectionChangedEventHandler collectionChanged = CollectionChanged;
            if (collectionChanged != null)
                foreach (NotifyCollectionChangedEventHandler nh in collectionChanged.GetInvocationList())
                {
                    var dispObj = nh.Target as DispatcherObject;

                    Dispatcher dispatcher = dispObj?.Dispatcher;
                    if (dispatcher != null && !dispatcher.CheckAccess())
                    {
                        dispatcher.BeginInvoke(
                            (Action)(() => nh.Invoke(this,
                                                     new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))),
                            DispatcherPriority.DataBind);
                        continue;
                    }

                    nh.Invoke(this, e);
                }
        }
    }
}