using System;

using System.Collections.Generic;

using System.Linq.Expressions;

using System.Reactive.Linq;

using Splat;

namespace ReactiveUI

{

/// <summary>

/// This class is the final fallback for WhenAny, and will simply immediately

/// return the value of the type at the time it was created. It will also

/// warn the user that this is probably not what they want to do

/// </summary>

public class POCOObservableForProperty : ICreatesObservableForProperty

{

public int GetAffinityForObject(Type type, string propertyName, bool beforeChanged = false)

{

return 1;

}

static readonly Dictionary<Type, bool> hasWarned = new Dictionary<Type, bool>();

public IObservable<IObservedChange<object, object>> GetNotificationForProperty(object sender, Expression expression, bool beforeChanged = false)

{

var type = sender.GetType();

if (!hasWarned.ContainsKey(type)) {

this.Log().Warn(

"{0} is a POCO type and won't send change notifications, WhenAny will only return a single value!",

type.FullName);

hasWarned[type] = true;

}

return Observable.Return(new ObservedChange<object, object>(sender, expression), RxApp.MainThreadScheduler)

.Concat(Observable.Never<IObservedChange<object, object>>());

}

}

}