using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Android.App;

using Android.Content;

using Android.OS;

using Android.Runtime;

using Android.Views;

using Android.Widget;

using System.Runtime.Serialization;

using System.ComponentModel;

using System.Reflection;

using System.Reactive.Linq;

using System.Reactive.Subjects;

using System.Reactive.Concurrency;

using System.Reactive.Threading.Tasks;

using System.Threading;

using System.Threading.Tasks;

using System.Reactive.Disposables;

using System.Diagnostics.Contracts;

using System.Runtime.CompilerServices;

using Splat;

using System.Reactive;

namespace ReactiveUI

{

/// <summary>

/// This is an Activity that is both an Activity and has ReactiveObject powers

/// (i.e. you can call RaiseAndSetIfChanged)

/// </summary>

public class ReactiveActivity<TViewModel> : ReactiveActivity, IViewFor<TViewModel>, ICanActivate

where TViewModel : class

{

protected ReactiveActivity() { }

TViewModel _ViewModel;

public TViewModel ViewModel {

get { return _ViewModel; }

set { this.RaiseAndSetIfChanged(ref _ViewModel, value); }

}

object IViewFor.ViewModel {

get { return _ViewModel; }

set { _ViewModel = (TViewModel)value; }

}

}

/// <summary>

/// This is an Activity that is both an Activity and has ReactiveObject powers

/// (i.e. you can call RaiseAndSetIfChanged)

/// </summary>

public class ReactiveActivity : Activity, IReactiveObject, IReactiveNotifyPropertyChanged<ReactiveActivity>, IHandleObservableErrors

{

public event PropertyChangingEventHandler PropertyChanging {

add { PropertyChangingEventManager.AddHandler(this, value); }

remove { PropertyChangingEventManager.RemoveHandler(this, value); }

}

void IReactiveObject.RaisePropertyChanging(PropertyChangingEventArgs args)

{

PropertyChangingEventManager.DeliverEvent(this, args);

}

public event PropertyChangedEventHandler PropertyChanged {

add { PropertyChangedEventManager.AddHandler(this, value); }

remove { PropertyChangedEventManager.RemoveHandler(this, value); }

}

void IReactiveObject.RaisePropertyChanged(PropertyChangedEventArgs args)

{

PropertyChangedEventManager.DeliverEvent(this, args);

}

/// <summary>

/// Represents an Observable that fires *before* a property is about to

/// be changed.

/// </summary>

public IObservable<IReactivePropertyChangedEventArgs<ReactiveActivity>> Changing {

get { return this.getChangingObservable(); }

}

/// <summary>

/// Represents an Observable that fires *after* a property has changed.

/// </summary>

public IObservable<IReactivePropertyChangedEventArgs<ReactiveActivity>> Changed {

get { return this.getChangedObservable(); }

}

/// <summary>

/// When this method is called, an object will not fire change

/// notifications (neither traditional nor Observable notifications)

/// until the return value is disposed.

/// </summary>

/// <returns>An object that, when disposed, reenables change

/// notifications.</returns>

public IDisposable SuppressChangeNotifications()

{

return this.suppressChangeNotifications();

}

public IObservable<Exception> ThrownExceptions { get { return this.getThrownExceptionsObservable(); } }

readonly Subject<Unit> activated = new Subject<Unit>();

public IObservable<Unit> Activated { get { return activated; } }

readonly Subject<Unit> deactivated = new Subject<Unit>();

public IObservable<Unit> Deactivated { get { return deactivated; } }

protected override void OnPause()

{

base.OnPause();

deactivated.OnNext(Unit.Default);

}

protected override void OnResume()

{

base.OnResume();

activated.OnNext(Unit.Default);

}

readonly Subject<Tuple<int, Result, Intent>> activityResult = new Subject<Tuple<int, Result, Intent>>();

public IObservable<Tuple<int, Result, Intent>> ActivityResult {

get { return activityResult; }

}

protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)

{

base.OnActivityResult(requestCode, resultCode, data);

activityResult.OnNext(Tuple.Create(requestCode, resultCode, data));

}

public Task<Tuple<Result, Intent>> StartActivityForResultAsync(Intent intent, int requestCode)

{

// NB: It's important that we set up the subscription *before* we

// call ActivityForResult

var ret = ActivityResult

.Where(x => x.Item1 == requestCode)

.Select(x => Tuple.Create(x.Item2, x.Item3))

.FirstAsync()

.ToTask();

StartActivityForResult(intent, requestCode);

return ret;

}

public Task<Tuple<Result, Intent>> StartActivityForResultAsync(Type type, int requestCode)

{

// NB: It's important that we set up the subscription *before* we

// call ActivityForResult

var ret = ActivityResult

.Where(x => x.Item1 == requestCode)

.Select(x => Tuple.Create(x.Item2, x.Item3))

.FirstAsync()

.ToTask();

StartActivityForResult(type, requestCode);

return ret;

}

}

}