public void ThreeLevels()
{
var fake = new Fake();
var observable = new PropertyPathObservable <Fake, bool>(fake, x => x.Next.Next.IsTrue);
observable.Subscribe(_changes.Add);
fake.Next = new Level();
Assert.AreEqual(0, _changes.Count);
fake.Next.Next = new Level
{
Next = new Level()
};
Assert.AreEqual(1, _changes.Count);
fake.Next.Next = null;
Assert.AreEqual(2, _changes.Count);
fake.Next = null;
Assert.AreEqual(2, _changes.Count);
fake.Next = new Level
{
Next = new Level
{
IsTrue = true
}
};
Assert.AreEqual(3, _changes.Count);
fake.Next.Next.IsTrue = false;
Assert.AreEqual(4, _changes.Count);
fake.Next.Next = null;
Assert.AreEqual(5, _changes.Count);
fake.Next = null;
Assert.AreEqual(5, _changes.Count);
}
public void SubscribeToExistsingChangeLastValueInPath()
{
var fake = new Fake {
Next = new Level()
};
var observable = new PropertyPathObservable <Fake, bool>(fake, x => x.Next.IsTrue);
observable.Subscribe(_changes.Add);
fake.Next.IsTrue = !fake.Next.IsTrue;
Assert.AreEqual(1, _changes.Count);
}
public void TwoLevelsValueType()
{
var fake = new Fake();
var observable = new PropertyPathObservable <Fake, bool>(fake, x => x.Next.IsTrue);
observable.Subscribe(_changes.Add);
fake.Next = new Level();
Assert.AreEqual(1, _changes.Count);
fake.Next.IsTrue = !fake.Next.IsTrue;
Assert.AreEqual(2, _changes.Count);
fake.Next = null;
Assert.AreEqual(3, _changes.Count);
}
public void TwoLevelsReferenceType()
{
var fake = new Fake();
var observable = new PropertyPathObservable <Fake, Level>(fake, x => x.Next.Next);
observable.Subscribe(_changes.Add);
fake.Next = new Level();
Assert.AreEqual(0, _changes.Count);
fake.Next.Next = new Level();
Assert.AreEqual(1, _changes.Count);
fake.Next.Next = null;
Assert.AreEqual(2, _changes.Count);
fake.Next = null;
Assert.AreEqual(2, _changes.Count);
}
public void TwoLevelsExisting()
{
var fake = new Fake {
Next = new Level {
Next = new Level()
}
};
var observable = new PropertyPathObservable <Fake, Level>(fake, x => x.Next.Next);
observable.Subscribe(_changes.Add);
fake.Next.Next = new Level();
Assert.AreEqual(1, _changes.Count);
fake.Next.Next = null;
Assert.AreEqual(2, _changes.Count);
fake.Next = null;
Assert.AreEqual(2, _changes.Count);
}
public void Unsubscribes()
{
var fake = new Fake();
var observable = new PropertyPathObservable <Fake, bool>(fake, x => x.Next.IsTrue);
observable.Subscribe(_changes.Add);
fake.Next = new Level
{
Next = new Level()
};
Assert.AreEqual(1, _changes.Count);
var temp = fake.Next;
fake.Next = null;
Assert.AreEqual(2, _changes.Count);
temp.IsTrue = !temp.IsTrue;
Assert.AreEqual(2, _changes.Count);
}
internal static IObservable <EventPattern <PropertyChangedEventArgs> > ObservePropertyChanged <TNotifier, TProperty>(
this TNotifier source,
PropertyPath <TNotifier, TProperty> property,
bool signalInitial = true)
where TNotifier : INotifyPropertyChanged
{
var observable = new PropertyPathObservable <TNotifier, TProperty>(source, property);
if (signalInitial)
{
return(Observable.Defer(
() =>
{
var current = new EventPattern <PropertyChangedEventArgs>(
observable.Sender,
observable.PropertyChangedEventArgs);
return Observable.Return(current).Concat(observable);
}));
}
return(observable);
}
