private void UnHookNotifyChildPropertyChangedHandler(NotifyChildPropertyChangedEventHandlerDescriptor handlerDescriptor)
{
object currentValue = handlerDescriptor.Reference.Target;
if (currentValue != null)
{
NotifyPropertyChangedAccessor.RemoveChildPropertyChangedHandler(currentValue, handlerDescriptor.Handler);
}
}
private void HookNotifyChildPropertyChangedHandler(object instance, string locationName)
{
object currentValue = instance as INotifyPropertyChanged;
if (currentValue != null &&
instrumentedTypes.GetOrAdd(currentValue.GetType(), type => type.IsDefined(typeof(NotifyPropertyChangedAttribute), true)))
{
string locationNameClosure = locationName;
NotifyChildPropertyChangedEventHandlerDescriptor handlerDescriptor = new NotifyChildPropertyChangedEventHandlerDescriptor(
currentValue, (_, a) => this.NotifyChildPropertyChangedEventHandler(locationNameClosure, a));
this.notifyChildPropertyChangedHandlers.AddOrUpdate(locationNameClosure, handlerDescriptor);
NotifyPropertyChangedAccessor.AddChildPropertyChangedHandler(currentValue, handlerDescriptor.Handler);
}
}
private static void RaisePropertyChangesInternal(
ChangedPropertiesAccumulator accumulator, bool raiseChildPropertyChanges, Func <WeakPropertyDescriptor, bool> propertySelectorPredicate)
{
areEventsFiring = true;
accumulator.Compact();
List <WeakPropertyDescriptor> objectsToRaisePropertyChanged;
int loopCount = 0;
Dictionary <WeakPropertyDescriptor, int> raiseCounts = accumulator.ToDictionary(w => w, w => 0);
do
{
objectsToRaisePropertyChanged = accumulator.Where(propertySelectorPredicate).ToList();
foreach (WeakPropertyDescriptor w in objectsToRaisePropertyChanged)
{
int raiseCount = raiseCounts.GetOrCreate(w, () => 0);
//INPC handler may raise INPC again and process some of our events;
//we're working on accumulator copy, so only way to know it is to have a flag on the descriptor
if (w.Processed || raiseChildPropertyChanges ? raiseCount > 0 : raiseCount > 1)
{
w.Processed = true;
continue;
}
w.Processed = true;
accumulator.Remove(w);
object cpc = w.Instance.Target;
if (cpc != null) //Target may not be alive any more
{
raiseCounts[w]++;
if (raiseChildPropertyChanges)
{
NotifyPropertyChangedAccessor.RaiseChildPropertyChanged(cpc, w.PropertyPath);
}
else
{
NotifyPropertyChangedAccessor.RaisePropertyChanged(cpc, w.PropertyPath);
}
}
}
//Notifications may cause generation of new notifications, continue until there is nothing left to raise
}while (objectsToRaisePropertyChanged.Count > 0 && ++loopCount <= 32);
areEventsFiring = false;
//TODO: Verify the loop above will always stop.
//If there's a risk it won't, call RaiseChildPropertyChanged from NPCAttribute.ChildPropertyChangedEventHandler to bubble up CNPC notifications
//(this may lead to a lot of unneccessary recursion, however, and a lot of continuations on w.Processed check above)
// if we encounter infinite loop generate meaningful exception for bug report.
if (loopCount == 32)
{
throw new NotifyPropertyChangedAlgorithmInfiniteLoop("Encountered infinite loop while raising PropertyChanged events");
}
}
public void HookPropertyChangedHandler()
{
NotifyPropertyChangedAccessor.AddPropertyChangedHandler(this.instance, this.OnPropertyChanged);
}