private static void SubscribeProgressToChain(Promise promise, Internal.IProgressListener progressListener, ref ValueLinkedStack <Internal.PromisePassThrough> passThroughs)
{
Promise next;
// If the promise is not waiting on another promise (is the root), it sets next to null, does not add the listener, and returns false.
// If the promise is waiting on another promise that is not its previous, it adds the listener, transforms progresslistener, sets next to the one it's waiting on, and returns true.
// Otherwise, it sets next to its previous, adds the listener only if it is a WaitPromise, and returns true.
while (promise.SubscribeProgressIfWaiterAndContinueLoop(ref progressListener, out next, ref passThroughs))
{
promise = next;
}
// promise is the root of the promise tree.
switch (promise._state)
{
case State.Pending:
{
progressListener.SetInitialAmount(promise._waitDepthAndProgress);
break;
}
case State.Resolved:
{
progressListener.SetInitialAmount(promise._waitDepthAndProgress.GetIncrementedWholeTruncated());
break;
}
default: // Rejected or Canceled:
{
progressListener.Retain();
progressListener.CancelOrIncrementProgress(promise, promise._waitDepthAndProgress.GetIncrementedWholeTruncated().ToUInt32());
break;
}
}
}
protected virtual bool SubscribeProgressAndContinueLoop(ref Internal.IProgressListener progressListener, out Promise previous)
{
progressListener.Retain();
_progressListeners.Push(progressListener);
return((previous = _valueOrPrevious as Promise) != null);
}