internal void _addListener(_FutureListener listener)
{
D.assert(listener._nextListener == null);
if (_mayAddListener)
{
listener._nextListener = (_FutureListener)_resultOrListeners;
_resultOrListeners = listener;
}
else
{
if (_isChained)
{
// Delegate listeners to chained source future.
// If the source is complete, instead copy its values and
// drop the chaining.
_Future source = _chainSource;
if (!source._isComplete)
{
source._addListener(listener);
return;
}
_cloneResult(source);
}
D.assert(_isComplete);
// Handle late listeners asynchronously.
_zone.scheduleMicrotask(() => {
_propagateToListeners(this, listener);
return(null);
});
}
}
