private bool AddOrUpdateListener(BagNode propStoreNode, string pathComp, SourceKindEnum sourceKind, OSCollection <T> pathListeners, int nPtr)
{
bool result;
if (pathListeners.Count > nPtr)
{
ObservableSource <T> listener = pathListeners[nPtr];
if (propStoreNode.CompKey != listener.CompKey || sourceKind != listener.SourceKind)
{
listener.Dispose();
ObservableSource <T> newListener = CreateAndListen(propStoreNode, pathComp, sourceKind);
pathListeners[nPtr] = newListener;
result = true;
}
else
{
result = false;
}
}
else
{
ObservableSource <T> newListener = CreateAndListen(propStoreNode, pathComp, sourceKind);
pathListeners.Add(newListener);
result = true;
}
return(result);
}
private bool disposedValue = false; // To detect redundant calls
protected virtual void Dispose(bool disposing)
{
if (!disposedValue)
{
if (disposing)
{
// TODO: dispose managed state (managed objects).
if (_rootListener != null)
{
_rootListener.Dispose();
}
_pathListeners.Clear();
_ourNode = null;
_storeNodeUpdateReceiver_PropBag = null;
_storeNodeUpdateReceiver_PropNode = null;
_storeNodeUpdateReceiver_Value = null;
}
// TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
// TODO: set large fields to null.
disposedValue = true;
}
}
private bool HandleNodeUpdate(BagNode next,
string[] pathElements, OSCollection <T> pathListeners, int nPtr, out PropNode sourcePropNode)
{
bool complete = false;
sourcePropNode = null;
// Process each step, except for the last.
for (; next != null && nPtr < pathElements.Length - 1; nPtr++)
{
string pathComp = pathElements[nPtr];
if (pathComp == "..")
{
bool listenerWasAdded = AddOrUpdateListener(next, pathComp, SourceKindEnum.Up, pathListeners, nPtr);
string mg = listenerWasAdded ? "added" : "updated";
System.Diagnostics.Debug.WriteLine($"The Listener for step: {pathComp} was {mg}.");
next = next.Parent?.Parent;
}
else
{
if (TryGetPropBag(next, out IPropBag propBag))
{
bool listenerWasAdded = AddOrUpdateListener(propBag, next.CompKey, pathComp, SourceKindEnum.Down, pathListeners, nPtr);
string mg = listenerWasAdded ? "added" : "updated";
System.Diagnostics.Debug.WriteLine($"The Listener for step: {pathComp} was {mg}.");
if (TryGetChildProp(next, /*propBag, */ pathComp, out PropNode child))
{
next = child.Child;
}
else
{
System.Diagnostics.Debug.WriteLine("Could not get reference to the PropItem's PropStoreNode during binding update.");
next = null;
}
}
else
{
System.Diagnostics.Debug.WriteLine("The weak reference to the PropBag refers to a ProBag which 'is no longer with us.'");
next = null;
}
}
}
// Add the terminal node.
if (next != null)
{
System.Diagnostics.Debug.Assert(nPtr == pathElements.Length - 1, $"The counter variable: nPtr should be {pathElements.Length - 1}, but is {nPtr} instead.");
if (TryGetPropBag(next, out IPropBag propBag))
{
string pathComp = pathElements[nPtr];
bool listenerWasAdded = AddOrUpdateListener(propBag, next.CompKey, pathComp, SourceKindEnum.TerminalNode, pathListeners, nPtr);
string mg = listenerWasAdded ? "added" : "updated";
System.Diagnostics.Debug.WriteLine($"The Listener for terminal step: {pathComp} was {mg}.");
// We have created or updated the listener for this step, advance the pointer.
nPtr++;
// We have subscribed to the property that is the source of the binding.
complete = true;
// Let's try to get the value of the property for which we just started listening to changes.
if (TryGetChildProp(next, /*propBag,*/ pathComp, out sourcePropNode))
{
if (NotifyReceiverWithStartingValue(sourcePropNode))
{
System.Diagnostics.Debug.WriteLine($"The receiver has been notified during refresh. " +
$"Source: {((IPropBag)propBag).FullClassName}, {pathComp}");
}
else
{
System.Diagnostics.Debug.WriteLine("The binding source has been reached, but the receiver was not notified during refresh. " +
$"Source: {((IPropBag)propBag).FullClassName}, {pathComp}");
}
}
else
{
System.Diagnostics.Debug.WriteLine("Could not get reference to the PropItem's PropStoreNode during binding update.");
}
}
else
{
System.Diagnostics.Debug.WriteLine("The weak reference to the PropBag refers to a ProBag which 'is no longer with us.'");
}
}
for (; nPtr < pathListeners.Count; nPtr++)
{
ObservableSource <T> listener = pathListeners[nPtr];
listener.Dispose();
pathListeners.RemoveAt(nPtr);
}
return(complete);
}
