private void RemoveTreeSubscription(PropertyNotifier <T> tree)
{
foreach (var item in ReferenceCountTracker.Items)
{
tree.UnsubscribeFromChanges(item);
}
}
private void SetupTreeSubscription(PropertyNotifier <T> tree)
{
foreach (var item in ReferenceCountTracker.Items)
{
tree.SubscribeToChanges(item);
}
}
private static void OnItemChanged(PropertyNotifier <T> tree, object itemThatChanged, PropertyChangedEventArgs args)
{
var itemChanged = tree.ItemChanged;
if (itemChanged != null)
{
itemChanged(tree, (T)itemThatChanged, args);
}
}
private static void OnItemChanging(PropertyNotifier <T> tree, object itemThatIsChanging, PropertyChangingEventArgs args)
{
var itemChanging = tree.ItemChanging;
if (itemChanging != null)
{
itemChanging(tree, (T)itemThatIsChanging, args);
}
}
/// <summary>
/// Adds a property to monitor for change events.
/// </summary>
/// <typeparam name="TResult"></typeparam>
/// <param name="expression">The expression that points to the property</param>
/// <returns>Property Notifier used to register change events on</returns>
public PropertyNotifier <T> AddProperty <TResult>(Expression <Func <T, TResult> > expression)
{
var tree = PropertyNotifier <T> .Create(expression);
_Properties.Add(tree);
SetupTreeSubscription(tree);
return(tree);
}
/// <summary>
/// Stops listening for change events on the specified property
/// </summary>
/// <param name="tree"></param>
/// <returns></returns>
public bool RemoveProperty(PropertyNotifier <T> tree)
{
var removed = _Properties.Remove(tree);
if (removed)
{
RemoveTreeSubscription(tree);
}
return(removed);
}