/// <summary>
/// Unregisters action from each added and removed item.
/// </summary>
/// <param name="handler">Action which will be invoked for each added and removed item.</param>
/// <param name="runForExistingItems">Indicated if <paramref name="handler"/> will be invoked for existing items.</param>
public void UnregisterHandler(ItemHandlerDelegate <T> handler, bool runForExistingItems = false)
{
if (handler == null)
{
throw new ArgumentNullException(nameof(handler));
}
if (!_handlers.Remove(handler) || !runForExistingItems)
{
return;
}
var array = this.ToArray();
for (var index = 0; index < array.Length; index++)
{
var item = array[index];
try
{
RunHandlerForItem(handler, false, item, index);
}
catch { /* NEPP-1432 - Sometimes on finalizing throws exception in handler. */ }
}
}
/// <summary>
/// Registers action for each added and removed item.
/// </summary>
/// <param name="handler">Action which will be invoked for each added and removed item.</param>
/// <param name="runForExistingItems">Indicated if <paramref name="handler"/> will be invoked for existing items.</param>
public void RegisterHandler(ItemHandlerDelegate <T> handler, bool runForExistingItems = false)
{
if (handler == null)
{
throw new ArgumentNullException(nameof(handler));
}
_handlers.Add(handler);
if (!runForExistingItems)
{
return;
}
var array = this.ToArray();
for (var index = 0; index < array.Length; index++)
{
var item = array[index];
RunHandlerForItem(handler, true, item, index);
}
}
protected virtual void RunHandlerForItem(ItemHandlerDelegate <T> handler, bool inserted, T item, int index)
{
handler?.Invoke(inserted, item, index);
}
/// <summary>
/// Unregisters action from each added and removed item.
/// </summary>
/// <param name="handler">Action which will be invoked for each added and removed item.</param>
/// <param name="runForExistingItems">Indicated if <paramref name="handler"/> will be invoked for existing items.</param>
public void UnregisterHandler(ItemHandlerDelegate <T> handler, bool runForExistingItems = false)
{
_observableCollectionWrap.UnregisterHandler(handler, runForExistingItems);
}
