/// <summary>
/// Returns <see langword = "true" /> if there is a subscriber matching
/// <see cref = "T:Senticode.Xamarin.Tools.Core.Events.SubscriptionToken" />.
/// </summary>
/// <param name = "token">
/// The <see cref = "T:Senticode.Xamarin.Tools.Core.Events.SubscriptionToken" /> returned by
/// <see cref = "T:Senticode.Xamarin.Tools.Core.Events.EventBase" /> while subscribing to the event.
/// </param>
/// <returns>
/// <see langword = "true" /> if there is a <see cref = "T:Senticode.Xamarin.Tools.Core.Events.SubscriptionToken" /> that
/// matches; otherwise <see langword = "false" />.
/// </returns>
public virtual bool Contains(SubscriptionToken token)
{
var subscriptions = Subscriptions;
var lockTaken = false;
try
{
Monitor.Enter(subscriptions, ref lockTaken);
return(Subscriptions.FirstOrDefault(evt => evt.SubscriptionToken == token) != null);
}
finally
{
if (lockTaken)
{
Monitor.Exit(subscriptions);
}
}
}
/// <summary>
/// Removes the subscriber matching the <see cref = "T:Senticode.Xamarin.Tools.Core.Events.SubscriptionToken" />.
/// </summary>
/// <param name = "token">
/// The <see cref = "T:Senticode.Xamarin.Tools.Core.Events.SubscriptionToken" /> returned by
/// <see cref = "T:Senticode.Xamarin.Tools.Core.Events.EventBase" /> while subscribing to the event.
/// </param>
public virtual void Unsubscribe(SubscriptionToken token)
{
var subscriptions = Subscriptions;
var lockTaken = false;
try
{
Monitor.Enter(subscriptions, ref lockTaken);
var eventSubscription = Subscriptions.FirstOrDefault(evt => evt.SubscriptionToken == token);
if (eventSubscription == null)
{
return;
}
Subscriptions.Remove(eventSubscription);
}
finally
{
if (lockTaken)
{
Monitor.Exit(subscriptions);
}
}
}