/// <summary>
/// Adds a weak subscription to the specified handler.
/// </summary>
/// <param name="source">
/// The object that is the source of the event.
/// </param>
/// <param name="eventName">
/// The name of the event.
/// </param>
/// <param name="handler">
/// The handler to subscribe.
/// </param>
static public void Subscribe <THandler>(object source, string eventName, THandler handler) where THandler : class
{
// Verify delegate type
VerifyDelegate <THandler>();
// Try to find existing
var reg = FindRegistration(source, eventName);
// If not found, create one and store it
if (reg == null)
{
reg = new WeakEvent(source, eventName);
registrations.Add(reg);
#if WEAK_LOGGING
Debug.WriteLine(string.Format("Creating new registration for event '{0}' and object ID {1}. Total registrations: {2}", eventName, source.GetHashCode(), registrations.Count));
#endif
}
#if WEAK_LOGGING
else
{
Debug.WriteLine(string.Format("Reusing existing registration for event '{0}' and object ID {1}. Total registrations: {2}", eventName, source.GetHashCode(), registrations.Count));
}
#endif
// Add the subscription
reg.Subscribe(handler as Delegate);
}
static private WeakEvent FindRegistration(object source, string eventName)
{
// Look for registration
WeakEvent reg = null;
for (int iReg = registrations.Count - 1; iReg >= 0; iReg--)
{
// Get the registration
reg = registrations[iReg];
// If the source is dead, remove the registration
if ((reg != null) && (!reg.source.IsAlive))
{
registrations.RemoveAt(iReg);
#if WEAK_LOGGING
Debug.WriteLine(string.Format("Removing registration for event '{0}' due to expired object instance. New total registrations: {1}", eventName, registrations.Count));
#endif
reg = null;
}
// If it's the right source, done searching
if ((reg.source.Target == source) && (reg.eventName == eventName))
{
break;
}
else
{
reg = null;
}
}
// Done searching
return(reg);
}