/// <summary>
/// Objects call this to unsubscribe to events of a given type.
/// </summary>
/// <param name="handler">The function that was called when the event occurred.</param>
/// <typeparam name="T">The type of the event.</typeparam>
public void Unregister <T>(CustomEvent.Handler handler) where T : CustomEvent
{
Type type = typeof(T);
CustomEvent.Handler handlers;
if (registeredHandlers.TryGetValue(type, out handlers))
{
handlers -= handler;
if (handlers == null)
{
registeredHandlers.Remove(type);
}
else
{
registeredHandlers[type] = handlers;
}
}
}
/// <summary>
/// Objects call this function to subscribe to events of a given type.
/// </summary>
/// <param name="handler">The function to be called when the event occurs.</param>
/// <typeparam name="T">The type of the event.</typeparam>
public void Register <T>(CustomEvent.Handler handler) where T : CustomEvent
{
Type type = typeof(T);
/*
*
* If there's already an event of that type, add this handler to the list of handlers for that event.
*
* If not, add that event to the dictionary, with this handler as the first item in the list.
*
* Note that there's no explicit list, because in C# delegates are both references to a function and a list
* of functions.
*
*/
if (registeredHandlers.ContainsKey(type))
{
registeredHandlers[type] += handler;
}
else
{
registeredHandlers[type] = handler;
}
}