//To create a listener that doesnt need data, and can return a value back to wherever the function was Raised
public void AddEventListener <T>(string eventName, EventCallBackWithReturn <T> listener)
{
if (IsEventRegistered(eventName) == false)
{
this.RegisterEvent(eventName);
}
this._events[eventName] = (EventCallBackWithReturn <T>) this._events[eventName] + listener;
}
//To remove an event listener that does not take in data, and returns a value
public void RemoveEventListener <T>(string eventName, EventCallBackWithReturn <T> listener)
{
if (IsEventRegistered(eventName) == false)
{
this.RegisterEvent(eventName);
}
this._events[eventName] = (EventCallBackWithReturn <T>) this._events[eventName] - listener;
if (this._events[eventName] == null)
{
this.RemoveEvent(eventName);
}
}
//To check if an event listener is already registered that does not take in data but does return a value
public bool IsEventListenerRegistered <T>(string eventName, EventCallBackWithReturn <T> listener)
{
bool result = false;
if (this.IsEventRegistered(eventName) == false)
{
return(result);
}
Delegate[] list = this._events[eventName].GetInvocationList();
foreach (Delegate d in list)
{
if ((EventCallBackWithReturn <T>)d == listener)
{
result = true;
break;
}
}
return(result);
}
