Simple EventManager

Alex June 21, 2022 0 Comments

using UnityEngine;
using UnityEngine.Events;
using System.Collections;
using System.Collections.Generic;

public class EventManager : MonoBehaviour {

private Dictionary <string, UnityEvent> eventDictionary;

private static EventManager eventManager;

public static EventManager instance
{
    get
    {
        if (!eventManager)
        {
            eventManager = FindObjectOfType (typeof (EventManager)) as EventManager;

            if (!eventManager)
            {
                Debug.LogError ("There needs to be one active EventManger script on a GameObject in your scene.");
            }
            else
            {
                eventManager.Init (); 
            }
        }

        return eventManager;
    }
}

void Init ()
{
    if (eventDictionary == null)
    {
        eventDictionary = new Dictionary<string, UnityEvent>();
    }
}

public static void StartListening (string eventName, UnityAction listener)
{
    UnityEvent thisEvent = null;
    if (instance.eventDictionary.TryGetValue (eventName, out thisEvent))
    {
        thisEvent.AddListener (listener);
    } 
    else
    {
        thisEvent = new UnityEvent ();
        thisEvent.AddListener (listener);
        instance.eventDictionary.Add (eventName, thisEvent);
    }
}

public static void StopListening (string eventName, UnityAction listener)
{
    if (eventManager == null) return;
    UnityEvent thisEvent = null;
    if (instance.eventDictionary.TryGetValue (eventName, out thisEvent))
    {
        thisEvent.RemoveListener (listener);
    }
}

public static void TriggerEvent (string eventName)
{
    UnityEvent thisEvent = null;
    if (instance.eventDictionary.TryGetValue (eventName, out thisEvent))
    {
        thisEvent.Invoke ();
    }
}

}