Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
A lightweight Scriptable Object event system for Unity.
using System;
using System.Collections.Generic;
using UnityEngine;
public abstract class BaseGameEvent : ScriptableObject
{
#if UNITY_EDITOR
[TextArea] public string developerDescription = "";
#endif
private readonly List<Action> listeners = new ();
public void Raise()
{
for (var i = listeners.Count - 1; i >= 0; i--)
{
listeners[i].Invoke();
}
}
public void RegisterListener(Action listener)
{
if (!listeners.Contains(listener)) { listeners.Add(listener); }
}
public void UnregisterListener(Action listener)
{
if (listeners.Contains(listener)) { listeners.Remove(listener); }
}
}
public abstract class BaseGameEvent<T1> : BaseGameEvent
{
private readonly List<Action<T1>> listeners = new ();
public void Raise(T1 t1)
{
for (var i = listeners.Count - 1; i >= 0; i--)
{
listeners[i].Invoke(t1);
}
}
public void RegisterListener(Action<T1> listener)
{
if (!listeners.Contains(listener)) { listeners.Add(listener); }
}
public void UnregisterListener(Action<T1> listener)
{
if (listeners.Contains(listener)) { listeners.Remove(listener); }
}
}
public abstract class BaseGameEvent<T1,T2> : BaseGameEvent
{
private readonly List<Action<T1,T2>> listeners = new ();
public void Raise(T1 t1, T2 t2)
{
for (var i = listeners.Count - 1; i >= 0; i--)
{
listeners[i].Invoke(t1, t2);
}
}
public void RegisterListener(Action<T1,T2> listener)
{
if (!listeners.Contains(listener)) { listeners.Add(listener); }
}
public void UnregisterListener(Action<T1,T2> listener)
{
if (listeners.Contains(listener)) { listeners.Remove(listener); }
}
}
/* USE:
*************
[CreateAssetMenu()]
public class GameEvent : BaseGameEvent {}
public class IntGameEvent : BaseGameEvent<int> {}
public class IntStringGameEvent : BaseGameEvent<int,string> {}
**************
*/
///
/// examples of the three components required to utilize the system:
///
// the Scriptable Object Event definition
[CreateAssetMenu]
public class CoinGameEvent : BaseGameEvent<int>
{}
// the MonoBehaviour on each Coin to collect
public class Coin : MonoBehaviour
{
// the Scriptable Object Event we created via the Create Asset menu
[SerializeField] private CoinGameEvent coinEvent;
// raise our coin event whenever the user picks up a coin
void OnTriggerEnter2D(Collider2D other)
{
coinEvent.Raise(1);
Destroy(gameobject);
}
}
// this can also be a ScriptableObject since they still have OnEnable() and OnDisable() methods
public class CoinManager : MonoBehaviour
{
int coins;
// register to Listen for the Coin Event
void OnEnable() => coinEvent.RegisterListener(AddCoins);
void OnDisable() => coinEvent.UnregisterListener(AddCoins);
// add the number of coins in the Event to our total
void AddCoins(int value) => coins += value;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment