Unity Event Class
2019-03-11 / 10 min read
EventTriggerListener
using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
public class EventTriggerListener : MonoBehaviour, IPointerClickHandler, IPointerDownHandler, IPointerEnterHandler,
IPointerExitHandler, IPointerUpHandler, IDragHandler
{
public delegate void VoidDelegate1(GameObject go, PointerEventData eventData);
public event VoidDelegate1 OnClick;
public event VoidDelegate1 OnDown;
public event VoidDelegate1 OnEnter;
public event VoidDelegate1 OnExit;
public event VoidDelegate1 OnUp;
public event VoidDelegate1 OnDragging;
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static public EventTriggerListener Get(GameObject go)
{
EventTriggerListener listener = go.GetComponent<EventTriggerListener>();
if (listener == null) listener = go.AddComponent<EventTriggerListener>();
return listener;
}
public void OnPointerClick(PointerEventData eventData)
{
if (OnClick != null) OnClick(gameObject, eventData);
}
public void OnPointerDown(PointerEventData eventData)
{
if (OnDown != null) OnDown(gameObject, eventData);
}
public void OnPointerEnter(PointerEventData eventData)
{
if (OnEnter != null) OnEnter(gameObject, eventData);
}
public void OnPointerExit(PointerEventData eventData)
{
if (OnExit != null) OnExit(gameObject, eventData);
}
public void OnPointerUp(PointerEventData eventData)
{
if (OnUp != null) OnUp(gameObject, eventData);
}
public void OnDrag(PointerEventData eventData)
{
if (OnDragging != null) OnDragging(gameObject, eventData);
}
}
Messager
/*
* Advanced C# messenger by Ilya Suzdalnitski. V1.0
*
* Based on Rod Hyde's "CSharpMessenger" and Magnus Wolffelt's "CSharpMessenger Extended".
*
* Features:
* Prevents a MissingReferenceException because of a reference to a destroyed message handler.
* Option to log all messages
* Extensive error detection, preventing silent bugs
*
* Usage examples:
1. Messenger.AddListener<GameObject>("prop collected", PropCollected);
Messenger.Broadcast<GameObject>("prop collected", prop);
2. Messenger.AddListener<float>("speed changed", SpeedChanged);
Messenger.Broadcast<float>("speed changed", 0.5f);
*
* Messenger cleans up its evenTable automatically upon loading of a new level.
*
* Don't forget that the messages that should survive the cleanup, should be marked with Messenger.MarkAsPermanent(string)
*
*/
//#define LOG_ALL_MESSAGES
//#define LOG_ADD_LISTENER
//#define LOG_BROADCAST_MESSAGE
//#define REQUIRE_LISTENER
static public class Messenger
{
#region Internal variables
//Disable the unused variable warning
#pragma warning disable 0414
//Ensures that the MessengerHelper will be created automatically upon start of the game.
static private MessengerHelper messengerHelper =
(new GameObject("MessengerHelper")).AddComponent<MessengerHelper>();
#pragma warning restore 0414
static public Dictionary<string, Delegate> eventTable = new Dictionary<string, Delegate>();
//Message handlers that should never be removed, regardless of calling Cleanup
static public List<string> permanentMessages = new List<string>();
#endregion
#region Helper methods
//Marks a certain message as permanent.
static public void MarkAsPermanent(string eventType)
{
#if LOG_ALL_MESSAGES
Debug.Log("Messenger MarkAsPermanent \t\"" + eventType + "\"");
#endif
permanentMessages.Add(eventType);
}
static public void Cleanup()
{
#if LOG_ALL_MESSAGES
Debug.Log("MESSENGER Cleanup. Make sure that none of necessary listeners are removed.");
#endif
List<string> messagesToRemove = new List<string>();
foreach (KeyValuePair<string, Delegate> pair in eventTable)
{
bool wasFound = false;
foreach (string message in permanentMessages)
{
if (pair.Key == message)
{
wasFound = true;
break;
}
}
if (!wasFound)
messagesToRemove.Add(pair.Key);
}
foreach (string message in messagesToRemove)
{
eventTable.Remove(message);
}
}
static public void PrintEventTable()
{
Debug.Log("\t\t\t=== MESSENGER PrintEventTable ===");
foreach (KeyValuePair<string, Delegate> pair in eventTable)
{
Debug.Log("\t\t\t" + pair.Key + "\t\t" + pair.Value);
}
Debug.Log("\n");
}
#endregion
#region Message logging and exception throwing
static public void OnListenerAdding(string eventType, Delegate listenerBeingAdded)
{
#if LOG_ALL_MESSAGES || LOG_ADD_LISTENER
Debug.Log("MESSENGER OnListenerAdding \t\"" + eventType + "\"\t{" + listenerBeingAdded.Target + " -> " + listenerBeingAdded.Method + "}");
#endif
if (!eventTable.ContainsKey(eventType))
{
eventTable.Add(eventType, null);
}
Delegate d = eventTable[eventType];
if (d != null && d.GetType() != listenerBeingAdded.GetType())
{
throw new ListenerException(string.Format(
"Attempting to add listener with inconsistent signature for event type {0}. Current listeners have type {1} and listener being added has type {2}",
eventType, d.GetType().Name, listenerBeingAdded.GetType().Name));
}
}
static public void OnListenerRemoving(string eventType, Delegate listenerBeingRemoved)
{
#if LOG_ALL_MESSAGES
Debug.Log("MESSENGER OnListenerRemoving \t\"" + eventType + "\"\t{" + listenerBeingRemoved.Target + " -> " + listenerBeingRemoved.Method + "}");
#endif
if (eventTable.ContainsKey(eventType))
{
Delegate d = eventTable[eventType];
if (d == null)
{
throw new ListenerException(string.Format(
"Attempting to remove listener with for event type \"{0}\" but current listener is null.",
eventType));
}
else if (d.GetType() != listenerBeingRemoved.GetType())
{
throw new ListenerException(string.Format(
"Attempting to remove listener with inconsistent signature for event type {0}. Current listeners have type {1} and listener being removed has type {2}",
eventType, d.GetType().Name, listenerBeingRemoved.GetType().Name));
}
}
// else {
// throw new ListenerException(string.Format("Attempting to remove listener for type \"{0}\" but Messenger doesn't know about this event type.", eventType));
// }
}
static public void OnListenerRemoved(string eventType)
{
if (eventTable[eventType] == null)
{
eventTable.Remove(eventType);
}
}
static public void OnBroadcasting(string eventType)
{
#if REQUIRE_LISTENER
if (!eventTable.ContainsKey(eventType)) {
throw new BroadcastException(string.Format("Broadcasting message \"{0}\" but no listener found. Try marking the message with Messenger.MarkAsPermanent.", eventType));
}
#endif
}
static public bool HasEventListener(string eventType)
{
return eventTable.ContainsKey(eventType);
}
static public BroadcastException CreateBroadcastSignatureException(string eventType)
{
return new BroadcastException(string.Format(
"Broadcasting message \"{0}\" but listeners have a different signature than the broadcaster.",
eventType));
}
public class BroadcastException : Exception
{
public BroadcastException(string msg)
: base(msg)
{
}
}
public class ListenerException : Exception
{
public ListenerException(string msg)
: base(msg)
{
}
}
#endregion
#region AddListener
//No parameters
static public void AddListener(string eventType, Action handler)
{
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Action) eventTable[eventType] + handler;
}
//Single parameter
static public void AddListener<T>(string eventType, Action<T> handler)
{
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Action<T>) eventTable[eventType] + handler;
}
//Two parameters
static public void AddListener<T, U>(string eventType, Action<T, U> handler)
{
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Action<T, U>) eventTable[eventType] + handler;
}
//Three parameters
static public void AddListener<T, U, V>(string eventType, Action<T, U, V> handler)
{
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Action<T, U, V>) eventTable[eventType] + handler;
}
#endregion
#region RemoveListener
//No parameters
static public void RemoveListener(string eventType, Action handler)
{
OnListenerRemoving(eventType, handler);
if (eventTable.ContainsKey(eventType))
{
eventTable[eventType] = (Action) eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
}
//Single parameter
static public void RemoveListener<T>(string eventType, Action<T> handler)
{
OnListenerRemoving(eventType, handler);
if (eventTable.ContainsKey(eventType))
{
eventTable[eventType] = (Action<T>) eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
}
//Two parameters
static public void RemoveListener<T, U>(string eventType, Action<T, U> handler)
{
OnListenerRemoving(eventType, handler);
if (eventTable.ContainsKey(eventType))
{
eventTable[eventType] = (Action<T, U>) eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
}
//Three parameters
static public void RemoveListener<T, U, V>(string eventType, Action<T, U, V> handler)
{
OnListenerRemoving(eventType, handler);
if (eventTable.ContainsKey(eventType))
{
eventTable[eventType] = (Action<T, U, V>) eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
}
#endregion
#region Broadcast
//No parameters
static public void DispatchEvent(string eventType)
{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d))
{
Action Action = d as Action;
if (Action != null)
{
Action();
}
else
{
throw CreateBroadcastSignatureException(eventType);
}
}
}
//Single parameter
static public void DispatchEvent<T>(string eventType, T arg1)
{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d))
{
Action<T> Action = d as Action<T>;
if (Action != null)
{
Action(arg1);
}
else
{
throw CreateBroadcastSignatureException(eventType);
}
}
}
//Two parameters
static public void DispatchEvent<T, U>(string eventType, T arg1, U arg2)
{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d))
{
Action<T, U> Action = d as Action<T, U>;
if (Action != null)
{
Action(arg1, arg2);
}
else
{
throw CreateBroadcastSignatureException(eventType);
}
}
}
//Three parameters
static public void DispatchEvent<T, U, V>(string eventType, T arg1, U arg2, V arg3)
{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d))
{
Action<T, U, V> Action = d as Action<T, U, V>;
if (Action != null)
{
Action(arg1, arg2, arg3);
}
else
{
throw CreateBroadcastSignatureException(eventType);
}
}
}
#endregion
}
//This manager will ensure that the messenger's eventTable will be cleaned up upon loading of a new level.
public sealed class MessengerHelper : MonoBehaviour
{
void Awake()
{
DontDestroyOnLoad(gameObject);
}
//Clean up eventTable every time a new level loads.
public void OnDisable()
{
Messenger.Cleanup();
}
}