*

Assets/Scripts/PlayerSensor.cs

@@ -0,0 +1,88 @@
+using UnityEngine;
+using System.Collections;
+
+public delegate void PlayerSensorDelegate(PlayerSensor senso, GameObject player);
+
+public class PlayerSensor : Predicate {
+	#region implemented abstract members of Predicate
+
+	protected override bool CheckInternal ()
+	{
+		return isPlayerInside;
+	}
+
+	protected override bool CheckInternal (object param)
+	{
+		return Check();
+	}
+
+	#endregion
+
+    public bool sensorEnabled = true;
+	private bool isPlayerInside;
+	public event PlayerSensorDelegate PlayerEnter;
+    private PlayerController _player;
+    public PlayerController Player {
+        get { return _player; }
+    }
+	protected virtual void OnPlayerEnter (GameObject player)
+	{
+		var handler = PlayerEnter;
+		if (handler != null)
+			handler (this, player);
+	}
+
+	public event PlayerSensorDelegate PlayerExit;
+
+	protected virtual void OnPlayerExit (GameObject player)
+	{
+		var handler = PlayerExit;
+		if (handler != null)
+			handler (this, player);
+	}
+
+  
+
+	void OnTriggerEnter2D(Collider2D other) {
+	    if (!sensorEnabled) {
+	        return;
+	    }
+
+		if(isPlayerInside){
+			return;
+		}
+
+	  
+
+        _player = other.gameObject.GetComponent<PlayerController>();
+
+
+
+        if (_player != null) {
+            
+			isPlayerInside = true;
+
+            OnPlayerEnter(_player.gameObject);
+		}
+	}
+	
+	void OnTriggerExit2D(Collider2D other) {
+        if (!sensorEnabled) {
+            return;
+        }
+		if(!isPlayerInside){
+			return;
+		}
+
+
+        var p = other.gameObject.GetComponent<PlayerController>();
+
+
+        if (_player == p) {
+           
+			isPlayerInside = false;
+            OnPlayerExit(_player.gameObject);
+            _player = null;
+		}
+	}
+}