MetalGear2D.Unity/Assets/Scripts/PlayerSensor.cs

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;
		}
	}
}