using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

[RequireComponent(typeof(Button))]
[AddComponentMenu("UGUI/UI/UIButtonScale")]
public class UIButtonScale : MonoBehaviour,IPointerDownHandler,IPointerUpHandler
{
	public float Speed = 0.02f;	
	public Vector3 To = new Vector3 (0.8f, 0.8f, 0.8f);
    
    Vector3 _from = Vector3.one;
    bool _bScale = false; // scale down, false; scale up, ture
    bool _bRunning = false;
    Button _Button;

    void Awake()
    {
        _Button = gameObject.GetComponent<Button>();
        _from = transform.localScale;
    }

    /*void Start()
    {
        //_from = transform.localScale;
    }*/

    void OnDisable()
    {
        SetNormal();
    }

    void OnApplicationFocus(bool focus)
    {
        if(!focus)
        {
            SetNormal();
        }
    }

	public void OnPointerDown (PointerEventData event_data)
	{
        if (null != _Button && !_Button.interactable)
        {
            return;
        }

		_bScale = false;
		_bRunning = true;
	}

	public void OnPointerUp (PointerEventData event_data)
	{
        /*if(!_Button.interactable && !_bRunning)
        {
            return;
        }*/

        _bScale = true;
		_bRunning = true;
	}

    public void SetNormal()
    {
        _bScale = true;
        _bRunning = false;
        transform.localScale = _from;
    }

	void Update()
	{
        if(!_bRunning)
        {
            return;
        }

		if (!_bScale)
        {
			transform.localScale -= _from * Speed;

			if (transform.localScale.x <= To.x) 
            {
				transform.localScale = To;
				_bRunning = false;
			}
		} 
        else 
        {
			transform.localScale += _from * Speed;

			if (transform.localScale.x >= _from.x)
            {
				transform.localScale = _from;
				_bRunning = false;
			}
		}
	}
}