using System.Collections;
using System.Collections.Generic;
using System.Threading;
using UnityEngine;
using UnityEngine.UI;

public class ScrollTest2 : MonoBehaviour
{
    // Start is called before the first frame update
    private ScrollRect scroll;
    private Transform content;
    private float contentSize;
    [SerializeField] Button L, R;
    void Start()
    {
        scroll = gameObject.GetComponent<ScrollRect>();
        content = gameObject.transform.Find("Viewport").Find("Content");
        
        contentSize = 1f/(content.childCount-2);
        scroll.horizontalNormalizedPosition = contentSize / 2;
        if (L != null) 
        {
            L.onClick.AddListener(goLeft);
        }
        if (R != null)
        {
            R.onClick.AddListener(goRight);
        }
    }
    void goLeft()
    {
        if (scroll.horizontalNormalizedPosition <= contentSize) return;
        start = true;
        scrollValue = -1 * contentSize / 30;
    }
    void goRight()
    {
        if ((scroll.horizontalNormalizedPosition + contentSize)>=1) return;
        start = true;
        scrollValue = contentSize / 30;
    }
    private bool start = false, _lock = false;
    private float scrollValue = 0,totalScrollValue = 0;
    // Update is called once per frame
    void Update()
    {
        if (start)
        {
            if (_lock) return;
            _lock = true;
            totalScrollValue += scrollValue;
            if (System.Math.Abs(totalScrollValue) >= contentSize)
            {
                scrollValue = 0;
                start = false;
                totalScrollValue = 0;
            }
            else 
            {
                scroll.horizontalNormalizedPosition += scrollValue;
            }
            _lock = false;
        }
    }
}