using System.Collections;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using TMPro; 

public class DropdownRebuildTrigger : MonoBehaviour, IPointerClickHandler
{
    private TMP_Dropdown _dropdown;

    void Awake()
    {
        _dropdown = GetComponent<TMP_Dropdown>();
    }

    // 当点击Dropdown时触发
    public void OnPointerClick(PointerEventData eventData)
    {
        // 只有当Dropdown是可以交互的，才处理
        if (_dropdown != null && _dropdown.interactable)
        {
            StartCoroutine(RebuildLayoutNextFrame());
        }
    }

    IEnumerator RebuildLayoutNextFrame()
    {
        // 等待当前帧结束（等待Dropdown内部逻辑完成列表的Instantiate）
        yield return new WaitForEndOfFrame();

        // 只有当列表确实处于展开状态时，才刷新
        if (_dropdown.IsExpanded)
        {
            LayoutRebuilder.ForceRebuildLayoutImmediate(_dropdown.transform.Find("Dropdown List/Viewport").gameObject.GetComponent<RectTransform>());
        }
    }
}