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


public class InputUI : MonoBehaviour
{
    public InputField inputField;

    private void Start()
    {
        EventTrigger trigger = inputField.gameObject.AddComponent<EventTrigger>();

        // 添加点击事件
        EventTrigger.Entry clickEntry = new EventTrigger.Entry();
        clickEntry.eventID = EventTriggerType.PointerClick;
        clickEntry.callback.AddListener((data) => { HidePlaceholder(); });
        trigger.triggers.Add(clickEntry);

        // 添加鼠标离开事件
        EventTrigger.Entry exitEntry = new EventTrigger.Entry();
        exitEntry.eventID = EventTriggerType.PointerExit;
        exitEntry.callback.AddListener((data) => { ShowPlaceholder(); });
        trigger.triggers.Add(exitEntry);
    }

    private void HidePlaceholder()
    {
        if (inputField.placeholder != null)
        {
            inputField.placeholder.gameObject.SetActive(false);
        }
    }

    private void ShowPlaceholder()
    {
        if (inputField.placeholder != null && string.IsNullOrEmpty(inputField.text))
        {
            inputField.placeholder.gameObject.SetActive(true);
        }
    }
}