using UnityEngine;
using UnityEngine.UI;
using System.Collections;
/// <summary>
/// UI提示
/// </summary>
public class ImageTips : MonoBehaviour
{
    private Image image; // UI Image组件
    public float fadeDuration = 1.0f; // 每次淡入淡出的持续时间
    private RectTransform selfRect;
    public Vector2 sizeOffset = new Vector2(100, 100);

    public void ShowTips(RectTransform target)
    {
        gameObject.SetActive(true);
        selfRect = GetComponent<RectTransform>();
        image = GetComponent<Image>();
        selfRect.SetParent(target);
        selfRect.anchorMin = Vector2.zero;
        selfRect.anchorMax = new Vector2(1, 1);
        selfRect.offsetMax = Vector2.zero;
        selfRect.offsetMin = Vector2.zero;
        //selfRect.sizeDelta = target.sizeDelta + sizeOffset;
        if (gameObject.activeSelf)
            StartCoroutine(FlashRoutine());
    }

    public void HideTips()
    {
        transform.parent = null;
        StopCoroutine(FlashRoutine());
        gameObject.SetActive(false);
    }
    private IEnumerator FlashRoutine()
    {
        while (true)
        {
            yield return StartCoroutine(Fade(1.0f, fadeDuration));
            yield return StartCoroutine(Fade(0.0f, fadeDuration));
        }
    }

    private IEnumerator Fade(float targetAlpha, float duration)
    {
        float startAlpha = image.color.a;
        float elapsed = 0.0f;

        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            float newAlpha = Mathf.Lerp(startAlpha, targetAlpha, elapsed / duration);
            Color color = image.color;
            color.a = newAlpha;
            image.color = color;
            yield return null;
        }

        // 确保最终值准确
        Color finalColor = image.color;
        finalColor.a = targetAlpha;
        image.color = finalColor;
    }
}