using UnityEngine;

public class SafeArea : MonoBehaviour
{
    RectTransform rectTransform;
    Rect lastSafeArea = new Rect(0, 0, 0, 0);
    Vector2 lastScreenSize = new Vector2(0, 0);
    ScreenOrientation lastOrientation = ScreenOrientation.AutoRotation;

    void Awake()
    {
        rectTransform = GetComponent<RectTransform>();
        Refresh();
    }

    void Update()
    {
        if (lastSafeArea != Screen.safeArea ||
            lastScreenSize.x != Screen.width ||
            lastScreenSize.y != Screen.height ||
            lastOrientation != Screen.orientation)
        {
            Refresh();
        }
    }

    void Refresh()
    {
        Rect safeArea = Screen.safeArea;
        if (safeArea != lastSafeArea) ApplySafeArea(safeArea);
    }

    void ApplySafeArea(Rect r)
    {
        lastSafeArea = r;
        lastScreenSize.x = Screen.width;
        lastScreenSize.y = Screen.height;
        lastOrientation = Screen.orientation;

        Vector2 anchorMin = r.position;
        Vector2 anchorMax = r.position + r.size;

        anchorMin.x /= Screen.width;
        anchorMin.y /= Screen.height;
        anchorMax.x /= Screen.width;
        anchorMax.y /= Screen.height;

        rectTransform.anchorMin = anchorMin;
        rectTransform.anchorMax = anchorMax;
    }
}