gistfile1.txt

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

public class Swapper : MonoBehaviour
{
    public void Swap()
    {
        var rt = GetComponent<RectTransform>();

        var m = rt.anchorMin;
        m.x = 1 - m.x;
        rt.anchorMin = m;

        var n = rt.anchorMax;
        n.x = 1 - n.x;
        rt.anchorMax = n;

        var p = rt.anchoredPosition;
        p.x = -p.x;
        rt.anchoredPosition = p;

        var k = rt.pivot;
        k.x = 1 - k.x;
        rt.pivot = k;

        var lg = GetComponent<HorizontalLayoutGroup>();
        if (lg != null)
        {
            Transform[] tt = new Transform[transform.childCount];
            for (int i = 0; i < transform.childCount; i++)
            {
                tt[i] = transform.GetChild(i);
            }

            for (int i = 0; i < transform.childCount; i++)
            {
                tt[i].SetSiblingIndex(transform.childCount - 1 - i);
            }
        }
    }

    [ContextMenu("Swap All")]
    public void SwapAll()
    {
        foreach (var o in FindObjectsOfType<Swapper>())
        {
            o.Swap();
        }
    }
}