[Unity] Quickly snap rect to any target RectTransform

SnapRectTransform.cs

// The idea is super simple: 
// 1. Set rect transform to be moved to be children of target Rect.
// 2. As a children -> Set local position to 0,0,0
// 3. Set parent of our transform to the old parent (again)
// 
// This script is originally used for a HandTutorialObject, so that it points to correct UI Object. This is done because setting
// rectTransform.position proved to be incorrect when target Rect inside a LayoutGroup, ... etc.
using System.Collections;
using UnityEngine;

public static class RectTransformExtensions
{
    /// <summary>
    /// Snap this RectTransform to target’s pivot position visually,
    /// even if anchors/pivots don’t match.
    /// </summary>
    public static void SnapTo(this RectTransform self, RectTransform target, MonoBehaviour runner)
    {
        if (!self || !target || !runner) return;
        runner.StartCoroutine(SnapCoroutine(self, target));
    }

    private static IEnumerator SnapCoroutine(RectTransform self, RectTransform target)
    {
        // Save original parent and sibling index
        Transform originalParent = self.parent;
        int originalSibling = self.GetSiblingIndex();

        // Step 1: temporarily reparent to target
        self.SetParent(target, false);
        yield return null; // wait one frame

        // Step 2: set local position = (0,0,0)
        self.localPosition = Vector3.zero;
        yield return null;

        // Step 3: restore parent while keeping new world pos
        self.SetParent(originalParent, true);
        self.SetSiblingIndex(originalSibling);
    }
}