Unity: Fit size of parent to size of childs

Question

I have an empty in a Canvas that has multiple objects as children. More children are added to the parent as the game progresses. I want the parent to fit the size to its children.

I already read a lot about this topic, but every time I came across the ContentSizeFitter, which unfortunately does not work for me, because it needs a layout group, which I do not have, because the children do not have an order and are wildly placed.

I am using Unity 2018.3.4f1 Personal.

Not sized parent:

Sized parent (Red: New, Green: Old):

Structure:

Canvas
 |- Empty
     |- Child 1
     |- Child 2
     |- Child X

Answer 1

I have written a small piece of code that does its job, or does it the way I want and it is enough for me:

using UnityEngine;

public class SizeFitter : MonoBehaviour {
    public void CheckForChanges() {
        RectTransform children = transform.GetComponentInChildren<RectTransform>();

        float min_x, max_x, min_y, max_y;
        min_x = max_x = transform.localPosition.x;
        min_y = max_y = transform.localPosition.y;

        foreach (RectTransform child in children) {
            Vector2 scale = child.sizeDelta;
            float temp_min_x, temp_max_x, temp_min_y, temp_max_y;

            temp_min_x = child.localPosition.x - (scale.x / 2);
            temp_max_x = child.localPosition.x + (scale.x / 2);
            temp_min_y = child.localPosition.y - (scale.y / 2);
            temp_max_y = child.localPosition.y + (scale.y / 2);

            if (temp_min_x < min_x)
                min_x = temp_min_x;
            if (temp_max_x > max_x)
                max_x = temp_max_x;

            if (temp_min_y < min_y)
                min_y = temp_min_y;
            if (temp_max_y > max_y)
                max_y = temp_max_y;
        }

        GetComponent<RectTransform>().sizeDelta = new Vector2(max_x - min_x, max_y - min_y);
    }
}