CirclePanel

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

namespace AnimalSimulator.PaintMode.UI.ColorPanel
{
    public class CirclePanel : MonoBehaviour
    {
        [SerializeField] private float _sensitivity = 2f;
        [SerializeField] private bool _invert;
        [SerializeField] private FloatReactiveProperty _angle = new FloatReactiveProperty(10f);
        [SerializeField] private float _radius = 340f;
        [SerializeField] private float _itemSize = 50f;
        [SerializeField] private Transform _contentContainer;

        [SerializeField] private DragHandler _dragHandler;


        [SerializeField] private GridLayoutGroup.Axis _axis;
        private readonly List<Transform> _objects = new List<Transform>();

        [SerializeField] private float _debugAngle = 45f;

        private void OnEnable()
        {
            _angle.TakeUntilDisable(this).Subscribe(f => CalculatePositions());
            _dragHandler.OnDrag.TakeUntilDisable(this).Subscribe(data => Rotate(data.delta));
        }

        public void AddObject(GameObject @object, bool reCalculatePositions = false)
            => AddObject(@object.transform, reCalculatePositions);

        public void AddObject(Transform @object, bool reCalculatePositions = false)
        {
            @object.parent = _contentContainer;
            _objects.Add(@object);

            if (reCalculatePositions)
                CalculatePositions();
        }

        public void CalculatePositions()
        {
            Quaternion rotationStep = Quaternion.Euler(0, 0, _angle.Value);
            Vector3 localPosition = rotationStep * Vector3.up * _radius;

            foreach (Transform child in _contentContainer)
            {
                localPosition = rotationStep * localPosition;
                child.localPosition = localPosition;
            }
        }

        private void Rotate(Vector2 delta)
        {
            bool isHorizontal = _axis == GridLayoutGroup.Axis.Horizontal;

            float angle = isHorizontal ? delta.x : delta.y;

            int invert = _invert ? -1 : 1;

            angle *= _sensitivity * invert;

            var position = transform.position;

            transform.RotateAround(position, Vector3.forward, angle);
        }

        private void OnDrawGizmos()
        {
            Gizmos.color = Color.red;
            var position = transform.position;
            Vector3 offsetPosition = Quaternion.Euler(0, 0, z: _debugAngle) * Vector3.up * _radius;
            Vector3 targetPosition = position + offsetPosition;
            Gizmos.DrawLine(position, targetPosition);

            Gizmos.color = Color.green;
            Gizmos.DrawWireSphere(targetPosition, _itemSize);
        }
    }
}