BracerLib/Assets/Scripts/UI/SceneLoadingManager.cs

using System.Collections;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace BracerLib.UI
{
    public class SceneLoadingManager : MonoBehaviour
    {
        private static SceneLoadingManager _instance;

        public static void LoadScenes(string[] scenePath, LoadSceneMode sceneMode)
        {
            if (!ValidInstance())
                return;

            _instance.TryLoadScenes(scenePath, sceneMode);
        }

        public static void Show()
        {
            if (ValidInstance())
                _instance.Toggle(true);
        }

        public static void Hide()
        {
            if (ValidInstance())
                _instance.Toggle(false);
        }

        private static bool ValidInstance()
        {
            if (_instance != null)
                return true;

            Debug.LogError("No Load Screen Manager found.");

            return false;
        }

        [SerializeField]
        private GameObject _loadingScreenGameObject;

        private Coroutine _sceneLoadingCoroutine;

        private void Awake()
        {
            DontDestroyOnLoad(_loadingScreenGameObject);
            if (_instance != null)
            {
                Debug.LogError("Multiple LoadScreenManagers found. Please delete one", this);
                Destroy(this);

                return;
            }

            _instance = this;
        }

        private void TryLoadScenes(string[] scenePaths, LoadSceneMode sceneMode)
        {
            if (_sceneLoadingCoroutine != null)
            {
                Debug.LogError("SceneLoadingManager is already loading scenes.");

                return;
            }

            _sceneLoadingCoroutine = StartCoroutine(LoadSceneCoroutine(scenePaths, sceneMode));
        }

        private IEnumerator LoadSceneCoroutine(string[] scenePaths, LoadSceneMode sceneMode)
        {
            Show();

            for (var i = 0; i < scenePaths.Length; i++)
                yield return SceneManager.LoadSceneAsync(scenePaths[i], sceneMode);

            Hide();
            _sceneLoadingCoroutine = null;
        }

        private void Toggle(bool state)
        {
            _loadingScreenGameObject.SetActive(state);
        }
    }
}