Add PreloadedAssetLoader.

Assets/UnityScreenNavigator/Runtime/Foundation/AssetLoader/PreloadedAssetLoader.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Object = UnityEngine.Object;
+
+namespace UnityScreenNavigator.Runtime.Foundation.AssetLoader
+{
+    /// <summary>
+    ///     <see cref="IAssetLoader" /> that allows you to register preloaded assets.
+    /// </summary>
+    public sealed class PreloadedAssetLoader : IAssetLoader
+    {
+        private int _nextControlId;
+
+        public Dictionary<string, Object> PreloadedObjects { get; } = new Dictionary<string, Object>();
+
+        public AssetLoadHandle<T> Load<T>(string key) where T : Object
+        {
+            var controlId = _nextControlId++;
+
+            var handle = new AssetLoadHandle<T>(controlId);
+            var setter = (IAssetLoadHandleSetter<T>)handle;
+            T result = null;
+            if (PreloadedObjects.TryGetValue(key, out var obj))
+                result = obj as T;
+
+            setter.SetResult(result);
+            var status = result != null ? AssetLoadStatus.Success : AssetLoadStatus.Failed;
+            setter.SetStatus(status);
+            if (result == null)
+            {
+                var exception = new InvalidOperationException($"Requested asset（Key: {key}）was not found.");
+                setter.SetOperationException(exception);
+            }
+
+            setter.SetPercentCompleteFunc(() => 1.0f);
+            setter.SetTask(Task.FromResult(result));
+            return handle;
+        }
+
+        public AssetLoadHandle<T> LoadAsync<T>(string key) where T : Object
+        {
+            return Load<T>(key);
+        }
+
+        public void Release(AssetLoadHandle handle)
+        {
+            // This class does not release any objects.
+        }
+    }
+}

Assets/UnityScreenNavigator/Runtime/Foundation/AssetLoader/PreloadedAssetLoaderObject.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using Object = UnityEngine.Object;
+
+namespace UnityScreenNavigator.Runtime.Foundation.AssetLoader
+{
+    [CreateAssetMenu(fileName = "PreloadedAssetLoader", menuName = "Resource Loader/Preloaded Asset Loader")]
+    public sealed class PreloadedAssetLoaderObject : AssetLoaderObject, IAssetLoader
+    {
+        [SerializeField] private List<KeyAssetPair> _preloadedObjects = new List<KeyAssetPair>();
+
+        private readonly PreloadedAssetLoader _loader = new PreloadedAssetLoader();
+
+        public List<KeyAssetPair> PreloadedObjects => _preloadedObjects;
+
+        private void OnEnable()
+        {
+            foreach (var preloadedObject in _preloadedObjects)
+                _loader.PreloadedObjects.Add(preloadedObject.Key, preloadedObject.Asset);
+        }
+
+        public override AssetLoadHandle<T> Load<T>(string key)
+        {
+            return _loader.Load<T>(key);
+        }
+
+        public override AssetLoadHandle<T> LoadAsync<T>(string key)
+        {
+            return _loader.LoadAsync<T>(key);
+        }
+
+        public override void Release(AssetLoadHandle handle)
+        {
+            _loader.Release(handle);
+        }
+
+        [Serializable]
+        public class KeyAssetPair
+        {
+            [SerializeField] private string _key;
+            [SerializeField] private Object _asset;
+
+            public string Key
+            {
+                get => _key;
+                set => _key = value;
+            }
+
+            public Object Asset
+            {
+                get => _asset;
+                set => _asset = value;
+            }
+        }
+    }
+}