Initial Commit

Library/PackageCache/com.unity.collab-proxy@1.3.9/Editor/Common/ScriptableObjectSingleton.cs

@@ -0,0 +1,83 @@
+using System;
+using System.IO;
+using System.Linq;
+using JetBrains.Annotations;
+using UnityEditorInternal;
+using UnityEngine;
+using UnityEngine.Assertions;
+using Object = UnityEngine.Object;
+
+namespace Unity.Cloud.Collaborate.Common
+{
+    internal class ScriptableObjectSingleton<T> : ScriptableObject where T : ScriptableObject
+    {
+        static T s_Instance;
+        public static T Instance
+        {
+            get
+            {
+                if (s_Instance == null)
+                    CreateAndLoad();
+                return s_Instance;
+            }
+        }
+
+        protected ScriptableObjectSingleton()
+        {
+            if (s_Instance != null)
+            {
+                Debug.LogError("Singleton already exists!");
+            }
+            else
+            {
+                s_Instance = this as T;
+                Assert.IsFalse(s_Instance == null);
+            }
+        }
+
+        static void CreateAndLoad()
+        {
+            Assert.IsTrue(s_Instance == null);
+
+            var filePath = GetFilePath();
+            if (!string.IsNullOrEmpty(filePath) && File.Exists(filePath))
+            {
+                InternalEditorUtility.LoadSerializedFileAndForget(filePath);
+            }
+
+            if (s_Instance == null)
+            {
+                var inst = CreateInstance<T>() as ScriptableObjectSingleton<T>;
+                Assert.IsFalse(inst == null);
+                inst.hideFlags = HideFlags.HideAndDontSave;
+                inst.Save();
+            }
+
+            Assert.IsFalse(s_Instance == null);
+        }
+
+        protected void Save()
+        {
+            if (s_Instance == null)
+            {
+                Debug.LogError("Cannot save singleton, no instance!");
+                return;
+            }
+
+            var locationFilePath = GetFilePath();
+            var directoryName = Path.GetDirectoryName(locationFilePath);
+            if (directoryName == null) return;
+            Directory.CreateDirectory(directoryName);
+            InternalEditorUtility.SaveToSerializedFileAndForget(new Object[]{ s_Instance }, locationFilePath, true);
+        }
+
+        [CanBeNull]
+        static string GetFilePath()
+        {
+            var attr = typeof(T).GetCustomAttributes(true)
+                                .OfType<LocationAttribute>()
+                                .FirstOrDefault();
+            return attr?.FilePath;
+        }
+    }
+}