Fix issue with partially unloaded scenes(?)

Author: sinai-dev

src/ObjectExplorer/SceneExplorer.cs

@@ -27,7 +27,7 @@ public SceneExplorer(ObjectExplorerPanel parent)
             Parent = parent;
 
             SceneHandler.OnInspectedSceneChanged += SceneHandler_OnInspectedSceneChanged;
-            SceneHandler.OnLoadedScenesChanged += SceneHandler_OnLoadedScenesChanged;
+            SceneHandler.OnLoadedScenesUpdated += SceneHandler_OnLoadedScenesUpdated;
         }
 
         public override GameObject UIRoot => uiRoot;
@@ -87,7 +87,7 @@ public void JumpToTransform(Transform transform)
             Tree.JumpAndExpandToTransform(transform);
         }
 
-        private void OnDropdownChanged(int value)
+        private void OnSceneSelectionDropdownChanged(int value)
         {
             if (value < 0 || SceneHandler.LoadedScenes.Count <= value)
                 return;
@@ -101,7 +101,7 @@ private void OnDropdownChanged(int value)
         private void SceneHandler_OnInspectedSceneChanged(Scene scene)
         {
             if (!sceneToDropdownOption.ContainsKey(scene))
-                PopulateSceneDropdown();
+                PopulateSceneDropdown(SceneHandler.LoadedScenes);
 
             if (sceneToDropdownOption.ContainsKey(scene))
             {
@@ -122,17 +122,17 @@ private void OnSelectedSceneChanged(Scene scene)
                 refreshRow.SetActive(!scene.IsValid());
         }
 
-        private void SceneHandler_OnLoadedScenesChanged(List<Scene> loadedScenes)
+        private void SceneHandler_OnLoadedScenesUpdated(List<Scene> loadedScenes)
         {
-            PopulateSceneDropdown();
+            PopulateSceneDropdown(loadedScenes);
         }
 
-        private void PopulateSceneDropdown()
+        private void PopulateSceneDropdown(List<Scene> loadedScenes)
         {
             sceneToDropdownOption.Clear();
             sceneDropdown.options.Clear();
 
-            foreach (var scene in SceneHandler.LoadedScenes)
+            foreach (var scene in loadedScenes)
             {
                 if (sceneToDropdownOption.ContainsKey(scene))
                     continue;
@@ -198,11 +198,11 @@ public override void ConstructUI(GameObject content)
             var dropLabel = UIFactory.CreateLabel(dropRow, "SelectorLabel", "Scene:", TextAnchor.MiddleLeft, Color.cyan, false, 15);
             UIFactory.SetLayoutElement(dropLabel.gameObject, minHeight: 25, minWidth: 60, flexibleWidth: 0);
 
-            var dropdownObj = UIFactory.CreateDropdown(dropRow, "SceneDropdown", out sceneDropdown, "<notset>", 13, OnDropdownChanged);
+            var dropdownObj = UIFactory.CreateDropdown(dropRow, "SceneDropdown", out sceneDropdown, "<notset>", 13, OnSceneSelectionDropdownChanged);
             UIFactory.SetLayoutElement(dropdownObj, minHeight: 25, flexibleHeight: 0, flexibleWidth: 9999);
 
             SceneHandler.Update();
-            PopulateSceneDropdown();
+            PopulateSceneDropdown(SceneHandler.LoadedScenes);
             sceneDropdown.captionText.text = sceneToDropdownOption.First().Value.text;
 
             // Filter row

src/ObjectExplorer/SceneHandler.cs

@@ -17,10 +17,11 @@ public static Scene? SelectedScene
             get => selectedScene;
             internal set
             {
-                if (selectedScene != null && selectedScene == value)
+                if (selectedScene.HasValue && selectedScene == value)
                     return;
                 selectedScene = value;
                 OnInspectedSceneChanged?.Invoke((Scene)selectedScene);
+                ExplorerCore.Log($"Set selected scene to {value?.name}");
             }
         }
         private static Scene? selectedScene;
@@ -30,7 +31,7 @@ internal set
 
         /// <summary>All currently loaded Scenes.</summary>
         public static List<Scene> LoadedScenes { get; private set; } = new();
-        private static HashSet<Scene> previousLoadedScenes;
+        //private static HashSet<Scene> previousLoadedScenes;
 
         /// <summary>The names of all scenes in the build settings, if they could be retrieved.</summary>
         public static List<string> AllSceneNames { get; private set; } = new();
@@ -39,7 +40,7 @@ internal set
         public static event Action<Scene> OnInspectedSceneChanged;
 
         /// <summary>Invoked whenever the list of currently loaded Scenes changes. The argument contains all loaded scenes after the change.</summary>
-        public static event Action<List<Scene>> OnLoadedScenesChanged;
+        public static event Action<List<Scene>> OnLoadedScenesUpdated;
 
         /// <summary>Generally will be 2, unless DontDestroyExists == false, then this will be 1.</summary>
         internal static int DefaultSceneCount => 1 + (DontDestroyExists ? 1 : 0);
@@ -84,23 +85,20 @@ internal static void Init()
 
         internal static void Update()
         {
-            // check if the loaded scenes changed. always confirm DontDestroy / HideAndDontSave
-            int confirmedCount = DefaultSceneCount;
-            bool inspectedExists = (SelectedScene.HasValue && SelectedScene.Value.handle == -12) 
-                                   || (SelectedScene.HasValue && SelectedScene.Value.handle == -1);
+            // Inspected scene will exist if it's DontDestroyOnLoad or HideAndDontSave
+            bool inspectedExists = 
+                SelectedScene.HasValue 
+                && ((DontDestroyExists && SelectedScene.Value.handle == -12) 
+                    || SelectedScene.Value.handle == -1);
 
             LoadedScenes.Clear();
 
             for (int i = 0; i < SceneManager.sceneCount; i++)
             {
                 Scene scene = SceneManager.GetSceneAt(i);
-                if (scene == default || !scene.isLoaded)
+                if (scene == default || !scene.isLoaded || !scene.IsValid())
                     continue;
 
-                // If no changes yet, ensure the previous list contained the scene
-                if (previousLoadedScenes != null && previousLoadedScenes.Contains(scene))
-                    confirmedCount++;
-
                 // If we have not yet confirmed inspectedExists, check if this scene is our currently inspected one.
                 if (!inspectedExists && scene == SelectedScene)
                     inspectedExists = true;
@@ -112,17 +110,12 @@ internal static void Update()
                 LoadedScenes.Add(new Scene { m_Handle = -12 });
             LoadedScenes.Add(new Scene { m_Handle = -1 });
 
-            bool anyChange = confirmedCount != LoadedScenes.Count;
-
-            previousLoadedScenes = new HashSet<Scene>(LoadedScenes);
-
             // Default to first scene if none selected or previous selection no longer exists.
             if (!inspectedExists)
                 SelectedScene = LoadedScenes.First();
 
             // Notify on the list changing at all
-            if (anyChange)
-                OnLoadedScenesChanged?.Invoke(LoadedScenes);
+            OnLoadedScenesUpdated?.Invoke(LoadedScenes);
 
             // Finally, update the root objects list.
             if (SelectedScene != null && ((Scene)SelectedScene).IsValid())