fix: System.NullReferenceException: Object reference not set to an instance of an object.

Author: Genouka

UndertaleModTool/Editors/UndertaleCodeEditor.xaml.cs

@@ -1723,29 +1723,66 @@ private void OpenCompletionWindow(TextEditor editor, bool memberAccess)
             if (items.Count == 0)
                 return;
 
+            // Never create the completion window for an editor that isn't connected to a
+            // presentation source (e.g. during tab teardown); showing a Window under such
+            // conditions crashes inside WPF window creation.
+            if (PresentationSource.FromVisual(editor.TextArea) is null || Window.GetWindow(editor.TextArea) is null)
+                return;
+
             List<ICompletionData> dataList = new List<ICompletionData>(items.Count);
             foreach (GmlCompletionItem item in items)
                 dataList.Add(new GmlCompletionData(item));
 
-            CompletionWindow window = new(editor.TextArea)
+            CompletionWindow window;
+            try
             {
-                MaxHeight = 320,
-                CloseAutomatically = true
-            };
-            window.CompletionList.IsFiltering = true;
-            foreach (ICompletionData completionData in dataList)
-                window.CompletionList.CompletionData.Add(completionData);
-
-            // Show the typed word in gray inside the completion box
-            int wordStart = caret;
-            string docText = code;
-            while (wordStart > 0 && wordStart - 1 < docText.Length && IsWordChar(docText[wordStart - 1]))
-                wordStart--;
-            window.StartOffset = wordStart;
-
-            _completionWindow = window;
-            window.Closed += (s2, e2) => _completionWindow = null;
-            window.Show();
+                window = new CompletionWindow(editor.TextArea)
+                {
+                    MaxHeight = 320,
+                    CloseAutomatically = true
+                };
+                window.CompletionList.IsFiltering = true;
+                foreach (ICompletionData completionData in dataList)
+                    window.CompletionList.CompletionData.Add(completionData);
+
+                // Show the typed word in gray inside the completion box
+                int wordStart = caret;
+                string docText = code;
+                while (wordStart > 0 && wordStart - 1 < docText.Length && IsWordChar(docText[wordStart - 1]))
+                    wordStart--;
+                window.StartOffset = wordStart;
+
+                _completionWindow = window;
+                window.Closed += (s2, e2) => _completionWindow = null;
+            }
+            catch (Exception ex)
+            {
+                Trace.WriteLine("UndertaleCodeEditor: failed to build completion window: " + ex);
+                CloseCompletionWindow();
+                return;
+            }
+
+            // Show the window outside of the text-input call stack. Creating the HWND while
+            // WPF is still dispatching the WM_CHAR transaction can fail inside
+            // Window.CreateSourceWindow (NullReferenceException), taking down the whole app.
+            // Deferring the call lets input processing finish first, and any residual failure
+            // is contained instead of crashing on every keystroke.
+            window.Dispatcher.BeginInvoke(new Action(() =>
+            {
+                try
+                {
+                    if (!ReferenceEquals(_completionWindow, window))
+                        return; // superseded or closed meanwhile
+                    window.Show();
+                }
+                catch (Exception ex)
+                {
+                    Trace.WriteLine("UndertaleCodeEditor: failed to show completion window: " + ex);
+                    if (ReferenceEquals(_completionWindow, window))
+                        _completionWindow = null;
+                    try { window.Close(); } catch { /* already closing */ }
+                }
+            }), System.Windows.Threading.DispatcherPriority.Background);
         }
 
         private void UpdateFolding()

UndertaleModTool/Scripts/Special Scripts/PLACEHOLDER.csx

@@ -0,0 +1,278 @@
+// Made with the help of QuantumV and The United Modders Of Pizza Tower Team
+using System.Text;
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+using UndertaleModLib.Util;
+using System.Collections.Generic;
+
+EnsureDataLoaded();
+
+string objectFolder = GetFolder(FilePath) + "Decompiled" + Path.DirectorySeparatorChar + "objects" + Path.DirectorySeparatorChar;
+
+if (Directory.Exists(objectFolder))
+{
+    Directory.Delete(objectFolder, true);
+}
+
+public class AssetReference
+{
+    public string name { get; set; }
+    public string path { get; set; }
+}
+public class GMEvent
+{
+    public string resourceType { get; set; } = "GMEvent";
+    public string resourceVersion { get; set; }  = "1.0";
+    public string name { get; set; } = "";
+    public bool isDnD { get; set; }  = false;
+    public uint eventNum { get; set; } = 0;
+    public uint eventType { get; set; } = 0;
+    public AssetReference collisionObjectId { get; set; } = null;
+}
+public class GMObjectProperty
+{
+    public string resourceType { get; set; } = "GMObjectProperty";
+
+    public string resourceVersion { get; set; } = "1.0";
+
+    public string name { get; set; }
+
+    public int varType { get; set; } = 0;
+
+    public string value { get; set; }
+    public bool rangeEnabled { get; set; } = false;
+    public double rangeMin { get; set; } = 0.0;
+    public double rangeMax { get; set; } = 10.0;
+    public List<string> listItems { get; set; } = new List<string>{};
+    public bool multiselect { get; set; } = false;
+    public List<string> filters { get; set; } = new List<string>{};
+}
+
+public class ObjectData
+{
+    public string resourceType { get; set; } = "GMObject";
+
+    public string resourceVersion { get; set; } = "1.0";
+
+    public string name { get; set; }
+
+    public AssetReference spriteId { get; set; } = new AssetReference();
+    public AssetReference spriteMaskId { get; set; } = new AssetReference();
+    public bool visible { get; set; }
+
+    public bool solid { get; set; }
+    public bool persistent { get; set; }
+    public bool managed { get; set; }
+    public AssetReference parentObjectId { get; set; } = new AssetReference();
+    public List<GMEvent> eventList { get; set; } = new List<GMEvent>();
+    public List<GMObjectProperty> properties { get; set; } = new List<GMObjectProperty>();
+    public AssetReference parent { get; set; } = new AssetReference();
+}
+
+string GetFolder(string path)
+{
+    return Path.GetDirectoryName(path) + Path.DirectorySeparatorChar;
+}
+
+ThreadLocal<GlobalDecompileContext> DECOMPILE_CONTEXT = new ThreadLocal<GlobalDecompileContext>(() => new GlobalDecompileContext(Data));
+
+Regex assignmentRegex = new Regex(
+    @"^(\w+) = (.+)$",
+    RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.ECMAScript
+);
+// get variable definitions from a precreate event
+List<GMObjectProperty> GetObjectProperties(UndertalePointerList<UndertaleGameObject.Event> evList)
+{
+    List<GMObjectProperty> list = new List<GMObjectProperty> { };
+    if (evList == null) return list;
+    foreach (UndertaleGameObject.Event ev in evList)
+    {
+        foreach (UndertaleGameObject.EventAction action in ev.Actions)
+        {
+            UndertaleCode code = action.CodeId;
+            if (code == null) continue;
+            string gml = "";
+            try
+            {
+                gml = new Underanalyzer.Decompiler.DecompileContext(DECOMPILE_CONTEXT.Value, code).DecompileToString();
+            }
+            catch (Exception e) { }
+            foreach (Match match in assignmentRegex.Matches(gml))
+            {
+                list.Add(new GMObjectProperty
+                {
+                    varType = 4, // expression
+                    name = match.Groups[1].Captures[0].Value,
+                    value = match.Groups[2].Captures[0].Value,
+                });
+            }
+        }
+    }
+    return list;
+}
+
+SetProgressBar(null, "Objects", 0, Data.GameObjects.Count);
+StartProgressBarUpdater();
+await Task.Run(() => Parallel.ForEach(Data.GameObjects, (UndertaleGameObject gameObject) => {
+    string objectDir = objectFolder + gameObject.Name.Content + Path.DirectorySeparatorChar;
+    Directory.CreateDirectory(objectDir);
+    ObjectData objectData = new ObjectData()
+    {
+        name = gameObject.Name.Content,
+        spriteId = gameObject.Sprite != null ? new AssetReference()
+        {
+            name = gameObject.Sprite.Name.Content,
+            path = $"sprites/{gameObject.Sprite.Name.Content}/{gameObject.Sprite.Name.Content}.yy"
+        } : null,
+        spriteMaskId = gameObject.TextureMaskId != null ? new AssetReference()
+        {
+            name = gameObject.TextureMaskId.Name.Content,
+            path = $"sprites/{gameObject.TextureMaskId.Name.Content}/{gameObject.TextureMaskId.Name.Content}.yy"
+        } : null,
+        visible = gameObject.Visible,
+        solid = gameObject.Solid,
+        persistent = gameObject.Persistent,
+        managed = gameObject.Managed,
+        parentObjectId = gameObject.ParentId != null ? new AssetReference()
+        {
+            name = gameObject.ParentId.Name.Content,
+            path = $"objects/{gameObject.ParentId.Name.Content}/{gameObject.ParentId.Name.Content}.yy"
+        } : null,
+        parent = new AssetReference()
+        {
+            name = "Objects",
+            path = "folders/Objects.yy"
+        },
+    };
+    for (var i = 0; i < gameObject.Events.Count; i++)
+    {
+        var evList = gameObject.Events[i];
+        // PreCreate is used by variable definitions
+        if ((EventType)i == EventType.PreCreate)
+        {
+            objectData.properties = GetObjectProperties(evList);
+            continue;
+        }
+        foreach (var ev in evList)
+        {
+            AssetReference collObjRef = null;
+            uint subtype = ev.EventSubtype;
+            if ((EventType)i == EventType.Collision)
+            {
+                subtype = 0;
+                var collObj = Data.GameObjects[(int)ev.EventSubtype];
+                if (collObj != null)
+                {
+                    collObjRef = new AssetReference()
+                    {
+                        name = collObj.Name.Content,
+                        path = $"objects/{collObj.Name.Content}/{collObj.Name.Content}.yy"
+                    };
+                }
+            }
+            objectData.eventList.Add(new GMEvent()
+            {
+                eventType = (uint)i,
+                eventNum = subtype,
+                collisionObjectId = collObjRef
+            });
+
+            if (ev.Actions.Count > 0)
+            {
+                var action = ev.Actions[0];
+                var code = action.CodeId;
+                var subtypeString = subtype.ToString();
+                if ((EventType)i == EventType.Collision)
+                {
+                    subtypeString = Data.GameObjects[(int)ev.EventSubtype].Name.Content;
+                }
+                var gmlPath = $"{objectDir}{((EventType)i).ToString()}_{subtypeString}.gml";
+                try
+                {
+                    File.WriteAllText(gmlPath, (code != null ? ConvertEnumToConst(new Underanalyzer.Decompiler.DecompileContext(DECOMPILE_CONTEXT.Value, code).DecompileToString()) : ""));
+                }
+                catch (Exception e)
+                {
+                    File.WriteAllText(gmlPath, "/*\nDECOMPILER FAILED!\n\n" + e.ToString() + "\n*/");
+                }
+            }
+            else
+            {
+                var gmlPath = $"{objectDir}Create_0.gml";
+                File.WriteAllText(gmlPath, "/* Empty Sprite */");
+            }
+        }
+    }
+    string json = JsonConvert.SerializeObject(objectData, Formatting.Indented);
+    File.WriteAllText(objectDir + gameObject.Name.Content + ".yy", json);
+    IncrementProgressParallel();
+}));
+
+await StopProgressBarUpdater();
+HideProgressBar();
+
+public string ConvertEnumToConst(string inputCode)
+{
+    // 存储所有枚举定义和替换映射
+    var enumDefinitions = new Dictionary<string, Dictionary<string, int>>();
+    var replaceDict = new Dictionary<string, string>();
+    var sbDefinitions = new StringBuilder();
+
+    // 匹配所有枚举定义
+    var enumRegex = new Regex(@"enum\s+(\w+)\s*\{(.*?)\}", RegexOptions.Singleline);
+    var enumMatches = enumRegex.Matches(inputCode);
+
+    foreach (Match enumMatch in enumMatches)
+    {
+        string enumName = enumMatch.Groups[1].Value;
+        string enumContent = enumMatch.Groups[2].Value;
+        var members = new Dictionary<string, int>();
+
+        // 解析枚举成员（支持显式赋值）
+        int currentValue = 0;
+        var memberRegex = new Regex(@"\s*(\w+)\s*(=\s*(\d+))?\s*,?");
+        var memberMatches = memberRegex.Matches(enumContent);
+
+        foreach (Match memberMatch in memberMatches)
+        {
+            if (!memberMatch.Success) continue;
+
+            string memberName = memberMatch.Groups[1].Value;
+            string explicitValue = memberMatch.Groups[3].Value;
+
+            if (!string.IsNullOrEmpty(explicitValue))
+            {
+                currentValue = int.Parse(explicitValue);
+            }
+
+            members[memberName] = currentValue;
+
+            // 添加到替换字典
+            string fullName = $"{enumName}.{memberName}";
+            string replacement = $"global.{enumName}__{memberName}";
+            replaceDict[fullName] = replacement;
+
+            // 生成定义行
+            sbDefinitions.AppendLine($"{replacement} = {currentValue};");
+
+            currentValue++; // 为下一个成员递增
+        }
+
+        enumDefinitions[enumName] = members;
+    }
+
+    // 移除所有枚举定义
+    string outputCode = enumRegex.Replace(inputCode, "");
+
+    // 替换所有枚举引用
+    foreach (var kvp in replaceDict)
+    {
+        outputCode = outputCode.Replace(kvp.Key, kvp.Value);
+    }
+
+    // 在代码开头插入定义
+    return sbDefinitions.ToString() + outputCode;
+}