Fix edit menu crashes in non-editor tabs

SkEditor/Controls/MainMenuControl.axaml.cs

@@ -1,6 +1,7 @@
 using Avalonia.Controls;
 using CommunityToolkit.Mvvm.Input;
 using FluentAvalonia.UI.Controls;
+using FluentAvalonia.UI.Windowing;
 using SkEditor.API;
 using SkEditor.Controls.Docs;
 using SkEditor.Utilities;
@@ -12,6 +13,7 @@
 using SkEditor.Views.Generators;
 using SkEditor.Views.Generators.Gui;
 using SkEditor.Views.Settings;
+using System;
 
 namespace SkEditor.Controls;
 public partial class MainMenuControl : UserControl
@@ -41,29 +43,35 @@ private void AssignCommands()
         MenuItemCloseAllLeft.Command = new RelayCommand(FileCloser.CloseAllToTheLeft);
         MenuItemCloseAllRight.Command = new RelayCommand(FileCloser.CloseAllToTheRight);
 
-        MenuItemCopy.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor.Copy());
-        MenuItemPaste.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor.Paste());
-        MenuItemCut.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor.Cut());
-        MenuItemUndo.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor.Undo());
-        MenuItemRedo.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor.Redo());
-        MenuItemDelete.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor.Delete());
-        MenuItemGoToLine.Command = new RelayCommand(() => SkEditorAPI.Windows.ShowWindow(new GoToLine()));
+        MenuItemCopy.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.Copy());
+        MenuItemPaste.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.Paste());
+        MenuItemCut.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.Cut());
+        MenuItemUndo.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.Undo());
+        MenuItemRedo.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.Redo());
+        MenuItemDelete.Command = new RelayCommand(() => SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.Delete());
+        MenuItemGoToLine.Command = new RelayCommand(() => ShowDialogIfEditorIsOpen(new GoToLineWindow()));
         MenuItemTrimWhitespaces.Command = new RelayCommand(() => CustomCommandsHandler.OnTrimWhitespacesCommandExecuted(SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.TextArea));
 
-        MenuItemDuplicate.Command = new RelayCommand(() => CustomCommandsHandler.OnDuplicateCommandExecuted(SkEditorAPI.Files.GetCurrentOpenedFile().Editor.TextArea));
-        MenuItemComment.Command = new RelayCommand(() => CustomCommandsHandler.OnCommentCommandExecuted(SkEditorAPI.Files.GetCurrentOpenedFile().Editor.TextArea));
+        MenuItemDuplicate.Command = new RelayCommand(() => CustomCommandsHandler.OnDuplicateCommandExecuted(SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.TextArea));
+        MenuItemComment.Command = new RelayCommand(() => CustomCommandsHandler.OnCommentCommandExecuted(SkEditorAPI.Files.GetCurrentOpenedFile().Editor?.TextArea));
 
         MenuItemRefreshSyntax.Command = new RelayCommand(async () => await SyntaxLoader.RefreshSyntaxAsync());
 
         MenuItemSettings.Command = new RelayCommand(() => new SettingsWindow().ShowDialog(SkEditorAPI.Windows.GetMainWindow()));
-        MenuItemGenerateGui.Command = new RelayCommand(() => new GuiGenerator().ShowDialog(SkEditorAPI.Windows.GetMainWindow()));
-        MenuItemGenerateCommand.Command = new RelayCommand(() => new CommandGenerator().ShowDialog(SkEditorAPI.Windows.GetMainWindow()));
-        MenuItemRefactor.Command = new RelayCommand(() => new RefactorWindow().ShowDialog(SkEditorAPI.Windows.GetMainWindow()));
+        MenuItemGenerateGui.Command = new RelayCommand(() => ShowDialogIfEditorIsOpen(new GuiGenerator()));
+        MenuItemGenerateCommand.Command = new RelayCommand(() => ShowDialogIfEditorIsOpen(new CommandGenerator()));
+        MenuItemRefactor.Command = new RelayCommand(() => ShowDialogIfEditorIsOpen(new RefactorWindow()));
         MenuItemMarketplace.Command = new RelayCommand(() => new MarketplaceWindow().ShowDialog(SkEditorAPI.Windows.GetMainWindow()));
 
         MenuItemDocs.Command = new RelayCommand(AddDocsTab);
     }
 
+    private static void ShowDialogIfEditorIsOpen(AppWindow window)
+    {
+        if (SkEditorAPI.Files.GetCurrentOpenedFile().IsEditor)
+            window.ShowDialog(SkEditorAPI.Windows.GetMainWindow());
+    }
+
     public static void AddDocsTab()
     {
         FluentIcons.Avalonia.Fluent.SymbolIconSource icon = new()

SkEditor/Utilities/Editor/CustomCommandsHandler.cs

@@ -2,6 +2,7 @@
 using AvaloniaEdit.Document;
 using AvaloniaEdit.Editing;
 using SkEditor.API;
+using SkEditor.Utilities.Files;
 using SkEditor.Utilities.Parser;
 using SkEditor.Views;
 using System;
@@ -12,7 +13,10 @@ public class CustomCommandsHandler
 {
     public static void OnCommentCommandExecuted(object target)
     {
-        TextEditor editor = SkEditorAPI.Files.GetCurrentOpenedFile().Editor;
+        OpenedFile file = SkEditorAPI.Files.GetCurrentOpenedFile();
+        if (!file.IsEditor) return;
+
+        TextEditor editor = file.Editor;
 
         var document = editor.Document;
         var selectionStart = editor.SelectionStart;

SkEditor/Utilities/Files/FileBuilder.cs

@@ -255,7 +255,7 @@ public static MenuFlyout GetContextMenu(TextEditor editor)
             new { Header = "MenuHeaderRedo", Command = new RelayCommand(() => editor.Redo()), Icon = Symbol.Redo },
             new { Header = "MenuHeaderDuplicate", Command = new RelayCommand(() => CustomCommandsHandler.OnDuplicateCommandExecuted(editor.TextArea)), Icon = Symbol.Copy },
             new { Header = "MenuHeaderComment", Command = new RelayCommand(() => CustomCommandsHandler.OnCommentCommandExecuted(editor.TextArea)), Icon = Symbol.Comment },
-            new { Header = "MenuHeaderGoToLine", Command = new RelayCommand(() => SkEditorAPI.Windows.ShowWindow(new GoToLine())), Icon = Symbol.Find },
+            new { Header = "MenuHeaderGoToLine", Command = new RelayCommand(() => SkEditorAPI.Windows.ShowWindow(new GoToLineWindow())), Icon = Symbol.Find },
             new { Header = "MenuHeaderTrimWhitespaces", Command = new RelayCommand(() => CustomCommandsHandler.OnTrimWhitespacesCommandExecuted(editor.TextArea)), Icon = Symbol.Remove },
             new { Header = "MenuHeaderDelete", Command = new RelayCommand(editor.Delete), Icon = Symbol.Delete },
             new { Header = "MenuHeaderRefactor", Command = new RelayCommand(() => CustomCommandsHandler.OnRefactorCommandExecuted(editor)), Icon = Symbol.Rename },