[RegPreview] Various improvements on how files are saved

src/modules/registrypreview/RegistryPreviewUILib/RegistryPreviewMainPage.Events.cs

@@ -23,6 +23,9 @@ public sealed partial class RegistryPreviewMainPage : Page
     {
         private readonly DispatcherQueue _dispatcherQueue = DispatcherQueue.GetForCurrentThread();
 
+        // Indicator if we loaded/reloaded/saved a file and need to skip TextChanged event one time.
+        private static bool editorContentChangedScripted;
+
         /// <summary>
         /// Event that is will prevent the app from closing if the "save file" flag is active
         /// </summary>
@@ -107,11 +110,17 @@ private async void OpenButton_Click(object sender, RoutedEventArgs e)
                 {
                     case ContentDialogResult.Primary:
                         // Save, then continue the file open
-                        SaveFile();
+                        if (!AskFileName(string.Empty) ||
+                            !SaveFile())
+                        {
+                            return;
+                        }
+
                         break;
                     case ContentDialogResult.Secondary:
                         // Don't save and continue the file open!
                         saveButton.IsEnabled = false;
+                        UpdateUnsavedFileIndicator(false);
                         break;
                     default:
                         // Don't open the new file!
@@ -138,11 +147,15 @@ private async void OpenButton_Click(object sender, RoutedEventArgs e)
             {
                 // mute the TextChanged handler to make for clean UI
                 MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
+                editorContentChangedScripted = true;
+
+                // update file name
                 _appFileName = storageFile.Path;
                 UpdateToolBarAndUI(await OpenRegistryFile(_appFileName));
 
                 // disable the Save button as it's a new file
                 saveButton.IsEnabled = false;
+                UpdateUnsavedFileIndicator(false);
 
                 // Restore the event handler as we're loaded
                 MonacoEditor.TextChanged += MonacoEditor_TextChanged;
@@ -154,31 +167,33 @@ private async void OpenButton_Click(object sender, RoutedEventArgs e)
         /// </summary>
         private void SaveButton_Click(object sender, RoutedEventArgs e)
         {
-            SaveFile();
+            if (!AskFileName(string.Empty))
+            {
+                return;
+            }
+
+            // save and update window title
+            _ = SaveFile();
         }
 
         /// <summary>
         /// Uses a picker to save out a copy of the current reg file
         /// </summary>
         private async void SaveAsButton_Click(object sender, RoutedEventArgs e)
         {
-            // Save out a new REG file and then open it - we have to use the direct Win32 method because FileOpenPicker crashes when it's
-            // called while running as admin
-            IntPtr windowHandle = WinRT.Interop.WindowNative.GetWindowHandle(_mainWindow);
-            string filename = SaveFilePicker.ShowDialog(
-                windowHandle,
-                resourceLoader.GetString("SuggestFileName"),
-                resourceLoader.GetString("FilterRegistryName") + '\0' + "*.reg" + '\0' + resourceLoader.GetString("FilterAllFiles") + '\0' + "*.*" + '\0' + '\0',
-                resourceLoader.GetString("SaveDialogTitle"));
+            // mute the TextChanged handler to make for clean UI
+            editorContentChangedScripted = true;
+            MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
 
-            if (filename == string.Empty)
+            if (!AskFileName(_appFileName) || !SaveFile())
             {
                 return;
             }
 
-            _appFileName = filename;
-            SaveFile();
             UpdateToolBarAndUI(await OpenRegistryFile(_appFileName));
+
+            // restore the TextChanged handler
+            MonacoEditor.TextChanged += MonacoEditor_TextChanged;
         }
 
         /// <summary>
@@ -187,12 +202,14 @@ private async void SaveAsButton_Click(object sender, RoutedEventArgs e)
         private async void RefreshButton_Click(object sender, RoutedEventArgs e)
         {
             // mute the TextChanged handler to make for clean UI
+            editorContentChangedScripted = true;
             MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
 
             // reload the current Registry file and update the toolbar accordingly.
             UpdateToolBarAndUI(await OpenRegistryFile(_appFileName), true, true);
 
             saveButton.IsEnabled = false;
+            UpdateUnsavedFileIndicator(false);
 
             // restore the TextChanged handler
             MonacoEditor.TextChanged += MonacoEditor_TextChanged;
@@ -257,7 +274,12 @@ private async void WriteButton_Click(object sender, RoutedEventArgs e)
                 {
                     case ContentDialogResult.Primary:
                         // Save, then continue the file open
-                        SaveFile();
+                        if (!AskFileName(string.Empty) ||
+                            !SaveFile())
+                        {
+                            return;
+                        }
+
                         break;
                     case ContentDialogResult.Secondary:
                         // Don't save and continue the file open!
@@ -354,7 +376,13 @@ private void MonacoEditor_TextChanged(object sender, EventArgs e)
             _dispatcherQueue.TryEnqueue(() =>
             {
                 RefreshRegistryFile();
-                saveButton.IsEnabled = true;
+                if (!editorContentChangedScripted)
+                {
+                    saveButton.IsEnabled = true;
+                    UpdateUnsavedFileIndicator(true);
+                }
+
+                editorContentChangedScripted = false;
             });
         }
     }

src/modules/registrypreview/RegistryPreviewUILib/RegistryPreviewMainPage.Utilities.cs

@@ -11,6 +11,7 @@
 using System.Linq;
 using System.Reflection;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.UI.Input;
@@ -22,6 +23,9 @@ namespace RegistryPreviewUILib
 {
     public sealed partial class RegistryPreviewMainPage : Page
     {
+        private static readonly string _unsavedFileIndicator = "* ";
+        private static readonly char[] _unsavedFileIndicatorChars = [' ', '*'];
+
         private static SemaphoreSlim _dialogSemaphore = new(1);
         private string lastKeyPath;
 
@@ -830,10 +834,16 @@ private async void HandleDirtyClosing(string title, string content, string prima
             {
                 case ContentDialogResult.Primary:
                     // Save, then close
-                    SaveFile();
+                    if (!AskFileName(string.Empty) ||
+                        !SaveFile())
+                    {
+                        return;
+                    }
+
                     break;
                 case ContentDialogResult.Secondary:
                     // Don't save, and then close!
+                    UpdateUnsavedFileIndicator(false);
                     saveButton.IsEnabled = false;
                     break;
                 default:
@@ -902,11 +912,63 @@ public void ChangeCursor(UIElement uiElement, bool wait)
             type.InvokeMember("ProtectedCursor", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.SetProperty | BindingFlags.Instance, null, uiElement, new object[] { cursor }, CultureInfo.InvariantCulture);
         }
 
+        public void UpdateUnsavedFileIndicator(bool show)
+        {
+            // get and cut current title
+            string currentTitle = Regex.Replace(_mainWindow.Title, APPNAME + @"$|\s-\s" + APPNAME + @"$", string.Empty);
+
+            // verify
+            bool titleContainsIndicator = currentTitle.StartsWith(_unsavedFileIndicator, StringComparison.CurrentCultureIgnoreCase);
+
+            // update
+            if (!titleContainsIndicator && show)
+            {
+                _updateWindowTitleFunction(_unsavedFileIndicator + currentTitle);
+            }
+            else if (titleContainsIndicator && !show)
+            {
+                _updateWindowTitleFunction(currentTitle.TrimStart(_unsavedFileIndicatorChars));
+            }
+        }
+
+        /// <summary>
+        /// Ask the user for the file path if it is unknown because of an unsaved file
+        /// </summary>
+        /// <param name="fileName">If not empty always ask for a file path and use the value as name.</param>
+        /// <returns>Returns true if user selected a path, otherwise false</returns>
+        public bool AskFileName(string fileName)
+        {
+            if (string.IsNullOrEmpty(_appFileName) || !string.IsNullOrEmpty(fileName) )
+            {
+                string fName = string.IsNullOrEmpty(fileName) ? resourceLoader.GetString("SuggestFileName") : fileName;
+
+                // Save out a new REG file and then open it - we have to use the direct Win32 method because FileOpenPicker crashes when it's
+                // called while running as admin
+                IntPtr windowHandle = WinRT.Interop.WindowNative.GetWindowHandle(_mainWindow);
+                string filename = SaveFilePicker.ShowDialog(
+                    windowHandle,
+                    fName,
+                    resourceLoader.GetString("FilterRegistryName") + '\0' + "*.reg" + '\0' + resourceLoader.GetString("FilterAllFiles") + '\0' + "*.*" + '\0' + '\0',
+                    resourceLoader.GetString("SaveDialogTitle"));
+
+                if (filename == string.Empty)
+                {
+                    return false;
+                }
+
+                _appFileName = filename;
+            }
+
+            return true;
+        }
+
         /// <summary>
         /// Wrapper method that saves the current file in place, using the current text in editor.
         /// </summary>
-        private void SaveFile()
+        private bool SaveFile()
         {
+            bool saveSuccess = true;
+
             ChangeCursor(gridPreview, true);
 
             // set up the FileStream for all writing
@@ -930,10 +992,13 @@ private void SaveFile()
                 streamWriter.Close();
 
                 // only change when the save is successful
+                _updateWindowTitleFunction(_appFileName);
                 saveButton.IsEnabled = false;
             }
             catch (UnauthorizedAccessException ex)
             {
+                saveSuccess = false;
+
                 // this exception is thrown if the file is there but marked as read only
                 ShowMessageBox(
                     resourceLoader.GetString("ErrorDialogTitle"),
@@ -942,6 +1007,8 @@ private void SaveFile()
             }
             catch
             {
+                saveSuccess = false;
+
                 // this catch handles all other exceptions thrown when trying to write the file out
                 ShowMessageBox(
                     resourceLoader.GetString("ErrorDialogTitle"),
@@ -959,6 +1026,8 @@ private void SaveFile()
 
             // restore the cursor
             ChangeCursor(gridPreview, false);
+
+            return saveSuccess;
         }
 
         /// <summary>