[RegPreview] Various improvements on how files are saved

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

@@ -22,6 +22,10 @@ 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.
+        // (Solves the problem that enabling the event handler fires it one time.)
+        private static bool editorContentChangedScripted;
+
         /// <summary>
         /// Event that is will prevent the app from closing if the "save file" flag is active
         /// </summary>
@@ -76,6 +80,67 @@ private async void GridPreview_Loaded(object sender, RoutedEventArgs e)
             MonacoEditor.Focus(FocusState.Programmatic);
         }
 
+        /// <summary>
+        /// New button action: Ask to save last changes and reset editor content to reg header only
+        /// </summary>
+        private async void NewButton_Click(object sender, RoutedEventArgs e)
+        {
+            // Check to see if the current file has been saved
+            if (saveButton.IsEnabled)
+            {
+                ContentDialog contentDialog = new ContentDialog()
+                {
+                    Title = resourceLoader.GetString("YesNoCancelDialogTitle"),
+                    Content = resourceLoader.GetString("YesNoCancelDialogContent"),
+                    PrimaryButtonText = resourceLoader.GetString("YesNoCancelDialogPrimaryButtonText"),
+                    SecondaryButtonText = resourceLoader.GetString("YesNoCancelDialogSecondaryButtonText"),
+                    CloseButtonText = resourceLoader.GetString("YesNoCancelDialogCloseButtonText"),
+                    DefaultButton = ContentDialogButton.Primary,
+                };
+
+                // Use this code to associate the dialog to the appropriate AppWindow by setting
+                // the dialog's XamlRoot to the same XamlRoot as an element that is already present in the AppWindow.
+                if (ApiInformation.IsApiContractPresent("Windows.Foundation.UniversalApiContract", 8))
+                {
+                    contentDialog.XamlRoot = this.Content.XamlRoot;
+                }
+
+                ContentDialogResult contentDialogResult = await contentDialog.ShowAsync();
+                switch (contentDialogResult)
+                {
+                    case ContentDialogResult.Primary:
+                        // Save, then continue the new action
+                        if (!AskFileName(string.Empty) ||
+                            !SaveFile())
+                        {
+                            return;
+                        }
+
+                        break;
+                    case ContentDialogResult.Secondary:
+                        // Don't save and continue the new action!
+                        break;
+                    default:
+                        // Don't open the new action!
+                        return;
+                }
+            }
+
+            // mute the TextChanged handler to make for clean UI
+            MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
+
+            // reset editor, file info and ui.
+            _appFileName = string.Empty;
+            ResetEditorAndFile();
+
+            // disable buttons that do not make sense
+            UpdateUnsavedFileState(false);
+            refreshButton.IsEnabled = false;
+
+            // restore the TextChanged handler
+            ButtonAction_RestoreTextChangedEvent();
+        }
+
         /// <summary>
         /// Uses a picker to select a new file to open
         /// </summary>
@@ -106,11 +171,15 @@ 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;
                         break;
                     default:
                         // Don't open the new file!
@@ -137,14 +206,16 @@ private async void OpenButton_Click(object sender, RoutedEventArgs e)
             {
                 // mute the TextChanged handler to make for clean UI
                 MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
+
+                // update file name
                 _appFileName = storageFile.Path;
                 UpdateToolBarAndUI(await OpenRegistryFile(_appFileName));
 
                 // disable the Save button as it's a new file
-                saveButton.IsEnabled = false;
+                UpdateUnsavedFileState(false);
 
                 // Restore the event handler as we're loaded
-                MonacoEditor.TextChanged += MonacoEditor_TextChanged;
+                ButtonAction_RestoreTextChangedEvent();
             }
         }
 
@@ -153,66 +224,49 @@ private async void OpenButton_Click(object sender, RoutedEventArgs e)
         /// </summary>
         private void SaveButton_Click(object sender, RoutedEventArgs e)
         {
-            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"));
-
-            if (filename == string.Empty)
+            if (!AskFileName(string.Empty))
             {
                 return;
             }
 
-            _appFileName = filename;
-            SaveFile();
-            UpdateToolBarAndUI(await OpenRegistryFile(_appFileName));
+            // save and update window title
+            // error handling and ui update happens in SaveFile() method
+            _ = SaveFile();
         }
 
         /// <summary>
-        /// Reloads the current REG file from storage
+        /// Uses a picker to save out a copy of the current reg file
         /// </summary>
-        private async void RefreshButton_Click(object sender, RoutedEventArgs e)
+        private async void SaveAsButton_Click(object sender, RoutedEventArgs e)
         {
             // mute the TextChanged handler to make for clean UI
             MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
 
-            // reload the current Registry file and update the toolbar accordingly.
-            UpdateToolBarAndUI(await OpenRegistryFile(_appFileName), true, true);
+            if (!AskFileName(_appFileName) || !SaveFile())
+            {
+                return;
+            }
 
-            // disable the Save button as it's a new file
-            saveButton.IsEnabled = false;
+            UpdateToolBarAndUI(await OpenRegistryFile(_appFileName));
 
             // restore the TextChanged handler
-            MonacoEditor.TextChanged += MonacoEditor_TextChanged;
+            ButtonAction_RestoreTextChangedEvent();
         }
 
         /// <summary>
-        /// Resets the editor content
+        /// Reloads the current REG file from storage
         /// </summary>
-        private async void NewButton_Click(object sender, RoutedEventArgs e)
+        private async void RefreshButton_Click(object sender, RoutedEventArgs e)
         {
             // Check to see if the current file has been saved
             if (saveButton.IsEnabled)
             {
                 ContentDialog contentDialog = new ContentDialog()
                 {
                     Title = resourceLoader.GetString("YesNoCancelDialogTitle"),
-                    Content = resourceLoader.GetString("YesNoCancelDialogContent"),
-                    PrimaryButtonText = resourceLoader.GetString("YesNoCancelDialogPrimaryButtonText"),
-                    SecondaryButtonText = resourceLoader.GetString("YesNoCancelDialogSecondaryButtonText"),
-                    CloseButtonText = resourceLoader.GetString("YesNoCancelDialogCloseButtonText"),
+                    Content = resourceLoader.GetString("ReloadDialogContent"),
+                    PrimaryButtonText = resourceLoader.GetString("ReloadDialogPrimaryButtonText"),
+                    CloseButtonText = resourceLoader.GetString("ReloadDialogCloseButtonText"),
                     DefaultButton = ContentDialogButton.Primary,
                 };
 
@@ -227,32 +281,25 @@ private async void NewButton_Click(object sender, RoutedEventArgs e)
                 switch (contentDialogResult)
                 {
                     case ContentDialogResult.Primary:
-                        // Save, then continue the file open
-                        SaveFile();
-                        break;
-                    case ContentDialogResult.Secondary:
-                        // Don't save and continue the file open!
-                        saveButton.IsEnabled = false;
+                        // Don't save and continue the reload action!
                         break;
                     default:
-                        // Don't open the new file!
+                        // Don't continue the reload action!
                         return;
                 }
             }
 
             // mute the TextChanged handler to make for clean UI
             MonacoEditor.TextChanged -= MonacoEditor_TextChanged;
 
-            // reset editor, file info and ui.
-            _appFileName = string.Empty;
-            ResetEditorAndFile();
+            // reload the current Registry file and update the toolbar accordingly.
+            UpdateToolBarAndUI(await OpenRegistryFile(_appFileName), true, true);
 
-            // restore the TextChanged handler
-            MonacoEditor.TextChanged += MonacoEditor_TextChanged;
+            // disable the Save button as it's a new file
+            UpdateUnsavedFileState(false);
 
-            // disable buttons that do not make sense
-            saveButton.IsEnabled = false;
-            refreshButton.IsEnabled = false;
+            // restore the TextChanged handler
+            ButtonAction_RestoreTextChangedEvent();
         }
 
         /// <summary>
@@ -313,15 +360,20 @@ private async void WriteButton_Click(object sender, RoutedEventArgs e)
                 switch (contentDialogResult)
                 {
                     case ContentDialogResult.Primary:
-                        // Save, then continue the file open
-                        SaveFile();
+                        // Save, then continue the merge action
+                        if (!AskFileName(string.Empty) ||
+                            !SaveFile())
+                        {
+                            return;
+                        }
+
                         break;
                     case ContentDialogResult.Secondary:
-                        // Don't save and continue the file open!
-                        saveButton.IsEnabled = false;
+                        // Don't save and continue the merge action!
+                        UpdateUnsavedFileState(false);
                         break;
                     default:
-                        // Don't open the new file!
+                        // Don't merge the file!
                         return;
                 }
             }
@@ -411,10 +463,29 @@ private void MonacoEditor_TextChanged(object sender, EventArgs e)
             _dispatcherQueue.TryEnqueue(() =>
             {
                 RefreshRegistryFile();
-                saveButton.IsEnabled = true;
+                if (!editorContentChangedScripted)
+                {
+                    UpdateUnsavedFileState(true);
+                }
+
+                editorContentChangedScripted = false;
             });
         }
 
+        /// <summary>
+        /// Sets indicator for programatic text change and adds text changed handler
+        /// </summary>
+        /// <remarks>
+        /// Use this always, if button actions temporary disable the text changed event
+        /// </remarks>
+        private void ButtonAction_RestoreTextChangedEvent()
+        {
+            // Solves the problem that enabling the event handler fires it one time.
+            // These one time fired event would causes wrong unsaved changes state.
+            editorContentChangedScripted = true;
+            MonacoEditor.TextChanged += MonacoEditor_TextChanged;
+        }
+
         // Commands to show data preview
         public void ButtonExtendedPreview_Click(object sender, RoutedEventArgs e)
         {