Add save prompt and modify CodeEditor and TextEditor

Author: diluculo

src/Gemini.Demo/Modules/TextEditor/ViewModels/EditorViewModel.cs

@@ -4,15 +4,19 @@
 using Gemini.Demo.Modules.TextEditor.Views;
 using Gemini.Framework;
 using Gemini.Framework.Threading;
+using System.ComponentModel.Composition;
 
 namespace Gemini.Demo.Modules.TextEditor.ViewModels
 {
+    [Export(typeof(EditorViewModel))]
+    [PartCreationPolicy(CreationPolicy.NonShared)]
 #pragma warning disable 659
     public class EditorViewModel : PersistedDocument
 #pragma warning restore 659
     {
         private EditorView _view;
 		private string _originalText;
+        private bool notYetLoaded = false;
 
         protected override Task DoNew()
         {
@@ -38,6 +42,12 @@ protected override Task DoSave(string filePath)
 
         private void ApplyOriginalText()
         {
+            // At StartUp, _view is null, so notYetLoaded flag is added
+            if (_view == null)
+            {
+                notYetLoaded = true;
+                return;
+            }
             _view.textBox.Text = _originalText;
 
             _view.textBox.TextChanged += delegate
@@ -49,6 +59,12 @@ private void ApplyOriginalText()
 		protected override void OnViewLoaded(object view)
 		{
             _view = (EditorView) view;
+
+            if (notYetLoaded)
+            {
+                ApplyOriginalText();
+                notYetLoaded = false;
+            }
 		}
 
         public override bool Equals(object obj)

src/Gemini.Demo/Modules/TextEditor/Views/EditorView.xaml

@@ -11,5 +11,5 @@
              FontFamily="Consolas"
              FontSize="14"
              ScrollViewer.VerticalScrollBarVisibility="Visible"
-             ScrollViewer.HorizontalScrollBarVisibility="Visible"/>
+             ScrollViewer.HorizontalScrollBarVisibility="Visible" TextWrapping="Wrap" AcceptsReturn="True"/>
 </UserControl>

src/Gemini.Modules.CodeEditor/ViewModels/CodeEditorViewModel.cs

@@ -5,6 +5,9 @@
 using Gemini.Framework;
 using Gemini.Framework.Threading;
 using Gemini.Modules.CodeEditor.Views;
+using Gemini.Modules.StatusBar;
+using System.ComponentModel;
+using Caliburn.Micro;
 
 namespace Gemini.Modules.CodeEditor.ViewModels
 {
@@ -17,31 +20,25 @@ public class CodeEditorViewModel : PersistedDocument
         private readonly LanguageDefinitionManager _languageDefinitionManager;
         private string _originalText;
         private ICodeEditorView _view;
+        private IStatusBar _statusBar;
+        private bool notYetLoaded = false;
 
         [ImportingConstructor]
         public CodeEditorViewModel(LanguageDefinitionManager languageDefinitionManager)
         {
             _languageDefinitionManager = languageDefinitionManager;
         }
 
-        public override bool ShouldReopenOnStart
-        {
-            get { return true; }
-        }
-
-        public override void SaveState(BinaryWriter writer)
-        {
-            writer.Write(FilePath);
-        }
-
-        public override void LoadState(BinaryReader reader)
-        {
-            Load(reader.ReadString());
-        }
-
         protected override void OnViewLoaded(object view)
         {
             _view = (ICodeEditorView) view;
+            _statusBar = IoC.Get<IStatusBar>();
+
+            if (notYetLoaded)
+            {
+                ApplyOriginalText();
+                notYetLoaded = false;
+            }
         }
 
         public override bool Equals(object obj)
@@ -76,20 +73,52 @@ protected override Task DoSave(string filePath)
 
         private void ApplyOriginalText()
         {
+            // At StartUp, _view is null, so notYetLoaded flag is added
+            if (_view == null)
+            {
+                notYetLoaded = true;
+                return;
+            }
             _view.TextEditor.Text = _originalText;
 
             _view.TextEditor.TextChanged += delegate
             {
                 IsDirty = string.Compare(_originalText, _view.TextEditor.Text) != 0;
             };
 
+            UpdateStatusBar();
+
+            // To update status bar items, Caret PositionChanged event is added
+            _view.TextEditor.TextArea.Caret.PositionChanged += delegate
+            {
+                UpdateStatusBar();
+            };
+
             var fileExtension = Path.GetExtension(FileName).ToLower();
 
             ILanguageDefinition languageDefinition = _languageDefinitionManager.GetDefinitionByExtension(fileExtension);
 
             SetLanguage(languageDefinition);
         }
 
+        /// <summary>
+        /// Update Column and Line position properties when caret position is changed
+        /// </summary>
+        private void UpdateStatusBar()
+        {
+            int lineNumber = _view.TextEditor.Document.GetLineByOffset(_view.TextEditor.CaretOffset).LineNumber;
+            int colPosition = _view.TextEditor.TextArea.Caret.VisualColumn + 1;
+
+            // TODO: Now I don't know about Ch#
+            //int charPosition = _view.TextEditor.CaretOffset;
+
+            if (_statusBar != null && _statusBar.Items.Count >= 3)
+            {
+                _statusBar.Items[1].Message = string.Format("Ln {0}", lineNumber);
+                _statusBar.Items[2].Message = string.Format("Col {0}", colPosition);
+            }
+        }
+
         private void SetLanguage(ILanguageDefinition languageDefinition)
         {
             _view.TextEditor.SyntaxHighlighting = (languageDefinition != null)

src/Gemini/Framework/PersistedDocument.cs

@@ -1,5 +1,11 @@
+using Caliburn.Micro;
+using Gemini.Framework.Services;
+using Gemini.Properties;
+using Microsoft.Win32;
 using System.IO;
+using System.Linq;
 using System.Threading.Tasks;
+using System.Windows;
 
 namespace Gemini.Framework
 {
@@ -25,10 +31,78 @@ public bool IsDirty
             }
         }
 
-        public override void CanClose(System.Action<bool> callback)
+        // ShouldReopenOnStart, SaveState and LoadState are default methods of PersistedDocument.
+        public override bool ShouldReopenOnStart
         {
-            // TODO: Show save prompt.
-            callback(!IsDirty);
+            get { return (FilePath != null); }  // if FilePath is null, SaveState() will generate an NullExceptionError
+        }
+                
+        public override void SaveState(BinaryWriter writer)
+        {
+            writer.Write(FilePath);
+        }
+
+        public override async void LoadState(BinaryReader reader)
+        {
+            await Load(reader.ReadString());
+        }
+
+        public override async void CanClose(System.Action<bool> callback)
+        {
+            if (IsDirty)
+            {
+                // Show save prompt.  
+                // Note that CanClose method of Demo ShellViewModel blocks this. 
+                string title = IoC.Get<IMainWindow>().Title;
+                string fileName = Path.GetFileNameWithoutExtension(FileName);
+                string fileExtension = Path.GetExtension(FileName);
+                var fileType = IoC.GetAll<IEditorProvider>()
+                                  .SelectMany(x => x.FileTypes)
+                                  .SingleOrDefault(x => x.FileExtension == fileExtension);
+
+                string message = string.Format(Resources.SaveChangesBeforeClosingMessage, fileType.Name, fileName);
+                var result = MessageBox.Show(message, title, MessageBoxButton.YesNoCancel, MessageBoxImage.Warning);
+
+                if (result == MessageBoxResult.Yes)
+                {
+                    if (IsNew)
+                    {
+                        // Ask new file path.
+                        var filter = string.Empty;
+                        if (fileType != null)
+                            filter = fileType.Name + "|*" + fileType.FileExtension + "|";
+                        filter += Properties.Resources.AllFiles + "|*.*";
+
+                        var dialog = new SaveFileDialog() { FileName = this.FileName, Filter = filter };
+                        if (dialog.ShowDialog() == true)
+                        {
+                            // Save file.
+                            await Save(dialog.FileName);
+
+                            // Add to recent files. Temporally, commented out.
+                            //IShell _shell = IoC.Get<IShell>();
+                            //_shell.RecentFiles.Update(dialog.FileName);
+                        }
+                        else
+                        {
+                            callback(false);
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        // Save file.
+                        await Save(FilePath);
+                    }
+                }
+                else if (result == MessageBoxResult.Cancel)
+                {
+                    callback(false);
+                    return;
+                }
+            }
+
+            callback(true);
         }
 
         private void UpdateDisplayName()