Add save prompt and modify CodeEditor and TextEditor

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

@@ -12,6 +12,7 @@
              BorderThickness="0"
              FontFamily="Consolas"
              FontSize="14"
+             TextWrapping="Wrap"
              ScrollViewer.VerticalScrollBarVisibility="Auto"
              ScrollViewer.HorizontalScrollBarVisibility="Auto"/>
 </UserControl>

src/Gemini/Framework/Document.cs

@@ -1,7 +1,3 @@
-using System.IO;
-using System.Linq;
-using System.Threading.Tasks;
-using System.Windows.Input;
 using Caliburn.Micro;
 using Gemini.Framework.Commands;
 using Gemini.Framework.Services;
@@ -14,10 +10,14 @@
 using Gemini.Modules.UndoRedo.Commands;
 using Gemini.Modules.UndoRedo.Services;
 using Microsoft.Win32;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Input;
 
 namespace Gemini.Framework
 {
-	public abstract class Document : LayoutItemBase, IDocument, 
+    public abstract class Document : LayoutItemBase, IDocument, 
         ICommandHandler<UndoCommandDefinition>,
         ICommandHandler<RedoCommandDefinition>,
         ICommandHandler<SaveFileCommandDefinition>,
@@ -125,22 +125,21 @@ async Task ICommandHandler<SaveFileAsCommandDefinition>.Run(Command command)
 	    }
 
 	    private static async Task DoSaveAs(IPersistedDocument persistedDocument)
-	    {
-            // Show user dialog to choose filename.
-            var dialog = new SaveFileDialog();
-            dialog.FileName = persistedDocument.FileName;
+	    {   
             var filter = string.Empty;
-
             var fileExtension = Path.GetExtension(persistedDocument.FileName);
             var fileType = IoC.GetAll<IEditorProvider>()
                 .SelectMany(x => x.FileTypes)
                 .SingleOrDefault(x => x.FileExtension == fileExtension);
             if (fileType != null)
                 filter = fileType.Name + "|*" + fileType.FileExtension + "|";
-
             filter += "All Files|*.*";
-            dialog.Filter = filter;
 
+            // Show user dialog to choose filename.
+            // Note that SaveFileDialog may need Administrator right.
+            var dialog = new SaveFileDialog();
+            dialog.FileName = persistedDocument.FileName;       
+            dialog.Filter = filter;
             if (dialog.ShowDialog() != true)
                 return;
 

src/Gemini/Framework/PersistedDocument.cs

@@ -1,6 +1,12 @@
+using Caliburn.Micro;
+using Gemini.Framework.Services;
+using Gemini.Properties;
+using Microsoft.Win32;
 using System.IO;
-using System.Threading;
 using System.Threading.Tasks;
+using System.Windows;
+using System.Linq;
+using System.Threading;
 
 namespace Gemini.Framework
 {
@@ -26,10 +32,82 @@ public bool IsDirty
             }
         }
 
+        // ShouldReopenOnStart, SaveState and LoadState are default methods of PersistedDocument.
+        public override bool ShouldReopenOnStart
+        {
+            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 Task<bool> CanCloseAsync(CancellationToken cancellationToken)
         {
-            // TODO: Show save prompt.
-            return Task.FromResult(!IsDirty);
+            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 + "|*.*";
+
+                        // note that SaveFileDialog may need Administrator right.
+                        var dialog = new SaveFileDialog();
+                        dialog.FileName = this.FileName;
+                        dialog.Filter = filter;
+                        if (dialog.ShowDialog() == true)
+                        {
+                            // Save file.
+#pragma warning disable 4014
+                            Save(dialog.FileName);
+#pragma warning restore 4014
+                            // Add to recent files. Temporally, commented out.
+                            //IShell _shell = IoC.Get<IShell>();
+                            //_shell.RecentFiles.Update(dialog.FileName);
+                        }
+                        else
+                        {
+                            return Task.FromResult(false);
+                        }
+                    }
+                    else
+                    {
+                        // Save file.
+#pragma warning disable 4014
+                        Save(FilePath);
+#pragma warning restore 4014
+                    }
+                }
+                else if (result == MessageBoxResult.Cancel)
+                {
+                    return Task.FromResult(false);
+                }
+            }
+
+            return Task.FromResult(true);
         }
 
         private void UpdateDisplayName()