The XML Notepad Form

 using System; 
 using System.Drawing; 
 using System.IO; 
 using System.Windows.Forms; 
 using NUnit.Framework; 
 using System.Collections; 
 using System.Text.RegularExpressions; 
 namespace Notepad { 
 class XMLNotepad : Form { 
 public TestableTextBox textbox; 
 private TextModel model; 
 private MenuItem insertPre; 
 private MenuItem insertSection; 
 private MenuItem openFile; 
 private MenuItem saveFile; 
 private ModelAction enterAction; 
 private ModelAction shiftEnterAction; 
 private ModelAction insertSectionAction; 
 private ModelAction insertPreTagAction; 
 private ModelAction saveAction; 
 private ModelAction loadAction; 
 private String fileName; 
 private Boolean displayDialog = true; 
 public delegate void ModelAction(); 
 public MenuItem MenuForAccelerator(string accelerator) { 
 if (accelerator == "&S") return insertSection; 
 if (accelerator == "&P") return insertPre; 
 if (accelerator == "^O") return openFile; 
 if (accelerator == "^S") return saveFile; 
 return null; 
 } 
 [STAThread] 
 static void Main(string[] args) { 
 Application.Run(new XMLNotepad()); 
 } 
 public XMLNotepad() { 
 initialize(new TextModel()); 
 } 
 public XMLNotepad(TextModel model) { 
 initialize(model); 
 } 
 private void initialize(TextModel model) { 
 InitializeDelegates(model); 
 this.model = model; 
 this.Text = "XML Notepad"; 
 MenuItem fileMenu = new MenuItem("&File"); 
 MenuItem newFile = new MenuItem("&New"); 
 newFile.Click += new EventHandler(MenuFileNewOnClick); 
 newFile.Shortcut = Shortcut.CtrlN; 
 fileMenu.MenuItems.Add(newFile); 
 openFile = new MenuItem("&Open..."); 
 openFile.Click += new EventHandler(MenuFileOpenOnClick); 
 openFile.Shortcut = Shortcut.CtrlO; 
 fileMenu.MenuItems.Add(openFile); 
 saveFile = new MenuItem("&Save"); 
 saveFile.Click += new EventHandler(MenuFileSaveOnClick); 
 saveFile.Shortcut = Shortcut.CtrlS; 
 fileMenu.MenuItems.Add(saveFile);       MenuItem saveAsFile = new MenuItem("Save &As..."); 
 saveAsFile.Click += new EventHandler(MenuFileSaveAsOnClick); 
 fileMenu.MenuItems.Add(saveAsFile); 
 insertSection = new MenuItem ( 
 "Insert &Section", 
 new EventHandler(MenuInsertSection)); 
 insertPre = new MenuItem ( 
 "Insert &Pre", 
 new EventHandler(MenuInsertPre)); 
 this.Menu = new MainMenu(new MenuItem[] {fileMenu, insertPre, 
 insertSection} ); 
 this.textbox = new TestableTextBox(); 
 this.textbox.Parent = this; 
 this.textbox.Dock = DockStyle.Fill; 
 this.textbox.BorderStyle = BorderStyle.None; 
 this.textbox.Multiline = true; 
 this.textbox.ScrollBars = ScrollBars.Both; 
 this.textbox.AcceptsTab = true; 
 this.textbox.KeyDown += new KeyEventHandler(XMLKeyDownHandler); 
 this.textbox.KeyPress += new KeyPressEventHandler(XMLKeyPressHandler); 
 this.textbox.Visible = true; 
 this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); 
 this.ClientSize = new System.Drawing.Size(292, 266); 
 this.Controls.AddRange(new System.Windows.Forms.Control[] { 
 this.textbox}); 
 this.Name = "XMLNotepad"; 
 } 
 private void InitializeDelegates(TextModel model) { 
 enterAction = new ModelAction(model.Enter); 
 shiftEnterAction = new ModelAction(model.InsertReturn); 
 insertSectionAction = new ModelAction(model.InsertSectionTags); 
 insertPreTagAction = new ModelAction(model.InsertPreTag); 
 saveAction = new ModelAction(this.SaveFile); 
 loadAction = new ModelAction(this.LoadFile); 
 } 
 void MenuInsertSection(object obj, EventArgs ea) {       CallModel(insertSectionAction); 
 } 
 
 void MenuInsertPre(object obj, EventArgs ea) { 
 CallModel(insertPreTagAction); 
 } 
 void MenuFileNewOnClick(object obj, EventArgs ea) { 
 } 
 void MenuFileSaveOnClick(object obj, EventArgs ea) { 
 CallModel(saveAction); 
 } 
 void MenuFileOpenOnClick(object obj, EventArgs ea) { 
 FileOperation(new OpenFileDialog(), loadAction); 
 } 
 void MenuFileSaveAsOnClick(object obj, EventArgs ea) { 
 FileOperation(new SaveFileDialog(), saveAction); 
 } 
 private void FileOperation(FileDialog dialog, ModelAction action) { 
 if (displayDialog) { 
 DialogFileAction(dialog, action); 
 } 
 else { 
 CallModel(action); 
 } 
 displayDialog = true; 
 } 
 private void DialogFileAction(FileDialog dialog, ModelAction action) { 
 dialog.Filter = "xml files (*.xml)*.xmlAll files (*.*)*.*"; 
 dialog.FilterIndex = 2 ; 
 dialog.RestoreDirectory = true ; 
 if(dialog.ShowDialog() == DialogResult.OK) { 
 fileName = dialog.FileName; 
 CallModel(action); 
 } 
 } 
 void SaveFile() { 
 using ( StreamWriter writer = File.CreateText(fileName) ) { 
 model.Save(writer); 
 } 
 } 
 void LoadFile() { 
 using ( StreamReader reader = File.OpenText(fileName) ) { 
 model.Load(reader); 
 } 
 } 
 public void XMLKeyPressHandler(object objSender, KeyPressEventArgs kea) { 
 if ((int) kea.KeyChar == (int) Keys.Enter) { 
 kea.Handled = true;         // this code is here to avoid putting extra enters in the window. 
 // if removed, when you hit enter, the new <P> line breaks in two: 
 // <P> 
 // </P>  like that. 
 } 
 } 
 
 private void CallModel(ModelAction modelAction) { 
 GetText(); 
 modelAction(); 
 PutText(textbox, model.LinesArray(), model.SelectionStart); 
 } 
 public void XMLKeyDownHandler(object objSender, KeyEventArgs kea) { 
 if (kea.KeyCode == Keys.Enter && kea.Modifiers == Keys.None) { 
 CallModel(enterAction); 
 kea.Handled = true; 
 } 
 else if (kea.KeyCode == Keys.Enter && kea.Modifiers == Keys.Shift) { 
 CallModel(shiftEnterAction); 
 kea.Handled = true; 
 } 
 } 
 internal void PutText(ITestTextBox textbox, string[] lines, 
 int selectionStart) { 
 // this is Feature Envy big time. 
 textbox.Lines = lines; 
 textbox.SelectionStart = selectionStart; 
 textbox.ScrollToCaret(); 
 } 
 private void GetText() { 
 model.SetLines(textbox.Lines); 
 model.SelectionStart = textbox.SelectionStart; 
 } 
 internal void CustomerTestPutText() { 
 PutText(textbox, model.LinesArray(), model.SelectionStart); 
 } 
 internal void SetFileName(String name) { 
 fileName = name; 
 } 
 internal void SetNoFileDialog() { 
 displayDialog = false; 
 } 
 } 
 }