Menu Array

My first move will be to replace the scalar NotepadMenuItem variables with a single array. I ll do that in small steps so as not to go wrong. First I ll put the menu items into an array and make the MenuForAccelerator() method use the array. Then I ll eliminate the scalars. Just for convenience, I think I ll start with an ArrayList, even though I m not sure if I can use it in the menu creation. The ArrayList will make for cleaner code ”at least I think it will:

 class XMLNotepad : Form { 
 public TestableTextBox textbox; 
 private TextModel model; 
 private MenuItem insertPre; 
 private MenuItem insertSection; 
 private MenuItem insertUnorderedList; 
 private MenuItem insertOrderedList; 
  private ArrayList insertMenus;  
 private MenuItem openFile; 
 private MenuItem saveFile; 
 private ModelAction enterAction; 
 private ModelAction shiftEnterAction; 
 private ModelAction saveAction; 
 private ModelAction loadAction; 
 private String fileName; 
 private Boolean displayDialog = true; 
 public delegate void ModelAction(); 
 public MenuItem MenuForAccelerator(string accelerator) { 
 if (accelerator == "^O") return openFile; 
 if (accelerator == "^S") return saveFile; 
  foreach( NotepadMenuItem m in insertMenus) {   if (m.Text.IndexOf(accelerator)  >  = 0)  
  return m;  
  }  
   return null; 
 } 
 private void initialize(TextModel model) { 
 ... 
  insertMenus = new ArrayList();  
 insertSection = new NotepadMenuItem ( 
 "Insert &Section", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.Section); 
  insertMenus.Add(insertSection);  
 insertPre = new NotepadMenuItem ( 
 "Insert &Pre", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.Pre ); 
  insertMenus.Add(insertPre);  
   insertUnorderedList = new NotepadMenuItem ( 
 "Insert &UL", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.UnorderedList ); 
  insertMenus.Add(insertUnorderedList);  
 insertOrderedList = new NotepadMenuItem ( 
 "Insert &OL", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.OrderedList ); 
  insertMenus.Add(insertOrderedList);  
 this.Menu = new MainMenu(new MenuItem[] 
 {fileMenu, insertPre, insertSection, insertUnorderedList, 
 insertOrderedList} ); 

There s no complaining about this. The code is pretty clear, and it works the first time. Now let s use the ArrayList to define the main menu. That makes the above code look like this:

 insertMenus = new ArrayList(); 
  insertMenus.Add  (new NotepadMenuItem ( 
 "Insert &Section", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.Section)); 
  insertMenus.Add  (new NotepadMenuItem ( 
 "Insert &Pre", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.Pre )); 
  insertMenus.Add  (new NotepadMenuItem ( 
 "Insert &UL", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.UnorderedList )); 
  insertMenus.Add  (new NotepadMenuItem ( 
 "Insert &OL", 
 new EventHandler(MenuInsertTags), 
 TextModel.Tags.OrderedList )); 
 this.Menu = new MainMenu(new MenuItem[] {fileMenu} ); 
  this.Menu.MenuItems.   AddRange((MenuItem[])  insertMenus.ToArray(typeof(NotepadMenuItem)));  

I don t like that ugly typeof() usage, but it s a small price to pay for the use of the ArrayList elsewhere. We could build a custom class to avoid the typeof, but until Microsoft gives us generics, that seems like too much work for the benefit.

Lesson: Quick Reflection

The work I ve done so far in this chapter, including writing this much of the chapter, took me about thirty minutes. Already the code ”and the process ”is a bit better. Now when we add a new menu item, we don t have to add a private variable for each one or remember to add it to the MenuFor Accelerator() method ”a noticeable improvement. Thinking of the private menu items reminds me ”let s remove those to get this:

 

 class XMLNotepad : Form { 
 public TestableTextBox textbox; 
 private TextModel model; 
  //    private MenuItem insertPre;  
  //    private MenuItem insertSection;  
  //    private MenuItem insertUnorderedList;  
  //    private MenuItem insertOrderedList;  
   private ArrayList insertMenus; 
 private MenuItem openFile; 
 private MenuItem saveFile; 
 private ModelAction enterAction; 
 private ModelAction shiftEnterAction; 
 private ModelAction saveAction; 
 private ModelAction loadAction; 
 private String fileName; 
 private Boolean displayDialog = true; 
 ... 

I m showing them commented out for your convenience, but now I ll delete them for real. And the code compiles, and the tests run correctly.