Inside Macintosh: Cyberdog Programmer's Kit / Part 2 - Programming in Cyberdog

Chapter 3 - Adding Cyberdog Features to an OpenDoc Part

Implementing the Cyberdog Preferences Command

The Cyberdog Preferences command responds to its corresponding menu item to display the Cyberdog Preferences dialog box. When your part is activated, its AdjustMenus method is called to set up its menus. You can modify this method to enable the Cyberdog Preferences menu item. To enable the Cyberdog preferences menu item, you must take these actions:

• Set the menu item string and enable a command for the preferences.
• Call the Cyberdog service menu's Adjust method

Listing 3-15 shows the button part's AdjustMenus method.

Listing 3-15 The button part's AdjustMenus method

void CybTxtBtn::AdjustMenus( Environment* ev,
                       ODFrame* frame )
{
   if (frame->IsRoot(ev))
   {
      // A root part must validate the menu bar before displaying it
      // because a part can swap the base menu bar at any time.
      CheckMenus(ev, kODNULL);
   }     
   // After copying the base menu bar, install your part's menus.
   ...
   TRY
      ...
      ODArbitrator* arbitrator 
                     = ODGetSession(ev,fSelf)->GetArbitrator(ev);
      TempODFrame menuOwner 
         = arbitrator->AcquireFocusOwner(ev, gGlobals->fMenuFocus);
      if ( ODObjectsAreEqual(ev, frame, menuOwner) )
      {
         Str63 text;
         ...
         ODGetIndString(text, kMenuStringResID, kDefaultContent2ID);
         // Create an IText object to pass into the menu bar.
         TempODIText prefItem(CreateIText(gGlobals->fEditorsScript,
                         gGlobals->fEditorsLanguage,
                         (StringPtr)&text));
         // Change the text of the "Preferences" menu item.
         fMenuBar->SetItemString(ev, kODCommandPreferences, prefItem);
         fMenuBar->EnableCommand(ev, kODCommandPreferences, kODTrue);
      }
      // Allow Cyberdog services to enable or disable their menu items.
      if(fCyberServiceMenu)
         fCyberServiceMenu->Adjust(ev, frame);
   CATCH_ALL
   ENDTRY
}

Note

In this example, the part's standard Preferences menu item, specified by kODCommandPreferences, is replaced by the Cyberdog Preferences menu item. u

When a menu event occurs, you should call the Cyberdog service menu's DoCommand method to allow a Cyberdog service to handle the event. If the Cyberdog Preferences menu item is selected, you must call the Cyberdog session's ShowPreferencesDialog method to display the Cyberdog Preferences dialog box. Listing 3-16 shows the button part's HandleMenuEvent method.

Listing 3-16 The button part's HandleMenuEvent method

ODBoolean CybTxtBtn::HandleMenuEvent(Environment* ev,
                            ODEventData* event,
                            ODFrame* frame )
{
   ODULong menuResult = event->message;
   ODUShort menu = HiWord(menuResult);
   ODUShort item = LoWord(menuResult);
   ODBoolean handled = kODTrue;
   ODULong commandID;
   
   commandID = fMenuBar->GetCommand(ev, menu, item);
   
   // Give Cyberdog the first chance at the command.
   if (fCyberServiceMenu)
      handled = fCyberServiceMenu->DoCommand(ev, commandID, frame);

   if (handled == kODFalse)
   {
      switch (commandID)
      {
         ...
         // The Cyberdog Preferences command was sent.
         // Show the Cyberdog Preferences dialog box.
         case kODCommandPreferences:
            CyberSession* cyberSession = GetCyberSession(ev);
            cyberSession->ShowPreferencesDialog(ev);
            handled = kODTrue;
         break;
         ...
         default:
            handled =  kODFalse;
      }
   }
   return handled;
}