Updating Job Object Information(IM:XP)

Inside Macintosh: QuickDraw GX Printing /: Chapter 2 - Core Printing Features / Using Core Printing Features

Updating Job Object Information

When you receive a resume event, you should use the GXUpdateJob function to update the job object because the printing environment may have changed while the user was switched out of your application. For example, the user may have changed the desktop printer's settings, such as paper-tray information, while using another application.

Listing 2-17 shows an example of how to update the job object for a document. The GXUpdateJob function is called from the MyDoEvent function in response to a resume event.

Listing 2-17 Updating a job when receiving resume events

OSErr MyDoEvent(EventRecord *event)
{
   OSErr          err = noErr;
   WindowPtr      curWindow;
   MyDocumentPtr  windowDoc;

   switch (event->what)
   {
      /*
         Application-specific code to handle mouse-down events,
         update events, and so on.
      */
      case osEvt:
         switch ((event->message >> 24) & 0x0FF)
         {

            case suspendResumeMessage:
               SetCursor(&qd.arrow);

/* On a suspend event, coerce the scrap. */
               if ((event->message & resumeFlag) == 0)
               {
                  ZeroScrap();
                  TEToScrap();
               }
               else
               {

/* 
   On a resume event, call GXUpdateJob on all of the documents' 
   job objects. The user may have just changed something which 
   affects the job objects, such as the size of the paper in the 
   printer.

   Since your application stores the document pointers in the 
   reference constant fields of the documents' windows, loop 
   through each window, extract the document pointers, and update 
   the associated job objects.
*/
                  if (event->message & convertClipboardFlag)
                     TEFromScrap();
                  curWindow = FrontWindow();
                  while (curWindow != nil)
                  {
                     if (((WindowPeek) curWindow)->windowKind == 
                                                         userKind)
                     {
                        windowDoc = (MyDocumentPtr) 
                                          GetWRefCon(curWindow);
                        GXUpdateJob(windowDoc->documentJob);
                     }
                     curWindow = (WindowPtr) ((WindowPeek) 
                                          curWindow)->nextWindow;
                  }
               }
               break;
         }
         break;

      /*
         Application-specific code to handle high-level events.
      */
   }
   return err;
}