Technical Q&A

QD 41 - Using Background Printing When The Finder Isn't Present (4-Mar-96)

Note:

This isn't officially supported, and the methods used are likely to change, so you'll want to check new versions of System software to make sure your application still works correctly. This is a hard thing to do, and will only become harder under Copland (if it is possible at all). Note also that there are third-party background-printing solutions which are not covered here. You'll need to work with the various third-parties to solve compatibility problems with their products.

Here's the approach, in three parts:

A: Old print architecture, no desktop printing

Your application needs to monitor the Print Monitor Documents folder within the System Folder. On older versions of system software, this folder is called Spool Folder. When you see a file within that folder, you can launch Print Monitor and the file will be sent to the printer.

B: Old print architecture, with desktop printing installed

Before quitting the Finder, make sure desktop printers are all done printing (Any jobs currently in desktop printers stop when the Finder goes away). Once all DTPs are clear, follow the same steps as A.

C: QuickDraw GX

Watch the Print Monitor Documents folder, and launch PrinterShare GX. Make sure to handle any events it passes back to you, since these are error conditions and the user will need to be alerted. Since PrinterShare GX looks for the Finder by looking for a process whose ProcessType is 'FNDR', you'll have to mimic that behavior. You can use the application AETracker to find out which events you will need to handle. (AETracker is available on the Developer CD Series in the Testing & Debugging folder on the ToolChest Edition.)