Technical Q&As


GXPD 21 - Creating a GX Printing Extension to Obtain Print Job Information (1-July-95)


Important for all Apple Printing and Graphics Developers:

The information in this Technical Q & A is still relevant up to and including Mac OS 7.6 with QuickDraw GX 1.1.5. Beginning with the release of Mac OS 8.0, however, Apple plans to deliver a system which incorporates QuickDraw GX graphics and typography only. QuickDraw GX printer drivers and GX printing extensions will not be supported in Mac OS 8.0 or in future Mac OS releases. Apple's goal is to simplify the user experience of printing by unifying the Macintosh graphic and printing architectures and standardizing on the classic Printing Manager.

For details on Apple's official announcement, refer to </dev/technotes/gxchange.html>

Q I am attempting to write a GX Printing Extension in which I can get the job information from the gxJobTag collection item during the despooling phase. I need to get access to the print queues, so that I can know about every job that is being printed when it prints. I want to set the default printer and get a list of all installed desktop printers.

A There is no supported mechanism an application can use to rearrange desktop printer queues. The only way for the queues to be manipulated is by direct action by the user. There is no API to allow an application to act on behalf of the user.

If this functionality is implemented in a future version, it would best be achieved by making the desktop-printer Finder extension (the part of GX which is responsible for DTP icons and queues) fully scriptable. This would enable both end users and applications to automate DTPs by sending the appropriate AppleScript to the Finder.

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