The Spool Library: 8 Debugging Tips

Though GEOS provides an easy-to-use printer interface, mistakes are sure to happen. You may find the following information useful in catching your mistakes or for testing rigorously.

Under Swat, you can see the various threads the Spooler works with. There is always one spool thread running in the background. When the first job is queued on a printer, you can see that a new thread is created for that printer. When the last job for a printer is completed, the thread exits again.

Here are the most common printing mistakes:

Forgetting to add the Print Control object to the application's Active List (the GAGCNLT_SELF_LOAD_OPTIONS GCN list).
Not setting the document name (see Document Name Output ).
Setting the number of pages (page range) incorrectly.

GEOS SDK TechDocs |

7 Other Printing Components