2
December 15, 1997
X Print Service Overview
2
X Print Service Overview
Release 6.4
X Version 11
1.2
X Print Service Key Concepts
The center of the X Print Service is the X Print Server. To an X application, it should look and behave like a
regular X Server with the following enhancements.
Figure 0-1.X Print Service Key Concepts Diagram
When the X Print Server starts, it may read a configuration file for instructions concerning which print DDX
drivers to load and which printer names to support. It may also read some DDX dependent configuration
files.
At this point, the X Print Server knows which printers to support, and has access to printer model configura-
tion files that describe the capabilities of the printer models. Parallel to the printer model configuration files
are some printer attribute configuration files which can be modified if per-printer customization is desired.
When an application wishes to print, it can make a display connection to the X Print Server and ask to see
the list of available printers by way of the
XpGetPrinterList request. Once the application has selected a
printer, it can create and set a Print Context using
XpCreateContext and XpSetContext.
The Print Context represents the embodiment of the printer selected. It is initialized by the X Print Server at
XpCreateContext time to contain a printer's default capabilities as well as the description of its overall capa-
bilities, and to maintain the state of settings on the printer, the state of rendering against the printer, and the
rendered output. The Print Context affects how the DDX driver generates its page description language
(PDL), and how the PDL is submitted to a spooler. The Print Context may also affect fonts and other ele-
X Application
DIX + OS +
Print DDX
Print Extension
Print Contexts
Fonts + Other
Print Spooler
Print Dialog Manager
XpGetPrinterList
XpCreateContext
XpStartJob
...x rendering...
XpEndJob
XpSetContext
XpGetAttributes
XpSetAttributes
XpNotifyPdm
Printers config file
(config needed)
Printer model files
(provided by printer vendors)
Printer attribute files
(some config needed)
DDX config files
(provided by DDX vendors)
Job, Document & Page attributes
Server & Printer attributes