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Functional specification
14
CDE/Motif PST
CDEnext
1.4
The Printer Vendor's View
The printer vendor is the person or company that will wish to enhance the X Print Service so that it can support a
new model of printer or page description language. Enhancements may be as simple as providing new printer
model configuration files to providing a new ddx driver and corresponding Print Dialog manager.
The major points of enhancability within the X Print Service are:
x
The ddx driver layer in the X Print Server. New ddx drivers can be added to support new page description
languages, provide more capabilities, or provide tighter integration with a given printer model.
x
The Print Dialog Manager, either as a new executable or enhancement of an existing Print Dialog
Manager, to provide dialogs that expose highly printer specific options to the user and that communicates
through the Print Context attributes with the ddx driver.
x
The printer model files. These files describe the capabilities and defaults of printers based by model.
1.5
The System Administrator's View
The system administrator is the person who will configure and maintain the system processes and files associated
with the X Print Service. The X Print Service has built-in fallback defaults for nearly everything, but can be highly
configured to custom environments.
The X Print Service architecture has been designed so that support for specific page description languages and
spooler subsystems is isolated to the X Print Server's ddx layer and a corresponding layer in the Dt Print Dialog
Manager. With this architecture, support for new page description languages and spooler subsystems can be
centrally added without having to reconfigure applications.
Support for specific types of printers and descriptions of the printer topology is also centralized in configuration
files maintained by the X Print Server. Using libXp, the configuration information can be retrieved by applications
and the Dt Print Dialog Manager.
The key areas of configuration and system administration are:
x
X Print Service Startup - Deciding if a "per user session" or "global service" model of operation is desired.
For the per user session model, the session manager (e.g. dtsession) could, if extended, start the Print X
Server and Dt Print Page Manager. For the global session model, a script (or program) could be
responsible for starting the X Print Servers and Dt Print Dialog Managers. And depending on the system
administrator's security demands, the script may also distribute authorization information (e.g. MIT-
MAGIC-COOKIE-1's) so that the servers can be accessed by applications (users).
x
X Print Server Startup - Configuration files to control which printers are available.
x
Attribute files - A collection of files that define the full range of capabilities of the printers accessed by the
X Print Servers (e.g. 150, 300 and 600dpi supported), and default values (e.g. use 300dpi).
x
Printer Model files - A collection of files typically supplied by a printer vendor to describe the capabilities
of specific printer models (e.g. Laserjet 4si). These files will generally not require reconfiguration, but may
be useful to reference when configuring files that describe the actual physical printers available (e.g.
eliminate the selection of duplex printing because the printer's duplexer isn't working).