7
CDE/Motif PST
CDEnext
X P
RINT
S
ERVICE
O
VERVIEW
This Functional Specification describes, from the end user's and application developer's perspective, all the public
components, APIs and GUIs that make up the X Print Service. The X Print Service enables X rendering to non-
display devices such as printers and fax machines. For CDEnext, support for PCL and Postscript printers will be
developed, and the architecture remains extensible to allow support for other non-display devices.
A companion book, The X Print Service Design Specification, serves as the blueprint document for the X Print
Service, and addresses architecture, design opportunities and decisions, and other aspects of the X Print Service.
1.1
X Print Service Overview
The X Print Service from CDEnext is an architectural-level solution and sample implementation which allows X
imaging to non-display devices such as printers. It is called the X "Print" Service because the primarily
application of the technology will be towards printing, but the technology will in fact be applicable to a range of
non-display devices. To date, print rendering technologies have evolved separately from display rendering
technologies. The thrust of the X Print Service is to converge the evolution of these print and display technologies.
For example, today's X environment provides a number of APIs and technologies for rendering to a display,
including:
x
Xlib
x
PEXlib
x
X Imaging Extension
x
OSF/Motif Toolkit
x
Scalable Fonts
By retaining and supplementing these (and many more) standard APIs with one small print-specific API:
x
libXp
The X Print Service will allow an existing X application to render against a printer in addition to traditional display
devices (note: the CDEnext sample implementation will not initially support all the X APIs).
1.1.1
X Print Service Core Components
The X Print Service is made up of the following core components (proposed for standardization via the X
Consortium):
x
X Print Extension - a new X-Server Extension and corresponding X Print Extension Protocol.
x
libXp - the X Print Extension Library which provides an API for applications to the X Print Extension
Protocol.