XpCreateContext(3Xp) XPRINT FUNCTIONS XpCreateContext(3Xp)NAMEXpCreateContext - Creates and initializes a new print context.
SYNOPSIS
cc [ flag... ] file... -lXp [ library... ]
#include <X11/extensions/Print.h>
XPContext XpCreateContext ( display, printer_name )
Display *display;
char *printer_name;
ARGUMENTS
display
Specifies a pointer to the Display structure; returned from
XOpenDisplay.
printer_name
The name of a printer on display. String encoded as COM‐
POUND_TEXT.
DESCRIPTIONXpCreateContext creates a new print context that is initialized with
the default printer attributes and other information available for
printer_name on display. A print context maintains the printer name,
print attributes, font capabilities, print (rendering) state and
results, and is the object upon which the Xp calls act.
If the library fails to generate a new print context-id, a value of
None is returned, otherwise a print context-id is always returned. If
printer_name is invalid, a BadMatch is generated later by the X Print
Server.
A call to XpGetPrinterList will return a valid list of values for
printer_name. All printer name values in the X Print Service are
encoded as COMPOUND_TEXT (of which the ISO-8859-1 code-set is a proper
subset).
As soon as a print context is created, the print attributes in it can
be accessed and modified by calling XpGetAttributes and XpSetAt‐
tributes, and the event selections in it can be modified by calling
XpSelectInput and XpInputSelected. Other Xp calls that explicitly take
a print context-id as a parameter will operate directly on that print
context. All Xp and X calls without a print context-id parameter (for
example, all rendering oriented calls like XpStartJob and XDrawLine)
require that a print context be set on the display connection (see
XpSetContext). Failure to set a print context prior to calling a print-
context-dependent call will result in the generation of an XPBadContext
error.
The XPContext returned by XpCreateContext is an XID, and can be used to
set the print context on display connections by calling XpSetContext.
The XPContext id can be shared between processes and display connec‐
tions. It is the responsibility of the clients sharing a print context
to coordinate their usage of the context; for example they must ensure
that in-use print contexts are not prematurely destroyed.
The context_id remains valid for all clients until 1) the client creat‐
ing the print context closes its display connection, or 2) any client
calls XpDestroyContext. The context_id can be kept valid after the cre‐
ating client's display connection closes if XSetCloseDownMode is called
on display with RetainPermanent or RetainTemporary.
After creating a print context, and possibly modifying the XPDocAttr
attribute document-format using a value from the list of available for‐
mats shown in the XPPrinterAttr attribute document-formats-supported,
the application must query the X Print Server via XpGetScreenOfContext
for the screen that has been associated with the print context, and
then create all server resources that will be used in the print job on
that screen. Failure to do so will result in undefined behavior.
When XpCreateContext is called, the client's locale (see XpSetLocale‐
Hinter) is included in the request as a "hint" to the X Print Server.
If supported by the implementation, the X Print Server will use the
hint to initialize the attribute pools with any localized attribute
values (for example, the human readable XPPrinterAttr attribute
"descriptor" may be available in several different languages, and the
hint will be used to select one). If the X Print Server cannot under‐
stand the hint, the X Print Server chooses a default value.
This function can generate a BadMatch error if the specified
printer_name does not exist on display, or if the print server could
not interpret the code set specified in printer_name.
DIAGNOSTICS
BadMatch The value specified for doc_fmt is not valid for the
current document type or the value specified for draw‐
able is not valid for the print context and print
screen.
SEE ALSOXpDestroyContext(3Xp), XpGetAttributes(3Xp), XpGetPrinterList(3Xp),
XpGetScreenOfContext(3Xp), XpInputSelected(3Xp), XpSelectInput(3Xp),
XpSetAttributes(3Xp), XpSetContext(3Xp), XpSetLocaleHinter(3Xp),
XpStartJob(3Xp)X Version 11 libXp 1.0.0 XpCreateContext(3Xp)
