XpCreateContext
Section: XPRINT FUNCTIONS (3Xp)
Updated: libXp 1.0.3
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NAME
XpCreateContext - 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 COMPOUND_TEXT.
DESCRIPTION
XpCreateContext 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 XpSetAttributes, 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 connections. 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 creating the
print context closes its display connection, or 2) any client calls
XpDestroyContext. The context_id can be kept valid after the creating 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 formats 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 XpSetLocaleHinter) 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 understand 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 drawable is not valid for the print context and print
screen.
SEE ALSO
XpDestroyContext(3Xp),
XpGetAttributes(3Xp),
XpGetPrinterList(3Xp),
XpGetScreenOfContext(3Xp),
XpInputSelected(3Xp),
XpSelectInput(3Xp),
XpSetAttributes(3Xp),
XpSetContext(3Xp),
XpSetLocaleHinter(3Xp),
XpStartJob(3Xp)
Index
- NAME
-
- SYNOPSIS
-
- ARGUMENTS
-
- DESCRIPTION
-
- DIAGNOSTICS
-
- SEE ALSO
-