XpCreateContext.man   [plain text]

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.TH XpCreateContext 3Xp __xorgversion__ "XPRINT FUNCTIONS"
.SH NAME
XpCreateContext \- Creates and initializes a new print context.
.SH SYNOPSIS
.br
      cc [ flag... ] file... -lXp [ library... ]	
.br
      #include <X11/extensions/Print.h>
.LP    
.B XPContext XpCreateContext
(
.I display, 
.I printer_name
)
.br
      Display *\fIdisplay\fP\^;
.br
      char *\fIprinter_name\fP\^;
.if n .ti +5n
.if t .ti +.5i
.SH ARGUMENTS
.TP
.I display
Specifies a pointer to the Display structure; returned from XOpenDisplay.
.TP
.I printer_name
The name of a printer on display. String encoded as COMPOUND_TEXT.
.SH DESCRIPTION
.LP
XpCreateContext creates a new print context that is initialized with the default 
printer attributes and other information available for 
.I 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 
.I printer_name 
is invalid, a BadMatch is generated later by the 
.I X Print Server.

A call to XpGetPrinterList will return a valid list of values for 
.I 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 
.I 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 
.I client's 
locale (see XpSetLocaleHinter) is 
included in the request as a "hint" to the 
.I X Print Server. 
If supported by the 
implementation, the 
.I 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 
.I X Print Server 
cannot understand the hint, the 
.I X Print Server 
chooses a default value.

This function can generate a BadMatch error if the specified
.I printer_name
does not exist on display, or if the print server could not interpret the code 
set specified in 
.I printer_name.
.SH DIAGNOSTICS
.TP 15
.SM 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.
.SH "SEE ALSO"
.BR XpDestroyContext (3Xp),
.BR XpGetAttributes (3Xp),
.BR XpGetPrinterList (3Xp),
.BR XpGetScreenOfContext (3Xp),
.BR XpInputSelected (3Xp),
.BR XpSelectInput (3Xp),
.BR XpSetAttributes (3Xp),
.BR XpSetContext (3Xp),
.BR XpSetLocaleHinter (3Xp),
.BR XpStartJob (3Xp)