XpCreateContext



XpCreateContext

NAME
SYNOPSIS
ARGUMENTS
DESCRIPTION
DIAGNOSTICS
SEE ALSO

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)






Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.