libXp

libXp(3Xp)		       XPRINT FUNCTIONS			   libXp(3Xp)



NAME
       libXp - X Print Client Library

SYNOPSIS
       cc [ flag...  ] file...-lXp [ library...	 ]
       #include <X11/extensions/Print.h>

DESCRIPTION
       libXp  provides	public APIs to allow client applications to render to
       non-display devices.

       When an application wishes to print, it makes a display connection  to
       the X print server and asks to see the list of printers available with
       an XpGetPrinterList() request. Once the	application  has  selected  a
       printer,	 it  creates and sets a print context using XpCreateContext()
       and XpSetContext().

       The Print Context represents the embodiment of the  printer  selected.
       It  is  initialized  by the Xprint server at XpCreateContext() time to
       contain a printer’s default capabilities, as well as, the  description
       of  its	overall capabilties, and to maintain the state of settings on
       the printer, the state of rendering against the printer, and the	 ren-
       dered output.

       The  Print  Context  affects  how  the  DDX  driver generates its page
       description language (PDL) and how the PDL is submitted to a  spooler.
       The  print context may also affect fonts and other elements in the dix
       layer of the X Print Server. The print contexts can  be	shared	among
       processes.  Applications can enlist the help of secondary processes to
       manipulate print options in the Print context rather  than  taking  on
       the task directly.

       Once an application has set options within the print context, it makes
       calls such as XpStartJob() to delineate	jobs,  documents,  and	pages
       within a sequence of normal X calls.

       A  job  is a collection of documents, where each document is in turn a
       collection of pages. When XpEndJob() is called, the resulting  PDL  is
       either  sent to a print spooler or can be retrieved by the application
       itself.

       The developer basically has to make changes to the  X  application  to
       make use of the X Print Service.


       A  simple  X  application supplemented with some of the libXp routines
       might look like this:




       #include <X11/Xlib.h>
       #include <X11/extensions/Print.h>

       main()
       {
	   Display *pdpy;
	   Screen *pscreen;
	   Window pwin;
	   XPPrinterList plist;
	   XPContext pcontext;
	   int plistCnt;
	   char *attrPool;
       #define NPOOLTYPES 5
	   XPAttributes poolType[NPOOLTYPES] = {XPJobAttr,XPDocAttr,XPPageAttr,
				 XPPrinterAttr,XPServerAttr};
	   int i;
	   unsigned short width, height;
	   XRectangle rect;
	   char *printServerName = ":1";
	   char *mylaser = "varos";

	   /*
	    * connect to the X print server
	    */
	   pdpy = XOpenDisplay( printServerName );

	   /*
	    * see if the printer "mylaser" is available
	    */

	   plist =  XpGetPrinterList (pdpy, mylaser, &plistCnt );

	   /*
	    * Initialize a print context representing "mylaser"
	    */

	   pcontext = XpCreateContext( pdpy, plist[0].name );
	   XpFreePrinterList( plist );

	    /*
	     * Possibly modify attributes in the print context
	     */
	   for(i=0;i < NPOOLTYPES;i++) {
	    if(attrPool = XpGetAttributes( pdpy, pcontext, poolType[i] )) {
		/* twiddle attributes */
		/*
		  XpSetAttributes( pdpy, pcontext, poolType[i],
				   attrPool, XPAttrMerge );
		*/
		XFree(attrPool);
	    }
	   }


	   /*
	    * Set a print server, then start a print job against it
	    */

	   XpSetContext( pdpy, pcontext );
	   XpStartJob( pdpy, XPSpool );

	   /*
	    * Generate the first page
	    */

	   pscreen = XpGetScreenOfContext( pdpy, pcontext );
	   XpGetPageDimensions( pdpy, pcontext, &width, &height,
		       &rect);
	   pwin = XCreateSimpleWindow( pdpy, RootWindowOfScreen( pscreen ),
			   rect.x, rect.y, rect.width, rect.height, 2,
			   BlackPixelOfScreen( pscreen),
			   WhitePixelOfScreen( pscreen));

	   XpStartPage( pdpy, pwin );
	   /* usual rendering stuff..... */
	   XpEndPage( pdpy );

	   XpStartPage( pdpy, pwin );
	   /* some more rendering.....	 */
	   XpEndPage( pdpy );

	   /*
	    * End the print job - the final results are sent by the X print
	    * server to the spooler sub system.
	    */

	   XpEndJob( pdpy );
	   XpDestroyContext( pdpy, pcontext );
	   XCloseDisplay( pdpy );
       }


SEE ALSO
       Xprt(1), XpCreateContext(3Xp),  XpDestroyContext(3Xp),  XpEndJob(3Xp),
       XpEndPage(3Xp),	XpFreePrinterList(3Xp),	 XpGetAttributes(3Xp), XpGet-
       PageDimensions(3Xp),   XpGetPrinterList(3Xp),	XpSetAttributes(3Xp),
       XpSetContext(3Xp), XpStartJob(3Xp), XpStartPage(3Xp)

       X Print Service Extension Library



								   libXp(3Xp)