REF XHouseKeeping                                 A.Schoter, August 1991

        COPYRIGHT University of Sussex 1991. All Rights Reserved.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<<                             >>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<<        X HOUSEKEEPING       >>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<<                             >>>>>>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

The procedures described in this REF file implement the equivalent  Xlib
C functions related  to display handling,  event processing, and  memory
management.



---------------------
1  List of procedures
---------------------

The procedures below are made available by doing:

        uses xlib, XHouseKeeping;

For details see:

                     Xlib - C Language X Interface,
                       MIT X Consortium Standard,
                         X Version 11, Release 4

        Copyright (C) 1985, 1986, 1987, 1988, 1989 Massachusetts
        Institute of Technology,  Cambridge, Massachusetts,  and
        Digital Equipment Corporation, Maynard, Massachusetts.


XOpenDisplay(string) -> DspPtr                               [procedure]
        This function  takes  the name  of  a server  specified  by  the
        string, and opens  a connection  to the server  for the  display
        hardware.  The   display  string   should  be   in  the   format
        'hostname:number', where 'hostname'  is the name  of a  machine,
        and 'number' is the number of  the display on that machine.  For
        example, 'psune:3' would  be display 3  on the machine  'psune'.
        Most workstations are equipped with a single display only, which
        is conventionally referred to as  display number 0. If the  call
        is successful, it returns a pointer to an Display structure. The
        procedure returns a null pointer on any failure (for example  if
        the environemnt  variable DISPLAY  is not  set, or  if the  host
        named is nonexistant). Note that  any open connection is  closed
        on exit from Poplog.


XCloseDisplay(DspPtr)                                        [procedure]
        Closes the connection associated with the specified DISPLAY. All
        windows or other resources that  the caller has created on  this
        display server are  destroyed; they should  never be  referenced
        again. Any output  events that  have been buffered  but not  yet
        sent are discarded. The effect of XCloseDisplay is automatically
        achieved if the XDisplay structure becomes garbage collected, or
        if the  Poplog  process exits.  An  XDisplay structure  will  be
        garbage collected if the  client has no  references to it.  If a
        client has  created  window,  font, bitmap,  pixmap,  or  cursor
        resource ID's with this  display server, they  must not be  used
        after calling XCloseDisplay.


XFlush(DspPtr)                                               [procedure]
        XFlush sends  (`flushes') all  output  requests that  have  been
        buffered but not  yet sent. Flushing  is done automatically  the
        next  time  input  is   read  (with  XPending,  XNextEvent,   or
        XWindowEvent), so  most  clients should  not  need to  use  this
        procedure.


XSync(DspPtr,int)                                            [procedure]
        XSync flushes the output buffer, then waits until all events and
        errors resulting  from previous  calls  have been  received  and
        processed by the X server. Events are placed on the input queue.
        The client's  XError  function is  called  once for  EACH  error
        received. Even fewer  clients need to  use this subroutine  than
        XFlush.

        int is a flag, discard, which  if true, XSync then discards  all
        events on the input queue  (including those events that were  on
        the queue before XSync was called).


XFree(uint)                                                  [procedure]
XNoOp(DspPtr)                                                [procedure]
        These procedures implement the equivalent C functions.




--- C.x/x/pop/ref/XHouseKeeping
--- Copyright University of Sussex 1991. All rights reserved.
