#include "copyright.h"

/* $XConsortium: XChProp.c,v 11.16 88/09/06 16:04:34 jim Exp $ */
/* Copyright    Massachusetts Institute of Technology    1986	 */

#include "Xlibint.h"

XChangeProperty (dpy, w, property, type, format, mode, data, nelements)
  register Display *dpy;
  Window w;
  Atom property, type;
  int format;			/* 8, 16, or 32 */
  int mode;			/* PropModeReplace, PropModePrepend,
				 * PropModeAppend */
  unsigned char *data;
  int nelements;
{
  register xChangePropertyReq *req;
  register long nbytes = nelements;

  LockDisplay (dpy);
  GetReq (ChangeProperty, req);
  req->window = w;
  req->property = property;
  req->type = type;
  req->format = format;
  req->mode = mode;
  req->nUnits = nelements;

  switch (format) {
  case 8:
    req->length += (nelements + 3) >> 2;
    Data (dpy, (char *) data, nbytes);
    break;

  case 16:
    req->length += (nelements + 1) >> 1;
    nbytes <<= 1;
    Data16 (dpy, (short *) data, nbytes);
    break;

  case 32:
    req->length += nelements;
    nbytes <<= 2;
    Data32 (dpy, (long *) data, nbytes);
    break;

  default:
     /* XXX this is an error! */ ;
  }

  UnlockDisplay (dpy);
  SyncHandle ();
}