Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!athena.mit.edu!bjaspan
From: bjaspan@athena.mit.edu (Barr3y Jaspan)
Newsgroups: comp.windows.x
Subject: Re: Athena asciiStringWidget questions
Message-ID: <15485@bloom-beacon.MIT.EDU>
Date: 29 Oct 89 01:21:39 GMT
References: <8909252128.AA28066@mbunix.mitre.org> <8910262127.AA20276@expo.lcs.mit.edu>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: bjaspan@athena.mit.edu (Barr3y Jaspan)
Organization: Massachusetts Institute of Technology
Lines: 72


I have written a function that takes a text widget and a string and
appends the string to the widget, deleting text from the beginning if
necessary.  I wrote it a little while ago and haven't used it lately,
so it might have undergone bit rot, but it worked when I used it.  (It
does some less-than-brilliant things in case of error.. you probably
will want to fix that.)

Barr3y Jaspan, bjaspan@athena.mit.edu
MIT Project Athena

----- snip snip -----

/* 
 * AppendString.c -- appends a string to the end of a text widget.  It
 * assumes the widget is in the proper state to accept input in this manner
 * (ie: it does no error checking.)
 *
 * Written by Barry Jaspan (bjaspan@ATHENA.MIT.EDU)
 */

#include <stdio.h>
#include <X11/Intrinsic.h>
#include <X11/StringDefs.h>
#include <X11/AsciiText.h>

void AppendString(w, value, maxlen)
    Widget w;
    caddr_t value;
    int maxlen;
{
    XtTextBlock text;
    static XtTextPosition last=0;
    unsigned long	length;
    int retval;

    length = (unsigned long) strlen((char *) value);
    if (length == 0) {
	 printf("Length of %s = %ld\n",(char *) value, length);
	XBell( XtDisplay(w), 0 );
	return; }

    /* If this text puts us over the buffer len, just delete enough */
    /* text from the front to compensate.  Not an ideal algorithm. */
    if ((last+length)>maxlen) {
	 text.ptr = "";
	 text.firstPos = 0;
	 text.length = 0;
	 text.format = FMT8BIT;
	 XtTextReplace(w,(XtTextPosition)0,(XtTextPosition)length,&text);
	 last -= length;
	 XtTextSetInsertionPoint(w, (XtTextPosition) last);
         XtTextSetLastPos(w, (XtTextPosition) last); }

    text.ptr = (char *) value;
    text.firstPos = 0;
    text.length = length;
    text.format = FMT8BIT;

    if ((retval=XtTextReplace(w, last, last, &text))!=0) {
	 XBell(XtDisplay(w), 0);
	 printf("TextReplace returned %d\n",retval); }
    else {
	XtTextSetInsertionPoint(w, last + text.length);
	last += (XtTextPosition) length;
   }
}

Barry Jaspan
Project Athena ``Watchmaker''
SIPB (Student Information Processing Board) Member
OLC Volunteer