It should be possible to hook into the <<MenuSelect>> virtual event bound to the popup menu but I am having a hard time figuring out how to do so...

Another less elegant way is to just poll the state of the -wrap option and do your callback when it changes. 

use warnings;
use strict;
use Tk;


my $mw = new MainWindow;
$mw->geometry("200x200");
my $frame = $mw->Frame()->pack;

my $textbox = $frame->Scrolled('Text',
    -scrollbars => 'soe',
    -foreground => 'blue',
    -background => 'white',
    -wrap => 'none',
  )->pack;
$textbox->insert('end', "This is scrolled widget.\nThis is scrolled wi
+dget.This is scrolled widget"); 

my $wrapmonitor = $textbox->cget('wrap');
$textbox->repeat(100, 
    sub { 
        if ( $textbox->cget('wrap') ne $wrapmonitor ){
            $wrapmonitor = $textbox->cget('wrap');
            mycallback($wrapmonitor) #whatever
        }
    }
);

MainLoop;

sub mycallback {
    print shift, "\n";
}

[download]

In reply to Re: Perl Tk Scrolled widget callbacks by thundergnat
in thread Perl Tk Scrolled widget callbacks by ghosh123

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.