Very nice tybalt89!

One suggestion I'd offer is to trap the '<Motion>' event as well, to see the window move any time mouse button 1 is down (not just the final release).

You can do that with these minor modifications to your solution: 

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1196818

use strict;
use warnings;
use Tk;

# golux:  flag to detect mouse button 1 pressed
my $b_mouse1 = 0;

sub xy { $_[0]->XEvent->x, $_[0]->XEvent->y }

my $mw = MainWindow->new;
$mw->overrideredirect(1);

$mw->Label(
  -text => 'Press 1, Move, then Release in green Canvas to move window
+',
  )->pack(-fill => 'x');

my $c = $mw->Canvas(-width => 500, -height => 400,
  -bg => 'green',
  )->pack;

$c->Tk::bind('<1>' => \&leftdown);
$c->Tk::bind('<Motion>' => \&motion);       # golux:  also detect Moti
+on
$c->Tk::bind('<ButtonRelease-1>' => \&leftup);

$mw->Button(-text => 'Exit', -command => sub { $mw->destroy },
  )->pack(-fill => 'x');

MainLoop;

my ($startx, $starty);

sub leftup
  {
  # golux:  moved the "heavy lifting" into subroutine motion(); the
  # only thing we need do here is clear the mouse button 1 down flag.
  $b_mouse1 = 0;
  }

sub leftdown
  {
  $b_mouse1 = 1;
  ($startx, $starty) = &xy;
  }

sub motion {
  $b_mouse1 or return;
  my $oldposition = $mw->geometry;
  my ($endx, $endy) = &xy;
  my $deltax = $endx - $startx;
  my $deltay = $endy - $starty;
  #  golux:  Not enough to look for \d+, we need to look for [-\d]+, s
+ince
  #  the (X,Y) coordinates can also be negative
  my $newposition = $oldposition =~
    s/\+\K([-\d]+)\+([-\d]+)$/ ($1 + $deltax) . '+' . ($2 + $deltay) /
+er;
  $mw->geometry( $newposition );
  print "$newposition\n";
}

[download]

Instead of moving the window at the end, this moves it any time motion is detected; the only thing needed when mouse button 1 is released is to clear the flag $b_mouse1.

I should elaborate on one thing -- when I tested this (in Windows) I noticed that dragging the window too far up or left caused it to become "stuck". The reason turned out that the one (or both) of the (X, Y) coordinates were negative, which needed to be checked for in your regex to overcome that problem.

say  substr+lc crypt(qw $i3 SI$),4,5

In reply to Re^2: want way to drag tk window by golux
in thread want way to drag tk window by redss

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.