Hi Necos,

Just a quick suggestion (must run off). What I frequently do with Tk apps (and I write lots of them) is to create an anonymous hash to hold all the widgets that I might need to address elsewhere.. Then I can pass that hash around and avoid globals. For example (psuedo code):

my $w;
$w->{main} = MainWindow->new;
$w->{other_widgets} = $w->{main}->Label->....
# and then later...
&subroutine($w);

sub subroutine
{
    my $w = shift;
    # Do stuff with $w here now like normal
    $w->{main}->configure( -title => "new title" );
}
[download]

My personal rule is that if I get the variable used only once warning then I've done something wrong with my design and implementation and I should rework my solution.

Update: demerphq makes a good point. To add to what is said there, I'd like to comment that there are lots of ways to reference a variable without context;

1 if $a; # for example
[download]

Another thing that I've done in the past when stuck with these kinds of warnings is to create a special subroutine just to reference them (assuming their global status):

sub unused
{
    warn "sub unused was used!!!\n";
    return;
    1 if $a;
    1 if $b;
}
[download]

But I really feel that if you are in this situation you may wish to think carefully if there is a better way to accomplish what you are trying to do.

Again, good luck - {NULE} (/Update).

Final Update: Here is sample code that accomplishes what Necos wanted.

#! /usr/bin/perl -w

use strict;
use Tk;
use Tk::Toplevel;

################
# Main Routine #
################

my $w;

$w->{main} = MainWindow->new(-title => 'Tk Hash');
$w->{main}->Button(-text => "Click me to open a new toplevel", -comman
+d => [ \&new_tl, $w ])->pack;
$w->{main}->Button(-text => "Click me to test for other button", -comm
+and => [ \&test_tl, $w ])->pack;

MainLoop;

exit;

###############
# Subroutines #
###############

sub new_tl
{
    my $w = shift;

    if ( not Tk::Exists $w->{toplevel} )
    {
        $w->{toplevel} = $w->{main}->Toplevel( -takefocus => 1, -title
+ => 'Top Level' );
        $w->{testbutton} = $w->{toplevel}->Button(-text => 'Null butto
+n');
    }
    else
    {
        $w->{toplevel}->deiconify();
        $w->{toplevel}->raise();
        $w->{toplevel}->focusForce();
    }
}

sub test_tl
{
    my $w = shift;

    if ( Tk::Exists $w->{testbutton} )
    {
        print "testbutton exists\n";
    }
    else
    {
        print "testbutton does not exist\n";
    }
}
[download]

{NULE}
--
http://www.nule.org

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.