#!/usr/bin/env perl

use strict;
use warnings;

use constant {
    TIMER_INTERVAL => 1_000,
    NOTIFY_PERIOD => 10_000,
};

use Tk;

my $mw = MainWindow::->new();
$mw->configure(-title => 'Status Notification Manager');
$mw->geometry('320x60+50+100');
#$mw->withdraw();

my $status = _get_status();
my $last_status = $status;
my $status_msg;
_set_status_msg($status, \$status_msg);

my $timer_id = $mw->repeat(TIMER_INTERVAL, sub {
    $status = _get_status();

    if ($status ne $last_status) {
        $last_status = $status;
        _set_status_msg($status, \$status_msg);

        my $notify_panel = $mw->Toplevel();
        $notify_panel->geometry('200x50-0-0');
        $notify_panel->overrideredirect(1);

        my $msg_F = $notify_panel->Frame(
        )->pack(
            -side => 'left',
            -fill => 'both',
            -expand => 1,
        );
        $msg_F->Label(
            -text => $status_msg,
            -anchor => 'w',
        )->pack(
            -side => 'left',
            -padx => 5,
        );

        my $x_F = $notify_panel->Frame(
        )->pack(
            -side => 'left',
            -fill => 'y',
        );
        my $x_B = $x_F->Button(
            -text => 'X',
            -bg => '#ff0000',
            -bd => 1,
            -relief => 'flat',
            -anchor => 'ne',
            -command => sub {
                if (Exists($notify_panel)) {
                    $notify_panel->destroy();
                }
            },
        )->pack();

        $notify_panel->raise();
        $notify_panel->bell();
        $mw->after(NOTIFY_PERIOD, sub {
            if (Exists($notify_panel)) {
                $notify_panel->destroy();
            }
        });
    }

    return;
});

$mw->Button(
    -text => 'Exit',
    -command => sub { $timer_id->cancel(); exit; },
)->pack(-pady => 5);

my $status_bar_F = $mw->Frame(
)->pack(-side => 'bottom', -fill => 'x');
$status_bar_F->Label(
    -textvariable => \$status_msg,
    -anchor => 'w',
    -relief => 'sunken',
)->pack(-fill => 'x');

MainLoop;

sub _get_status {
    join ':', map sprintf('%02d', $_), (localtime())[2,1];
}

sub _set_status_msg {
    my ($status, $msg_ref) = @_;

    $$msg_ref = 'Status: ' . $status;

    return;
}

##</code><code>##

ken@titan ~/tmp
$ ./pm_11126974_tk_status_change_2.pl &
[1] 618

ken@titan ~/tmp
$ kill -HUP 618

ken@titan ~/tmp
$ 
[1]+  Hangup                  ./pm_11126974_tk_status_change_2.pl

ken@titan ~/tmp
$