#! perl -slw
use strict;
use warnings;

use Time::HiRes qw[ time ];
use Tk::Canvas;

my $inc              = 1;  #degrees to move each frame
my $length           = 10;  #seconds to take
my ($width, $height) = (480,480);
my $trip_point       = 90;
my $code             = 'A123BC';

my $repeatTime = ($length * 1000) / (360 / $inc);
my $mw = MainWindow->new;
my $canvas = $mw->Canvas(
    -width  => $width,
    -height => $height,
    -bg     => 'black',
)->pack;

my $start = 359;

my $arc = 
    $canvas->createArc(
        0, 0, $width, $height,
        -fill    => 'white',
		-outline => undef,
        -extent  => $start,
		-start   => 90,
		-tag     => 'arc',
    );

## Bind action to space bar
$mw->bind( '<space>', sub {
    my $rep;
    my $tripped = 0;
	
    ## Set up the repeating callback with the delay calculated earlier
     $rep = $mw->repeat( $repeatTime, sub {
		$start -= $inc;
		$canvas->itemconfigure('arc', -extent => $start );
		if ($start < 0) {
			$canvas->itemconfigure('arc', -extent => 0);
		    $rep->cancel;
		    printf "\a";
            $canvas->createText($width / 2, $height /2, 
                -text => $code,
				-tag  => 'code',
				-fill => 'red',
            );		
		} elsif ($start < $trip_point and !$tripped) {
		    printf "\a";
			$tripped = 1;
			$canvas->itemconfigure('arc', -fill => 'red');
		}
	});
});

$mw->MainLoop;