#!/usr/bin/perl -w

use strict;
use vars qw($VERSION $aboutWindow $mainWindow $camelanim);
use Tk;

$VERSION = "0.01";

# Make the main window, menu bar and Help menu.
$mainWindow = new MainWindow (-title => "A program",);
my $mb = $mainWindow->Frame(-relief => 'raised', -borderwidth => 2);
$mb->pack(
          -fill => 'x',
          -expand => 'false',
         );
my $helpB = $mb->Menubutton(
                            -text => 'Help',
                            -underline => 0,
                           );
$helpB->menu(-tearoff => 0);
$helpB->pack(-side => 'right');
$helpB->command(
                -label => 'About...',
                -underline => 0,
                -command => \&aboutViewer,
               );
MainLoop;

# Show module information.
sub aboutViewer {
    require Tk::Animation;
    require Tk::ROText;
    if ($aboutWindow) {
        $aboutWindow->deiconify;
        $aboutWindow->focus;
        $camelanim->start_animation(200);
    }
    $aboutWindow = $mainWindow->Toplevel(-title => 'About Viewer');
    my $top = $aboutWindow->Frame->pack(-fill => 'x', -expand => 'true',);
    my $right = $top->Frame->pack(-side => 'right');
    my $left = $top->Frame->pack(-side => 'left');
    $left->Message(
                  -text => "Copyright (C) 2001 by Your Name Here",
                  -relief => 'flat',
                  -width => 400,
                 )->pack(-fill => 'x', -expand => 'true',);
    $camelanim = $right->Animation(
                                   '-format' => 'gif',
                                   -file => Tk->findINC('anim.gif')
                                  ) unless $camelanim;
    $right->Label(-image => $camelanim)->pack;
    $camelanim->start_animation(200);
    my $aboutText = $aboutWindow->Scrolled(
                                           'ROText',
                                           -scrollbars => 'oe',
                                           -wrap => 'word',
                                           -width => 40,
                                           -height => 20,
                                          )->pack(
                                                  -fill => 'x',
                                                  -expand => 'true',
                                                 );
    $aboutText->insert('end',"$0 $::VERSION\n") if defined($::VERSION);
    foreach (&moduleDump) {
        $aboutText->insert('end',$_);
    }
    $aboutWindow->Button(Name => 'okayButton',
                         -text => 'Okay',
                         -command => sub { $aboutWindow->withdraw; },
                        )->pack(-side => 'bottom');

    $aboutWindow->bind(
                       '<Destroy>',
                       sub {
                           undef($aboutWindow);
                           $camelanim->stop_animation;
                       }
                      );
    $aboutWindow->bind(
                       '<Unmap>',
                       sub {
                           $camelanim->stop_animation;
                       }
                      );
}

# Roll credits.
sub moduleDump {
    my ($module, $line, @out, %package_stab, $package_version);
    foreach (sort(keys %INC)) {
	next unless /^[A-Z]/;
	$module = $_;
	$module =~ s/\.pm$//;
	$module =~ s/\//::/g;

	%package_stab = eval("%{*" . $module . "::}");
	if (exists $package_stab{'VERSION'}) {
	    $package_version = $package_stab{'VERSION'};
	    $package_version = $$package_version;
	    if (defined($package_version)) {
		$line = $module . " version $package_version\n";
	    }
	    else {
		$line = $module . ", no version\n";
	    }
	}
	else {
	    $line = $module . ", no version\n";
	}
	push @out, $line;
    }
    return @out;
}