#!/usr/bin/perl
use warnings;
use strict;
use Tk;

#create a new MainWindow
my $mw = MainWindow->new( -background => 'black' );

#fullscreen
$mw->geometry($mw->screenwidth.'x'.$mw->screenheight);

#remove window chrome
$mw->overrideredirect(1);

#create a Tk::Frame to act as the top app bar hotspot.
my $top_appbar = $mw->Frame( -background => $mw->cget(-background), -height => 10 )->pack( -side => 'top', -fill => 'x' );
$top_appbar->bind('<Any-Enter>' => sub { \&AppBar($top_appbar, 'show', 'top'); } );
$top_appbar->bind('<Any-Leave>' => sub { \&AppBar($top_appbar, 'hide', 'top'); } );

#create a Tk::Frame to act as the bottom app bar hotspot
my $bottom_appbar = $mw->Frame( -background => $mw->cget(-background), -height => 10 )->pack( -side => 'bottom', -fill => 'x' );
$bottom_appbar->bind('<Any-Enter>' => sub { \&AppBar($bottom_appbar, 'show', 'bottom'); } );
$bottom_appbar->bind('<Any-Leave>' => sub { \&AppBar($bottom_appbar, 'hide', 'bottom'); } );

#create a Tk::Frame to hold the application's content
my $content = $mw->Frame( -background => $mw->cget(-background), -height => $mw->screenheight-20 )->pack( -fill => 'x' );
$content->Label( -text => 'This is where the application content is displayed (buttons, images, etc...)', -background => $mw->cget(-background), -foreground => 'gray' )->pack();

sub AppBar {
	my $self   = shift;
	my $method = shift;
	my $name   = shift;
	if ($method eq 'show'){
		#change the appbar's height and color to make it visable and useable
		$self->configure( -background => 'gray' );
		$self->configure( -height => 50) if $name eq 'top';
		if ( $name eq 'top' ){
			$top_appbar->{label1} = $top_appbar->Label( -text => 'The navigation bar, or top app bar, is the recommended place to put navigation controls that let the user access other areas of the app (buttons).', -background => 'gray', -foreground => 'black' )->pack( -side => 'left' );
		} elsif ( $name eq 'bottom' ){
			$bottom_appbar->{label1} = $bottom_appbar->Label( -text => 'The bottom app bar is the recommended place to put commands (buttons).', -background => 'gray', -foreground => 'black'  )->pack( -side => 'left' );
			$self->configure( -height => 50);
			$mw->configure( -height => $mw->screenheight-60 );
		}
	} elsif ($method eq 'hide'){
		#change the appbar's height and color to make it hidden and not useable
		$self->configure( -background => $mw->cget(-background) );
		$self->configure( -height => 10) if $name eq 'top';
		if ( $name eq 'top'){
			$top_appbar->{label1}->packForget();
		} elsif ( $name eq 'bottom' ){
			$bottom_appbar->{label1}->packForget();
			$self->configure( -height => 10 );
			$mw->configure( -height => $mw->screenheight-20 );
		}
	}
	$mw->update();
}

$mw->MainLoop();