use strict;
use warnings;

use Data::Dumper;

# The "use Tk" MUST be before "use POE"...
use Tk;
use Tk::DialogBox;
use POE;
use POE::Wheel::Run;

# Create GUI window...
my $top = $::poe_main_window;
$top->geometry('300x50');
$top->title("PID=$$");
$top->protocol('WM_DELETE_WINDOW', sub{exit});

# Create button to push...
$top->Button(-text=>"Don't Push Me - WAIT", -command=>sub{
	print STDERR "Parent Asking User\n";
	print STDERR "Got: ", AskUser("PID=$$"), "\n";
})->pack;
print STDERR "Parent PID=$$\n";

my $session=_poeSetup();

# Go...
$poe_kernel->run();

sub _poeSetup {
	my $session = POE::Session->create(
		inline_states=>{
			KidAsk => sub {
				print STDERR "GUI Request from Child...\n";
				my $ret=AskUser("PID=$$");
				print STDERR "Got: $ret\n";
				return($ret);
			},
			KidOut => sub {
				my ($heap, $line, $wid)=@_[HEAP, ARG0, ARG1];
				my $child = $heap->{Kids}{WID}{$wid};
				print STDERR $child->PID . " OUT: $line\n";
			},
			KidErr => sub {
				my ($heap, $line, $wid)=@_[HEAP, ARG0, ARG1];
				my $child = $heap->{Kids}{WID}{$wid};
				print STDERR $child->PID . " ERR: $line\n";
			},
			KidClose => \&_DoClose,
			_start => sub {
				my ($kernel, $heap) = @_[KERNEL, HEAP];
				$kernel->alias_set('GUI');
				my $child = POE::Wheel::Run->new(
					Program => sub {
						print STDERR "Sleeping...";
						system("sleep 3");
						print STDERR "GUI Request from $$\n";
# Question 1			my $ret = $kernel->post('GUI','KidAsk');
# Question 2			my $ret = $kernel->yield('AskEvent');
						print STDERR "DONE: $ret\n";
						system("tail -f /etc/profile");
					},
					StdoutEvent => 'KidOut',
					StderrEvent => 'KidErr',
					CloseEvent => 'KidClose',
# Question 2		AskEvent => 'KidAsk',
				);
				$kernel->sig_child($child->PID, '_DoSig');
				$heap->{Kids}{WID}{$child->ID} = $child;
				$heap->{Kids}{PID}{$child->PID} = $child;
# Verification	$kernel->yield('KidAsk');
			}
		},
	);
	return($session);
}

#################################
# POE Session Supporting Routines
#################################
sub _DoClose {
	my $wid = $_[ARG0];
	my $child = $_[HEAP]{Kids}{WID}{$wid};

	unless (defined $child) {
		print STDERR "wid $wid closed all pipes.\n";
		return;
	}

	print STDERR "wid $wid closed all pipes.\n";
	delete $_[HEAP]{Kids}{PID}{$child->PID};
}

sub _DoSig {
	print STDERR "pid $_[ARG1] exited with status $_[ARG2].\n";
	my $child = delete $_[HEAP]{Kids}{PID}{$_[ARG1]};

	return unless defined $child;

	delete $_[HEAP]{Kids}{WID}{$child->ID};
}

sub AskUser
{
	my $txt = shift || 'No text passed';
	print STDERR "$txt\n";

	my $top = $::poe_main_window;

	# Create a dialog box to ask for a password...
	my $d = $top->DialogBox(
		-title=>"$txt",
		-buttons=>['Ok', 'Cancel'],
		-default_button=>'Ok',
	);

	# Add the entry widget where user will type password...
	my $e = $d->add('Entry', -width=>30, -show => '*')->pack;
	$d->add('Label', -text => "What is your favorite color?")->pack;
		
	my $ans = $d->Show();

	# If user didn't say ok...
	if ($ans ne "Ok") { die( "I give up, exiting...\n") };
	
	# Get & return what the user typed...
	my $pw = $e->get;
	return($pw);
}