use UI::State;
my $state = UI::State->new;

# Define the states we will use
$state->add_states( qw/ menu new open options / );

$state->state( menu => {
	# Class that handles this state
	class => 'My::UI::Menu',
	# States allowed to jump to. The 'exit'
	# state is always implicitly available.
	next  => [qw/ new open options exit /],
});
$state->state( new => {
	class => 'My::UI::New',
	next  => [qw/ menu exit /],
});
$state->state( open => {
	class => 'My::UI::Open',
	next  => [qw/ menu exit /],
});
$state->state( options => {
	class => 'My::UI::Options',
	next  => [qw/ menu /],
});

# Error! State 'foo' was not declared in add_states()
$state->state( foo => {
	class => 'My::UI::Foo',
	next  => [qw/ menu exit /],
});
$state->state( new => {
	class => 'My::UI::New',
	
	# Error! State 'bar' was not declared in add_states()
	next  => [qw/ menu bar exit /],
});

# Start running from 'menu'
$state->run( 'menu' );