my $e = $canvas->createRectangel(
    10, 10,
    20, 20,
    -fill => 'red',
    -outline => 'white',
    -tags => ['rotes rechteck'],
);

$canvas->bind(
    'rotes rechteck',
    '<B3>',
    [
        sub {
            my $menu = 'erstelle Tk::Menu mit zusätzlichen Infos';
            $menu->post( $_[0], $_[1] );
        },
        Tk::Ev('X'),
        Tk::Ev('Y'),
    ],
);