package CGI::tab;

require Exporter;
our @ISA = ("Exporter");
my @tabs;
my $posn = 0;

sub start_tabs {
    my $sum = 0;
    for (@_) {
        push @tabs, ($_ - $sum);
        $sum += $tabs[$#tabs];
    }
    my $output = '<table cellpadding=0 cellspacing=0 border=0><tr height=0>';
    $output .= "<td width=$_></td>" for @tabs;
    $output .= '<td></td></tr><tr><td>';
    return $output;
}

sub t {
    if ($posn == @tabs) {
        $posn = 0;
        return '</td></tr><tr><td>';
    }
    else {
        $posn ++;
        return '</td><td>';
    }
}

sub r {
    my $colspan = @tabs - $posn;
    $posn = 0;
    if ($colspan) {
        return "</td><td colspan=$colspan></td></tr><tr><td>";
    }
    else {
        return '</td></tr><tr><td>';
    }
}

sub end_tabs {
    my $colspan = @tabs - $posn;
    undef @tabs;
    $posn = 0;
    if ($colspan) {
        return "</td><td colspan=$colspan></td></tr></table>";
    }
    else {
        return '</td></tr></table>';
    }
}

our @EXPORT = qw/start_tabs t r end_tabs/;

1;