=head1 NAME

Tk::Optionmenu - Let the user select one of some predefined options values

=for pm Tk/Optionmenu.pm

=for category Tk Widget Classes

=head1 SYNOPSIS

    use Tk::Optionmenu;

    $opt = $w->Optionmenu(
			-options => REFERENCE_to_OPTIONLIST,
			-command => CALLBACK,
			-variable => SCALAR_REF,
			);

    $opt->addOptions( OPTIONLIST );

    # OPTION LIST is
    #   a)  $val1, $val2, $val3,...
    #   b)  [ $lab1=>$val1], [$lab2=>val2], ... ]
    #   c)  combination of a) and b), e.g.,
    #       val1, [$lab2=>val2], val3, val4, [...], ...

=head1 DESCRIPTION

The B<Optionmenu> widget allows the user chose between a given set
of options.

If the user should be able to change the available option have a look
at L<Tk::BrowseEntry>.

=head1 OPTIONS

=over 4

=item -options

(Re)sets the list of options presented.

=item -command

Defines the L<callback|Tk::callbacks> that is invokes when a new option
is selected.

=item -variable

Reference to a scalar that contains the current value of the
selected option.

=item -textvariable

Reference to a scalar that contains the text label of the current value of the
selected option.

=back

=head1 METHODS

=over 4

=item addOptions

Adds OPTION_LIST to the already available options.

=back

=head1 EXAMPLE

 use Tk;
 my $mw = MainWindow->new();

 my ($var, $tvar);
 my $opt = $mw->Optionmenu(
        -options => [[jan=>1], [feb=>2], [mar=>3], [apr=>4]],
        -command => sub { print "got: ", shift, "\n" },
        -variable => \$var,
        -textvariable => \$tvar
       )->pack;

 $opt->addOptions([may=>5],[jun=>6],[jul=>7],[aug=>8]);

 my $f = $mw->Frame(-relief=>'groove', -borderwidth => 2)->pack;
 $f->Label(-textvariable=>\$tvar)->pack(-side => 'left');
 $f->Label(-text => " -> ")->pack(-side => 'left');
 $f->Label(-textvariable=>\$var)->pack(-side => 'left');

 $mw->Button(-text=>'Exit', -command=>sub{$mw->destroy})->pack;

 MainLoop;

=head1 SEE ALSO

L<Tk::Menubutton>, L<Tk::BrowseEntry>

=cut