package Menu;

=head1 NAME

Menu -- Menu utilities for extropy

=head1 SYNOPSIS

my $command = Menu->menu("Do this", THIS,
                         "Do that", THAT,
                         "Do something else", SOMETHING);

=head1 DESCRIPTION

This package provides menu utilities for the extropy.
system.

=head1 VERSION

0.001 (last update:  6/30/04)

=head1 AUTHOR

Chet Langin, clangin@siu.edu

SIU Plant Biotechnology and Genomics Core-facility

=head1 BUGS

None known.

=head1 SEE ALSO

extropy ExtropyUtils ExtropyConstants Extropy::MenuMain

=head1 COPYRIGHT

Copyright 2004, Chet Langin, All Rights Reserved.

This program is free software.  You may copy or
redistribute it under the same terms as Perl itself.

=head1 METHODS

The remainder of this document describes the methods available to the
programmer.

=cut

# load the pragmas
use warnings;
use strict;

# load other modules
use ExtropyUtils;
use ExtropyConstants;


# ********************************  menu  *****************************

=head2 menu(...)

Displays a menu and returns an integer which represents the selection.

The parameters are string/int pairs that indicate menu
items and the integers representing each item.  When an item is
selected, the integer representing that item is returned.

For example:

my $command = Menu->menu("Do this", THIS,
                         "Do that", THAT,
                         "Do something else", SOMETHING);

The first argument indicates that six more arguments follow.

The menu items that will be displayed are "Do this," "Do that," and
"Do something else."

If "Do that" is selected, the constant THAT will be returned.

=cut

# --------------------------------------------------------------------

sub menu {
  shift;
  my $num_params = scalar @_;
  my $num_items = $num_params / 2;
  my @item_array = ();
  my @command_array = ();
  my @char_array = ();
  my $user_input = "";
  my $command = NONE;

  for(my $lcv = 0; $lcv < $num_items; $lcv++) {
    $item_array[$lcv] = shift;
    $command_array[$lcv] = shift;
    $item_array[$lcv] =~ /\((\w)\)/;
    $char_array[$lcv] = $1;
  } # for

  my $repeat = TRUE;
  while($repeat) {
    print("\n\n");
    print("    **************************************\n");
    print("    ***********  extropy menu  ***********\n");
    print("    **************************************\n");
    print("    *                                    *\n");
    for(my $lcv = 0; $lcv < $num_items; $lcv++) {
      my $item_number = $lcv + 1;
      my $output = sprintf("% 2s  %-28s", $item_number, $item_array[$lcv]);
      print("    *  $output  *\n");
    } # for
    print("    *                                    *\n");
    print("    **************************************\n");
    print("    **************************************\n\n");
    print("    Enter a menu item...\n\n    ");
    chomp($user_input = <STDIN>);
    $user_input =~ s/^\s*//;
    $user_input =~ s/\s*$//;
    for(my $lcv = 0; $lcv < $num_items; $lcv++) {
      my $item_number = $lcv + 1;
      if($user_input eq $item_number ||
         uc($user_input) eq uc($char_array[$lcv])) {
        $command = $command_array[$lcv];
        $repeat = FALSE;
      } # if
    } # for
    if($repeat) {
      message_start;
      message("The last menu selection was not valid.");
      blank_line;
      message("Enter a menu item number or else enter the character");
      message("in parentheses () representing a menu item.");
      blank_line;
      message("For example, enter a \"1\" (without the quote marks)");
      message("to select the first menu item.");
      blank_line;
      message("Or enter \"Q\" (without the quote marks) to select the");
      message("(Q)uit menu item.");
      blank_line;
      press_enter;
      $repeat = FALSE;
    } # if
  } # while

  $command
} # menu

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