#!/usr/bin/perl

# DlMenu - an interactive menu system for an Xterm based on dialog
# Copyright (C) 1999, Matthew Lavy
# mml@mupsych.org
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


#--- CONFIGURATION SECTION ---

# change the line below to point to your config file
$CONF_FILE='/etc/dlmenu.conf';

# change the line below to name your menu
$MENU_TITLE='---- Menu System ----';

# change the line below to point to dialog on your system
$DIALOG='/usr/bin/dialog';
#--- END OF CONFIGURATION SECTION ---

##############################################################################
# UNLESS MODIFYING THE PROGRAM, YOU SHOULD NOT NEED TO EDIT BELOW THIS LINE
##############################################################################

sub readConfig()
{

	unless (open(FILE,$CONF_FILE)){
		print "Cannot open configuration file\n";
		return;
	}
	my %menus;
	my $menu_name;
	while ($line = <FILE>){
		chomp($line);
		next if $line =~/^[# ].*/; #it's a comment
		if($line =~/\[.*\]/){ #it's a section header
			$line =~ s/\[(.*)\]/$1/;
			$menu_name = $line;
		} else { #its a normal line
			my($title,$command)=split(/\s=\s/,$line);
			unless(! $title || ! $command) {
				push @{$menus{$menu_name}},[$title,$command];
			}
		}
	}
	close FILE;
	return %menus;
}


sub menuLoop(@)
{
	my @tags;
	my @MENU=@_;
	my $count = 1;
	my $item;
	foreach $item(@MENU){
		push @tags, $count;
		push @tags, "\"$$item[0]\"";
		$count++;
	}
	my $stopShowing=0;
	while(! $stopShowing){
		my $call = "$DIALOG_CMD --menu \"Choose an option\" 20 70 10 @tags";
		my $random = rand 25000;
		# thanks to the Perl Cookbook for suggesting this
		# hideous bit of console redirection!!
		chomp(my $pressed=`$call 3>&1 1>&2 2>&3 3>&-`);
		if($? == 0){
			# OK was pressed, so find out what to do
			my $execute=$MENU[$pressed-1][1];
			# does it correspond to a key in the MENUS hashtable?
			if($MENUS{$execute}){
				menuLoop(@{$MENUS{$execute}});
			} else {
				system($execute);
			}
		} else {
			# cancel was pressed
			$stopShowing=1;
		}
	}
}


sub reallyQuit()
{
	if(system("$DIALOG_CMD --yesno \"Are you sure you wish to exit?\" 10 45")){
		return 0; # Do not quit
	} else {
		return 1; # Quit
	}
}

# START OF MAIN SCRIPT
srand;
$DIALOG_CMD="$DIALOG --title \"${MENU_TITLE}\"";
%MENUS=readConfig();

if(! -x "/usr/bin/dialog"){
	print "This program requires dialog to be present\n";
	exit 1;
}

if(! %MENUS){
	#Note: @MENUS{MAIN} always exists otherwise readConfig() returns null
	print "There is no menu to display. Adio!\n";
	exit 2;
}


$finish=0;
while(! $finish){
	menuLoop(@{$MENUS{MAIN}});
	if(reallyQuit()) {
		$finish=1;
	}
}


#############################################################################################################
# The format of the %MENUS structure
# %menus = (
#		MAIN => [["Check with Pine","pine"],["Change your password","passwd"]["Submenu","SUB1"]],
#		SUB1 => [["Find out where your cam mail is delivered","finger -l goose"],["Eat fishes","xeyes &"]]
#	   );
##############################################################################################################