#  ProgresBar.pm  :   an object for generating simple.gif-based progress bars
#                     with a groovy little 3-d effect
#
# Author:  Steve McNabb  steve@tralt.com   
# my employer (Training Alternatives Inc.) has graciously 
# allowed me to release this tool as open source software
#
# This script is copyright 1999 Training Alternatives Inc
# all rights reserved - http://www.trainingalternatives.com
#
# you may use and/or modify this script under the same terms as 
# Perl itself.  See your distribution for details.
use GD;

package ProgressBar;

sub new
{
  my $self 	= {};
  bless 	$self;
  return 	$self;
}

sub makebar   #  $score value,  $total out of
{  #this sub will accept values from user or set defaults
  my $class = shift @_;
  my ($score, $total, $width , $height) = @_;


  my $avg_right = $score / $total;
  if(($avg_right > 0.95)&&($avg_right != 1.0)) { $avg_right = 0.95; }
  if($avg_right == 1.0) { $avg_right = 1;}

  # defaults 
  if(!$width) 	{ $width =  150; }
  if(!$height) 	{ $height = 10; }

  $prog_gif = new GD::Image($width,$height);

  #  for now, we will only allow pre-defined colours
  $white 	= $prog_gif->colorAllocate(255,255,255);
  $black 	= $prog_gif->colorAllocate(0,0,0);       
  $red 		= $prog_gif->colorAllocate(255,0,0); 
  $lt_red 	= $prog_gif->colorAllocate(255,160,160);
  $dk_red 	= $prog_gif->colorAllocate(170,0,0);    
  $green 	= $prog_gif->colorAllocate(0,200,0);
  $lt_green = $prog_gif->colorAllocate(100,255,100);
  $dk_green = $prog_gif->colorAllocate(0,150,0);


  #lay down the base image color (the colour of the "done" part)
  $prog_gif->rectangle(0,0,$width-1,$height-1,$green);
  $prog_gif->fill(1,1,$green);

  #now the "wrong" part
  if($avg_right != 1.0) { $midpoint = $width*$avg_right; } #so we only need to calculate this once

  if($avg_right != 1)
  {

  $prog_gif->rectangle($midpoint,0,$width,$height,$black);
  $prog_gif->fill($midpoint+1, $height-1, $red);

  #let's 3-d the red part (add dark lines to bottom and right, light lines to top and left)
  $prog_gif->line($midpoint+1,1,$width-1,1,$lt_red); 
  $prog_gif->line($midpoint+1,1,$midpoint+1, $height-1, $lt_red); 	
  $prog_gif->line($midpoint+2,$height-2,$width-1, $height-2, $dk_red);  
  $prog_gif->line($width-2,2,$width-2,$height-2,$dk_red); 
  #now let's 3-d the green part
  $prog_gif->line(1,1,$midpoint-1,1,$lt_green);  
  $prog_gif->line(1,1,1,$height-1,$lt_green); 
  $prog_gif->line(1,$height-2,$midpoint-1,$height-2,$dk_green);  
  $prog_gif->line($midpoint-1, 1, $midpoint-1, $height-2,$dk_green); 
  }

  if($avg_right == 1) 
  {
  #just make the whole thing green -- we're at full
  $midpoint = $width;
  $prog_gif->line(1,1,$midpoint-1,1,$lt_green);  
  $prog_gif->line(1,1,1,$height-1,$lt_green); 
  $prog_gif->line(1,$height-2,$midpoint-1,$height-2,$dk_green);  
  $prog_gif->line($midpoint-1, 1, $midpoint-1, $height-2,$dk_green); 
}
# Put a black frame around the bar
$prog_gif->rectangle(0,0,$width-1,$height-1,$black);

# fire 'er back
  binmode STDOUT; #WINDOWS SUCKS! :p
  print "Content-type: image/gif\n\n";
  print STDOUT $prog_gif->gif;

  exit; 
}

1;

=item Name

ProgressBar.pm - a module for making progress bars 

=item Synopsis
 
    use ProgressBar; 
	$my_bar = new ProgressBar;
	$my_bar->MakeBar(25,50,100,20);   #$my_bar->Makebar(score, out-of-total,optional width, optional height) 
    #this will return a binary mode stream (.gif) and appropriate content header
       
Here is an example of how to use this module as a real-time generated progress bar gif


Script:  (part one -- saved as /cgi-bin/progress.cgi)

  
  use ProgressBar;
  use CGI qw(:standard);

  if(param())
  {
	my $score = param("score");
	my $total = param("total");

  $foo = new ProgressBar;

  $foo->MakeBar($score,$total,"400","10");  #400 pixels wide, 10 pixels high..defaults to 150 x 10


  }


Image reference:  (part two - included in html file that will reference this script as an image)

Note:  in this case, I am passing score and total as regular old
       CGI name/value pairs ...your milage may vary

         <img src="/cgi-bin/progress.cgi?score=60total=100">
		 
=item Author

Steve McNabb steve@tralt.com