Here is a basic Tk::Canvas script to do it. You can do what ever you want in the callback. I just print the x,y position, and the x axis label.

#!/usr/bin/perl
use warnings;
use strict;
use Tk;

my $w=20;
my $x=0;
my $y=0;

my %colors = (
   0 => ['black','yellow'], 
   1 => ['yellow','black'], 
   2 => ['green','white'],    
   3 => ['lightgreen','white'], 
   4 => ['grey','red'], 
   5 => ['red','grey'], 
   6 => ['lightsteelblue','white',], 
   7 => ['blue','white',], 
   8 => ['orange','grey45'], 
   9 => ['grey45','orange'], 
);

my %bardata = (
   0 => 100 + rand 200,
   1 => 100 +rand 200,
   2 => 100 +rand 200,
   3 => 100 +rand 200,
   4 => 100 +rand 200,
   5 => 100 +rand 200,
   6 => 100 +rand 200,
   7 => 100 +rand 200,
   8 => 100 +rand 200,
   9 => 100 +rand 200,
);

my %bars;

my $mw=tkinit;
my $c = $mw->Canvas(-bg=>'white')->pack(-expand=>1,-fill=>'both');

foreach my $key(sort keys %bardata) {
  $bars{$key} = $c->createRectangle($x,$y,$x+20,$bardata{$key},
             -fill=> ${$colors{$key}}[0],
             -tags=>[ $key]
          );

my $text = $c->createText($x+10,$y+10,
           -anchor=>'center',
       -fill => ${$colors{$key}}[1],
       -text => $key
          );
      
      $x+=20;
}

$mw->Button(
    -text    => "Save",
    -command => [sub {
         $c->update;
         my @capture=();
         my ($x0,$y0,$x1,$y1)=$c->bbox('all');
         @capture=('-x'=>$x0,'-y'=>$y0,-height=>$y1-$y0,-width=>$x1-$x
+0);
         $c -> postscript(-colormode=>'color',
                               -file=>$0.'.ps',
                   -rotate=>90,
                   -width=>800,
                   -height=>500,    
                   @capture);
                               
                  } 
   
  ]  )->pack;
 
$c->Tk::bind("<Button-1>", [ \&print_xy, Ev('x'), Ev('y') ]);
 
# adjust canvas size to show all
my ($x0,$y0,$x1,$y1)=$c->bbox('all');
$c->configure(  -width=>($x1-$x0)+20, -height=>($y1-$y0)+20 );
 
MainLoop;
##########################################################

sub print_xy {
  #print "@_\n";
  my ($canv, $x, $y) = @_;
  print "(x,y) = ", $canv->canvasx($x), ", ", $canv->canvasy($y), "\t"
+;
  my $current = $canv->find(qw/withtag current/);
  my (@tags) = $canv->gettags($current);
  print "for @tags\n\n";
}
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