#!/usr/bin/perl
use Tk;
use Tk::Canvas;
use Tk::Label;

my $mw = tkinit(-title, 'Canvas');
$mw->geometry('250x500');

my $frame = $mw->Frame(-width, 250, -height, 250)->pack(-fill, 'both', -expand,1);

my $canvas = $frame->Scrolled('Canvas', -width, 300, -height, 300,
   -bg=>'white',
   -scrollbars, 'osoe'
   )->pack(-fill,'both',-expand,1);

my $btn = $mw->Button(-text, "Add Stuff", -command,\&addStuff)
   ->pack();

my $btn1 = $mw->Button(-text, "Add More Stuff", -command,\&addmoreStuff)
   ->pack();


MainLoop;

sub addStuff{
   $canvas->createText(500, 500, -text, "Some text @ 500, 500." );
   $canvas->createRectangle(  50,  50, 110, 110, -fill, 'red');
   $canvas->createRectangle( 150, 150, 210, 210, -fill, 'green');
   $canvas->createRectangle( 250, 250, 310, 310, -fill, 'blue');
   $canvas->createText(20, 20, -text, "Some text @ 20, 20." );
#
# Your can use an array for your bounding box
# commented out to show both ways to set the scrollregion
# Just make sure you are 1 less on lower right and bottom
# Or you will have out of bounds array... easy to forget
# if you don't use a frame with your canvas

$canvas->configure(-scrollregion => [ 0, 0, 599, 599]);
#   $canvas->configure(-scrollregion => [$canvas->bbox('all')]);
}

sub addmoreStuff{
   $canvas->createText(1500, 1500, -text, "Some text @ 1500, 1500." );
   $canvas->createRectangle(  5000,  5000, 1100, 1100, -fill, 'red');
   $canvas->createRectangle( 1500, 1500, 2100, 2100, -fill, 'green');
   $canvas->createRectangle( 2500, 2500, 3100, 3100, -fill, 'blue');
   $canvas->createText(2000, 10, -text, "Some text @ 2000, 10." );
#
# Your can use an array for your bounding box
# commented out to show both ways to set the scrollregion
# Just make sure you are 1 less on lower right and bottom
# Or you will have out of bounds array... easy to forget
# if you don't use a frame with your canvas

#$canvas->configure(-scrollregion => [ 0, 0, 599, 599]);
   $canvas->configure(-scrollregion => [$canvas->bbox('all')]);
}