#!/usr/bin/perl -w
use strict;
use Tk;
use Tk::JPEG;

my $c;

my $dir = ".";
my @fl = <*.jpg>;

print "@fl\n";

my $main = new MainWindow;

#make just 2 photo objects and reuse them, so your
#memory won't increase with every image.
# and load photo into a widget, not the main window
# let the label set the size of the window
# you could do it in the main if you want, it just
# isn't usually done like that, because you usually
# pack other things into the main window.

my $photo_obj = $main->Photo(-file => '' );
my $photo_obj_scaled = $main->Photo(-file => '' );

my $display = $main->Label(-width => 200, 
                           -height => 200,
			   -image => $photo_obj_scaled,
			  )->pack(-fill=>'both', -expand=>1); 

nextp();

my $nxt = $main->Button('-text' => "Next", '-command' => \&nextp)->pack();

$main->Button(-text => 'exit',
              -command => sub{destroy $main}
              )->pack(-anchor => 'e');
MainLoop;


sub loadpic {
    my $filename = shift;
    my $size;
    my $orientation;
    $photo_obj->blank; #clear out old jpg
    $photo_obj_scaled->blank;
    my ($h,$w) = ($main->height, $main->width);
    #
    # how to scale the pic?

    #Tk can only zoom or shrink by a factor, so
    #you need to determine the size of the image
    #then decide whether it needs shrinking or zooming.
    #but Tk itself won't get the size of the image without
    #external modules like Image::Info 

    #I just show a shrink here, for demoing the idea.
    
    $photo_obj->read($filename); 
    $photo_obj_scaled->copy($photo_obj, -subsample => 4,4 );      
    
    $display->configure(-image => $photo_obj_scaled);

    return;
}

sub nextp {

    push (@fl,shift(@fl)); #circular list

    my $f = $fl[0];
    loadpic("$dir/$f");
    return;
}

##</code><code>##

#!/usr/bin/perl -w
use strict;
use Tk;
use Tk::JPEG;
use Image::Magick;
use MIME::Base64;

my $im = Image::Magick->new; # a single object for thumbnails
my $c;
my $dir = ".";
my @fl = <*.jpg>;
print "@fl\n";

my $main = new MainWindow;

my $photo_obj = $main->Photo(-file => '' );

my $display = $main->Label(-width => 200, 
                           -height => 200,
			   -image => $photo_obj,
			  )->pack(-fill=>'both', -expand=>1); 

&loadpic( $fl[0] );

my $nxt = $main->Button('-text' => "Next", '-command' => \&nextp)->pack();

$main->Button(-text => 'exit',
              -command => sub{destroy $main}
              )->pack(-anchor => 'e');

# hack to make first photo show up
$main->bind("<Visibility>", sub { $nxt->invoke });

MainLoop;


sub loadpic {
    my $filename = shift;

    $photo_obj->blank; #clear out old jpg

    my ($h,$w) = ($display->height, $display->width);
    #
# how to scale the pic?
   # Create new size version
   $im->Read($filename);
   $im->Scale( geometry => $w.'x'.$h );
   #Tk needs base64 encoded image files
   my $data = encode_base64( $im->ImageToBlob() );
   undef @$im; # blank $im object 

   $photo_obj->put($data); 
   $display->configure(-image => $photo_obj);

}

sub nextp {
    push (@fl,shift(@fl)); #circular list

    my $f = $fl[0];
    loadpic("$dir/$f");
}