http://qs321.pair.com?node_id=294381

tos has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks,

for a little photo-sort-application, which i'm working on, i need to find out the filename of an selected image. The selection is done by left-mouse-click on the displayed photo (i took one from here). Here an fully functional excerpt

#!/perl # based on Steven Lidie's "Canvas Item Demonstration" (widget-Demo) use strict; use warnings; use Tk; use Data::Dumper; sub items_drag { #---------------------------------------------------- use Data::Dumper; my($c, $x, $y, $iinfo) = @_; $x = $c->canvasx($x); $y = $c->canvasy($y); my $af = $c->itemcget('current', -image); print "\$af: $af\n"; print Data::Dumper->Dump([$af], [qw(af *ary)]); } my %iinfo = (); # item information hash $iinfo{areaX1} = 0; $iinfo{areaY1} = 0; $iinfo{areaX2} = 0; $iinfo{areaY2} = 0; $iinfo{restore_cmd} = ''; my $top = MainWindow->new(); my $c = $top->Canvas('-width' => 300, -height => 245)->pack(); $c->createImage("2c", "2c", -image => $top->Photo(-file => "monk2sm.gi +f")); $c->CanvasBind('<1>' => sub {items_drag shift, $Tk::event->x, $Tk::event->y, \%iinfo}); MainLoop;
On mouse-click the items-drag-subroutine tells me that $af is an reference on an anonymous hash with confession Tk::Photo, ...

# aperl canvas.pl $af: Tk::Photo=HASH(0x19f4fbc) $af = bless( {}, 'Tk::Photo' );
...but that's all. I assumed that Data::Dumper would show me a nice nested datastructure which contains the filename amongst other attributes.

Can anybody show me how to retrieve the desired attribute-value or perhaps show me my logical flaw.

greetings, tos

Replies are listed 'Best First'.
Re: retrieving Tk::Photo's attributes
by PodMaster (Abbot) on Sep 26, 2003 at 12:07 UTC