Re^4: Question about embedded Tk::Canvas

[emilbarton]

The ancestors from the main window are:

  $tracker_window =  MainWindow->new..
  $TrackBook = $tracker_window->NoteBook..
  $TrackTabs{'Tracks'} = $TrackBook..
  $Matrix = $TrackTabs{'Tracks'}->Scrolled..  
  $canvas = $Mainwin->Scrolled('Canvas')->grid..
  my $real = $canvas->Subwidget("canvas"); # for bindings..
  $CstObj->{'matrix'}->windowConfigure( "$i,1", -window => $canvas )..

[kschwab]

Right. So your issue is retrieving a reference to the canvas object. The easiest approach would probably be to store a reference to it when you create it. You seem to be creating a module anyway...so perhaps something like:

package YourPackage;
use strict;use warnings;
use Tk;
use Tk::Canvas;
sub new {
   my $class = shift;
   my $self = bless {}, $class;
   my $mw = MainWindow->new();
   $self->{'mainwin'}=$mw;
   $self->{'mycanvas'}=$mw->Canvas();
   return $self;
}
sub getcanvas {
   my $self=shift;
   printf "Returning a %s\n",ref($self->{'mycanvas'});
   return $self->{'mycanvas'}
}
package main;
my $YP = YourPackage->new();
my $canvas=$YP->getcanvas();

[emilbarton]

Ok, it seems quite a bit of a modification on my script. I don't understand why retrieving a reference aftewards should disturb but I'll apply this solution.

Thank you very much for your help.

[kschwab]

Looking at your code on github, it's because of this:

my $canvas = $Mainwin->Scrolled('Canvas')->grid;
my $real = $canvas->Subwidget("canvas");

Based on your choice of the variable name $real, you seem to already know what the issue is here :) $canvas isn't a 'Canvas'.