Well, I think it maybe a widget layout design problem on your part, which probably can be easily fixed by carefully allowing all the child widgets to repack themselves, according to the new size.

If you want to remove a frameful of widgets, you should remove it's child widgets first with packForget. (Its like you can't remove a directory which still has subdirs). In other words, don't use complete Frame removal to remove a set of widgets, remove each widget itself, and leave the Frame. Then when you do a resize, and want to repack your frame, each widget gets repacked, and will do so according to the new reported size of the Frame they are being packed into.

I hope that made sense. Play with the following code, it creates new widgets on a rebuild, but you could repack your hidden widgets instead. A second example is also provided.

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

my $top = new MainWindow;

my @counts = ('a'..'z');
my %cbuttons;

my $frame = $top->Frame()->pack();

setup_page();


$top->Button(-text => "packForget",
          -command => sub{
               my @w = $frame->packSlaves;
              foreach (@w) { $_->packForget; }
         })->pack();


$top->Button(-text => "repack",
          -command => sub{ &setup_page  })->pack();

$top->Button(-text => "Exit",
         -command => sub {exit})->pack;

MainLoop;
             

sub setup_page{
for (1..4){

 my $text = shift @counts;
  $cbuttons{$_}{'cb'} = $frame->Checkbutton(
    -text     => $text,
    -variable => \$cbuttons{$_}{'val'},
    -command  => \&SetState,
   )->pack;
  }
}
[download]

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

my $mw = MainWindow->new;
my $vh = $mw->vrootheight;
my $vw = $mw->vrootwidth;
$mw->geometry($vw.'x'.$vh.'+0+0');
$mw->overrideredirect(1); #grabs full control

$mw->fontCreate('big',
   -family=>'arial',
  -weight=>'bold',
  -size=>int(-18*18/14));

my $topframe = $mw->Frame->pack();
my $frame = $mw->Frame->pack();
my $txt;  #make these globals so you reuse them
my $canvas; #and avoid memory gains of making too many 
            #redundant widgets
my $count = 0;

# instead of a button you could make navigation arrows
$topframe->Button(-text => "Change Screen",
          -command => sub{
               #clean out frame's children
               my @w = $frame->packSlaves;
              foreach (@w) { $_->packForget; }
              #clean out frame
              $frame->packForget;
      
                  $count++;
                  &build($count);
            })->pack(-side=>'left',-padx=>20);

$topframe->Button(-text => "Exit",
         -command => sub {exit})->pack(-side=>'right',-padx=>20);

&build(0); #setup first screen

MainLoop;
             
sub build {
my $count = shift;

 $txt = $frame->Text(-bg=>'white',-font=>'big',-height=>5)->pack(-fill
+=>'x');
 $txt->insert('end',"\t\t\t\t Page $count");
# Note that the 'virtual window' height and width are $vh and $vw
# respectively, so we use those dimensions for our Canvas height 
# and width, and let the Canvas expand and fill in both x and y
# directions.
#
$canvas = $frame->Canvas(
   -width => $vw, 
   -height => $vh, 
   -background =>'blue', 
  )->pack(-expand => 1, -fill => 'both');

$canvas->createRectangle(80, 80, 200, 200, -fill => 'yellow'); 

$canvas->createText(125, 125, 
                -fill => 'black',
                -text => "page $count",
                -font => 'big',
                ); 

$frame->pack(); #reshow it
$mw->update;

}
[download]