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

I created a scrolled list box but when I populate it with more entries than can be displayed (more than 5 entries), the scroll bar is greyed out - not allowing me to scroll. Resizing the window after it's populated activates the scroll bar, as does a separate function that fills that box. I'm running on a Windows XP machine. Hopefully this is all the relevent code needed to determine the problem.

my $frm1 = $mw -> Frame(-bg=>'LightSkyBlue1') -> pack(-fill => 'x');
my $frm11 = $frm1 -> Frame(-bg=>'LightSkyBlue1') -> pack(-fill => 'x')
+;

my $lst = $frm11 -> Scrolled('Listbox',
                              -width => 50,
                              -height => 5, 
                              -scrollbars => 'oe', 
                              -selectmode => 'single') -> pack();

(generate @lst_files)

$lst -> delete ('0.0', 'end');
$lst -> insert('end', @lst_files);
$mw->update;

[download]

Replies are listed 'Best First'.
Re: Inactive Scroll Bar - Scrolled Listbox
by zentara (Cardinal) on Apr 12, 2011 at 16:26 UTC
    I don't see your problem, but you are not showing a complete running example. How does this run for you? 
    #!/usr/bin/perl -w
use strict;
use Tk;

my $main = MainWindow->new;

my $list = $main->Scrolled('Listbox', -scrollbars => 'e',
                           -selectmode => 'single')->pack;

foreach my $i (1..100) {
   $list->insert('end', "item $i");
}

my $button = $main->Button(-text => "Scroll to Bottom of List",
                           -command => \&scroll_to_bottom)->pack;
MainLoop;

sub scroll_to_bottom {
   my ($first, $last) = $list->Subwidget("yscrollbar")->get;
   print "Listbox window is from $first to $last\n";

   # set to end of list
   my $winsize = $last - $first;
   $first = 1.0 - $winsize;
   $last = 1.0;
   $list->Subwidget("yscrollbar")->set($first, $last);

   $list->see('end'); #scroll all the way down
   #$list->see('55'); #scroll to some index

   print "Set listbox window from $first to $last\n";
}

    [download]
    I'm not really a human, but I play one on earth.
    Old Perl Programmer Haiku ................... flash japh
[reply]
[d/l]

      The code you posted works fine. What part is of my code would you like to see? It's a very large script so I tried to pull the parts related to the scroll bar.

[reply]

        Here is a complete runnable example, that demonstrates the problem:

        use strict;
use warnings;
use Tk;

my $mw = tkinit;
my $frm1 = $mw -> Frame(-bg=>'LightSkyBlue1') -> pack(-fill => 'x');
my $frm11 = $frm1 -> Frame(-bg=>'LightSkyBlue1') -> pack(-fill => 'x')
+;

my $lst = $frm11 -> Scrolled('Listbox',
                              -width => 50,
                              -height => 5,
                              -scrollbars => 'oe',
                              -selectmode => 'single') -> pack();
$mw->update;
$lst -> delete ('0.0', 'end');
$lst -> insert('end',(0..10));
$mw->update;
# force scrollbar refresh:
#  my $sb = $lst->Subwidget('yscrollbar');
#  $sb->set( $sb->get );

MainLoop;

        [download]
        See also:
        Re: Perl/Tk Optional Vertical Scrollbar Bugfix

        Cheers, Christoph
[reply]
[d/l]

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