shortyfw06 has asked for the wisdom of the Perl Monks concerning the following question:

For an entry widget in Tk, I used the following validate command to only allow negative and positive integers. This would give an immediate error if a letter or other character was entered. In Tkx, I do not get an error when the entry is invalid. Is there a different way to do this in Tkx? 

#! perl
use strict;
use warnings;
use Tk;

my $value;
my $mw  = new MainWindow;
my $ent = $mw->Entry(-textvariable    => \$value,
                     -validate        => 'key',
                     -validatecommand => sub { $_[0] =~ /^(?:|-|\d+|-\
+d+)$/ },
                     -invalidcommand  => \&lam_num_error)->pack();

my $print_button = $mw->Button(-text    => "Print",
                               -command => \&printx,
                               -font    => "ansi 10 bold")->pack();

my $reset_frm = $mw->Frame();
$reset_frm->pack(-fill => 'both');
my $reset_button = $reset_frm->Button(-text    => "Reset",
                                      -command => \&do_reset,
                                      -font    => "ansi 10 bold")->pac
+k();
MainLoop;

sub printx
{
    print $value unless $value eq '-';
}

sub do_reset
{
    $ent->delete(0, 'end');
}

sub lam_num_error
{
    $mw->messageBox(-message => "The input must be an integer.");
}

__END__

[download]

Replies are listed 'Best First'.
Re: Tk vs Tkx for -validatecommand
by zentara (Cardinal) on Sep 19, 2012 at 15:18 UTC
[reply]
[d/l]

      I tried the following which includes the callback. It isn't working properly. Does anyone see the problem? Thanks! 

      #! perl
use strict;
use warnings;
use Tkx;

my $value;
my $mw  = Tkx::widget->new(".");
my $ent = $mw->new_entry(-textvariable => \$value,-validate => 'key')-
+>g_pack();
$ent->configure(
                -validatecommand => [sub { $_[0] =~ /^(?:|-|\d+|-\d+)$
+/ }, Tkx::Ev('%P'), $ent],
        -invalidcommand  => \&lam_num_error);

my $print_button = $mw->new_button(-text    => "Print",
                               -command => \&printx,
                               -font    => "ansi 10 bold")->g_pack();

my $reset_frm = $mw->new_frame();
$reset_frm->g_pack(-fill => 'both');
my $reset_button = $reset_frm->new_button(-text    => "Reset",
                                      -command => \&do_reset,
                                      -font    => "ansi 10 bold")->g_p
+ack();
Tkx::MainLoop();

sub printx
{
    print $value unless $value eq '-';
}

sub do_reset
{
    $ent->delete(0, 'end');
}

sub lam_num_error
{
    Tkx::tk___mmessageBox(-message => "The input must be an integer.")
+;
}

__END__

      [download]
[reply]
[d/l]

        :) You're still stuck in your Tk.pm-isms

        If you run your program you'll get a nice error 

        Can't call method "configure" without a package or object reference

        [download]

        g_pack doesn't return an object

[reply]
[d/l]

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