perl/tk changing button commands

[Anonymous Monk]

i have a perl/tk program witch is just a text widget, and a button, and i want the text to change everytime i click the button. so i need to be able to change the command of the button each time it is clicked, does anybody know how to do this? here is the code:

#!/usr/bin/perl 

use strict;
use warnings;
use Tk;

sub one;

my $main = MainWindow->new;

my $label1 = $main->Text
(
    '-width'=>'50'
)->pack;

my $button = $main->Button
(
    -text=>'next',
    -command=>sub{one}
)->pack;

MainLoop;

sub one
{
    my $talk2="number1";
    my $talk="this text will be changing after every click of the butt
+on.";
    $label1 -> insert('1.0',"$talk");
    my $button = $main->Button(-text=>'next',-command=>sub{two})->pack
+;
}

sub two
{
# change the text box again
}

[Improv]

Some comments
• I doubt you really mean to be adding all those new buttons everytime you click 'next', right? You might want to read up about how the Tk event loop works.
• You had the syntax for -command incorrect. You either pass it an anonymous subroutine (as in the $button2 example below) or a code reference, with \&
See below for corrected code.
Read more... (719 Bytes)

[hiseldl]

If you want to change the action of the button every time it is pressed, then you need to leave out the -command switch and bind the 'ButtonPress' action later. This will allow you to re-bind the action once you have pressed the button. Here's an example:

#!/usr/bin/perl

use strict;
use warnings;
use Tk;

my $main = MainWindow->new;

my $text = $main->Scrolled('Text', 
               -width=>'50'
              )->pack;

my $button = $main->Button(-text=>'next',
              )->pack;

$button->bind('<ButtonPress>', \&one);

MainLoop;

sub one
  {
    my $talk="One! Click for two.\n";
    $text -> insert('1.0',"$talk");
    $button->bind('<ButtonPress>', \&two);
  }

sub two
  {
    my $talk="One! Click for three.\n";
    $text -> insert('1.0',"$talk");
    $button->bind('<ButtonPress>', \&three);
  }

sub three
  {
    my $talk="One! Click for one.\n";
    $text -> delete('1.0', 'end');
    $text -> insert('1.0',"$talk");
    $button->bind('<ButtonPress>', \&one);
  }

Cheers!

--
hiseldl
What time is it? It's Camel Time!

[kelan]

How about just having an array that holds whatever pieces of text you want and looping through it. (Untested)

#!/usr/bin/perl

use strict;
use warnings;
use Tk;

my $main = MainWindow->new;

my $label1 = $main->Text(
  -width => 50
)->pack;

my $count = 0;
my @texts = (
  "This is the first piece.\n",
  "This is the second.\n",
  "This is the third.\n",
  "etc...\n",
);

my $button = $main->Button(
  -text => "Next",
  -command => sub {
    $label1->insert('1.0', $texts[$count++]);
  }
)->pack;

MainLoop;

kelan

---

Perl6 Grammar Student