Re^4: disable button

I'm not sure how to pass $push to the subroutine; specifically in the same statement in which it is being defined.

The other alternative is to declare the variable first, before using it, then it will be available throughout the line:


my $push;



$push = $mw->Button( -text => "test ",
    -command => sub {
        #disable $push 
        $push->configure(-state=>'disabled');
  
        #do something

        #enable $push
        $push->configure(-state=>'normal');
    },
)->pack();
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As long as you're not trying to use the value of the variable before it has been set, e.g. on the right-hand side of the assignment. But here, the variable is merely being bound, inside the anonymous subroutine.

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Re^5: disable button by zentara (Cardinal) on Feb 05, 2009 at 20:58 UTC
jdporter, I think you may be missing the fine point of his question. It's about passing the button itself, in the format `[\&callback,$val,'somedata']` I'm not exceptionally clear on why it has this effect, but look at the following example. Your way still dosn't pass the button object, while the second way does. `#!/usr/bin/perl use warnings; use strict; use Tk; my $mw = tkinit; my $push; # dosn't work $push = $mw->Button(-text => "test ", -command =>[\&save_parms,$push,'somedata'] )->pack(); # works my $push1 = $mw->Button(-text => "test1 ", )->pack(); $push1->configure( -command =>[\&save_parms,$push1,'somedata']); MainLoop; sub save_parms { print "@_\n"; }` [download] I'm not really a human, but I play one on earth Remember How Lucky You Are	[reply] [d/l] [select]

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Re^5: disable button
by zentara (Cardinal) on Feb 05, 2009 at 20:58 UTC

jdporter

[\&callback,$val,'somedata']

I'm not exceptionally clear on why it has this effect, but look at the following example. Your way still dosn't pass the button object, while the second way does.

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

my $mw = tkinit; 

my $push;   # dosn't work
$push = $mw->Button(-text => "test ",
           -command =>[\&save_parms,$push,'somedata']
            )->pack();


# works
my $push1 = $mw->Button(-text => "test1 ",
           )->pack();

$push1->configure( -command =>[\&save_parms,$push1,'somedata']);

MainLoop;

sub save_parms {
   print "@_\n";
}
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