Perl/Tk widget removal problem...

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

Esteemed Monks,

In the following code a button is placed in a grid inside a frame inside a NoteBook tab.

sub doFileImportUi {
    my ($pg, $dbh) = @_;

    $pg->Label(-text => 'File', -width => '10')->grid(
        $pg->LabEntry(-width => '30', -textvariable => \$state->{ImpFi
+le}), $pg->Button(-text => 'Browse', -command => [ \&getImportFile, $
+pg, $dbh], -width => '10'));
    $pg->Label(-text => 'DataSource', -justify => 'right', -width => '
+20')
            ->grid(my $ds_list = $pg->BrowseEntry(-variable => \$state
+->{dsSrcName}, -browsecmd => \&doGetDatasource, -listcmd => [ \&doLoa
+dDs, $pg, $dbh ], -width => '20'), -sticky => 'w');
    my $gbtn = $pg->Button(-text => 'Next Phase')->grid();

    $gbtn->configure(  -command => [ \&doImportFile, $pg, $dbh, $gbtn 
+]);
    my @listname = &doLoadDs($pg, $dbh);
    $ds_list->insert('end', @listname);

}
[download]

When I click on that button and go to the doImportFile() sub I want to remove the button. According to the grid manpage it is possible, but if I use this code, which seems plausible according to the manpage:

    $pg->gridRemove($gbtn);
[download]

Then I get the error:

--- Begin Traceback ---
Failed to AUTOLOAD 'Tk::Frame::gridRemove' at start3.pl line 437
Carp::croak at K:/Perl/lib/Carp.pm line 191
Tk::Widget::__ANON__ at K:/Perl/site/lib/Tk/Widget.pm line 338
main::doImportFile at start3.pl line 437
[\&main::doImportFile,{},{},{}]
Tk callback for .notebook.page4.button1
Tk::__ANON__ at K:/Perl/site/lib/Tk.pm line 228
Tk::Button::butUp at K:/Perl/site/lib/Tk/Button.pm line 111
(command bound to event)
[download]

Does any one have a suggestion to offer about how to remove the button from the window?

jdtoronto

Comment on Perl/Tk widget removal problem... Select or Download Code

Replies are listed 'Best First'.
Re: Perl/Tk widget removal problem... by batkins (Chaplain) on Aug 29, 2003 at 17:49 UTC
I don't have too much experience with the grid manager, but I think the problem may be that $pg was never actually gridded in. Try saving the wdigets to variables and then calling gridRemove on them. For example: `sub doFileImportUi { ... my $lbl1 = $pg->Label(-text => 'File', -width => '10'); my $entr1 = $pg->LabEntry(-width => '30', -textvariable => \$state +->{ImpFile}), $pg->Button(-text => 'Browse', -command => [ \&getImpor +tFile, $pg, $dbh], -width => '10'); $lb1->grid($entr1); ... }` [download] Then later on, do `$lbl1->gridRemove($entr1);` [download] Of course, you'd want to use more meaningful variable names than those, but I think that should do the trick. it says she can do math, but will she recognize 8 / 0? We can only hope they've put in those safeguards. Worst case scenario: She succeeds in dividing by zero, and suddenly little Tiphany-Amber's bedroom becomes the center of a howling vortex of nonspace, frying the neighborhood with sparkling discharges of zero-point energy. - slashdot	[reply] [d/l] [select]
Re: Perl/Tk widget removal problem... by bbfu (Curate) on Aug 29, 2003 at 18:48 UTC
Use `gridForget()` instead. You'll lose your configuration options, but it seems to work. And some sample code, just because: `#!/usr/bin/winperl use warnings; use strict; use Tk; my $mw = MainWindow->new(); $mw->Label(-text => 'Do it')->grid(); my $btn; $btn = $mw->Button( -text => 'Click me', -command => sub { $btn->gridForget() }, )->grid(); MainLoop;` [download] bbfu Black flowers blossom Fearless on my breath	[reply] [d/l] [select]
Re: Re: Perl/Tk widget removal problem... by jdtoronto (Prior) on Aug 29, 2003 at 19:19 UTC
Thanks batkin and bbfu. Two valuable suggestions, thank you! I solved my problem by making the GUI look even cleaner, I put the upper part of the thing in a frame called $upp and the button in $lower, then I add to $upper as needed and the button stays below and gets re-configured every time. Just tested it, looks nice and works well with less code. jdtoronto	[reply]
Re: Perl/Tk widget removal problem... by converter (Priest) on Aug 29, 2003 at 20:04 UTC
I was just poking around in the Tk source (I think I'll be able to grok Lex Rex before I understand the Tk source) and it looks like there's no support for `gridRemove` in the code where I'd expect to find it. Maybe it was removed, or never added in the first place? In Tk/Widget.pm (I THINK this is part of the dispatch mechanism): `sub grid { local $SIG{'__DIE__'} = \&Carp::croak; my $w = shift; if (@_ && $_[0] =~ /^(?:bbox\|columnconfigure\|configure\|forget\|info\|lo +cation\|propagate\|rowconfigure\|size\|slaves)$/x) { my $opt = shift; Tk::grid($opt,$w,@_); } else { # Two things going on here: # 1. Add configure on the front so that we can drop leading '-' Tk::grid('configure',$w,@_); # 2. Return the widget rather than nothing return $w; } }` [download] Note that a direct call to `&Tk::grid` with the 'remove' argument works: `$ perl -MTk -e '$m=tkinit; $f=$m->Frame->pack; $b=$f->Button(-text=>"F +oo")->grid; $m->after(750,sub{Tk::grid("remove",$b)}); MainLoop'` [download] This patch to Tk/Widget.pm version 3.080 (Tk 800.024) seems to fix the problem for me: Read more... (2 kB) converter	[reply] [d/l] [select]
Re^2: Perl/Tk widget removal problem... by ig (Vicar) on Feb 19, 2011 at 05:44 UTC
More than 10 years later (Tk/Widget.pm version 4.035) and the bug (inconsistency between documentation and implementation) still exists. Fortunately, your patch still works, except for the line numbers. I have tested minimally and have no idea why this method is not supported. Maybe they have left it out for good reason that I am, thus far, blissfully unaware of.	[reply]
Re^3: Perl/Tk widget removal problem... by Anonymous Monk on Feb 19, 2011 at 11:31 UTC
Thanks for reporting the bug, finally :)	[reply]


Perl: the Markov chain saw
	PerlMonks