Perl Gtk2 - ->destroy() is Not Causing the Script to Exit

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

Hello Monks,

Perl: Strawberry Perl 5.18 (*on Windows XP)

A few months ago I wrote a very large GUI program using Perl Gtk2 which still seems to be working just fine. But I'm now
creating a MUCH smaller GUI script that I really just want to display a Popup window to ask the User Yes Or No. If they select
"No" then the script SHOULD exit. I don't remember ever having this issue in my last GUI program, but it was a while ago now and
I'm pretty confused by this error, and why the script won't exit.

Here is my Gtk2 code. At first I just created a MessageDialog object with 'undef' as its parent but I was getting errors. The error
wasn't specifically towards the parent window, but I decided to create a $window object (*toplevel) anyway and I just don't ever
issue the "->show_all" function to display it...

#!/usr/bin/perl

use strict;
use warnings;
use Gtk2 -init;
use Glib qw/TRUE FALSE/;


my $window = Gtk2::Window->new('toplevel');
$window->signal_connect(destroy => sub {Gtk2->main_quit;}); #<---ERROR
### $window->show_all;

my $msg_dialog = Gtk2::MessageDialog->new_with_markup($window, 'modal'
+, 'error', 'yes-no', "Would you like to retry the connection?");
$msg_dialog->set_title("No Connection Found");
$msg_dialog->set_destroy_with_parent(TRUE);
$msg_dialog->signal_connect (response => 
sub {
    my ($self, $response) = @_;
    if ($response eq 'yes') {
        $msg_dialog->hide();
        my_function("yes");

    } elsif ($response eq 'no') {
        $msg_dialog->destroy();
        $window->destroy;
    }
});

$msg_dialog->run();

Gtk2->main;
0;
[download]

So when I execute the script, the MessageDialog opens just fine and I click the "No" button and I get the following error:

Gtk-CRITICAL **: gtk_main_quit: assertion `main_loops != NULL' failed at C:\Documents and Settings\Administrator\My Documents \test_gtk.pl line 10.

Also, when the error gets displayed in the console window, the script basically just hangs until I do a Ctrl-C...

Anyone have any idea why this isn't working, am I missing something here?
Any thoughts or suggestions would be much appreciated, I'm not sure what else to try.

Thanks in Advance,
Matt

Comment on Perl Gtk2 - ->destroy() is Not Causing the Script to Exit Download Code

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Re: Perl Gtk2 - ->destroy() is Not Causing the Script to Exit by mmartin (Monk) on May 02, 2014 at 20:19 UTC
Humm... Well that's strange. If I remove the "signal_connect" statement for the $window object and leave everything else exactly how it is, the error goes away and it seems to be working just fine now. Anyone else think that's strange...? Since the issue SEEMS to be resolved I'm satisified with that, but I'm curious to know if anyone knows why I am getting that error with that line present. Was it deprecated or something like that..? I know I have that line in my other GUI program I mentioned in my OP and never saw that error... Weird! Thanks, Matt	[reply]
Re^2: Perl Gtk2 - ->destroy() is Not Causing the Script to Exit by Anonymous Monk on May 02, 2014 at 21:37 UTC
Anyone else think that's strange...? Nope, not really :) why I am getting that because of the way you write code :) write it like this ( cope with scoping , avoid closures, don't create objects you don't need, don't destroy objects while closureing over them, don't run mainloops for modal dialogs ... so you don't get order of destruction weirdness related messages ) #!/usr/bin/perl -- use strict; use warnings; use Gtk2 -init; use Glib qw/TRUE FALSE/; mme( @ARGV ) for 1 .. 2; sub mme { my $msg_dialog = Gtk2::MessageDialog->new_with_markup( undef, 'modal', 'error', 'yes-no', "Would you like to retry the connection?", ); $msg_dialog->set_title("No Connection Found"); $msg_dialog->set_destroy_with_parent(TRUE); $msg_dialog->signal_connect ( response => \&shimmy, ); printf "runned %s\n", $msg_dialog->run(); } sub shimmy { my ($self, $response) = @_; print "$self $response\n"; } __END__ Gtk2::MessageDialog=HASH(0xc6e674) yes runned yes Gtk2::MessageDialog=HASH(0xb33d24) no runned no [download] see sub DESTROY: Strange ordering of object destruction (global destruction order not guaranteed, Re^3: when is destroy function called ( perl -d:Trace dalek ) :) Re: Win32::GUI window freezing, even with threading. (win32-gui-tk-thread-dequeue.pl, Thread::Queue::popnow/push) + Re^4: Win32::GUI window freezing, even with threading. (Wrong solution), Re: Tk: Creating label in hash, Re: perl Tk thread help, Re: error on file open, Re^4: Query the height of Tk::Text widget with word wrap Gtk+/Gnome Application Development - The Main Loop 10.17. How do I run a dialog without running another main loop? Tutorials: Variable Scoping in Perl: the basics, Coping with Scoping , Mini-Tutorial: Perl's Memory Management, Lexical scoping like a fox, Read this if you want to cut your development time in half!, Closure on Closures , perlref#Circular References, Memory leaks and circular references, Circular references and Garbage collection., make perl release memory, about memory management , Re^3: Scope of lexical variables in the main script , Re: What's the weaken here for?, Devel::Cycle, Devel::NYTProf, Devel::Leak Devel::LeakTrace, WeakRef see Re: No such file or directory error/No such file or directory error, see template at (tye)Re: Stupid question (and see one discussion of that template at Re^2: RFC: Creating unicursal stars tk closures people, Re: TK Submenus (Tk::Menu , global variables/ spirit of strict), tk scoping function argument passing, can't share Tk mainwondow between threads	[reply] [d/l]
Re: Perl Gtk2 - ->destroy() is Not Causing the Script to Exit by sam_bakki (Pilgrim) on May 08, 2014 at 10:22 UTC
Hi mmartin The below code also would fix your problem. `$window->signal_connect(destroy => sub {Gtk2->main_quit() if (Gtk2->ma +in_level()); exit 0;}); #<---ERROR` [download] Thanks & Regards, Bakkiaraj M My Perl Gtk2 technology demo project - http://code.google.com/p/saaral-soft-search-spider/ , contributions are welcome.	[reply] [d/l]