http://www.perlmonks.org?node_id=11118320

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

This is my first attempt at writing a megawidgit in PERL. I have not been programming for 10yrs. I cant find any concise examples showing what must be in the module, and where the perl subroutines must go. Here is my code. It runs -- but it only hangs. I assume the widget is not being displayed, and its waiting for to choose something...

package Tk::ListBox; unshift (@INC , "/usr/pkg/lib/perl5/site_perl/5.30.0/x86_64-netbsd +-thread-multi/Tk"); unshift (@INC , "/usr/pkg/lib/perl5/vendor_perl/5.30.0/Cache/Memca +ched"); unshift (@INC , "/usr/pkg/lib/perl5/site_perl/5.30.0/Cache"); # Declare base class. use base qw/ Tk::Frame /; # Frame-based composite use Tk::Widget; # or use base qw/ Tk::Toplevel /; # Toplevel-based composite # or (Not a TopLevel wid +get) # use base qw/ Tk::Scrolled /; # use base qw/ Tk::Listbox /; use Tk::Listbox; use Tk::Button; use Tk::Entry; # use base qw/ Tk::Derived Tk::SomeWidget /; # derived from SomeWid +get # ## If it is a "composite widget", then its not "deri +ved" Construct Tk::Widget 'ListBox2'; # install MyNewWidget in pTk name +space sub ClassInit { # called once to initialize new class my($class, $mw) = @_; $class->SUPER::ClassInit($mw); } sub Populate { # called to build each widget instanc +e my($self, $args) = @_; $self->SUPER::Populate($args); my $o = $self -> ListBox2 -> pack(); $self->Advertise( 'listbox' => $o ); # advertise subwid +gets $self->Callback(); # invoke -command callbacks $self->Component(); # define a subwidget component $self->ConfigSpecs(); # define cget() / configure() options $self->Delegates(); # how methods are delegated to subwid +gets $self->Subwidget(); # map a subwidget name to subwidget r +eference }