Re: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl)

Passing arguments to event handlers in WxPerl is something you never have to do :)

Having code outside of subroutines is something you never have to do :) (really shouldn't )

EVT_COMBOBOX ... How is this done?

As documented :) my wxWidgets / wxPerl / wxGlade tutorial, wxperl_usage / wxperl-usage / wxPerl::Usage / Class Method Browser , available methods, method invocation syntax, link to docs

sub Combobox1action {
    my( $frame, $comboevent ) = @_;
    my $combobox  = $comboevent->GetEventObject;
    my $selection = $comboevent->GetString;
    $frame->SetTitle( "Combo box selected ($selection)" );
}
[download]

http://docs.wxwidgets.org/2.8.12/wx_wxcommandevent.html#wxcommandeventgetstring
http://docs.wxwidgets.org/2.8.12/wx_wxevent.html#wxeventgeteventobject

Re^2: How do i color font in a listbox? ( wx-listctrl-coloritems-findselect.pl )

wx-combobox-event.pl

#!/usr/bin/perl --
##
##
## perltidy -olq  -csc -csci=3 -cscl="sub : BEGIN END " -otr -opr -ce 
+-nibc -i=4 -pt=0   "-nsak=*"
## perltidy -olq  -csc -csci=10 -cscl="sub : BEGIN END if " -otr -opr 
+-ce -nibc -i=4 -pt=0   "-nsak=*"
## perltidy -olq  -csc -csci=10 -cscl="sub : BEGIN END if while " -otr
+ -opr -ce -nibc -i=4 -pt=0   "-nsak=*"
#!/usr/bin/perl --
use strict;
use warnings;
use Wx 0.86 qw(  );
Main( @ARGV );
exit( 0 );

sub Main {
    my $app = Wx::SimpleApp->new;
    my $f   = Wx::Frame->new( undef, -1, "", );
    my $cb  = Wx::ComboBox->new(
        $f,
        -1,
        "",
        [-1,-1,],
        [-1,-1,],
        [  22 .. 33 ],
    );
    $cb->SetFocus;
    $f->SetSizer( Wx::BoxSizer->new( Wx::wxVERTICAL() ) );
    $f->GetSizer->Add( $cb,  0, Wx::wxEXPAND() );
    $f->GetSizer->SetSizeHints( $f );
    $f->Show( 1 );
    $app->SetTopWindow( $f );
#~     Wx::Event::EVT_COMBOBOX( $app, $cb, \&Combobox1action );
    Wx::Event::EVT_COMBOBOX( $f, $cb, \&Combobox1action );
    $app->{cb}  = $cb;
    $app->MainLoop;
} ## end sub Main

sub Combobox1action {
    my( $frame, $comboevent ) = @_;
    my $combobox  = $comboevent->GetEventObject;
    my $selection = $comboevent->GetString;

#~     my $selection = $combobox->GetValue;
    $frame->SetTitle( "Combo box selected ($selection)" );
} ## end sub Combobox1action


__END__
[download]

Comment on Re: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl) Select or Download Code

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Re^2: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl) by pwn01 (Initiate) on Sep 19, 2014 at 15:12 UTC
I guess I'm still trying to develop an OO way of thinking. One more question. Is there an ideal place to do database operations? Should I do them right at the beginning and load up a bunch of variables?	[reply]
Re^3: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl) by Anonymous Monk on Sep 20, 2014 at 07:10 UTC
Put it in a subroutine , call subroutine and give it args, have subruotine return values, subroutines are easy to call repeatedly , programming is all about well named suboutines calling each other .... and zero global variables Main( @ARGV ); exit( 0 ); sub Main { my $lessons = DatabaseOperations( 'ro', 'sham', 'bo' ); my $myframe = MyFrame->new( $lessons ); ... $simpleapp->MainLoop; } ## FetchLessons?? sub DatabaseOperations { my( $ro, $sham, $bo ) = @_; my $dsn = "dbi:mysql:$ro"; my $dbh = DBI->connect( $dsn, $sham, $bo ) ... ... return \@lessonsimplename; } sub MyFrame::new { ## NO LONGER USING "fake" GLOBAL VARIABLE @lessonsimplename my( $lessonsimplename ) = @_; ... my $combobox1 = Wx::ComboBox->new( $panel, -1, $lessonsimplename->[0], [50, 110], [-1, -1], $lessonsimplename, 0, ... [download] The key is to put everything into well named subs :) subroutines that take arguments, not work with "fake" global variables , file scope my globals, lexical globals , global lexicals, fake globals they nullify the helpfulness of strict :) read about it http://perl.plover.com/flagbook/yak/Chi/slide040.html 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	[reply] [d/l]
Re^2: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl) by pwn01 (Initiate) on Sep 19, 2014 at 14:38 UTC
Thanks for the response. It think that you are on to the problem. Do the variables in MyFrame that I loaded with the data from the database have the right scope for the event handler sub to access them?	[reply]
Re^3: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl) by pwn01 (Initiate) on Sep 19, 2014 at 14:55 UTC
Got it!!! Thanks. Here is the code: `sub Combobox1action { my( $self, $event ) = @_; my $selection; $selection = $event->GetString(); $self->SetTitle( 'Combo box selected ( '.$selection.' )' ); }` [download] I guess I still need to clean up a little, but at least I've moved forward. Thanks all. Any other final suggestions are welcome.	[reply] [d/l]
Re^3: Passing arguments to event handlers in WxPerl (is something you never have to do; wx-combobox-event.pl) by pwn01 (Initiate) on Sep 19, 2014 at 18:23 UTC
I found the answer to the scope question.	[reply]