Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows

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

I have another Mousewheel question related to Tk::BrowseEntry.
On Linux when the pop-up listbox has a scrollbar, I can use the mousewheel to scroll the listbox without having to define any new bindings.
On Windows (Strawberry Perl) this does not work. The mousewheel does nothing.

So I have been trying to set up the binding myself but despite trying various subwidget targets (all those commented out in the example below) I haven't managed to get the mousewheel to scroll the listbox on Windows.

Does anybody know what the correct binding for this is?

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

my $mw=tkinit();
my $var='opt2';
my $b=$mw->BrowseEntry(-label      => "Choose:",
                       -variable   => \$var,
                       -style      => 'MSWin32',
                       -listheight => 5,
                       -browsecmd  => sub{ print STDOUT $var."\n" }
);
$b->insert("end", "opt1");
$b->insert("end", "opt2");
$b->insert("end", "opt3");
$b->insert("end", "opt4");
$b->insert("end", "opt5");
$b->insert("end", "opt6");
$b->insert("end", "opt7");
$b->insert("end", "opt8");
$b->insert("end", "opt9");
$b->insert("end", "optA");
$b->insert("end", "optB");
$b->insert("end", "optC");

#my $lbx=$b->Subwidget("slistbox")->Subwidget("yscrollbar");
#my $lbx=$b->Subwidget("slistbox")->Subwidget("scrolled");
#my $lbx=$b->Subwidget("slistbox")->Subwidget("listbox");
#my $lbx=$b->Subwidget("choices");
my $lbx=$b->Subwidget("slistbox");
$lbx->bind('<MouseWheel>',[sub{$_[0]->yview('scroll',-($_[1]/120)*3,'u
+nits')}, Ev("D")]);
$b->pack;

MainLoop;
[download]

Comment on Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows Download Code

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Re: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by beech (Parson) on Apr 03, 2017 at 03:47 UTC
Hi, See sub WheelsUp it works on windows	[reply]
Re^2: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by perltux (Monk) on Apr 03, 2017 at 13:09 UTC
Unfortunately, while your solution for my previous thread works great, I don't fully understand some of the code in your solution, so I'm a bit at a loss with regards to how to adapt it for the problem in this thread. :(	[reply]
Re^3: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by beech (Parson) on Apr 03, 2017 at 18:47 UTC
Hi, What did I miss? You only want to yview and not select? Can you not copy WheelsUp and do yview instead of updown? update: If you remove your bind call and replace it with `$mw->focusFollowsMouse;` then the Tk::Listbox natural wheel bindings work to scroll the listbox up down without changing the selection But if focusFollowsMouse is too much focus flipping, simply give the focus to the listbox when the button is pressed `$b->Subwidget('arrow')->configure( -command => [ 'focus', $b->Subwidget('slistbox') ], );` [download] Also, $mw->WidgetDump can help you peek inside	[reply] [d/l] [select]
Re^4: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by perltux (Monk) on Apr 04, 2017 at 00:15 UTC
Re^5: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by beech (Parson) on Apr 04, 2017 at 00:53 UTC
Some notes below your chosen depth have not been shown here
Re: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by kcott (Archbishop) on Apr 03, 2017 at 10:54 UTC
G'day perltux, "... but despite trying various subwidget targets ..." I often find checking the source code provides answers for this type of issue. In this case, `&SetBindings`, in http://cpansearch.perl.org/src/SREZIC/Tk-804.033/Tixish/BrowseEntry.pm, has: `... # bindings for listbox my $sl = $w->Subwidget('slistbox'); my $l = $sl->Subwidget('listbox'); $l->bind(...` [download] I don't have MSWin to check your specific OS problem. The DESCRIPTION of Tk::BrowseEntry starts: "BrowseEntry is a poor man's ComboBox." Instead of rolling your own bindings, and potentially other functionality, for Tk::BrowseEntry, perhaps consider using one of the more feature-rich widgets, such as Tk::JBrowseEntry or Tk::JComboBox. — Ken	[reply] [d/l] [select]
Re^2: Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows by perltux (Monk) on Apr 03, 2017 at 13:00 UTC
Yes, I did go through the source code of BrowseEntry.pm, that's how I found those various subwidgets to try (see the commented out lines in my example source code) but none of them seem to work when it comes to the mousewheel binding of the pop-up listbox on Windows. Tk::JBrowseEntry or Tk::JComboBox were considered in the past but they had other shortcomings that made them unsuitable and which made me choose BrowseEntry.	[reply]