Tk::BrowseEntry listbox scrollbar with Mousewheel on Windows

[perltux]

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;

[beech]

Hi,

See sub WheelsUp it works on windows

[perltux]

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. :(

[beech]

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') ],
);

Also, $mw->WidgetDump can help you peek inside

[kcott]

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(...

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.

[perltux]

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.