$ perldoc -l -m Tk
C:\citrusperl\vendor\lib\Tk.pm

$ ack -hi ">bind.*button" C:\citrusperl\vendor\lib\Tk |tail
 $mw->bind($class,'<Control-ButtonRelease-1>','Control_ButtonRelease_1');
 $mw->bind($class,'<ButtonRelease-1>','ButtonRelease_1');
 $mw->bind($class,'<B1-Motion>',[ 'Button1Motion' ] );
 $mw->bind($class,'<Double-ButtonPress-1>',['Double1']);
 $mw->bind($class,'<Control-ButtonPress-1>',['CtrlButton1']);
 $mw->bind($class,'<Control-Double-ButtonPress-1>',['CtrlButton1']);
    $e->bind('<ButtonRelease-1>' => sub {
    $e->bind('<ButtonRelease-1>' => undef);
 $mw->bind($class,'<Button-6>',     ['xview','scroll',-1,'units']);
 $mw->bind($class,'<Button-7>',     ['xview','scroll',1,'units']);

##</code><code>##

$ which -a widget
C:/citrusperl/vendor/bin/widget
C:/citrusperl/vendor/bin/widget.BAT

$ head C:/citrusperl/vendor/bin/widget
#!/usr/bin/perl

use 5.008;
use Config;
use Tk 804.000;
use lib Tk->findINC( 'demos/widget_lib' );
use Tk::widgets qw/ DialogBox ErrorDialog LabEntry ROText /;
use Tk::Config ();
use WidgetDemo;
use subs qw/