TK Toplevel Window List

[Anonymous Monk]

How can a Toplevel window list be retrieved for all toplevel windows? (including windows started from other instantiations of the program)

[kcott]

The following script will output a list of MainWindows and all (immediate) children for every instance that is running.

#!/usr/bin/env perl -T

use strict;
use warnings;

use Tk;

$ENV{HOME} =~ /^(.*)$/;
$ENV{HOME} = $1;

my $widget_list_joiner = '~';

my $mw = MainWindow->new(-title => 'Toplevel Lister');
$mw->geometry('400x300+50+50');

my $tl = $mw->Toplevel;
$tl->Button(-text => 'Close', -command => sub { $tl->withdraw })->pack
+;
$tl->raise;

my $action_F = $mw->Frame()->pack(-side => 'bottom');
my $exit_B = $action_F->Button(-text => 'Exit', -command => sub { exit
+ })->pack;

my $output_F = $mw->Frame()->pack;
my $info_T = $output_F->Scrolled('Text', -scrollbars => 'osoe')->pack;

$info_T->insert(end => '$mw->name : ' . $mw->name . "\n");

my @interps = $mw->interps;
$info_T->insert(end => '$mw->interps : ' . "\n");
for (sort @interps) {
    $info_T->insert(end => "\t$_\n");
    $info_T->insert(end => "\tToplevels:\n");
    my $toplevel_list = $mw->send($_ => undef);
    for (split $widget_list_joiner => $toplevel_list) {
        $info_T->insert(end => "\t\t$_\n");
    }
}

MainLoop;

sub Tk::Receive {
    my $mw = shift;
    return join $widget_list_joiner => $mw, $mw->children;
}

On the first run, the output looks like:

$mw->name : pm_tk_top_list
$mw->interps : 
    pm_tk_top_list
    Toplevels:
        MainWindow=HASH(0x7fecba93def0)
        Tk::Toplevel=HASH(0x7fecba9493b0)
        Tk::Frame=HASH(0x7fecba9a3900)
        Tk::Frame=HASH(0x7fecba9a3180)

With 3 instances running:

$mw->name : pm_tk_top_list #3
$mw->interps : 
    pm_tk_top_list
    Toplevels:
        MainWindow=HASH(0x7fecba93def0)
        Tk::Toplevel=HASH(0x7fecba9493b0)
        Tk::Frame=HASH(0x7fecba9a3900)
        Tk::Frame=HASH(0x7fecba9a3180)
    pm_tk_top_list #2
    Toplevels:
        MainWindow=HASH(0x7f87a113df20)
        Tk::Toplevel=HASH(0x7f87a11493b0)
        Tk::Frame=HASH(0x7f87a11a3900)
        Tk::Frame=HASH(0x7f87a11a3180)
    pm_tk_top_list #3
    Toplevels:
        MainWindow=HASH(0x7fbb3093df50)
        Tk::Toplevel=HASH(0x7fbb309493b0)
        Tk::Frame=HASH(0x7fbb309a3900)
        Tk::Frame=HASH(0x7fbb309a3180)

References:

• Tk::Widget for name(), interps() and children() methods.
• send for send() method and Tk::Receive subroutine.
• Tk distribution for everything else.

[Anonymous Monk]

Thanks! The ...->interps ... works great on the Linux side with X11. Thought maybe there was a data structure in the Perl interpreter which could be queried for all of the windows so it was OS independent. Sounds like not. Appreciate all of the help!!! Thanks!

[Anonymous Monk]

Finally was able to retrieve the window list from Perl

Win32 using some ugly code:<\p>

if ($^O eq "MSWin32")
{
    my @pt = `tasklist /v`; # Get the process list from Windows (NT, 2
+K, XP, 7)

    foreach my $p (@pt) # One process per line
    {
        if ($p =~ m/perl\.exe/ig) # Keep only the Perl processes
        {
            my @p2 = split(/\s+/, $p, 11); # Any space after 11 is par
+t of the window title
            my $nm = $p2[10];
            $nm =~ s/\s+$//g; # Remove trailing whitespace
            ...
        }
    }
}
else
{
    # Use interps approach
}

Thanks again for the great inputs!

[Anonymous Monk]

ask the window manager, if it is possible, window manager will know (hint, it manages windows )

Tk::Wm

[Anonymous Monk]

Thank you, but which function would produce a window list? Or perhaps, there is a structure which should be examined?

[thundergnat]

If you just wnat to get a list of all the toplevel windows from within a single process, it is pretty easy. Something like this perhaps.

use warnings;
use strict;
use Tk;

my $mw = MainWindow->new(-title => 'main window');

for (1..5) {
    $mw->Toplevel(-title => "toplevel #$_");
}

for ($mw, $mw->children) {
    print $_->cget('-title'),"\n" if /Toplevel/ or /MainWindow/;
}

MainLoop;

To find windows owned by other processes, you are going to need to interact with the OS window manager and that is going to be very specific to the your needs and the OS/WM you are using. There's no portable easy answer.

[Anonymous Monk]

Thank you, but which function would produce a window list?

Perhaps one with "list" in the documentation, there aren't that many functions, you can find it, grep/ack makes it easier