Re: Problem with Perl/Tk and Pixmap

[Andrew DeFaria <Andrew at DeFaria dot com>]

 On 12/16/2010 02:07 PM, Johannes v. Löwis wrote:
> I have a Perl/Tk script that is supposed to show a pixmap on the left
> side of the title bar of the main window. It works on Linux and on a
> rather old version of Cygwin 1.5.
> On Cygwin 1.7 (on XP Home and Prof) the following happens:
>
> $ ./logotest.pl
> Can't bless non-reference value at /usr/lib/perl5/vendor_perl/5.10/i686-cygwin/Tk/Image.pm line 23.
>
> $ cat logotest.pl
> #!/usr/bin/perl
> use strict;
> use warnings;
> use Tk;
>
> my $mw = new MainWindow;
> my $icon = '/* XPM */
> static char *Camel[] = {
> /* width height num_colors chars_per_pixel */
> "    32    32        2            1",
> /* colors */
> ". c #ffffff",
> "# c #7f7f00",
> /* pixels */
> "................................",
> "................................",
> "...................###..........",
> ".......####......######.........",
> "....####.##.....########........",
> "....########....#########.......",
> "......######..###########.......",
> "......#####..#############......",
> ".....######.##############......",
> ".....######.###############.....",
> ".....######################.....",
> ".....#######################....",
> ".....#######################....",
> "......#######################...",
> ".......####################.#...",
> "........###################.#...",
> "........###############.###.#...",
> "............#######.###.###.#...",
> "............###.###.##...##.....",
> "............###.###..#...##.....",
> "............##.####..#....#.....",
> "............##.###...#....#.....",
> "............##.##...#.....#.....",
> "............#...#...#.....#.....",
> "............#....#..#.....#.....",
> "............#.....#.#.....#.....",
> "............#.....###.....#.....",
> "...........##....##.#....#......",
> "...........#..............#.....",
> ".........###.............#......"
> "................................",
> "................................",
> };';
>
> $mw->Pixmap('logo', -data=>$icon);
> $mw->iconimage('logo');
> MainLoop;
>
> $ uname -a
> CYGWIN_NT-5.1 user-e90cadfdc0 1.7.7(0.230/5/3) 2010-08-31 09:58 i686 Cygwin
>
>
> Any ideas or suggestions what further information I could provide
> in order to sort this out?
Reproduced. Note you problem appears to be with Tk::Image, not with 
Cygwin, though you are right in that it works on Linux and complains and 
dies on Cygwin.

Interestingly, if you run your program and the Perl debugger (i.e. perl 
-d logtest.pl) then simply type c for continue it works fine.

Looking at Image.pm I see that if I break at Image.pm:23 there's a 
"return bless $obj,$package" statement. In the debugger, $obj is defined 
and there's no problem. If, however, I just run this without the 
debugger, but put some print statements in Image.pm, I see that $obj is 
indeed returned from $widget->Tk::image as undefined.

This appears to be a Perl/Tk bug.

Even stranger! Change your

  $mw->Pixmap('logo', -data=>$icon);

to

  my $foo $mw->Pixmap('logo', -data=>$icon);

and it works! So you have  a work around, and a bug to report.
--
Andrew DeFaria <http://defaria.com>
This is as bad as it can get, but don't bet on it.


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