package Tk::Foon;

use base qw(Tk::Label Tk::Derived); #<= changed order
Construct Tk::Widget 'Foon';

sub ClassInit  
{
  my($class, $mw) = @_;
  $class->SUPER::ClassInit($mw);
}

sub Populate
{
  my($self, $args) = @_;
  $self->SUPER::Populate($args);
  $self->ConfigSpecs('DEFAULT' => [ 'SELF' ]); 
}
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Very strange... I worry about doing that, however, because the man page for Tk::derived says:

Tk::Derived should precede any Tk widgets in the class's @ISA.

Update: And the reason for this appears to be so that you can pass your own arguments. If I switch the order so List appears first and Derived second, then when I create my new object with some option that I want to handle, like my $x = $mw->Foon(-taco => 'bell', -foreground => 'brown');, all the options go to the Label first, which doesn't understand -taco.

Daniel Ashbrook

  my($class, $mw) = @_;
  $class->SUPER::ClassInit($mw);
  my($self, $args) = @_;
  $self->SUPER::Populate($args);
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  my($class, @mw) = @_;
  $class->SUPER::ClassInit(@mw);
  my($self, @args) = @_;
  $self->SUPER::Populate(@args);
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$arg is a hashref to the aruments, as shown with Data::Dumper

sub Populate
{
  my($self, $args) = @_;
  print Dumper($args);
  $self->SUPER::Populate($args);
  $self->ConfigSpecs('DEFAULT' => [ 'SELF' ]); 
}
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which prints:

$VAR1 = {
          '-background' => 'blue',
          '-foreground' => 'red'
        };
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Also, changing the order of background and foreground has no effect. It seems that something is swallowing -foreground before it gets to the Label in the derived widget, since a Label given the same arguments has the expected effect. Perhaps configuring the Label individually inside Foon might work.

--Bob Niederman, http://bob-n.com

I recall reading somewhere that the -background and -foreground options are special-cased in a few places in the Tk code and that this can cause unpredictable behavior in some cases (or something to that effect). Adding entries for the options to the call to ConfigSpecs should solve the problem:

  $self->ConfigSpecs(
      -background   => [qw/SELF Background background/],
      -foreground   => [qw/SELF Foreground foreground/],
      'DEFAULT'     => [ 'SELF' ],
  );
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converter

That does it, all right. I actually just got a similar reply on the ptk mailing list; the person said that -foreground and -background are a little funny because they're aliased to -fg and -bg.

Thanks a lot!

Daniel Ashbrook

Interesting, in Derived.pm and Widget.pm you see a similar constructs only opposite

$specs->{'-foreground'} = \@fg,'foreground','Foreground',BLACK];
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Widget.pm

 $cw->ConfigSpecs('-scrollbars' => ['METHOD','scrollbars','Scrollbars'
+,'se'],
                  '-background' => [$w,'background','Background'],
                  '-foreground' => [$w,'foreground','Foreground'],
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I think it would be interesting to know what this is doing...