[Kde-perl] Qt::Slider revisited

[Wolfgang Hommel]

Greetings!

Although it's been briefly discussed on the list just two weeks ago, I'd 
really appreciate some details on the "Qt::Slider isn't displayed" 
issue. I'm referring to the code of PerlQT tutorial 6, presently 
available at

http://perlqt.sourceforge.net/index.php?page=viewcode&file=tutorials/t6/t6.pl

Specifically this part:

package LCDRange;
use Qt;
use Qt::isa qw(Qt::VBox);

sub NEW {
    shift->SUPER::NEW(@_);

    my $lcd = Qt::LCDNumber(2, this, "lcd");
    my $slider = Qt::Slider(&Horizontal, this, "slider");
    $slider->setRange(0, 99);
    $slider->setValue(0);
    $lcd->connect($slider, SIGNAL('valueChanged(int)'), SLOT('display(int)'));
}


Now, when I run the tutorial code on PerlQt 3.008, Qt 3.3.1, Linux,

- the Slider doesn't show up at all, but the LCD does, as it should
- if I use a Qt::Pushbutton instead of a Qt::Slider, both the LCD and 
the Pushbutton show up for each LCDRange instance
- running the original tutorial code (with the Slider), but as .cpp 
source, works fine as well (slider shows up)

Now, if the above package is changed to:

package LCDRange;
use Qt;
use Qt::isa qw(Qt::VBox);

my slider;
sub NEW {
    shift->SUPER::NEW(@_);

    my $lcd = Qt::LCDNumber(2, this, "lcd");
    $slider = Qt::Slider(&Horizontal, this, "slider");
    $slider->setRange(0, 99);
    $slider->setValue(0);
    $lcd->connect($slider, SIGNAL('valueChanged(int)'), SLOT('display(int)'));
}

(This has been suggested 2 weeks ago)

Then the Slider gets displayed, but (of course?) only the very last 
instance of all "LCDRange"s has got a Slider, the others don't; i.e., 
the example code creates 16 of them, but only the 16th (bottom right) 
got a Slider attached to it.

I can get it to work by actually using

package LCDRange;
use Qt;
use Qt::isa qw(Qt::VBox);

my $i = 0;
my @slider;
sub NEW {
    shift->SUPER::NEW(@_);

    my $lcd = Qt::LCDNumber(2, this, "lcd");
    $slider[$i] = Qt::Slider(&Horizontal, this, "slider");
    $slider[$i]->setRange(0, 99);
    $slider[$i]->setValue(0);
    $lcd->connect($slider[$i], SIGNAL('valueChanged(int)'), 
SLOT('display(int)'));
    $i++;
}

But I doubt that's elegant. :-)

Could someone please tell me,

- whether this is intentional behavior?
- why this only happens with Qt::Slider (does it?)?
- how the tutorial code should be modified more elegantly to make it 
work properly?

Thanks in advance,

Regards,
Wolfgang