need help in tutorial(alpha)

[Mat Wilson <mat jnm com au>]

Hi all,

i'm a newb coming from a windows background and have fallen in love with
linux and am trying my hand at perl and gtk at the same time. I cant
seem to get this example code to run

        use Glib qw/TRUE FALSE/;
        use Gtk2 '-init';
        
        my ($hscale, $vscale);
        
        sub cb_pos_menu_select
        {
                my ($widget, $pos) = @_;
                $hscale->set_value_pos($pos);
                $vscale->set_value_pos($pos);
        }
        
        sub cb_update_menu_select
        {
                my ($widget, $policy) = @_;
                $hscale->set_update_policy($policy);
                $vscale->set_update_policy($policy);
        }
        
        sub cb_digits_scale
        {
                my ($adjustment) = @_;
                # Set the number of decimal places to which adj->value is rounded
                $hscale->set_digits($adjustment->value);
                $vscale->set_digits($adjustment->value);
        }
        
        # We do not have a Glib::CLAMP function, so we provide it here.
        sub clamp ($val, $low, $high)
        {
                return (($val > $high) ? $high : (($val < $low) ? $low : $val));
        }
        
        sub cb_page_size
        {
                my ($get, $set) = @_;
                
                # Set the page size and page increment size of the sample
                # adjustment to the value specified by the "Page Size" scale
                $set->page_size($get->value);
                $set->page_increment($get->value);
        
                # This sets the adjustment and make it emit the "changed" signal to
                # reconfigure all the widgets that are attached to this signal.
                $set->set_value(clamp ($set->value,
                                       $set->upper - $set->page_size,
                                       $set->lower));
                
                $set->signal_emit("changed");
        }
        
        sub cb_draw_value
        {
                my $button = shift;
                $hscale->set_draw_value($button->get_active());
                $vscale->set_draw_value($button->get_active());
        }
        
        # Convenience functions
        sub make_menu_item
        {
                my ($name, $func, $data) = @_;
                $item = Gtk2::MenuItem->new_with_label($name);
                $item->signal_connect(activate => $func, $data);
                $item->show;
        
                return $item;
        }
        
        sub scale_set_default_values
        {
                my $scale = shift;
                $scale->set_update_policy('continuous');
                $scale->set_digits(1);
                $scale->set_value_pos('top');
                $scale->set_draw_value(TRUE);
        }
        
        # makes the sample window
        sub create_range_controls
        {
                # Standard window-creating stuff
                $window = Gtk2::Window->new('toplevel');
                $window->signal_connect(destroy => sub { Gtk2->main_quit; });
                $window->set_title("range controls");
        
                $box1 = Gtk2::VBox->new(FALSE, 0);
                $window->add($box1);
                $box1->show;
        
                $box2 = Gtk2::HBox->new(FALSE, 10);
                $box2->set_border_width(10);
                $box1->pack_start($box2, TRUE, TRUE, 0);
                $box2->show;
        
                # value, lower, upper, step_increment, page_increment, page_size
                # Note that the page_size value only makes a difference for
                # scrollbar widgets, and the highest value you'll get is actually
                # (upper - page_size).
                $adj1 = Gtk2::Adjustment->new(0.0, 0.0, 101.0, 0.1, 1.0, 1.0);
        
                $vscale = Gtk2::VScale->new($adj1);
                scale_set_default_values($vscale);
                $box2->pack_start($vscale, TRUE, TRUE, 0);
                $vscale->show;
        
                $box3 = Gtk2::VBox->new(FALSE, 10);
                $box2->pack_start($box3, TRUE, TRUE, 0);
                $box3->show;
        
                # Reuse the same adjustment
                $hscale = Gtk2::HScale->new($adj1);
                $hscale->set_size_request(200, -1);
                scale_set_default_values($hscale);
                $box3->pack_start($hscale, TRUE, TRUE, 0);
                $hscale->show;
                
                # Reuse the same adjustment again
                $scrollbar = Gtk2::HScrollBar->new($adj1);
                # Notice how this causes the scales to always be updated
                # continuously when the scrollbar is moved
                $scrollbar->set_update_policy('continuous');
                $box3->pack_start($scrollbar, TRUE, TRUE, 0);
                $scrollbar->show;
                
                $box2 = Gtk2::HBox->new(FALSE, 10);
                $box2->set_border_width(10);
                $box1->pack_start($box2, TRUE, TRUE, 0);
                $box2->show;
        
                # A checkbutton to control whether the value is displayed or not
                $button = Gtk2::CheckButton->new("Display value on scale widgets");
                $button->set_active(TRUE);
                $button->signal_connect(toggled => \&cb_draw_value);
                $box2->pack_start($button, TRUE, TRUE, 0);
                $button->show;
        
                $box2 = Gtk2::HBox->new(FALSE, 10);
                $box2->set_border_width(10);
        
                # An option menu to change the position of the value
                $label = Gtk2::Label->new("Scale Value Position:");
                $box2->pack_start($label, FALSE, FALSE, 0);
                $label->show;
        
                $opt = Gtk2::OptionMenu->new;
                $menu = Gtk2::Menu->new;
        
                $item = make_menu_item("Top", \&cb_pos_menu_select, 'top');
                $menu->append($item);
                
                $item = make_menu_item("Bottom", \&cb_pos_menu_select, 'bottom');
                $menu->append($item);
        
                $item = make_menu_item("Left", \&cb_pos_menu_select, 'left');
                $menu->append($item);
        
                $item = make_menu_item("Right", \&cb_pos_menu_select, 'right');
                $menu->append($item);
        
                $opt->set_menu($menu);
                $box2->pack_start($opt, TRUE, TRUE, 0);
                $opt->show;
        
                $box1->pack_start($box2, TRUE, TRUE, 0);
                $box2->show;
        
                $box2 = Gtk2::HBox->new(FALSE, 10);
                $box2->set_border_width(10);
        
                # Yet another option menu, this time for the update policy of the
                # scale widgets
                $label = Gtk2::Label->new("Scale Update Policy:");
                $box2->pack_start($label, FALSE, FALSE, 0);
                $label->show;
        
                $opt = Gtk2::OptionMenu->new;
                $menu = Gtk2::Menu->new;
        
                $item = make_menu_item("Continuous", \&cb_update_menu_select, 'continuous');
                $menu->append($item);
        
                $item = make_menu_item("Discontinuous", \&cb_update_menu_select, 'discontinuous');
                $menu->append($item);
        
                $item = make_menu_item("Delayed", \&cb_update_menu_select, 'delayed');
                $menu->append($item);
        
                $opt->set_menu($menu);
                $box2->pack_start($opt, TRUE, TRUE, 0);
                $opt->show;
        
                $box1->pack_start($box2, TRUE, TRUE, 0);
                $box2->show;
        
                $box2 = Gtk2::HBox->new(FALSE, 10);
                $box2->set_border_width(10);
        
                # An HScale widget for adjusting the number of digits on the
                # sample scales.
                $label = Gtk2::Label->new("Scale Digits:");
                $box2->pack_start($label, FALSE, FALSE, 0);
                $label->show;
        
                $adj2 = Gtk2::Adjustment->new(1.0, 0.0, 5.0, 1.0, 1.0, 0.0);
                $adj2->signal_connect(value_changed => \&cb_digits_scale);
                $scale = Gtk2::HScale->new($adj2);
                $scale->set_digits(0);
                $box2->pack_start($scale, TRUE, TRUE, 0);
                $scale->show;
        
                $box1->pack_start($box2, TRUE, TRUE, 0);
                $box2->show;
        
                $box2 = Gtk2::HBox->new(FALSE, 10);
                $box2->set_border_width(10);
        
                # And, one last HScale widget for adjusting the page size of the
                # scrollbar.
                $label = Gtk2::Label->new("Scrollbar Page Size:");
                $box2->pack_start($label, FALSE, FALSE, 0);
                $label->show;
        
                $adj2 = Gtk2::Adjustment->new(1.0, 1.0, 101.0, 1.0, 1.0, 0.0);
                $adj2->signal_connect(value_changed => \&cb_page_size, $adj1);
                $scale = Gtk2::HScale->new($adj2);
                $scale->set_digits(0);
                $box2->pack_start($scale, TRUE, TRUE, 0);
                $scale->show;
                
                $box1->pack_start($box2, TRUE, TRUE, 0);
                $box2->show;
        
                $separator = Gtk2::HSeparator->new;
                $box1->pack_start($separator, FALSE, TRUE, 0);
                $separator->show;
        
                $box2 = Gtk2::VBox->new(FALSE, 10);
                $box2->set_border_width(10);
                $box1->pack_start($box2, FALSE, TRUE, 0);
                $box2->show;
        
                $button = Gtk2::Button->new("Quit");
                $button->signal_connect(clicked => sub { Gtk2->main_quit; });
                $box2->pack_start($button, TRUE, TRUE, 0);
                $button->can_default(TRUE);
                $button->grab_default;
                $button->show;
        
                $window->show;
        }
        
        create_range_controls();
        
        Gtk2->main;
        
        0;
        

I think the error is the lines

                # This sets the adjustment and make it emit the "changed" signal to
                # reconfigure all the widgets that are attached to this signal.
                $set->set_value(clamp ($set->value,
                                       $set->upper - $set->page_size,
                                       $set->lower));
        
to do with the commas but i dont know how re-write this to get it to
work. (my perl reference doesn't explain how to fix this).

Thanks in advance.

Mat