Here is a Zinc version. There are some things to watch out for when you use alot of timers and movement on screen. You don't want to overload your timers with work, or they won't be able to complete their task, before their next cycle. This results in nothing appearing on the screen. In this example, if I tried to move all columns in a single timer, it would overload, so I cheated, and shared columns between a few timers.
There is also the relationship between timer speed, and pixels moved per cycle. You can choose a larger pixel movement per
larger timer increment, but it will look jerky. This shows smooth motion. I also cheated a bit, by making it not resizable, so I could predict the number of columns. and hard code them into the timers. It is possible to do it so the screen could be any size, but I'll leave all that code-juggling up to you. :-)
This should give you the basic idea.
#!/usr/bin/perl
use warnings;
use strict;
use Tk;
use Tk::Zinc;
my $width = 400;
my $height = 600;
my %tgroups;
my %scrollers;
my $mw = MainWindow->new;
$mw->protocol('WM_DELETE_WINDOW' => sub { &clean_exit });
$mw->geometry($width.'x'.$height);
$mw->configure(-background => 'black');
$mw->resizable(0,0);
$mw->fontCreate('medium',
-family=>'courier',
-weight=>'bold',
-size=>int(-14*14/10));
my $zinc = $mw->Zinc(-width => $width, -height => $height,
-backcolor => 'black',
-borderwidth => 0,
-relief => 'sunken',
-cursor => "top_left_arrow",
)->pack;
#create a group with it's origin at 0,0 upper left corner
$tgroups{0}= $zinc->add('group',1,-visible=> 1);
$zinc->scale( $tgroups{0}, 1, -1); #reverse direction of y axis so
# numbers increase going down
#create some vertical text
my @letters;
foreach my $i(33..126,161..255){
push @letters, chr($i);
}
my @shuffled = map {$_->[0]}
sort { $a->[1] <=> $b->[1]}
map {[$_, rand(1)]} @letters;
my $position = 0;
foreach my $letter( @shuffled ){
$zinc->add( 'text', $tgroups{0} ,
-position => [ 0, $position ],
-text => $letter,
-font => 'medium',
-color => 'green',
-priority => 2,
);
$position += 15;
}
###################################################
#clone and translate
# get width of column considering font
my @pos = $zinc->bbox( $tgroups{0} ); #(corner coords x,y,x1,y1)
my $widthcol = $pos[2] - $pos[0] + 10; # add a 5 pixel border
my $numcols = int($width/$widthcol) + 1; #20 cols
foreach my $j(1..$numcols){
$tgroups{$j} = $zinc->clone( $tgroups{0} );
$zinc->translate($tgroups{$j}, $j * $widthcol, int rand($height/8) )
+;
}
#start scroll
&scroll;
MainLoop;
##########################################################
sub clean_exit{
foreach my $scroller(keys %scrollers){
$scrollers{$scroller}->cancel;
}
undef $zinc;
$mw->destroy;
Tk::exit;
}
########################################################
sub scroll {
$scrollers{0} = $mw->repeat(25,sub {
foreach my $key(0,5,10,15,20 ){
$zinc->translate($tgroups{ $key },0, 5 );
my @pos = $zinc->bbox( $tgroups{$key} ); #(corner coo
+rds x,y,x1,y1)
if($pos[1] > $height/2){
$zinc->itemconfigure($tgroups{$key}, -visible => 0);
$zinc->translate($tgroups{$key}, 0, (-$pos[3] ));
$zinc->itemconfigure($tgroups{$key}, -visible => 1);
}
}
}
);
$scrollers{1} = $mw->repeat(20,sub {
foreach my $key(1,4,6,11,16,19){
$zinc->translate($tgroups{ $key },0,5);
my @pos = $zinc->bbox( $tgroups{$key} ); #(corner coo
+rds x,y,x1,y1)
if($pos[1] > $height){
$zinc->itemconfigure($tgroups{$key}, -visible => 0);
$zinc->translate($tgroups{$key}, 0, (-$pos[3] ));
$zinc->itemconfigure($tgroups{$key}, -visible => 1);
}
}
}
);
$scrollers{2} = $mw->repeat(30,sub {
foreach my $key(2,7,9,12,14,17){
$zinc->translate($tgroups{ $key },0,5);
my @pos = $zinc->bbox( $tgroups{$key} ); #(corner coo
+rds x,y,x1,y1)
if($pos[1] > $height){
$zinc->itemconfigure($tgroups{$key}, -visible => 0);
$zinc->translate($tgroups{$key}, 0, (-$pos[3] ));
$zinc->itemconfigure($tgroups{$key}, -visible => 1);
}
}
}
);
$scrollers{3} = $mw->repeat(36,sub {
foreach my $key(3,8,13,18){
$zinc->translate($tgroups{ $key },0,5);
my @pos = $zinc->bbox( $tgroups{$key} ); #(corner coo
+rds x,y,x1,y1)
if($pos[1] > $height){
$zinc->itemconfigure($tgroups{$key}, -visible => 0);
$zinc->translate($tgroups{$key}, 0, (-$pos[3] - $height)
+);
$zinc->itemconfigure($tgroups{$key}, -visible => 1);
}
}
}
);
return;
}
I'm not really a human, but I play one on earth.
flash japh
