Tk how-to?

[BrowserUk]

How does one run the Tk; demos?

Update: Would one of the 3 people who downvoted this post please explain to me, by /msg, or anonymous monk post if need be, why it warranted a downvote?

I invite all three of you to expend all your votes every day downvoting very node here, but do please explain why this one warranted it?

[thundergnat]

Run the 'widget' script in the Perl/bin directory.

[BrowserUk]

Thanks++. I search for everything starting with 'tk', and read UserGuide, WidgetDemo and browsed the sources of a dozen or more. If this is mentioned anywhere, I didn't find it.

[PodMaster]

perldoc Tk::UserGuide

NAME
  Perl/Tk - Writing Tk applications in Perl 5

DESCRIPTIONJ
  This document is for beginners. It assumes you know some Perl, and have
  it and Tk running. If you are *not* currently reading this document
  courtesy of the widget demonstration program, please be sure to run
  widget, as it will show you the various widget types supported by Tk and
  how to use them. widget should be installed in your default path, so
  type *widget* at a command prompt.

[converter]

I have a nice collection of Tk-related links on my home node. I'm sure you'll find more than enough there to get you started down the road of Tk madness.

[BrowserUk]

Nice collection of links. You don't know of one that describes how to bind to a Canvas redraw event do you?

[liverpole]

Greetings BrowserUk!

I just recently came across the infamous Canvas bind problem again.

According to Mastering Perl/Tk (published by O'Reilly), you need to use a different bind method with a Canvas object, called CanvasBind.  (This is described in chapter 9.4, and it's because a Canvas object has its own bind method).

Here's an example program I created to demonstrate.  When you resize the main window (and thus the Canvas object), it draws random squares as a result of the change in size and/or position (the event for which is a "<Configure>"):

#!/usr/bin/perl -w
                                                                      
+          
# Strict
use strict;
use warnings;
                                                                      
+          
# Libraries
use Tk;
                                                                      
+          
# Subroutines
sub random($) { int rand $_[0] }

sub random_square($) {
    my $can = shift;
    my ($x0, $y0, $x1, $y1) = (random 256, random 256, random 256, ran
+dom 256);
    $x1 += $x0; $y1 += $y0;
    my $bg = sprintf "#%02x%02x%02x", random 256, random 256, random 2
+56;
    $can->createRectangle($x0, $y0, $x1, $y1, -fill => $bg);
}

# Main program
my $mw = new MainWindow(-title => "Canvas binding test");
my $can = $mw->Canvas(-bg => 'white', -width => 512, -height => 512);
$can->pack(-expand => 1, -fill => 'both');
$can->CanvasBind('<Configure>', [\&random_square]);
MainLoop;

[zentara]

Yeah, it's not intuitive. :-) The Zinc demo is called "zinc-demos", and the gtk demo is called "gtk-demo". Maybe Tk should follow suit ... tk-demo ?

[davidrw]

Here's a Perl/Tk Tutorial .. i personally haven't gone through it yet but a friend of mine recently used it & told me about it.

And our PM Tutorials has a Tk Tutorial, Featuring Your Very Own "Perl Sig/OBFU Decoder Ring"

Update: oops .. i guess i missed the real question .. i got thrown by the title and the first reply

[BrowserUk]

I just wanted to know how to run the demos.

[Courage]

Your direct question was already answered, I only want to note to you that a very similar to perl/Tk module Tcl::Tk is a bit harder to use at the beginning, but a much more flexible and capable, so, if you're starting, better to use it.
There were some show-stoppers in perl/Tk that made me move to Tcl::Tk.
(I am one of a maintainer of it, BTW)