Re: Getting Keypresses

[James Brown]

Thanks for the example Sam, I appreciate it.

I will be using Festival for the speech synthesis part, although my work 
is cut out slightly thanks to the Festival component at 
http://www.cepstral.com/source/POE-Component-Festival/

Do you know if I can use the POE::Wheel::Curses on Windows as well? (I'm 
supposed to be supporting both platforms).

Thanks again,

James.

Sam Vilain wrote:

On Wed, 31 Dec 2003 00:36, James Brown wrote;

  > I'm relatively new to Perl and POE in particular, but I have a
  > University final year project to develop a small web browser for
  > the blind. The browser only needs to retrieve very simple web
  > pages (similar to a WAP browser on a mobile phone) and have a
  > simple keyboard input (only a couple of buttons with no GUI -
  > we're going to use a speech synthesiser instead).
Nice.  Are you using festival, or something better?  Going to make a
nice, re-usable POE component for it and release it to CPAN ?  ;-)
  > I've successfully used POE::Component::Client::UserAgent to
  > retrieve the web pages, but I would really appreciate some advice
  > on getting keyboard input. Which module should I use? Does anyone
  > have experience in taking keyboard input for a POE app?
See the attached, it's probably just enough to set you moving.  From
my early POE days :)
------------------------------------------------------------------------

#!/usr/bin/perl -w
#
#  This script is mainly a test of POE::Wheel::Curses
use strict;

use POE;
use Curses;             # for unctrl, etc
use POE::Wheel::Curses;
my $LOG;
sub logger { $LOG .= (shift @_)."\n" };
sub flushlog { print $LOG; $LOG="" };
sub _start {
    my $heap = $_[HEAP];
    logger ("_start(". join (", ", map { "\"$_\"" } @_[ARG0..$#_]).")");
    $heap->{console} = POE::Wheel::Curses->new
        ( InputEvent => 'keystroke_handler', );
}
# Generate events from console input.  Sets up Curses, too.

# A keystroke handler.  This is the body of the program's main input
# loop.
sub keystroke_handler {
    my ($keystroke, $wheel_id, $heap) = @_[ARG0, ARG1, HEAP];
    logger ("keystroke_handler(".
         join (", ", map { "\"$_\"" } @_[ARG0..$#_]).")");
    $|=1;
    # Control characters.  Change them into something printable via
    # Curses' unctrl function.
    if ($keystroke lt ' ') {
        $keystroke = '<' . uc(unctrl($keystroke)) . '>';
    }
    # Extended keys get translated into their names via Curses'
    # keyname function.
    elsif ($keystroke =~ /^\d{2,}$/) {
        $keystroke = '<' . uc(keyname($keystroke)) . '>';
    }
    # Just display it.
    #addstr( $heap->{console}, $keystroke );
    addstr( 0, 0, "You pressed $keystroke" );
    #noutrefresh( $heap->{console} );
    refresh();

    # this won't block unless we hit pipe buffers (user presses
    # Ctrl+S, etc)
    #doupdate;
    if ( $keystroke eq "q" ) {
        $_[KERNEL]->yield("_stop");
    }
}
sub _stop {

    logger ("keystroke_handler(".
         join (", ", map { "\"$_\"" } @_[ARG0..$#_]).")");
    my ($heap) = $_[HEAP];
    # This will close the console
    delete $heap->{console};
}
flushlog();

my $session = POE::Session->create
    (
     inline_states =>
     {
      _start => \&_start,
      "keystroke_handler" => \&keystroke_handler,
      _stop => \&_stop,
     },
    );
$poe_kernel->run();

flushlog();