Re: Morse input from keyboard

[tybalt89]

Keys can be a problem because of autorepeat, but here's one that uses the left mouse button for the keyer.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11112751
use warnings;
use Time::HiRes qw( time );
use Tk;

my $morse = '';
my $text = '';
my $down = 0;
my $lasttime = time;
my $interval = shift // 0.1; # seconds for timing
my $maxlength = 30;

my $mw = new MainWindow;
$mw->geometry('+500+500');
$mw->Label(-text => "Use left mouse button in green window.\n" .
  "Tweek \$interval to your coding speed")->pack;
my $t = $mw->Label(-textvariable => \$morse,
  -width => $maxlength,
  -bg => 'lightgreen',
  -font => 'courierbold 36',
  )->pack;
$mw->Label(-textvariable => \$text,
  -width => $maxlength,
  -font => 'courierbold 36',
  )->pack;
$mw->Button(-text => 'Clear', -command => sub { $morse = $text = '' },
  )->pack;
$mw->Button(-text => 'Exit', -command => sub {$mw->destroy})->pack;
$t->bind('<1>' => \&press );
$t->bind('<ButtonRelease-1>' => \&release );

MainLoop;

sub morse
  {
  $_[0] =~ tr/.-/01/r =~ s/\S+/
    my $pos = oct 'b1' . $&;
    $pos > 30 and $pos = 30;
    substr '__etianmsurwdkgohvf_l_pjbxcyzq?',
    $pos, 1
    /ger =~ s/ *\K //gr;
  }

sub press
  {
  if( time > $lasttime + 6 * $interval )
    {
    $morse .= '  ';
    }
  elsif( time > $lasttime + 2 * $interval )
    {
    $morse .= ' ';
    }
  length $morse > $maxlength and
    substr $morse, 0, length($morse) - $maxlength, '';
  $lasttime = time;
  }

sub release
  {
  if( time < $lasttime + 2 * $interval )
    {
    $morse .= '.';
    }
  else
    {
    $morse .= '-';
    }
  length $morse > $maxlength and
    substr $morse, 0, length($morse) - $maxlength, '';
  $text = morse($morse);
  $lasttime = time;
  }

[afoken]

Keys can be a problem because of autorepeat

There are generally several keys that are not subject to autorepeat. On A PC, both Shift keys, both Alt keys (right Alt = AltGr on international keyboards), both Ctrl keys, both Logo keys, Menu key, Shift/Caps Lock key, Scroll Lock key, Num Lock key, Pause key. Pause could be a little bit problematic because it can behave different from all other keys at the hardware level.

Polling the Shft, Ctrl, and Alt keys should be easy even through driver, operating system and toolkit layers.

Some systems may treat repeated key presses as shortcut for accessibility functions. Pressing shift five times makes Windows 7 (and others?) switch on "Sticky keys", keeping Num Lock pressed down for five seconds may enable "Toggle keys", keeping right shift pressed down for eight seconds enables "Filter keys". So you may want to use Ctrl or Alt on Windows instead, to prevent that from happening without reconfiguring Windows.

Alexander

[pierrot]

This is much more than I expected. Thank you very much.