#!/usr/bin/perl
# urdu.pl, written by Mike Foster
# feel free to reuse, modify, redistribute,
# bend, fold, staple, or mutilate.

use strict;
use warnings;
use Tk;

my $lastlength=1;
my $lastdepth=1;
my $mw = MainWindow->new(
    -background=>"darkviolet"
    );
$mw->title('Right-to-left text entry');

my $t1 = $mw->Text(
       -background=>"navy",
       -foreground=>"white",
       -height=>35,
       -width=>80,
       -wrap=>"word",
       -selectbackground=>"blueviolet"
       )->pack;
$t1->bind("<Key>" => \&rtl);

sub rtl {
	#gets end position
	my $depth = $t1->index('end');
	#reduces to line
	$depth =~ s/\..*$//;
	#converts back to an integer
	$depth--;
	if ($lastdepth < $depth) {
		$t1->SetCursor('insert - 1 lines lineend');
	}
	#remember where we were
	$lastdepth = $depth;
	
	#gets end of current line
	my $length = $t1->index('insert lineend');
	#reduces to character number
	$length =~ s/^.*\.//;
	#converts back to integer
	$length++;
	if ($lastlength < $length) {
		$t1->SetCursor('insert - 1 chars');
	}
	#remember where we were
	$lastlength = $length;
}

MainLoop;