// JavaScript Document
function bind(func, this_) {
  return function() {
    func.apply(this_, arguments);
  };
}

function Transliterator(input) {
  this.input = input;
  this.keyListener = bind(this.keyListener, this);
  function clearLastKey() {
    delete this.lastChar;
  }
  clearLastKey = bind(clearLastKey, this);
  input.addEventListener('click', clearLastKey, false);
  input.addEventListener('blur', clearLastKey, false);
}

Transliterator.lookup = {
  'A': '\u0410',                       'a': '\u0430',
  'B': '\u0411',                       'b': '\u0431',
  'V': '\u0412',                       'v': '\u0432',
  'G': '\u0413',                       'g': '\u0433',
  'D': '\u0414',                       'd': '\u0434',
  'E': '\u0415',                       'e': '\u0435',
  'Yo': '\u0401',                      'yo': '\u0451',
  'Zh': '\u0416',                      'zh': '\u0436',
  'Z': '\u0417',                       'z': '\u0437',
  'I': '\u0418',                       'i': '\u0438',
  'J': '\u0419',                       'j': '\u0439',
  'K': '\u041A',                       'k': '\u043A',
  'L': '\u041B',                       'l': '\u043B',
  'M': '\u041C',                       'm': '\u043C',
  'N': '\u041D',                       'n': '\u043D',
  'O': '\u041E',                       'o': '\u043E',
  'P': '\u041F',                       'p': '\u043F',
  'R': '\u0420',                       'r': '\u0440',
  'S': '\u0421',                       's': '\u0441',
  'T': '\u0422',                       't': '\u0442',
  'U': '\u0423',                       'u': '\u0443',
  'F': '\u0424',                       'f': '\u0444',
  'H': '\u0425',	'h': '\u0445',
  'C': '\u0426',	'c': '\u0446',
  'Ch': '\u0427',                      'ch': '\u0447',
  'Sh': '\u0428',                      'sh': '\u0448',
  'W': '\u0429',                       'w': '\u0449',
  '""': '\u042A',                      "''": '\u044A',
  'Y': '\u042B',                       'y': '\u044B',
  '"': '\u042C',                       "'": '\u044C',
  'Je': '\u042D',                      'je': '\u044D',
  'Yu': '\u042E',      'yu': '\u044E',
  'Ya': '\u042F',      'ya': '\u044F',

 	'-':	'-',
	// dont' show them:
 	'X':	'\u0425',		'x':	'\u0445',
	'Ts':	'\u0426',		'ts':	'\u0446',
	'Ju':	'\u042E',		'ju':	'\u044E',
	'Ja':	'\u042F',		'ja':	'\u044F' 
};

Transliterator.prototype.keyListener = function(event) {
  if(event.ctrlKey || event.altKey || event.metaKey) {
    return;
  }
  var sl = this.input.scrollLeft;
  var st = this.input.scrollTop;
  var curChar = String.fromCharCode(event.which);
  var rusText = Transliterator.lookup[this.lastChar + curChar.toLowerCase()];
  if(rusText) {
    event.preventDefault();
    var ss = this.input.selectionStart;
    this.input.value = this.input.value.substring(0, this.input.selectionStart - 1) + rusText + this.input.value.substring(this.input.selectionEnd, this.input.textLength);
    this.input.selectionStart = ss;
    this.input.selectionEnd = ss;
  } else {
    rusText = Transliterator.lookup[curChar];
    if(rusText) {
      event.preventDefault();
      var ss = this.input.selectionStart;
      this.input.value = this.input.value.substring(0, this.input.selectionStart) + rusText + this.input.value.substring(this.input.selectionEnd, this.input.textLength);
      this.input.selectionStart = ss + 1;
      this.input.selectionEnd = ss + 1;
    }
  }
  if(rusText) {
    this.input.scrollLeft = sl;
    this.input.scrollTop = st;
  }
  this.lastChar = curChar;
};

Transliterator.prototype.enable = function() {
  this.input.addEventListener('keypress', this.keyListener, false);
};

Transliterator.prototype.disable = function() {
  this.input.removeEventListener('keypress', this.keyListener, false);
};