/**
 * @constructor
 * @param input Reference to watched input element. Text input expected.
 * @param callBack Event handler. Function will be called on input change. Current value of input will be passed as 1st argument.
 * @param object Set variable <i>this</i> in called event handler, if event handler is non-static.
 * @param interval Set watch interval. Default is 200ms.
 * @class Instance of InputWatch watches input element and call event handler on input change.
 */
function InputWatch(input, callBack, object, interval) {
  if (interval==undefined)
    // 200ms interval by default
    interval = 200;
  
  /** @private */ this.input = input;
  /** @private */ this.callBack = callBack;
  /** @private */ this.object = object;
  /** @private */ this.lastVal = this.input.value;
  var cbInternal = function() {
    var val = this.input.value;
    if (val != this.lastVal) {
      this.lastVal = val;
      this.callBack.call(this.object, val);
    }
  }
  var cbInternalWrapper = function() {
    cbInternal.call(arguments.callee.object);
  }
  cbInternalWrapper.object = this;
  window.setInterval(cbInternalWrapper, interval);
}

/**
 * @constructor
 * @param searchStr Sting to search.
 * @class Search text in text.
 */
function SearchEngine(searchStr) {
  /**
   * Escape regular expressions in text
   * @param text Text to escape.
   * @return Escaped text.
   * @type String
   * @private
   */
  SearchEngine.prototype.escapeRegExp = function(text) {
    text = text.replace(/\\/g, '\\\\');
    text = text.replace(/\^/g, '\\^');
    text = text.replace(/\$/g, '\\$');
    text = text.replace(/\./g, '\\.');
    text = text.replace(/\*/g, '\\*');
    text = text.replace(/\+/g, '\\+');
    text = text.replace(/\?/g, '\\?');
    text = text.replace(/\=/g, '\\=');
    text = text.replace(/\!/g, '\\!');
    text = text.replace(/\:/g, '\\:');
    text = text.replace(/\|/g, '\\|');
    text = text.replace(/\//g, '\\/');
    text = text.replace(/\(/g, '\\(');
    text = text.replace(/\)/g, '\\)');
    text = text.replace(/\[/g, '\\[');
    text = text.replace(/\]/g, '\\]');
    text = text.replace(/\{/g, '\\{');
    text = text.replace(/\}/g, '\\}');
    return text;
  }
  /**
   * @private
   */
  SearchEngine.prototype.escapePunctation = function(text) {
    text = text.replace(/[aá]/g,  '[aá]');
    text = text.replace(/[cč]/g,  '[cč]');
    text = text.replace(/[dď]/g,  '[dď]');
    text = text.replace(/[eéě]/g, '[eéě]');
    text = text.replace(/[ií]/g,  '[ií]');
    text = text.replace(/[nň]/g,  '[nň]');
    text = text.replace(/[oó]/g,  '[oó]');
    text = text.replace(/[rř]/g,  '[rř]');
    text = text.replace(/[sš]/g,  '[sš]');
    text = text.replace(/[tť]/g,  '[tť]');
    text = text.replace(/[uúů]/g, '[uúů]');
    text = text.replace(/[yý]/g,  '[yý]');
    text = text.replace(/[zž]/g,  '[zž]');
    return text;
  }
  /** @private */ this.empty = (searchStr==undefined || searchStr.length==0);
  if (!this.empty) {
    var pattern = searchStr;
    pattern = this.escapeRegExp(pattern);       // Escape special chars
    pattern = this.escapePunctation(pattern);   // Escape punctation
    pattern = '('+pattern+')';                  // Mark re subgroup (for substitutions)
    /** @private */ this.re = new RegExp(pattern, 'gi');
  }
  /**
   * Search pattern in given text.
   * @param text Text to search in.
   * @return Return true if pattern was matched.
   * @type bool
   */
  SearchEngine.prototype.isMatch = function(text) {
    return !this.empty && (-1!= text.search(this.re));
  }
}

/**
 * @constructor
 * @class <b>Experimental!</b> Will be documented later.
 */
function SearchEngineChain(searchStr) {
  /** @private */ this.list = new Array();
  
  // Decomposite input to words using white spaces as separator
  var decomp = searchStr.split(/ +/);
  for (var i=0; i<decomp.length; i++) {
    var word = decomp[i];
    if (0!=word.length)
      // Crate SearchEngine object for current word
      this.list.push(new SearchEngine(word));
  }
}
SearchEngineChain.prototype.isMatch = function(text) {
  if (0==this.list.length)
    // empty search
    return false;
  
  // Walk trough chain
  for (var i=0; i<this.list.length; i++)
    if (!this.list[i].isMatch(text))
      // particular mismatch
      return false;
  
  // 100% match
  return true;
}

/**
 * @constructor
 * @param rootNode Root node for enumeration - his sons are enumerated.
 * @param tagName Name of XML elements to enumerate. Other elements (and nodes) are filtered.
 * @class Enumeration of son elements of an XML element.
 */
function ChildElementsEnumerator(rootNode, tagName) {
  /** @private */ this.nodeList = rootNode.childNodes;
  /** @private */ this.tagName = tagName.toLowerCase();
  /** @private */ this.nodeCount = this.nodeList.length;
  /**
   * Reset enumeration to first son element (if exists).
   */
  ChildElementsEnumerator.prototype.reset = function() {
    this.current = 0;
  }
  this.reset();
  /**
   * Return next son element of specified name, if such exists.
   * @return Return next son element of specified name, if such exists. Return null in other case.
   * @type Element
   */
  ChildElementsEnumerator.prototype.next = function() {
    for (; this.current < this.nodeCount; this.current++) {
      var node = this.nodeList[this.current];
      if (
          node.nodeType == 1 &&
          node.tagName.toLowerCase() == this.tagName)
        break;
    }
    if (this.current < this.nodeCount)
      return this.nodeList[this.current++];
    else
      return null;
  }
}

/**
 * Create instance of <code>XMLHttp</code> object.
 * (browser independency layer)
 * @return Return instance of <code>XMLHttp</code> object
 */
function createXmlHttp() {
  var xmlHttp = null;
  try {
    xmlHttp = new XMLHttpRequest();
  }
  catch(e) {
    try {
      xmlHttp = new ActiveXObject('Microsoft.XMLHttp');
    }
    catch(e) { }
  }
  return xmlHttp;
}

/**
 * Define DOM element's <code>innerText</code> property
 * if not already defined.
 * (browser independency layer)
 */
function patchInnerText() {
  if(typeof(HTMLElement) == "undefined" || typeof(document.documentElement.innerText) == "string")
    return;
  HTMLElement.prototype.__defineSetter__("innerText", function(text) {
      while (this.hasChildNodes())
        this.removeChild(this.firstChild);
      this.appendChild(document.createTextNode(text));
    });
  
  HTMLElement.prototype.__defineGetter__("innerText", function() {
      return this.textContent;
    });
}

/**
 * Dump object content to <code>#jsLog</code> block on page.
 * (useful for debug purposes)
 */
function dump(object) {
  if (null==object)
    return;
  log = document.getElementById('jsLog');
  if (null==log)
    return;
  var h1 = document.createElement('h1');
  h1.innerHTML = 'Dump';
  log.appendChild(h1);
  var text = new String;
  for(tmp in object)
    text += '<b>' + tmp + '</b>: ' + object[tmp] + '<br/>\n';
  var p = document.createElement('p');
  p.innerHTML = text;
  log.appendChild(p);
}

/**
 * @constructor
 * @class <b>Experimental!</b> Will be documented later.
 */
function PropStorage(obj, propList) {
  /** @private */ this.map = new Object;
  for (var i=0; i<propList.length; i++) {
    var property = propList[i];
    this.map[property] = obj[property];
  }
}
PropStorage.prototype.restore = function(obj) {
  for (var prop in this.map)
    obj[prop] = this.map[prop];
}