/* utility functions in UtilFuncs.namespace */
var UtilFuncs={};

/**
 * Alias function for getting element by id
 * @param {String} sId
 * @return {Object} DOM object with sId id
 */
UtilFuncs.gE = function(sId) {
  return document.getElementById(sId);
}

/**
 * A general-purpose function to get the absolute position
 * of the mouse.
 * @param {Object} e  Mouse event
 * @return {Object} Describes position
 */
UtilFuncs.getMousePosition = function(e) {
  var posX = 0;
  var posY = 0;
  if (!e) var e = window.event;
  if (e.pageX || e.pageY) {
    posX = e.pageX;
    posY = e.pageY;
  } else if (e.clientX || e.clientY){
    posX = e.clientX + 
      (document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft);
    posY = e.clientY + 
      (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop);
  }	
  return {left: posX, top: posY};  
};

/**
 * Gets position of element
 * @param {Object} element
 * @return {Object} Describes position
 */
UtilFuncs.getElementPosition = function(element) {
  var leftPos = element.offsetLeft;          // initialize var to store calculations
  var topPos = element.offsetTop;            // initialize var to store calculations
  var parElement = element.offsetParent;     // identify first offset parent element  
  while (parElement != null ) {                // move up through element hierarchy
    leftPos += parElement.offsetLeft;      // appending left offset of each parent
    topPos += parElement.offsetTop;  
    parElement = parElement.offsetParent;  // until no more offset parents exist
  }
  return {left: leftPos, top: topPos};
};

/**
 * Applies styles to DOM objects 
 * @param {String/Object} elements Either comma-delimited list of ids 
 *   or an array of DOM objects
 * @param {Object} styles Hash of styles to be applied
 */
UtilFuncs.style = function(elements, styles){
  if (typeof(elements) == 'string') {
    elements = UtilFuncs.getManyElements(elements);
  }
  for (var i = 0; i < elements.length; i++){
    for (var s in styles) { 
      elements[i].style[s] = styles[s];
    }
  }
};

/**
 * Gets DOM elements array according to list of IDs
 * @param {String} elementsString Comma-delimited list of IDs
 * @return {Array} Array of DOM elements corresponding to s
 */
UtilFuncs.getManyElements = function(idsString){		
  var idsArray = idsString.split(',');
  var elements = [];
  for (var i = 0; i < idsArray.length; i++){
    elements[elements.length] = UtilFuncs.gE(idsArray[i])
  };
  return elements;
};