/**
 * Copyright (c) 2009 Sergiy Kovalchuk (serg472@gmail.com)
 * 
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *  
 * Following code is based on Element.mask() implementation from ExtJS framework (http://extjs.com/)
 *
 */
;(function($){
  
  /**
   * Displays loading mask over selected element(s). Accepts both single and multiple selectors.
   *
   * @param label Text message that will be displayed on top of the mask besides a spinner (optional). 
   *        If not provided only mask will be displayed without a label or a spinner.   
   * @param delay Delay in milliseconds before element is masked (optional). If unmask() is called 
   *              before the delay times out, no mask is displayed. This can be used to prevent unnecessary 
   *              mask display for quick processes.     
   */
  $.fn.mask = function(label, delay){
    $(this).each(function() {
      if(delay !== undefined && delay > 0) {
            var element = $(this);
            element.data("_mask_timeout", setTimeout(function() { $.maskElement(element, label)}, delay));
      } else {
        $.maskElement($(this), label);
      }
    });
  };
  
  /**
   * Removes mask from the element(s). Accepts both single and multiple selectors.
   */
  $.fn.unmask = function(){
    $(this).each(function() {
      $.unmaskElement($(this));
    });
  };
  
  /**
   * Checks if a single element is masked. Returns false if mask is delayed or not displayed. 
   */
  $.fn.isMasked = function(){
    return this.hasClass("masked");
  };

  $.maskElement = function(element, label){
  
    //if this element has delayed mask scheduled then remove it and display the new one
    if (element.data("_mask_timeout") !== undefined) {
      clearTimeout(element.data("_mask_timeout"));
      element.removeData("_mask_timeout");
    }

    if(element.isMasked()) {
      $.unmaskElement(element);
    }
    
    if(element.css("position") == "static") {
      element.addClass("masked-relative");
    }
    
    element.addClass("masked");
    
    var maskDiv = $('<div class="loadmask"></div>');
    
    //auto height fix for IE
    if(navigator.userAgent.toLowerCase().indexOf("msie") > -1){
      maskDiv.height(element.height() + parseInt(element.css("padding-top")) + parseInt(element.css("padding-bottom")));
      maskDiv.width(element.width() + parseInt(element.css("padding-left")) + parseInt(element.css("padding-right")));
    }
    
    //fix for z-index bug with selects in IE6
    if(navigator.userAgent.toLowerCase().indexOf("msie 6") > -1){
      element.find("select").addClass("masked-hidden");
    }
    
    element.append(maskDiv);
    
    if(label !== undefined) {
      var maskMsgDiv = $('<div class="loadmask-msg" style="display:none;"></div>');
      maskMsgDiv.append('<div>' + label + '</div>');
      element.append(maskMsgDiv);
      
      //calculate center position
      maskMsgDiv.css("top", Math.round(element.height() / 2 - (maskMsgDiv.height() - parseInt(maskMsgDiv.css("padding-top")) - parseInt(maskMsgDiv.css("padding-bottom"))) / 2)+"px");
      maskMsgDiv.css("left", Math.round(element.width() / 2 - (maskMsgDiv.width() - parseInt(maskMsgDiv.css("padding-left")) - parseInt(maskMsgDiv.css("padding-right"))) / 2)+"px");
      
      maskMsgDiv.show();
    }
    
  };
  
  $.unmaskElement = function(element){
    //if this element has delayed mask scheduled then remove it
    if (element.data("_mask_timeout") !== undefined) {
      clearTimeout(element.data("_mask_timeout"));
      element.removeData("_mask_timeout");
    }
    
    element.find(".loadmask-msg,.loadmask").remove();
    element.removeClass("masked");
    element.removeClass("masked-relative");
    element.find("select").removeClass("masked-hidden");
  };
 
})(jQuery);