/**
 * @todo Move inline CSS out to external style sheet (theme style sheet)
 */
var show_full_size = function(image_url, image_width, image_height) {
  /*
   * Calculate the size of the image panel based on the size of the image and the size of the
   * window.  Scale the image so the entire panel fits in the view port.
   */
  function _auto_fit(imageWidth, imageHeight) {
    // ui-dialog gives a padding of 2 pixels
    var windowWidth = $(window).width() - 10;
    var windowHeight = $(window).height() - 10;

    /* If the width is greater then scale the image width first */
    if (imageWidth > windowWidth) {
      var ratio = windowWidth / imageWidth;
      imageWidth *= ratio;
      imageHeight *= ratio;
    }
    /* after scaling the width, check that the height fits */
    if (imageHeight > windowHeight) {
      var ratio = windowHeight / imageHeight;
      imageWidth *= ratio;
      imageHeight *= ratio;
    }

    // handle the case where the calculation is almost zero (2.14e-14)
    return {
      top: ((windowHeight - imageHeight) / 2).toFixed(2),
      left: ((windowWidth - imageWidth) / 2).toFixed(2),
      width: imageWidth.toFixed(2),
      height: imageHeight.toFixed(2)
    };
  }

  var width = $(document).width();
  var height = $(document).height();

  $("body").append('<div id="gFullsizeOverlay" class="ui-dialog-overlay" ' +
		   'style="border: none; margin: 0; padding: 0; background-color: #000; ' +
		   'position: absolute; top: 0px; left: 0px; ' +
		   'width: ' + width + 'px; height: ' + height + 'px; opacity: 0.7; filter: alpha(opacity=70);' +
		   '-moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; ' +
		   '-moz-background-inline-policy: -moz-initial; z-index: 1001;"> </div>');

  var image_size = _auto_fit(image_width, image_height);

  $("body").append('<div id="gFullsize" class="ui-dialog ui-widget" ' +
		   'style="overflow: hidden; display: block; ' +
		   'position: absolute; z-index: 1002; outline-color: -moz-use-text-color; ' +
		   'outline-style: none; outline-width: 0px; ' +
		   'height: ' + image_size.height + 'px; ' +
		   'width: ' + image_size.width + 'px; ' +
		   'top: ' + image_size.top + 'px; left: ' + image_size.left + 'px;">' +
		   '<img id="gFullSizeImage" src="' + image_url + '"' +
		   'height="' + image_size.height + '" width="' + image_size.width + '"/></div>');

  $("#gFullsize").append('<span id="gFullsizeClose" class="fg-button ui-icon ui-state-default ' +
			 'ui-icon-closethick ui-corner-all" style="z-index: 1003; position: absolute; ' +
			 'right: 1em; top: 1em;"></span>');
  $("#gFullsizeClose").click(function() {
			       $("#gFullsizeOverlay*").remove();
			       $("#gFullsize").remove();
			     });
  $(window).resize(function() {
		     $("#gFullsizeOverlay").width($(document).width());
		     $("#gFullsizeOverlay").height($(document).height());
		     image_size = _auto_fit(image_width, image_height);
		     $("#gFullsize").height(image_size.height);
		     $("#gFullsize").width(image_size.width);
		     $("#gFullsize").css("top", image_size.top);
		     $("#gFullsize").css("left", image_size.left);
		     $("#gFullSizeImage").height(image_size.height);
		     $("#gFullSizeImage").width(image_size.width);
		   });
};