/**
* @author trixta
*/
(function($){
$.userMode = (function(){
var userBg,
timer,
testDiv,
boundEvents = 0;

function testBg(){
testDiv = testDiv || $('<div></div>').css({position: 'absolute', left: '-999em', top: '-999px', width: '0px', height: '0px'}).appendTo('body');
var black = $.curCSS( testDiv.css({backgroundColor: '#000000'})[0], 'backgroundColor', true),
white = $.curCSS( testDiv.css({backgroundColor: '#ffffff'})[0], 'backgroundColor', true),
newBgStatus = (black === white || white === 'transparent');
if(newBgStatus != userBg){
userBg = newBgStatus;
$.event.trigger('_internalusermode');
}
return userBg;
}

function init(){
testBg();
timer = setInterval(testBg, 3000);
}

function stop(){
clearInterval(timer);
testDiv.remove();
testDiv = null;
}

$.event.special.usermode = {
setup: function(){
(!boundEvents && init());
boundEvents++;
var jElem = $(this)
.bind('_internalusermode', $.event.special.usermode.handler);
//always trigger
setTimeout(function(){
jElem.triggerHandler('_internalusermode');
}, 1);
                return true;
            },
teardown: function(){
                boundEvents--;
(!boundEvents && stop());
$(this).unbind('_internalusermode', $.event.special.usermode.handler);
                return true;
            },
            handler: function(e){
                e.type = 'usermode';
e.disabled = !userBg;
e.enabled = userBg;
                return jQuery.event.handle.apply(this, arguments);
            }
};

return {
get: testBg
};

})();

$.fn.userMode = function(fn){
return this[(fn) ? 'bind' : 'trigger']('usermode', fn);
};

$(function(){
$('html').userMode(function(e){
$('html')[e.enabled ? 'addClass' : 'removeClass']('hcm');
});
});
})(jQuery);