HTML5 video full-screen

// ==UserScript==
// @name HTML5 video full-screen
// @namespace http://rauscheronline.de
// @description adds fullscreen capability to every <video>
// just play the video and then hit SHIFT-ENTER or F11
// @include *
// ==/UserScript==

// Version 1.1

(function(){
addEventListener('DOMContentLoaded',init,false);
addEventListener('DOMContentLoaded',function(){
document.getElementsByTagName("body")[0].addEventListener('keydown',keyDownHandler,false);
},false);
addEventListener('DOMNodeInserted',init,false);
window.addEventListener('resize',resizeHandle,false);
var curVid=null;
var isFullscreen=false;
function init()
{
videos = document.getElementsByTagName("video");

for(var i=0; i<videos.length; i++)
{
var video=videos[i];
if (!video.myFullScreenEnabled)
{
video.addEventListener('play',playHandler,false);
video.addEventListener('stop',stopPauseHandler,false);
video.addEventListener('pause',stopPauseHandler,false);
video.myFullScreenEnabled = true;
//alert(video);
}
}
}

function playHandler(e)
{
//alert("das ist" + this)
if ((""+this) != "[object HTMLVideoElement]") //how to do this right?
return;

curVid = this;
}

function stopPauseHandler(e)
{
if ((""+this) != "[object HTMLVideoElement]") //how to do this right?
return;

if (curVid == this)
{
if (isFullscreen)
restoreScreen(this);
curVid=null; //no we can use F11 without making the video FS again...
}
}

function keyDownHandler(e)
{
//alert("key "+curVid +" e "+e.keyCode+" "+e.shiftKey);
if (curVid==null)
return;

//alt+enter or F11
if ((e.keyCode+""=="13"&&e.shiftKey)||e.keyCode+""=="122")
{
if (isFullscreen)
{
restoreScreen(curVid);
}
else
{
makeFullscreen(curVid);
}
}
}

//saves old style and sets new style to
/*video{
position: fixed;
top: 0;
left: 0;
width: <clientwidth>px;
height: <clientheight>px;
z-index: 1000000;
background-color: rgba(0,0,0,0.9);
}*/
var backup = null;
var oldVid;
function makeFullscreen(video)
{
if (backup!=null)
restoreScreen(video);

//backup old state
oldVid=video;
backup= new Object();
backup.position = video.style.position;
backup.top = video.style.top;
backup.left = video.style.left;
backup.width = video.style.width;
backup.height = video.style.height;
backup.zIndex = video.style.zIndex;
backup.backgroundColor = video.style.backgroundColor;
backup.border = video.style.border;

video.style.position = "fixed";
video.style.top = 0;
video.style.left = 0;
video.style.width = window.innerWidth+"px";
video.style.height = window.innerHeight+"px";
video.style.zIndex = 1000000000;
video.style.backgroundColor = "rgba(0,0,0,0.9)";
video.style.border = "none";

isFullscreen=true;
}

function restoreScreen(video)
{
//restore old state
video.style.position = backup.position;
video.style.top = backup.top;
video.style.left = backup.left;
video.style.width = backup.width;
video.style.height = backup.height;
video.style.zIndex = backup.zIndex;
video.style.backgroundColor = backup.backgroundColor;
video.style.border = backup.border;

isFullscreen=false;
}

function resizeHandle()
{
if (isFullscreen)
{
curVid.style.width = window.innerWidth+"px";
curVid.style.height = window.innerHeight+"px";
}
}

})();