<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Prevent Firefox from Moving After .exitFullscreen()</title>
<style>
button {
display: block;
padding: 0;
width: 32px;
height: 32px;
text-align: center;
cursor: pointer;
background-size: contain;
}
.expand {
background: url(http://imgh.us/expand_2.svg)no-repeat;
}
</style>
</head>
<body>
<!--I tried using the ~a~nchors, -id-, -name-, and -tabindex-
FF was ignoring my attempts to keep or get focus. Using named or
id ~a~nchors failed since the distance between desired spot
and the spot FF ends up at is short.-->
<div id='A' class='media'>A
<video id="vid1" class="vid fs" src="http://html5demos.com/assets/dizzy.mp4" controls></video>
</div>
<div id='B' class='media'>B
<img id='img1' class='img fs' src='http://imgh.us/Lenna.png'>
<button class='expand'></button>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
<script>
/* Several attempts to use the .focus() method
|| and focus events did not work for me, neither
|| has tabindex and anchors. If it appears that
|| my implementation is wrong (a strong possibility)
|| please inform me.
*/
$('button').click(function(e) {
e.preventDefault();
var tgt = $(this).prev();
fs(tgt[0]);
});
/* This function is for the MCVE
|| It enables the ~select~ to remove and re-insert
|| the test elements. By doing so, we can see
|| how the test elements behave in different
|| combinations. What I found out about FF is
|| that when exiting a full screened ~img~ that's
|| positioned last is that it will lose focus
|| and the viewport is scrolled up to the element
|| above it.
*/
$('#sel1').on('change', function(e) {
var V = $(this).val();
var first = $('#' + V).find(':first').attr('id');
if ($('#' + V).hasClass('media')) {
$('#' + V).fadeOut('#' + first);
} else {
$('#' + V).fadeIn('#' + first);
}
$('#' + V).toggleClass('media');
});
/* These 2 functions are responsible for
|| full screen. Please inform me if there's a
|| better way, or if anything is outdated. I
|| have researched the Fullscreen API and I
|| haven't found any updates of any use. I've
|| used these functions for the last 3 years
|| so maybe I might've missed something
|| critical.
*/ // There's no ms prefixes because I'm not concerned about IE.
var isFullScreen = function() {
return !!(document.fullscreenElement || document.webkitFullscreenElement || document.mozFullScreenElement);
}
// SOLUTION XXXXXXXXXX]START[XXXXXXXXXXXXXXX
var yOffset;
document.onmozfullscreenchange = function() {
if(!isFullScreen()){
window.scrollTo(0, yOffset);
}
};
// SOLUTION XXXXXXXXXXX]END[XXXXXXXXXXXXXXXX
function fs(target) {
if (!isFullScreen()) {
yOffset = pageYOffset;
if (target.requestFullscreen) {
target.requestFullscreen();
} else if (target.webkitRequestFullscreen) {
target.webkitRequestFullscreen();
} else if (target.mozRequestFullScreen) {
target.mozRequestFullScreen();
}
} else {
if (document.exitFullscreen) {
document.exitFullscreen();
} else if (document.webkitExitFullscreen) {
document.webkitExitFullscreen();
} else if (document.mozCancelFullScreen) {
document.mozCancelFullScreen();
}
}
}
</script>
</body>
</html>
Objective
=========
>Prevent Firefox from Moving After `.exitFullscreen()`
Behavior
-----------
>###Expected
>When exiting fullscreen mode, we should be at the same position that we were at before.
>###Experienced
>In FF, when exiting fullscreen mode, we are scrolled up as if the element above has a higher tab priority or more than likely is that tab index and focus are being ignored by FF.
Question
--------
> **How can I prevent Firefox from scrolling up after exiting fullscreen mode?**
1. To reproduce issue, use the `<select>` to remove items C, D, E, and F.
2. Next, fullscreen item B by clicking the icon below it.
3. Then exit full screen mode by hitting `ESC`.
4. Notice we have jumped up the page.