Javascript Modification for Mouse Leaving Browser Window - javascript

I have a Javascript that I use to display a lightbox when a visitor's mouse breaks the browser plane... here's my page: [http://mudchallenger.com/index-test2.html][1]
However, if you move your mouse too fast, it does not recognize that you've left the page and the script does not fire.
Does anyone know how to modify this script so that it fires if the mouse is not present in the window?
Here's the script:
var oldPosition = -1;
$(document).ready(function() {
$(document).mousemove(function(e) {
$('#exitpopup').css('left', (window.innerWidth / 2 - $('#exitpopup').width() / 2));
$('#exitpopup').css('top', (window.innerHeight / 2 - $('#exitpopup').height() / 2));
var position = e.pageY - $(window).scrollTop();
if(position < 10) {
if(oldPosition != -1) {
if(position < oldPosition) {
// Show the exit popup
$('#exitpopup_bg').fadeIn();
$('#exitpopup').fadeIn();
}
oldPosition = position;
} else {
oldPosition = position;
}
}
$('#divData').html(oldPosition + " : " + position);
});
$('#exitpopup_bg').click(function() {
$('#exitpopup_bg').fadeOut();
$('#exitpopup').slideUp();
});
});
I include this tag in the .html page
<?php require('exitpopup.php'); ?>
Here is the 'exitpopup.php' script
<script type="text/javascript">
var oldPosition = -1;
$(document).ready(function() {
$(document).mousemove(function(e) {
$('#exitpopup').css('left', (window.innerWidth / 2 - $('#exitpopup').width() / 2));
$('#exitpopup').css('top', (window.innerHeight / 2 - $('#exitpopup').height() / 2));
var position = e.pageY - $(window).scrollTop();
if(position < 20) {
if(oldPosition != -1) {
if(position < oldPosition) {
// Show the exit popup
$('#exitpopup_bg').fadeIn();
$('#exitpopup').fadeIn();
}
oldPosition = position;
} else {
oldPosition = position;
}
}
$('#divData').html(oldPosition + " : " + position);
});
$('#exitpopup_bg').click(function() {
$('#exitpopup_bg').fadeOut();
$('#exitpopup').slideUp();
});
});
</script>
<style type="text/css">
#exitpopup
{
text-align:center;
}
#exitpopup h1
{
margin-top:0px;
padding-top:0px;
}
#exitpopup p
{
text-align:left;
}
</style>
<div style="display: none; width:100%; height:100%; position:fixed; background:#000000; opacity: .9; filter:alpha(opacity=0.9); z-index:999998;" id="exitpopup_bg">
</div>
<div style="width:975px; height:575px; margin:0px auto; display:none; position:fixed; color:#000000; padding:0px; -webkit-border-radius: 2px; -moz-border-radius: 2px; border-radius: 2px; z-index:999999; background-image: url(exit-gate/exit-gate-bg2.png);" id="exitpopup">
</div>

I think you're overcomplicating thing with positioning.
$('html').hover(
function() {
console.log('Entered browser window')
},
function() {
console.log('Left browser window')
}
)
Detects both enter/leave or use just .mouseleave() on 'html' to detect when mouse left. So in your case remove your entire $(document).mousemove handler and replace it with
$('html').mouseleave(function() {
$('#exitpopup_bg').fadeIn();
$('#exitpopup').fadeIn();
})
Add left/top positioning of the popup as needed, but ideally it should be in CSS only

Related

How to find edge of div for touchscreen swipe div?

I now have a working touchscreen image slider but the only problem is that when I touchscreen the movement position begins from the center of the div and moves the whole div to be positioned with the pointer in the middle and lift off screen - and then attempt to do another movement. the movement position begins again in the center of the div.
I know I need to reset the co-ords somehow when I lift off screen, or maybe unbind, but I have no idea how to do this. It takes me days if not weeks to simply figure these things out without help. Don't get me wrong I'm all about learning for myself, but I also learn a great deal more where I can examine a working solution of my own code.
Here is a little HTML for the divs:
.container{
position:absolute;
top:0%;
left:0%;
width:500px;
height:100%;
}
.drag{
position: absolute;
top:1%;
left:0%;
width:100%;
height:15%;
-webkit-transform: translate3d(0,0,0);
border-style: solid; 2px;
border-color: blue;
z-index:1000;
}
</head>
<body>
<div id="container" class="container">
<div id='drag' class='drag'><!---video area--->
some images
</div>
</div>
Here is the code for the swipe events.
var dom = {
container: document.getElementById("container"),
drag: document.getElementById("drag"),
}
var container = {
x: dom.container.getBoundingClientRect().left,
y: dom.container.getBoundingClientRect().top,
w: dom.container.getBoundingClientRect().width,
h: dom.container.getBoundingClientRect().height
}
var drag = {
w: dom.drag.offsetWidth
}
target = null;
document.body.addEventListener('touchstart', handleTouchStart, false);
document.body.addEventListener('touchmove', handleTouchMove, false);
document.body.addEventListener('touchend', handleTouchEnd, false);
document.body.addEventListener('touchcancel', handleTouchCancel, false);
function handleTouchStart(e) {
if (e.touches.length == 1) {
var touch = e.touches[0];
target = touch.target;
}
}
function handleTouchMove(e) {
if (e.touches.length == 1) {
if(target === dom.drag) {
moveDrag(e);
}
}
}
function handleTouchEnd(e) {
if (e.touches.length == 0) { // User just took last finger off screen
target = null;
}
}
function handleTouchCancel(e) {
return;
}
function moveDrag(e) {
var touch = e.touches[0];
var posX = touch.pageX - container.x - drag.w / 2;
dom.drag.style.left = posX + "px";
}
I KNOW IT'S DOWN TO THIS LINE OF CODE:
var posX = touch.pageX - container.x - drag.w / 2;
HERE IS THE FIDDLE:
http://jsfiddle.net/xbmyazb2/20/

Issues with requestAnimationFrame

I have an issue:
document.querySelector('div').addEventListener('mousedown', function(){
hello = true
document.body.addEventListener('mousemove', function(e){
if (hello) {
document.querySelector('div').style.left = (e.clientX - 12.5) + 'px'
document.querySelector('div').style.top = (e.clientY - 12.5) + 'px'
}
})
this.addEventListener('mouseup', function(e){
hello = false
posY = Math.floor(parseInt(this.style.top))
function Fall() {
posY++
document.querySelector('div').style.top = posY + 'px'
if (posY != parseInt(window.innerHeight) - 25) requestAnimationFrame(Fall)
}
Fall()
})
})
body {
margin:0;
position:absolute;
height:100vh;
width:100vw;
overflow:hidden
}
div {
position:absolute;
height:25px;
width:25px;
border:1px #000 solid;
bottom:0
}
div:hover {
cursor:pointer;
}
<div></div>
In this code (also on jsFiddle, when I drop the div, I want the div to fall, and stop at the ground.
The first time, it works. But then, requestAnimationFrame is faster, it's like the first one isn't done...? And after that, the div didn't stop at the ground :(
Do I have to use setInterval instead of requestAnimationFrame?
Whenever the div is clicked (mousedown) theres another listener assigned. When you stop clicking, these listeners are all executed in order, so at the second click, there will be two loops running, after the third there will be three loops running and so on. You may just assign the listener once:
var hello,posY;
document.querySelector('div').addEventListener('mousedown', function(){
hello = true;
});
document.body.addEventListener('mousemove', function(e){
if (hello) {
document.querySelector('div').style.left = (e.clientX - 12.5) + 'px';
document.querySelector('div').style.top = (e.clientY - 12.5) + 'px';
}
});
document.querySelector('div').addEventListener('mouseup', function(e){
hello = false;
posY = Math.floor(parseInt(this.style.top));
function Fall() {
posY++;
document.querySelector('div').style.top = posY + 'px';
if (posY < parseInt(window.innerHeight) - 25) requestAnimationFrame(Fall);
}
Fall();
});
And please always end a statement with a semicolon...
The problem is that you're adding your mouseup handler every time the div receives a mousedown. You only want to do that once, so move that out of your mousedown handler. So you set up the animation twice on the second call (because both handlers respond), three times on the third (because all three handlers respond), etc. And since multiple handlers are updating poxY, it doesn't stop at the ground anymore because the != check fails for all but one of them. (See further notes under the snippet.)
document.querySelector('div').addEventListener('mousedown', function() {
hello = true
document.body.addEventListener('mousemove', function(e) {
if (hello) {
document.querySelector('div').style.left = (e.clientX - 12.5) + 'px'
document.querySelector('div').style.top = (e.clientY - 12.5) + 'px'
}
})
})
// Moved the below
document.querySelector('div').addEventListener('mouseup', function(e) {
hello = false
posY = Math.floor(parseInt(this.style.top))
function Fall() {
posY++
document.querySelector('div').style.top = posY + 'px'
if (posY != parseInt(window.innerHeight) - 25) requestAnimationFrame(Fall)
}
Fall()
})
body {
margin: 0;
position: absolute;
height: 100vh;
width: 100vw;
overflow: hidden
}
div {
position: absolute;
height: 25px;
width: 25px;
border: 1px #000 solid;
bottom: 0
}
div:hover {
cursor: pointer;
}
<div class="square"></div>
Some other observations:
Your code is falling prey to The Horror of Implicit Globals* — declare your variables
Rather than re-querying the DOM all the time, it would probably be best to query the DOM for the div once, and remember it in a variable
* (disclosure: that's a post on my anemic little blog)

how to move one div with another in javascript

I am trying to make a web app with two boxes, one contained in the other. The user should be able to click and move the inner box, however, the user should not be able to move this box outside the confines of the outer box. The user can move the outer box by dragging the inner box against one of the edges of the outer box. I know how to move the inner box, but the problem is how to move the other box with this restriction. Can anybody help me please? Here is what I did so far:
<!doctype html>
<head>
<title>JavaScript Game</title>
<style>
#container {
height:400px;
width:600px;
outline: 1px solid black;
position:absolute;
left:50px;
top: 0px;
background-color:green;
}
#guy {
position:absolute;
height:50px;
width:50px;
outline: 1px solid black;
background-color:red;
left: 200px;
top: 200px;
}
</style>
</head>
<body>
<div id="container"></div>
<div id="guy"></div>
<script>
var guy=document.getElementById("guy");
var cont=document.getElementById("container");
var lastX,lastY; // Tracks the last observed mouse X and Y position
guy.addEventListener("mousedown", function(event) {
if (event.which == 1) {
lastX = event.pageX;
lastY = event.pageY;
addEventListener("mousemove", moved);
event.preventDefault(); // Prevent selection
}
});
function buttonPressed(event) {
if (event.buttons == null)
return event.which != 0;
else
return event.buttons != 0;
}
function moved(event) {
if (!buttonPressed(event)) {
removeEventListener("mousemove", moved);
} else {
var distX = event.pageX - lastX;
var distY = event.pageY - lastY;
guy.style.left =guy.offsetLeft + distX + "px";
guy.style.top = guy.offsetTop + distY + "px";
lastX = event.pageX;
lastY = event.pageY;
}
}
</script>
</body>
You could add a check to see if moving the box would break bounds of cont.
try to use getBoundingClientRect()
Check the snippet below for the working code.
View in full screen for best results.
var guy=document.getElementById("guy");
var cont=document.getElementById("container");
var lastX,lastY; // Tracks the last observed mouse X and Y position
guy.addEventListener("mousedown", function(event) {
if (event.which == 1) {
lastX = event.pageX;
lastY = event.pageY;
addEventListener("mousemove", moved);
event.preventDefault(); // Prevent selection
}
});
function buttonPressed(event) {
if (event.buttons == null)
return event.which != 0;
else
return event.buttons != 0;
}
function moved(event) {
if (!buttonPressed(event)) {
removeEventListener("mousemove", moved);
} else {
var distX = event.pageX - lastX;
var distY = event.pageY - lastY;
guy.style.left =guy.offsetLeft + distX + "px";
guy.style.top = guy.offsetTop + distY + "px";
// ********************************************************************
// get bounding box borders
var contBounds = guy.getBoundingClientRect();
var guyBounds = cont.getBoundingClientRect();
// check bottom bounds
if (contBounds.bottom >= guyBounds.bottom){
cont.style.top = cont.offsetTop + distY + "px";
}
// check top bounds
if (contBounds.top <= guyBounds.top){
cont.style.top = cont.offsetTop + distY + "px";
}
// check left bounds
if (contBounds.left <= guyBounds.left){
cont.style.left = cont.offsetLeft + distX + "px";
}
// check right bounds
if (contBounds.right >= guyBounds.right){
cont.style.left = cont.offsetLeft + distX + "px";
}
// ********************************************************************
lastX = event.pageX;
lastY = event.pageY;
}
}
#container {
height:300px;
width:300px;
outline: 1px solid black;
position:absolute;
left:50px;
top: 0px;
background-color:#CCC;
}
#guy {
position:absolute;
height:50px;
width:50px;
outline: 1px solid black;
background-color:#000;
left: 200px;
top: 200px;
}
<div id="container"></div>
<div id="guy"></div>
try this link to get you started as far as keeping the "guy" inside the "contatiner": http://www.w3schools.com/html/html5_draganddrop.asp
their example shows how you can make an element only drop inside another element.
as far as moving the container...i would think that you could add some if else statements into the moved function that will test the position of the guy against the conatiner's outline and say that when they meet to move the container as well.
i am very new to javascript myself but this is just a suggestion from what i think i understand of it.

Scrolling function in JS marginTop is not changing

I have a function where I am trying to create a scrolling effect on the div's content by using an event for mouse wheel.
The listener:
document.getElementById('menu_base').addEventListener("mousewheel", scrollfunc, false);
I have this for my scroll event:
function scrollfunc(e){
console.log(e);
if(e.wheelDeltaY == 120) { //this does work
document.getElementById('menu_base').style.marginTop += 50; //no change
} else if(e.wheelDeltaY == -120){ //as does this
document.getElementById('menu_base').style.marginTop -= 50; //no change
}
}
The console.log shows:
WheelEvent {webkitDirectionInvertedFromDevice: false, wheelDeltaY: -120, wheelDeltaX: 0, wheelDelta: -120, webkitMovementY: 0…}
menu_base properties are:
.menu_base{
width:100%;
height:600px;
position:absolute;
left: 0;
top: 0;
text-align:center;
border:1px solid black;
overflow:hidden;
}
Yet the content does not move, marginTop does not seem to alter.
Any suggestions on what might be the probable cause ?
You need to define the marginTop with an unit, e.g. using px:
var menu_base = document.getElementById('menu_base');
function scrollfunc(e) {
console.log(e);
var mtop = parseInt(menu_base.style.marginTop, 10) || 0;
if (e.wheelDeltaY == 120) { //this does work
mtop += 50; //no change
} else if (e.wheelDeltaY == -120) { //as does this
mtop -= 50; //no change
}
menu_base.style.marginTop = mtop + 'px';
}
Fiddle

How can I make a div stick to the top of the screen once it's been scrolled to?

I would like to create a div, that is situated beneath a block of content but that once the page has been scrolled enough to contact its top boundary, becomes fixed in place and scrolls with the page.
You could use simply css, positioning your element as fixed:
.fixedElement {
background-color: #c0c0c0;
position:fixed;
top:0;
width:100%;
z-index:100;
}
Edit: You should have the element with position absolute, once the scroll offset has reached the element, it should be changed to fixed, and the top position should be set to zero.
You can detect the top scroll offset of the document with the scrollTop function:
$(window).scroll(function(e){
var $el = $('.fixedElement');
var isPositionFixed = ($el.css('position') == 'fixed');
if ($(this).scrollTop() > 200 && !isPositionFixed){
$el.css({'position': 'fixed', 'top': '0px'});
}
if ($(this).scrollTop() < 200 && isPositionFixed){
$el.css({'position': 'static', 'top': '0px'});
}
});
When the scroll offset reached 200, the element will stick to the top of the browser window, because is placed as fixed.
You've seen this example on Google Code's issue page and (only recently) on Stack Overflow's edit page.
CMS's answer doesn't revert the positioning when you scroll back up. Here's the shamelessly stolen code from Stack Overflow:
function moveScroller() {
var $anchor = $("#scroller-anchor");
var $scroller = $('#scroller');
var move = function() {
var st = $(window).scrollTop();
var ot = $anchor.offset().top;
if(st > ot) {
$scroller.css({
position: "fixed",
top: "0px"
});
} else {
$scroller.css({
position: "relative",
top: ""
});
}
};
$(window).scroll(move);
move();
}
<div id="sidebar" style="width:270px;">
<div id="scroller-anchor"></div>
<div id="scroller" style="margin-top:10px; width:270px">
Scroller Scroller Scroller
</div>
</div>
<script type="text/javascript">
$(function() {
moveScroller();
});
</script>
And a simple live demo.
A nascent, script-free alternative is position: sticky, which is supported in Chrome, Firefox, and Safari. See the article on HTML5Rocks and demo, and Mozilla docs.
As of January 2017 and the release of Chrome 56, most browsers in common use support the position: sticky property in CSS.
#thing_to_stick {
position: sticky;
top: 0px;
}
does the trick for me in Firefox and Chrome.
In Safari you still need to use position: -webkit-sticky.
Polyfills are available for Internet Explorer and Edge; https://github.com/wilddeer/stickyfill seems to be a good one.
And here's how without jquery (UPDATE: see other answers where you can now do this with CSS only)
var startProductBarPos=-1;
window.onscroll=function(){
var bar = document.getElementById('nav');
if(startProductBarPos<0)startProductBarPos=findPosY(bar);
if(pageYOffset>startProductBarPos){
bar.style.position='fixed';
bar.style.top=0;
}else{
bar.style.position='relative';
}
};
function findPosY(obj) {
var curtop = 0;
if (typeof (obj.offsetParent) != 'undefined' && obj.offsetParent) {
while (obj.offsetParent) {
curtop += obj.offsetTop;
obj = obj.offsetParent;
}
curtop += obj.offsetTop;
}
else if (obj.y)
curtop += obj.y;
return curtop;
}
* {margin:0;padding:0;}
.nav {
border: 1px red dashed;
background: #00ffff;
text-align:center;
padding: 21px 0;
margin: 0 auto;
z-index:10;
width:100%;
left:0;
right:0;
}
.header {
text-align:center;
padding: 65px 0;
border: 1px red dashed;
}
.content {
padding: 500px 0;
text-align:center;
border: 1px red dashed;
}
.footer {
padding: 100px 0;
text-align:center;
background: #777;
border: 1px red dashed;
}
<header class="header">This is a Header</header>
<div id="nav" class="nav">Main Navigation</div>
<div class="content">Hello World!</div>
<footer class="footer">This is a Footer</footer>
I had the same problem as you and ended up making a jQuery plugin to take care of it. It actually solves all the problems people have listed here, plus it adds a couple of optional features too.
Options
stickyPanelSettings = {
// Use this to set the top margin of the detached panel.
topPadding: 0,
// This class is applied when the panel detaches.
afterDetachCSSClass: "",
// When set to true the space where the panel was is kept open.
savePanelSpace: false,
// Event fires when panel is detached
// function(detachedPanel, panelSpacer){....}
onDetached: null,
// Event fires when panel is reattached
// function(detachedPanel){....}
onReAttached: null,
// Set this using any valid jquery selector to
// set the parent of the sticky panel.
// If set to null then the window object will be used.
parentSelector: null
};
https://github.com/donnyv/sticky-panel
demo: http://htmlpreview.github.io/?https://github.com/donnyv/sticky-panel/blob/master/jquery.stickyPanel/Main.htm
The simplest solution (without js) :
demo
.container {
position: relative;
}
.sticky-div {
position: sticky;
top: 0;
}
<div class="container">
<h1>
relative container & sticky div
</h1>
<div class="sticky-div"> this row is sticky</div>
<div>
content
</div>
</div>
This is how i did it with jquery. This was all cobbled together from various answers on stack overflow. This solution caches the selectors for faster performance and also solves the "jumping" issue when the sticky div becomes sticky.
Check it out on jsfiddle: http://jsfiddle.net/HQS8s/
CSS:
.stick {
position: fixed;
top: 0;
}
JS:
$(document).ready(function() {
// Cache selectors for faster performance.
var $window = $(window),
$mainMenuBar = $('#mainMenuBar'),
$mainMenuBarAnchor = $('#mainMenuBarAnchor');
// Run this on scroll events.
$window.scroll(function() {
var window_top = $window.scrollTop();
var div_top = $mainMenuBarAnchor.offset().top;
if (window_top > div_top) {
// Make the div sticky.
$mainMenuBar.addClass('stick');
$mainMenuBarAnchor.height($mainMenuBar.height());
}
else {
// Unstick the div.
$mainMenuBar.removeClass('stick');
$mainMenuBarAnchor.height(0);
}
});
});
As Josh Lee and Colin 't Hart have said, you could optionally just use position: sticky; top: 0; applying to the div that you want the scrolling at...
Plus, the only thing you will have to do is copy this into the top of your page or format it to fit into an external CSS sheet:
<style>
#sticky_div's_name_here { position: sticky; top: 0; }
</style>
Just replace #sticky_div's_name_here with the name of your div, i.e. if your div was <div id="example"> you would put #example { position: sticky; top: 0; }.
Here is another option:
JAVASCRIPT
var initTopPosition= $('#myElementToStick').offset().top;
$(window).scroll(function(){
if($(window).scrollTop() > initTopPosition)
$('#myElementToStick').css({'position':'fixed','top':'0px'});
else
$('#myElementToStick').css({'position':'absolute','top':initTopPosition+'px'});
});
Your #myElementToStick should start with position:absolute CSS property.
Here's one more version to try for those having issues with the others. It pulls together the techniques discussed in this duplicate question, and generates the required helper DIVs dynamically so no extra HTML is required.
CSS:
.sticky { position:fixed; top:0; }
JQuery:
function make_sticky(id) {
var e = $(id);
var w = $(window);
$('<div/>').insertBefore(id);
$('<div/>').hide().css('height',e.outerHeight()).insertAfter(id);
var n = e.next();
var p = e.prev();
function sticky_relocate() {
var window_top = w.scrollTop();
var div_top = p.offset().top;
if (window_top > div_top) {
e.addClass('sticky');
n.show();
} else {
e.removeClass('sticky');
n.hide();
}
}
w.scroll(sticky_relocate);
sticky_relocate();
}
To make an element sticky, do:
make_sticky('#sticky-elem-id');
When the element becomes sticky, the code manages the position of the remaining content to keep it from jumping into the gap left by the sticky element. It also returns the sticky element to its original non-sticky position when scrolling back above it.
My solution is a little verbose, but it handles variable positioning from the left edge for centered layouts.
// Ensurs that a element (usually a div) stays on the screen
// aElementToStick = The jQuery selector for the element to keep visible
global.makeSticky = function (aElementToStick) {
var $elementToStick = $(aElementToStick);
var top = $elementToStick.offset().top;
var origPosition = $elementToStick.css('position');
function positionFloater(a$Win) {
// Set the original position to allow the browser to adjust the horizontal position
$elementToStick.css('position', origPosition);
// Test how far down the page is scrolled
var scrollTop = a$Win.scrollTop();
// If the page is scrolled passed the top of the element make it stick to the top of the screen
if (top < scrollTop) {
// Get the horizontal position
var left = $elementToStick.offset().left;
// Set the positioning as fixed to hold it's position
$elementToStick.css('position', 'fixed');
// Reuse the horizontal positioning
$elementToStick.css('left', left);
// Hold the element at the top of the screen
$elementToStick.css('top', 0);
}
}
// Perform initial positioning
positionFloater($(window));
// Reposition when the window resizes
$(window).resize(function (e) {
positionFloater($(this));
});
// Reposition when the window scrolls
$(window).scroll(function (e) {
positionFloater($(this));
});
};
Here is an extended version to Josh Lee's answer. If you want the div to be on sidebar to the right, and float within a range (i.e., you need to specify top and bottom anchor positions). It also fixes a bug when you view this on mobile devices (you need to check left scroll position otherwise the div will move off screen).
function moveScroller() {
var move = function() {
var st = $(window).scrollTop();
var sl = $(window).scrollLeft();
var ot = $("#scroller-anchor-top").offset().top;
var ol = $("#scroller-anchor-top").offset().left;
var bt = $("#scroller-anchor-bottom").offset().top;
var s = $("#scroller");
if(st > ot) {
if (st < bt - 280) //280px is the approx. height for the sticky div
{
s.css({
position: "fixed",
top: "0px",
left: ol-sl
});
}
else
{
s.css({
position: "fixed",
top: bt-st-280,
left: ol-sl
});
}
} else {
s.css({
position: "relative",
top: "",
left: ""
});
}
};
$(window).scroll(move);
move();
}
I came across this when searching for the same thing. I know it's an old question but I thought I'd offer a more recent answer.
Scrollorama has a 'pin it' feature which is just what I was looking for.
http://johnpolacek.github.io/scrollorama/
The info provided to answer this other question may be of help to you, Evan:
Check if element is visible after scrolling
You basically want to modify the style of the element to set it to fixed only after having verified that the document.body.scrollTop value is equal to or greater than the top of your element.
The accepted answer works but doesn't move back to previous position if you scroll above it. It is always stuck to the top after being placed there.
$(window).scroll(function(e) {
$el = $('.fixedElement');
if ($(this).scrollTop() > 42 && $el.css('position') != 'fixed') {
$('.fixedElement').css( 'position': 'fixed', 'top': '0px');
} else if ($(this).scrollTop() < 42 && $el.css('position') != 'relative') {
$('.fixedElement').css( 'relative': 'fixed', 'top': '42px');
//this was just my previous position/formating
}
});
jleedev's response whould work, but I wasn't able to get it to work. His example page also didn't work (for me).
You can add 3 extra rows so when the user scroll back to the top, the div will stick on its old place:
Here is the code:
if ($(this).scrollTop() < 200 && $el.css('position') == 'fixed'){
$('.fixedElement').css({'position': 'relative', 'top': '200px'});
}
I have links setup in a div so it is a vertical list of letter and number links.
#links {
float:left;
font-size:9pt;
margin-left:0.5em;
margin-right:1em;
position:fixed;
text-align:center;
width:0.8em;
}
I then setup this handy jQuery function to save the loaded position and then change the position to fixed when scrolling beyond that position.
NOTE: this only works if the links are visible on page load!!
var listposition=false;
jQuery(function(){
try{
///// stick the list links to top of page when scrolling
listposition = jQuery('#links').css({'position': 'static', 'top': '0px'}).position();
console.log(listposition);
$(window).scroll(function(e){
$top = $(this).scrollTop();
$el = jQuery('#links');
//if(typeof(console)!='undefined'){
// console.log(listposition.top,$top);
//}
if ($top > listposition.top && $el.css('position') != 'fixed'){
$el.css({'position': 'fixed', 'top': '0px'});
}
else if ($top < listposition.top && $el.css('position') == 'fixed'){
$el.css({'position': 'static'});
}
});
} catch(e) {
alert('Please vendor admin#mydomain.com (Myvendor JavaScript Issue)');
}
});
In javascript you can do:
var element = document.getElementById("myid");
element.style.position = "fixed";
element.style.top = "0%";
Here's an example that uses jquery-visible plugin: http://jsfiddle.net/711p4em4/.
HTML:
<div class = "wrapper">
<header>Header</header>
<main>
<nav>Stick to top</nav>
Content
</main>
<footer>Footer</footer>
</div>
CSS:
* {
margin: 0;
padding: 0;
}
body {
background-color: #e2e2e2;
}
.wrapper > header,
.wrapper > footer {
font: 20px/2 Sans-Serif;
text-align: center;
background-color: #0040FF;
color: #fff;
}
.wrapper > main {
position: relative;
height: 500px;
background-color: #5e5e5e;
font: 20px/500px Sans-Serif;
color: #fff;
text-align: center;
padding-top: 40px;
}
.wrapper > main > nav {
position: absolute;
top: 0;
left: 0;
right: 0;
font: 20px/2 Sans-Serif;
color: #fff;
text-align: center;
background-color: #FFBF00;
}
.wrapper > main > nav.fixed {
position: fixed;
top: 0;
left: 0;
right: 0;
}
JS (include jquery-visible plugin):
(function($){
/**
* Copyright 2012, Digital Fusion
* Licensed under the MIT license.
* http://teamdf.com/jquery-plugins/license/
*
* #author Sam Sehnert
* #desc A small plugin that checks whether elements are within
* the user visible viewport of a web browser.
* only accounts for vertical position, not horizontal.
*/
var $w = $(window);
$.fn.visible = function(partial,hidden,direction){
if (this.length < 1)
return;
var $t = this.length > 1 ? this.eq(0) : this,
t = $t.get(0),
vpWidth = $w.width(),
vpHeight = $w.height(),
direction = (direction) ? direction : 'both',
clientSize = hidden === true ? t.offsetWidth * t.offsetHeight : true;
if (typeof t.getBoundingClientRect === 'function'){
// Use this native browser method, if available.
var rec = t.getBoundingClientRect(),
tViz = rec.top >= 0 && rec.top < vpHeight,
bViz = rec.bottom > 0 && rec.bottom <= vpHeight,
lViz = rec.left >= 0 && rec.left < vpWidth,
rViz = rec.right > 0 && rec.right <= vpWidth,
vVisible = partial ? tViz || bViz : tViz && bViz,
hVisible = partial ? lViz || rViz : lViz && rViz;
if(direction === 'both')
return clientSize && vVisible && hVisible;
else if(direction === 'vertical')
return clientSize && vVisible;
else if(direction === 'horizontal')
return clientSize && hVisible;
} else {
var viewTop = $w.scrollTop(),
viewBottom = viewTop + vpHeight,
viewLeft = $w.scrollLeft(),
viewRight = viewLeft + vpWidth,
offset = $t.offset(),
_top = offset.top,
_bottom = _top + $t.height(),
_left = offset.left,
_right = _left + $t.width(),
compareTop = partial === true ? _bottom : _top,
compareBottom = partial === true ? _top : _bottom,
compareLeft = partial === true ? _right : _left,
compareRight = partial === true ? _left : _right;
if(direction === 'both')
return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop)) && ((compareRight <= viewRight) && (compareLeft >= viewLeft));
else if(direction === 'vertical')
return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop));
else if(direction === 'horizontal')
return !!clientSize && ((compareRight <= viewRight) && (compareLeft >= viewLeft));
}
};
})(jQuery);
$(function() {
$(window).scroll(function() {
$(".wrapper > header").visible(true) ?
$(".wrapper > main > nav").removeClass("fixed") :
$(".wrapper > main > nav").addClass("fixed");
});
});
I used some of the work above to create this tech. I improved it a bit and thought I would share my work. Hope this helps.
jsfiddle Code
function scrollErrorMessageToTop() {
var flash_error = jQuery('#flash_error');
var flash_position = flash_error.position();
function lockErrorMessageToTop() {
var place_holder = jQuery("#place_holder");
if (jQuery(this).scrollTop() > flash_position.top && flash_error.attr("position") != "fixed") {
flash_error.css({
'position': 'fixed',
'top': "0px",
"width": flash_error.width(),
"z-index": "1"
});
place_holder.css("display", "");
} else {
flash_error.css('position', '');
place_holder.css("display", "none");
}
}
if (flash_error.length > 0) {
lockErrorMessageToTop();
jQuery("#flash_error").after(jQuery("<div id='place_holder'>"));
var place_holder = jQuery("#place_holder");
place_holder.css({
"height": flash_error.height(),
"display": "none"
});
jQuery(window).scroll(function(e) {
lockErrorMessageToTop();
});
}
}
scrollErrorMessageToTop();​
This is a little bit more dynamic of a way to do the scroll. It does need some work and I will at some point turn this into a pluging but but this is what I came up with after hour of work.
Not an exact solution but a great alternative to consider
this CSS ONLY Top of screen scroll bar. Solved all the problem with ONLY CSS, NO JavaScript, NO JQuery, No Brain work (lol).
Enjoy my fiddle :D all the codes are included in there :)
CSS
#menu {
position: fixed;
height: 60px;
width: 100%;
top: 0;
left: 0;
border-top: 5px solid #a1cb2f;
background: #fff;
-moz-box-shadow: 0 2px 3px 0px rgba(0, 0, 0, 0.16);
-webkit-box-shadow: 0 2px 3px 0px rgba(0, 0, 0, 0.16);
box-shadow: 0 2px 3px 0px rgba(0, 0, 0, 0.16);
z-index: 999999;
}
.w {
width: 900px;
margin: 0 auto;
margin-bottom: 40px;
}<br type="_moz">
Put the content long enough so you can see the effect here :)
Oh, and the reference is in there as well, for the fact he deserve his credit
CSS ONLY Top of screen scroll bar
sticky till the footer hits the div:
function stickyCostSummary() {
var stickySummary = $('.sticky-cost-summary');
var scrollCostSummaryDivPosition = $(window).scrollTop();
var footerHeight = $('#footer').height();
var documentHeight = $(document).height();
var costSummaryHeight = stickySummary.height();
var headerHeight = 83;
var footerMargin = 10;
var scrollHeight = 252;
var footerPosition = $('#footer').offset().top;
if (scrollCostSummaryDivPosition > scrollHeight && scrollCostSummaryDivPosition <= (documentHeight - footerHeight - costSummaryHeight - headerHeight - footerMargin)) {
stickySummary.removeAttr('style');
stickySummary.addClass('fixed');
} else if (scrollCostSummaryDivPosition > (documentHeight - footerHeight - costSummaryHeight - headerHeight - footerMargin)) {
stickySummary.removeClass('fixed');
stickySummary.css({
"position" : "absolute",
"top" : (documentHeight - footerHeight - costSummaryHeight - headerHeight - footerMargin - scrollHeight) + "px"
});
} else {
stickySummary.removeClass('fixed');
stickySummary.css({
"position" : "absolute",
"top" : "0"
});
}
}
$window.scroll(stickyCostSummary);

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