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Get amount of pixels scrolled from a div's height + its distance from the top

I'm looking for a way in jQuery or pure JS to get the amount of pixels scrolled, not from the top of the page, but from the bottom of a div.
In other words I need to turn the amount scrolled beyond a div's height + its pixel distance from the top of the page into a variable.
I want to append this parallax code below so instead of calculating from the top of the page, calculates from a target div's distance from the top + its height.
/* Parallax Once Threshold is Reached */
var triggerOne = $('#trigger-01').offset().top;
$(window).scroll(function(e){
if ($(window).scrollTop() >= triggerOne) {
function parallaxTriggerOne(){
var scrolled = $(window).scrollTop();
$('#test').css('top',+(scrolled*0.2)+'px');
}
parallaxTriggerOne();
} else {
$('#test').css('top','initial');
}
});
I realize I didn't phrase this quite clear enough, I'm looking to only get the value of the amount of pixels scrolled since passing a div, so for example if I had a 200px tall div at the very top of the page and I scrolled 20 pixels beyond it, that variable I need would equal 20, not 220.

You can get a div's position by using div.offsetTop,
adding div.offsetHeight into div's distance from top of page will give you bottom of div, then you can subtract from window's scroll to get your desired value.
Feel free to ask if you have any doubts.
var div = document.getElementById('foo');
let div_bottom = div.offsetTop + div.offsetHeight;
var doc = document.documentElement;
var left = (window.pageXOffset || doc.scrollLeft) - (doc.clientLeft || 0);
var scroll_top, scroll_after_div;
setInterval(function(){
scroll_top = (window.pageYOffset || doc.scrollTop) - (doc.clientTop || 0);
scroll_after_div = scroll_top - div_bottom;
console.log(scroll_after_div);
}, 1000);
body { margin: 0; }
<div id="foo" style="position:relative; top: 100px; height: 30px; width: 100%; background-color: #000;"></div>
<div id="bar" style="position:relative; top: 700px; height: 30px; width: 100%; background-color: #000;"></div>
In this snippet setInterval method is printing the scroll value each second, you can scroll and see the change in value.

To work out the distance from the top of the page to the bottom of an element, you can add an elements outerHeight() with its offset().top.
Example: https://jsfiddle.net/dw2jwLpw/
console.log(
$('.target').outerHeight() + $('.target').offset().top
);

In pure JS you can get the bottom of the div directly with document.getElementById("my-element").getBoundingClientRect().bottom.
In jQuery you can use $('#my-element').offset().top + $('#my-element').height()

Change Img based on Width of browser and Y position from top

I have some code that allows me to change the img src when I've scrolled from top < 120 px. But I need to change the image to another one when the browser is resized too.
So I should get, 1 image when I scroll down 120 px, 1 image if I already scrolled down 120px but I reduced size of browser to 850 pixels,
1 image if I'm at full top of browser, and another image if I reduce size of browser.
So far I can only change img src if I scroll 120px down, but how can I solve the browser size at the same time?
$(window).on('scroll', function () {
var scrollTop = $(window).scrollTop();
if (scrollTop > 120) {
$('#logo').attr('src', 'http://www.kubographics.com/adiacens/images/logo1-black.svg');
$('#logo').css('margin-top', '10px');
}
else {
('#logo').attr('src', '');
$('#logo').css('margin-top', '0px');
}
});
Thanks for your help!

To change the img use css media query
#logo {
background: url("http://www.kubographics.com/adiacens/images/logo1-black.svg")
}
#media (max-width: 850px) {
background: url("http://www.kubographics.com/adiacens/images/logo2-black.svg")
}

Change Image's Position based on scrollTop

I have a back to top image that popups when the user scrolls beyond 280. The issue is when you reach the bottom the image is over links in the footer. So I want to change the position of the image once the user is about 90px from the very bottom of the page - I want "bottom": '35px' to be 95. The page height is always changing fyi. Code I have:
function update() {
if ($(window).scrollTop() > 280) {
$('#btt').animate({
"bottom": '35px'
}, 300);
}
else {
$('#btt').animate({
"bottom": '-80px'
}, 300);
}
}
setInterval(update, 500);

It might be better to check for the scroll position only when the page has been scrolled rather than just checking every 1/2 second.
I've put together a working demo of what I think you want here: http://jsfiddle.net/swpqpv4r/5/
Basically we need to look at the scroll position of the bottom of the window as we scroll instead of the top by using document.body.scrollTop + $(win).height(). Normaly we might want to worry about what could happen if the window were to be resized, but we calculate this each time inside of the scroll event, so it shouldn't be an issue if the window changes sizes.
Next we need to know when the top of the footer has scrolled above the bottom of the window. We can use $("#footer").position().top; to see where it's top position is.
Hopefully the code is commented enough to help explain it. Let me know if you have any questions.
HTML
<header>Top</header>
<br><br><br> <!-- Lots of these for testing -->
<footer id="footer">Bottom</footer>
<a id="btt" href="javascript:{};">Back to top</a>
JavaScript
$(function(){
//select once and re-use later
var $win = $(window);
var $btt = $("#btt");
var $foot = $("#footer");
var bttDisplay = 500;
var footerHeight = $foot.outerHeight();
var footerTop = $foot.position().top;
function updateScroll() {
var scrollBottom = document.body.scrollTop + $win.height();
if (scrollBottom >= bttDisplay && scrollBottom <= footerTop) {
//show it by setting the bottom position to 0
animateBtt(0);
}else if (scrollBottom >= footerTop) {
//move it up above the footer's top position
animateBtt(footerHeight);
}else {
//hide it by setting the bottom position to the negative value of it's height
animateBtt($btt.height() * -1);
}
}
function animateBtt(pos){
$btt.animate({
"bottom": pos
}, 300);
}
//run initially
updateScroll();
//Create a var to hold the timer
var scrollTimer = null;
$win.on("scroll",function(ev){
//when scrolling, clear the timer
clearTimeout(scrollTimer);
//Now set the timer to run a function after a small delay.
//This prevents the update from happening too many times when you scroll
scrollTimer = setTimeout(updateScroll, 50);
});
//click to scroll back up
$btt.on("click",function(){
$('html, body').animate({scrollTop:0},300);
})
});
CSS
html,body{
margin:0;
padding:0;
}
header, footer{
background: #CCC;
padding: 10px;
}
#btt{
position:fixed;
height: 30px;
width: 100px;
text-align:center;
bottom: -30px;
right:0;
background: #F00;
color: #FFF;
z-index: 1000;
}

How to reliably get screen width WITH the scrollbar

Is there a way to reliably tell a browser's viewport width that includes the scrollbar, but not the rest of browser window)?
None of the properties listed here tell me the width of the screen INCLUDING the scrollbar (if present)

I figured out how to accurately get the viewport width WITH the scrollbar using some code from: http://andylangton.co.uk/blog/development/get-viewport-size-width-and-height-javascript
Put this inside your $(document).ready(function()
$(document).ready(function(){
$(window).on("resize", function(){
function viewport() {
var e = window, a = 'inner';
if (!('innerWidth' in window )) {
a = 'client';
e = document.documentElement || document.body;
}
return { width : e[ a+'Width' ] , height : e[ a+'Height' ] };
}
});
// Get the correct window sizes with these declarations
windowHeight = viewport().height;
windowWidth = viewport().width;
});
What it Does:
When your page is 'ready' or is resized, the function calculates the correct window height and width (including scrollbar).

I assume you want to know the viewport width with scrollbar included, because the screen it self does not have a scrollbar. In fact the Screen width and heigth will be the computer screen resolution itself, so I'm not sure what you mean with screen width with the scroll bar.
The viewport however, the area where only the page (and scroll bars) is presented to the user, meaning, no browser menus, no bookmarks or whatever, only the page rendered, is where such scroll bar may be present.
Assuming you want that, you can measure the client browser viewport size while taking into account the size of the scroll bars this way.
First don't forget to set you body tag to be 100% width and height just to make sure the measurement is accurate.
body {
width: 100%;
// if you wish to also measure the height don't forget to also set it to 100% just like this one.
}
Afterwards you can measure the width at will.
Sample
// First you forcibly request the scroll bars to be shown regardless if you they will be needed or not.
$('body').css('overflow', 'scroll');
// Viewport width with scroll bar.
var widthWithScrollBars = $(window).width();
// Now if you wish to know how many pixels the scroll bar actually has
// Set the overflow css property to forcibly hide the scroll bar.
$('body').css('overflow', 'hidden');
// Viewport width without scroll bar.
var widthNoScrollBars = $(window).width();
// Scroll bar size for this particular client browser
var scrollbarWidth = widthWithScrollBars - widthNoScrollBars;
// Set the overflow css property back to whatever value it had before running this code. (default is auto)
$('body').css('overflow', 'auto');
Hope it helps.

As long as body is 100%, document.body.scrollWidth will work.
Demo: http://jsfiddle.net/ThinkingStiff/5j3bY/
HTML:
<div id="widths"></div>
CSS:
body, html
{
margin: 0;
padding: 0;
width: 100%;
}
div
{
height: 1500px;
}
Script:
var widths = 'viewport width (body.scrollWidth): '
+ document.body.scrollWidth + '<br />'
+ 'window.innerWidth: ' + window.innerWidth + '<br />';
document.getElementById( 'widths' ).innerHTML = widths;
I put a tall div in the demo to force a scroll bar.

Currently the new vw and vh css3 properties will show full size including scrollbar.
body {
width:100vw;
height:100vh;
}
There is some discussion online if this is a bug or not.

there is nothing after scrollbar so "rest of the window" is what?
But yes one way to do it is make another wrapper div in body where everything goes and body has overflow:none; height:100%; width:100%; on it, wrapper div also also has 100% width and height. and overflow to scroll. SO NOW...the width of wrapper would be the width of viewport
See Example: http://jsfiddle.net/techsin/8fvne9fz/
html,body {
height: 100%;
overflow: hidden;
}
.wrapper {
width: 100%;
height: 100%;
overflow: auto;
}

With jQuery you can calculate the browser's scrollbar width by getting the width difference when overflow: hidden is set and overflow: scroll is set.
The difference in width will be the size of the scrollbar.
Here is a simple example that shows how you could do this.

You can get the window width with scrollbar , that way:
function scrollbar_width() {
if (jQuery('body').height() > jQuery(window).height()) {
/* Modified from: http://jdsharp.us/jQuery/minute/calculate-scrollbar-width.php */
var calculation_content = jQuery('<div style="width:50px;height:50px;overflow:hidden;position:absolute;top:-200px;left:-200px;"><div style="height:100px;"></div>');
jQuery('body').append(calculation_content);
var width_one = jQuery('div', calculation_content).innerWidth();
calculation_content.css('overflow-y', 'scroll');
var width_two = jQuery('div', calculation_content).innerWidth();
jQuery(calculation_content).remove();
return (width_one - width_two);
}
return 0;
}

Check out vw: http://dev.w3.org/csswg/css-values/#viewport-relative-lengths
body {
width: 100vw;
}
http://caniuse.com/#search=vw

This is my solution for removing the 'scrollbar shadow', because scrollWidth didn't work for me:
canvas.width = element.offsetWidth;
canvas.height = element.offsetHeight;
canvas.width = element.offsetWidth;
canvas.height = element.offsetHeight;
It's easy, but it works. Make sure to add a comment explaining why you assign the same value twice :)

Position fixed related parent container

I need solution to emulate fixed position, but relative parent div, not whole viewport. JS solutions are laggy. I need fixed related parent container, because if window has small height, div with fixed position enters into footer zone.
Example

Another approach re your update.
Try giving the fixed div z-index: 10;
And the footer div position: relative; z-index: 11
That should make the footer overlap the fixed div.

then it's not an issue of position:fixed, maybe you could just define a min-height to your body (or on the main wrapper if any) to avoid the short page problem

I have combined css and js:
$(document).ready(function () {
var $sidebar = $(".register-box"),
$window = $(window),
$content = $("#content"),
docHeight = $(document).height();
var entered = false;
$window.scroll(function () {
if ($window.height() < 795 && docHeight - $window.scrollTop() < 785) {
entered = true;
var pos = $sidebar.offset();
$sidebar.css('position', 'absolute').css('top', ($content.height() - ($sidebar.height() + 40)) + 'px');
}
else {
if (entered) {
entered = false;
$sidebar.css({
top: "",
left: "",
position: "fixed"
});
}
}
});
});
Code is not final, and numbers are hard coded, but it works, smooth enough.