Develop Reference

Calculating a responsive header's height and using the result in the style of another div's height

Please bear with me as I attempt to explain the issue I'm having. It's kinda tricky!
I have a fixed header that includes a responsive image, because of this, the height of the header depends on the width of the device. I also have a fixed footer sitting on the bottom of the screen. In-between the header and footer I have a fixed div with scrollable overflow positioned towards the left side of the screen. I need the fixed div in-between the header and footer to have a HEIGHT that is the following:
calc(100% - the header's height in px - the footer's height in px)
To do this, I know I need to use Javascript or jQuery, but I'm unsure how to go about setting that up. Furthermore, I need that styling to only be applied on a specific media query.
I have similar code that adds padding to the top and bottom of another div that is centered between the header and footer. This is the code that I'm using and it works perfectly (in the fiddle I've provided at the bottom, I don't use "DOMContentLoaded" because it doesn't quite work with JSFiddle like it should. same idea slightly different syntax in the fiddle) :
document.addEventListener("DOMContentLoaded", function() {
var headerHeight = document.getElementById('header').clientHeight;
document.getElementById("content").style.paddingTop = headerHeight + "px";
var footerHeight = document.getElementById('footer').clientHeight;
document.getElementById("content").style.paddingBottom = footerHeight + "px";
}, true);
window.addEventListener('resize', function() {
var headerHeight = document.getElementById('header').clientHeight;
document.getElementById("content").style.paddingTop = headerHeight+ "px";
var footerHeight = document.getElementById('footer').clientHeight;
document.getElementById("content").style.paddingBottom = footerHeight + "px";
}, true);
I need to use code similar to that, but instead of styling the div "content", I need to be styling a div titled "description" and instead of styling the padding, I need to be styling the height. The last difference is that the styling should only be applied to this media query:
#media screen and (orientation: landscape)
I've created a JSFiddle: http://jsfiddle.net/yg7mjhvn/
Thank you guys so much! I really appreciate it.

If I get it correctly, you just need to set the height of content/description div calc(100% - <header-height> - <footer-height>) with javascript.
So, to do that add a function setDescriptionHeight to your js code which sets the height of description div and add it as a load and resize event handler. All this will be done like this.
function setContentHeight() {
if (window.innerWidth > window.innerHeight) { // window.orientation === 90 for checking the real orientation
var headerHeight = document.getElementById('header').clientHeight;
var footerHeight = document.getElementById('footer').clientHeight;
document.getElementById("description").style.height = `calc(100% - ${headerHeight}px - ${footerHeight}px)`;
} else{
document.getElementById("description").style.height = "";
}
document.getElementById("description").style.top = `${headerHeight}px`;
}
window.addEventListener('load', setContentHeight, true);
window.addEventListener('resize', setContentHeight, true);
Now, you see that it has a condition window.orientation === 90. That is there to check whether the device is in landscape orientation, and if it is then the styling is done.
note that window.innerHeight < window.innerWidth simply detects whether the width is greater than the height. And, window.orientation === 90 checks the device orientation and it won't be 90 for a laptop or a dekstop screen. Moreover, it is deprecated now and you can see more about it here

Why can't I get the container width without the scrollbar?

I have a container (masonry grid) with some images. I have a function to calculate the the width of the container and an other function to calculate the width of each image. But the function to get the container width, doesn't work as excpected, because the width contains the scrollbar. Therefore the calculation of the images width is also incorrect.
//Function to calculate the width of the container
getContainerWidth() {
const postContainer = document.getElementsByClassName(
'container'
);
if (postContainer.length > 0) {
let containerWidth = postContainer[0].clientWidth;
containerWidth = `${containerWidth}px`;
this.setState({
containerWidth: containerWidth,
});
}
}
I have already tried verious functions (offsetWidth, clientWidth, scrollWidth...) but none of them worked for me. I have also tried to get the width of the scrollbar and subtract it from the container width. This worked, but I need a solution which works on different Browsers.
If the browser width is for example 1920px. Then the container-width is also 1920px, but it should be 1905px (1920 - scrollbar).

Get the ClientWidth
The Element.clientWidth property is zero for elements with no CSS or inline layout boxes, otherwise it's the inner width of an element in pixels. It includes padding but not the vertical scrollbar (if present, if rendered), border or margin.
Example
var width = element.clientWidth;

Responsive auto height container after animation

I change height of my element via javascript (couldn't change it via css from 0 to auto).
/* Function to animate height: auto */
function autoHeightAnimate(element, time){
var curHeight = element.height(), // Get Default Height
autoHeight = element.css('height', 'auto').height(); // Get Auto Height
element.height(curHeight); // Reset to Default Height
element.stop().animate({ height: autoHeight }, time); // Animate to Auto Height
}
After I resize my Chrome window the element doesn't automatically change its height, because it only changes after I click one of labels.
DEMO here.
Is possible to do it somehow via css? And if not how to do it via javascript/jQuery to make it changes after I scale my browser window?

In this cases you can use from resize function and set height when resize happened like this:
$( window ).resize(function() {
autoHeightAnimate('','');
});

Grow height of element on scroll safari bug

I have a fixed header div with a 200px height. On scroll, the height is reduced until it reaches a certain height (40px). This gives the effect of the header turning into a fixed header once user reaches the content container.
This works smooth in Firefox and Chrome, however, Safari is glitchy. Particularly, when user scrolls back up and the header increases in height. See JS Fiddle here.
$(window).scroll(function () {
var $scrollTop = $(window).scrollTop(),
$element = $('.content-container').offset().top,
$distance = ($element - $scrollTop);
if ($scrollTop < $element - $newHeight) {
header.height($distance);
}
});
What is causing safari to glitch so much on the height increase? What can I do to smooth this out?

The way to smoothen out this effect in Safari is to change the approach all together. Instead of changing the height of the header on scroll, make the content container position:relative; and set a higher z-index. Then when scroll reaches the bottom of your header (or wherever point you'd like to make the header sticky), change the z-index of the header to be higher than the content container and set it's height to your desired size.
Here is the JS. Please see this JS Fiddle for demo and the rest of code (css, html).
$(window).scroll(function () {
if ($scrollTop > $element - $newHeight) {
header.height($newHeight).css("z-index", 1000);
}
else {
header.css("z-index", 100).height($oldHeight);
}
});
Also, consider using requestAnimationFrame instead of onScroll. It''ll be lighter weight.

Disable scrolling but keep scrollbar CSS

I can't find a solution to this, there was a question over here, but the answers are not very usable (at least for me).
I have a JavaScript modal pop-up that disables everything on the background by placing transparent div over the page. It also disables the scrolling by setting the overflow to hidden, and must do so, because the page is scrollable with the mouse wheel otherwise and distracts the user.
The problem is, when hiding and showing the scrollbar the page resizes and the effect is ugly. Also, my page is designed in such a way that if I stop it from resizing that would be ugly either.
What I want is to disable the scrollbar, but keep it visible (the page content is longer than the screen fits). Is this somehow possible in CSS?

Instead of changing the css, which will remove the scrollbar, and as you said change the layout of the page, try calling a jquery function instead.
// call your pop up and inside that function add below
$('body').on('scroll mousewheel touchmove', function(e) {
e.preventDefault();
e.stopPropagation();
return false;
});
then when you close the modal, call the same function but replace on with off

Since scrollbars are not all 17px wide, I solved this with JavaScript. That is, I calculated the exact width of the scrollbar and added an equal amount of margin to the right of the body element. This also works when the scrollbar isn't present due to a high resolution or a lack of content.
function toggleMenu() {
// get width before hiding scrollbar
let oldWidth = document.documentElement.clientWidth;
// toggle CSS class that sets overflow to hidden
document.body.classList.toggle('MenuOpen');
// get new width after hiding scrollbar
let newWidth = document.documentElement.clientWidth;
// set margin-right value equal to width of the scrollbar
let scrollbarWidth = Math.max(0, newWidth - oldWidth);
document.body.style.marginRight = `${scrollbarWidth}px`;
}
...and my CSS looks like:
html {
background-color: #e6e6e6; /* color of fake scrollbar */
}
body.MenuOpen {
overflow: hidden;
}

Once you start showing your popup, give the body a class (like popupOpen). This should be an easy workaround.
.popupOpen {
overflow: hidden;
margin-right: 17px //size of the scrollbar in each browser
}
When you close your popup, simply remove the class from the body.