jQuery .height() not working with box-sizing: border-border - javascript

I have a nav bar that I have positioned 'fixed' at the top of my page. The problem that I have is that I want to displace the entire page down by the (dynamic) size of my nav depending on the size of the screen used. Basically, I want to move the whole page down the height of this nav. To do this, I'm going to be using a padding to the nav that will affect it's height. I am using a box-sizing:border-box attribute on this nav but whenever I try and load the page, it doesn't account for the extra height added with the padding when I use jQuery's .height() function.
The div with the 'displacement' class does not have anything to it except a 100% width initially. This is the ugly result along with all of the current code
http://jsbin.com/qomepe/2
Can anyone tell me why this is happening or if I've overlooked something?

Try using .outerHeight() to get the height of the navbar.
From jQuery API docs:
"The top and bottom padding and border are always included in the .outerHeight() calculation; if the includeMargin argument is set to true, the margin (top and bottom) is also included."
http://api.jquery.com/outerheight/

var height = $('header').outerHeight();
$('.displacement').css('height',height);
Try something like this

Related

Fixed side menu inside wrapper

So I have a site that is contained in a wrapper that has a max width. This site also has a fixed side menu that is toggled with a button.
My issue is having the fixed side menu to stay inside the page wrapper as fixed elements are relative to the window not the parent element.
Here is an example using position: fixed: https://jsfiddle.net/okavp4p1/
As you can see the menu is coming out from the side of the viewport, not the wrapper (grey area).
I have found away around this using position: absolute: https://jsfiddle.net/5q3hn1fq/
Here you can see the menu is coming out of the wrapper. (correct)
But I had to write some extra jQuery to spoof fixed positioning on scroll.
// Fix menu
$(window).on('load scroll resize', function() {
navigation.find('ul').css('top', $(window).scrollTop());
});
But doing it this way causes glitches/lag on most web browsers. Though the example isn't to bad when scrolling but when implementing this on an actual site with tons more elements/code it becomes very obvious.
Here is what it looks like in use when scrolling down the page:
I have thought of disabling scrolling when the menu is open but I was just wondering if anyone can help?
there is a work-around for this. you need to create a bar at the top with position:fixed. This bar should have height: 1px and no background-color so you can't see it.
then you can add your navigation inside of there, and float:right. when you float right, it will show up, but will be pinned to the invisible fixed bar at the top. also, you have to give the nav a width of 0 so its invisible. then you can transition its width to 100px or whatever you want on button click.
finally, use jQuery to set its height to the height of the window on resizing of the window, and when you show it.
here's the fiddle: https://jsfiddle.net/ahmadabdul3/pptggn6v/1/
since the bar is inside a position:relative bar, it shouldn't jump around as much (or at all)
do NOT add right or left padding to the navigation though, this will break the effect. instead, you can put a container around the nav, and make the nav width: 90% or something so it appears to have some padding.
here's an updated fiddle with how the padding should be: https://jsfiddle.net/ahmadabdul3/pptggn6v/2/
If performance accross all browsers is the issue, you could re-write your function using plain .js instead of jquery.
I couldn't replicate the jittery movement in chrome, but the below should be put less strain on the browser.
$(window).on('load scroll resize', function() {
document.getElementById('nav-list').style.top = window.scrollY + 'px';
});
https://jsfiddle.net/hb4zsL6g/

Calculating exact window height using jQuery

So I am redesigning my website: http://staging.slackrmedia.com/keenanpayne/, but I am coming across a small issue. I want each "pane" of the website to be the exact height of the window, no matter what the size. I also want the content therein to be exactly positioned in the center.
I am trying to accomplish this with jQuery at the moment:
function setSectionHeight() {
// Set section heights
windowHeightPadding = $(window).height() / 2;
firstSectionPadding = ($(window).height() - $('header').height()) / 2;
// Apply proper styling
$('section').css({"padding-top":windowHeightPadding,"padding-bottom":windowHeightPadding});
$('section.home').css({"padding-top": firstSectionPadding,"padding-bottom":windowHeightPadding});
}
setSectionHeight();
// Adjust section heights on window resize
$(window).on('resize', function(){
setSectionHeight();
});
So what this is doing is calculating the window height and dividing it by 2, so I can set the top and bottom padding on each section.
However, for the first section, to get the proper top and bottom padding, I need to subtract the height of the header, which is why I have a firstSectionPadding variable.
Then I just add the CSS to each section tag on my website, with separate styling for the home section tag.
This works pretty well, but as you can see when you visit my site, for some reason the heights are not correct.
Right now it looks like:
And it should look like:
I have absolutely no idea where this extra padding or space is coming from on the top. I think my equations are right, but perhaps there isn't something I'm taking into consideration?
This could be done with CSS. One div set to 100% height and width, with text-align:center; A second div within set to display:table and 100% height and width. Finally, a third div set to display:table-cell and vertical-align:center;

Use div's height to determine another div's padding or margin-top

I am using the following jQuery to work out the width of a div (thats in %), to then tell another div to set it's height to that in pixels.
<script>
$("#top").height($("#left").width());
$("#bottom").height($("#left").width());
</script>
It's working really well. Now my next problem is, that I want my div called 'wrapper' to have a padding-top or margin-top of the pixel value it returns for the height. I tried changing 'height' to 'padding-top', but that didn't seem to work.
The end result is a web page with a series of 4 black div acting as a border around the edge, it calculates 5% of the with of the window, and that determine's the pixel value for how how the top and bottom black div's are. That way it's exactly even. Now I want my inside wrapper div, to start exactly that far down the web page too.
Use the jQuery outerWidth function to retrieve the width inclusive of padding, borders and optionally margin as well (if you send true as the only argument to the outerWidth method).
Tested Solution: Find height of a div and use it as margin top of another div.
$('.topmargindiv').css('margin-top', function() {
return $('.divheight').height();
});

width of dynamically inserted div containing text

I have a script that dynamically inserts a div containing text in the dom. The text content is not known in advance.
I need to know the width of this div, but it seems that that the return value of document.defaultView.getComputedStyle(node, "").getPropertyValue("width") or node.offsetWidth cannot be trusted.
I used setInterval to log it, and the value changes over time. For instance, in my case it starts with 929px and then changes to 908px.
This div is in position absolute, it has whitespace nowrap, so I don't think it is being "pushed" by other dom elements or that it somehow changes once inserted.
Is there an elegant way to retrieve the width, or do I have to use an ugly setTimeout to retrieve it once the return value is stable ?
Try:
yourDOMElement.getClientBoundingRect()
This will return an object with top, left, right, bottom, height and width attributes. This should be cross-browser.
Note: If you are going to work with the position attributes (top, left, right, bottom, height) of the returned, take into account scroll offset if necessary.
Update: To ensure this works on older browsers that don't have the width/height attribute, calculate it subtracting right/bottom from left/top.
The viewport can change its size because of the scrollbar. Once the scrollbar appears, its width can no longer be used by the document. Force the scrollbar to exist before you measure the size by adding overflow: scroll or overflow-y:scroll to the <html> element.
The size of a block-level element is, by default, its container width minus margins and padding (even if it's positioned absolutely), which is ultimately the wiewport width unless you set a fixed width somewhere along the way.
Using jQuery, you should be able to do this:
var width = $("div-selector").width();
this is fairly easy?
open the page in a browser and press f12. With firefox there is a button "inspect element" on top and in chrome it's on the bottom. Click it and hover your mouse over it. This should give you the height and width in px. Never been wrong for me.
if it still doesn't show, click it and you can see it in the css panel of the console.

Applying position:absolute to a style via jQuery fails to center div horizontally upon first page load

This is a followup to my question here. I would like to understand why applying position:absolute to the CSS of a div via jQuery fails, while applying it in a static style works. Here are two jsfiddle examples:
Works: http://jsfiddle.net/jasper/Ty6Af/2/
No worky: http://jsfiddle.net/Ty6Af/3/
Note that the only difference between the two is where I apply position:absolute. Vertical centering always works, but horizontal centering does not work when the page loads for the first time. If you manually re-size the window the div will center correctly.
All of my testing has been on Chrome under Ubuntu thus far.
Anyway, I'm just now delving into the world of web development and these are exactly the kinds of 'quirks' that I need to begin understanding.
EDIT:
#Jasper found something interesting. If you make two calls to .css(), first applying position and subsequently applying a margin, it works. I would love to understand why. Here is an example: http://jsfiddle.net/jasper/Ty6Af/5/
So the issue is with how the width of the div is calculated by the browser depending on its position.
If the div is set to position : static (by default) then it's width is 100% of it's parents width and the element is not allowed to move around the page.
If the div is set to position : relative then it's width is 100% of it's parents width but it can be moved around with left.
If the div is set to position : absolute then its width is determined by the actual content of the div, for instance if there is only a 200px wide <span> element within the div then the div will be 200px wide.
You can test these observations by changing the CSS of your jsfiddle to specify position : relative (etc...) and remove the JavaScript that makes the div position : absolute, then use your Developer Tools to inspect the element and it's calculated width.
The problem with your code is that it sets the position : absolute at the same time it sets the margin of the element by using its width/height (which are calculated differently depending on the position of the element).
If you want to set the position of the div in JavaScript then you can do something like this:
$(function() {
//notice I cached the selector so it can be used in the future as well as set the position of the div
$signuparea = $('#signuparea').css({position : 'absolute'});
$(window).resize(function() {
$signuparea.css({
'margin-top' : '-' + Math.round($signuparea.height() / 2) + 'px',
'margin-left' : '-' + Math.round($signuparea.width() / 2) + 'px',
});
}).trigger('resize');
});
Here's a jsfiddle: http://jsfiddle.net/jasper/Ty6Af/8/
I believe the problem is that when you apply your left and right in your second fiddle, you have yet to add position absolute to the div. Hence, the browser has no idea what do with the left and right values and ignores them initially.
Practically speaking in your second fiddle, you only actually add the position:absolute on the resize trigger. So before you resize your actual div has no positioning.
If you instead add the position absolute on load it works fine:http://jsfiddle.net/Ty6Af/9/
Notice that if you give it position:relative from the start (like this http://jsfiddle.net/Ty6Af/11/ ) it allready applies both the left and right value. The reason you can't actually see the effect of "left" is because it is a block element.
I hope that answers your question, I'm not quite clear on where you are stuck.
http://jsfiddle.net/Ty6Af/7/ this should work, the trigger function in jquery has bugs with chrome so you have to run the function on load too.
The problem seems to be that position:absolute; negates the current layout and requires you to position it.....
See: http://jsfiddle.net/ZHaRD/
Which Jasper explains much more eloquently than myself!

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