How to prevent content jump after adding position:fixed to subhead? - javascript

I'm currently working on my new portfolio you can see here: http://katharinakoeth.de/neu/
And there's already my problem. As you can see, I added some jquery action to my subheads (i'm really a beginner when it comes to javascript) to change its position from inherit to fixed/sticky .. but when the change happens, my content jumps up because of the sudden space.
ยป it's most obvious with the "people I enjoy working with" ... the first person suddenly disappears as soon as the subhead becomes sticky.
Is there any way to either add extra space or prevent the jump in another way?

When you change those subheaders to position:fixed, they're removed from the flow of the document. They have a margin-bottom: 75px which is also removed from the flow when that happens.
Try changing that to a margin-top:75px to the start of the blocks below each subheader; that won't "disappear" when the subheads change position values, so your spacing should be preserved.

FYI, your fix.js file could probably be refactored down to something like this:
var $titles = $("header h2");
$(window).scroll(function(){
var win_top = $(this).scrollTop();
$titles.each(function(){
var div_top1 = $(this).offset().top;
if (win_top > div_top) $(this).addClass('stick')
else $(this).removeClass('stick');
});
});

Related

Using javascript to pause background scroll to allow for fixed elements to have slide show

Ok so the effect I am trying to emulate can be found on the nexus 5 site - http://www.google.com/nexus/5/ - when you scroll to the phone section. I've viewed source and looked through the code but there is over 13k lines of js so it was a waste.
Anyways what I did was add a class to fix the position of the images and created a background div that was like 5000px so it would appear to be fixed. The js fixed the position after the screen reached a certain point and then removed the fixed class after the end of the div.
My question is that i know this can be done better than my janky 'hack'. I'd love to hear your thoughts on better implementation.
This is part of the code that adds the fixed class
<script type="text/javascript">
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 500) {
$(".container").addClass("fixed");
}
if (scroll >= 8000) {
$(".container").removeClass("fixed");
}
});
Try this guide:
http://blog.teamtreehouse.com/multiplane-design-with-svgs-and-css-3d-transforms
Demo: http://codepen.io/nickpettit/full/eBCrK
Haven't done something like this before myself however. Also just a note that fixed position elements from my experience act up when viewed on tablet/smartphone.

window scroll method flickers in IE

This may come as a huge surprise to some people but I am having an issue with the IE browser when I am using the $(window).scroll method.
My goal:
I would like to have the menu located on the left retain it's position until the scroll reaches > y value. It will then fix itself to the top of the page until the scroll returns to a < y value.
My error:
Everything seems just fine in Chrome and Firefox but when I go to Internet Explorer it would seem the browser is moving #scroller every time the scroll value changes, this is causing a moving/flickering event.
If someone could point me to a resource or give me a workaround for this I would be very grateful!
Here is a fiddle:
http://jsfiddle.net/CampbeII/nLK7j/
Here is a link to the site in dev:
http://squ4reone.com/domains/ottawakaraoke/Squ4reone/responsive/index.php
My script:
$(window).scroll(function () {
var navigation = $(window).scrollTop();
if (navigation > 400) {
$('#scroller').css('top',navigation - 220);
} else {
$('#scroller').css('top',183);
$('#scroller').css('position','relative');
}
});
You might want to take a look at the jQuery Waypoints plugin, it lets you do sticky elements like this and a lot more.
If you want to stick with your current method, like the other answers have indicated you should toggle fixed positioning instead of updating the .top attribute in every scroll event. However, I would also introduce a flag to track whether or not it is currently stuck, this way you are only updating the position and top attributes when it actually make the transition instead of every scroll event. Interacting with the DOM is computationally expensive, this will take a lot of load off of the layout engine and should make things even smoother.
http://jsfiddle.net/WYNcj/6/
$(function () {
var stuck = false,
stickAt = $('#scroller').offset().top;
$(window).scroll(function () {
var scrollTop = $(window).scrollTop();
if (!stuck && scrollTop > stickAt) {
$('#scroller').css('top', 0);
$('#scroller').css('position','fixed');
stuck = true;
} else if (stuck && scrollTop < stickAt) {
$('#scroller').css('top', stickAt);
$('#scroller').css('position','absolute');
stuck = false;
}
});
});
Update
Switching the #scroller from relative to fixed removes it from the normal flow of the page, this can have unintended consequences for the layout as it re-flows without the missing block. If you change #scroller to use an absolute position it will be removed from the normal flow and will no longer cause these side-effects. I've updated the above example and the linked jsfiddle to reflect the changes to the JS/CSS.
I also changed the way that stickAt is calculated as well, it uses .offset() to find the exact position of the top of #scoller instead of relying on the CSS top value.
Instead of setting the top distance at each scroll event, please consider only switching between a fixed position and an absolute or relative position.All browsers will appreciate and Especially IE.
So you still listen to scroll but you now keep a state flag out of the scroll handler and simply evaluate if it has to switch between display types.
That is so much more optimized and IE likes it.
I can get flickers in Chrome as well if I scroll very quickly. Instead of updating the top position on scroll, instead used the fixed position for your element once the page has scrolled below the threshold. Take a look at the updated fiddle: http://jsfiddle.net/nLK7j/2/

Jquery Sticky Nav Issue

I'm been trying to get my head around issue and seem to cant find some help.
http://fiddle.jshell.net/DQgkE/7/show/
The experience is a bit jumpy and buggy now- but what i will like is
1) When you scroll down the page. I want the Sticky Nav to be (disable,dropped off, stop) at a specific location(chapter-3) on the page and the user should have the ability to keep scrolling down.
2) When the user is scrolling back up, the code will stick the nav back and carry it up until the nav reaches the original position at the top.
Below is a starting point.
3) Currently is kinda of doing that but there's some huge jump going on when scrolling back up
http://imakewebthings.com/jquery-waypoints/#doc-disable
using disable, destroy, enable option will be nice.
This is a original experience cleaned: http://fiddle.jshell.net/DQgkE/1/show/
Thanks for the help in Advance.
I'm not sure how this plugin you used work, but I have a solution I wrote a while back that I wrote in jquery. It has few variables at the top, the item you wanted sticky, the item where you want it to stop, and the class to add when it becomes sticky and padding at the top and bottom. I only modified the javascript portion in this fork.
EDIT
I went ahead and fixed the original code. Solution without waypoint plugin is in comments.
Here is the result:
http://fiddle.jshell.net/Taks7/show/
I would recommend to use jQuery (that was a surprise, right?! :P)
$(document).ready(function() { //when document is ready
var topDist = $("nav").position(); //save the position of your navbar !Don't create that variable inside the scroll function!
$(document).scroll(function () { //every time users scrolls the page
var scroll = $(this).scrollTop(); //get the distance of the current scroll from the top of the window
if (scroll > topDist.top - *distance_nav_from_top*) { //user goes to the trigger position
$('nav').css({position:"fixed", width: "100%", top:"*distance_nav_from_top*"}); //set the effect
} else { //window is on top position, reaches trigger position from bottom-to-top scrolling
$('nav').css({position:"static", width:"initial", top:"initial"}); //set them with the values you used before scrolling
}
});
});
I really hope I helped!

jQuery scrolling DIV is jumpy and positioned incorrectly

Not too long ago I asked about setting up a DIV which scrolls with the rest of the page. Post can be found here.
I've set this up, using the following code:
JS..
jQuery(function ($) {
var el = $('#sidebar'),
pos = el.position().top;
alert(pos);
$(window).scroll(function() {
el.toggleClass('fixed', $(this).scrollTop() >= pos);
});
});
CSS..
/* profile sidebar */
#sidebar>div{ width: 300px; margin-top: 10px; }
#sidebar.fixed>div{position:fixed;top:0}
A copy of the page can be found here. The alert was just some debugging.
The problem is, when you scroll a small amount, #sidebar suddenly appears at the very top of the page. In addition, sometimes as you scroll further down, the sidebar appears - and sometimes it doesn't.
Any idea what might be causing such seemingly random functionality?
I'm still trying to figure out why it works in the first place in the jsfiddle example, but anyway, I know how to fix it:
$(window).scroll(function() {
if($(this).scrollTop() >= pos){
el.addClass('fixed');
}else{
el.removeClass('fixed');
}
});
I tested this by unbinding the event you had and replacing it with this code. It seemed to work fine.
The reason I can't understand why it works in the example: toggleClass should be constantly adding and removing "fixed" if you have scrolled enough, because the conditional is true (true here means whether to toggle). The constant adding and removing of the fixed class causes the jumpy behavior.
You can watch this on your page: open up some dev tools (firegubg or Chrome) and watch what happens to your sidebar element.
[UPDATE]
Actually, I misread the docs. True means the class should be added (I don't think the docs are very clear though). Thus... the only way I could explain this is if #dunc was running jQuery v1.2 and the switch was getting ignored completely...

JavaScript to scroll long page to DIV

I have a link on a long HTML page. When I click it, I wish a div on another part of the page to be visible in the window by scrolling into view.
A bit like EnsureVisible in other languages.
I've checked out scrollTop and scrollTo but they seem like red herrings.
Can anyone help?
old question, but if anyone finds this through google (as I did) and who does not want to use anchors or jquery; there's a builtin javascriptfunction to 'jump' to an element;
document.getElementById('youridhere').scrollIntoView();
and what's even better; according to the great compatibility-tables on quirksmode, this is supported by all major browsers!
If you don't want to add an extra extension the following code should work with jQuery.
$('a[href=#target]').
click(function(){
var target = $('a[name=target]');
if (target.length)
{
var top = target.offset().top;
$('html,body').animate({scrollTop: top}, 1000);
return false;
}
});
How about the JQuery ScrollTo - see this sample code
You can use Element.scrollIntoView() method as was mentioned above. If you leave it with no parameters inside you will have an instant ugly scroll. To prevent that you can add this parameter - behavior:"smooth".
Example:
document.getElementById('scroll-here-plz').scrollIntoView({behavior: "smooth", block: "start", inline: "nearest"});
Just replace scroll-here-plz with your div or element on a website. And if you see your element at the bottom of your window or the position is not what you would have expected, play with parameter block: "". You can use block: "start", block: "end" or block: "center".
Remember: Always use parameters inside an object {}.
If you would still have problems, go to https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
There is detailed documentation for this method.
Click here to scroll
<A name='myAnchorALongWayDownThePage"></a>
No fancy scrolling but it should take you there.
The difficulty with scrolling is that you may not only need to scroll the page to show a div, but you may need to scroll inside scrollable divs on any number of levels as well.
The scrollTop property is a available on any DOM element, including the document body. By setting it, you can control how far down something is scrolled. You can also use clientHeight and scrollHeight properties to see how much scrolling is needed (scrolling is possible when clientHeight (viewport) is less than scrollHeight (the height of the content).
You can also use the offsetTop property to figure out where in the container an element is located.
To build a truly general purpose "scroll into view" routine from scratch, you would need to start at the node you want to expose, make sure it's in the visible portion of it's parent, then repeat the same for the parent, etc, all the way until you reach the top.
One step of this would look something like this (untested code, not checking edge cases):
function scrollIntoView(node) {
var parent = node.parent;
var parentCHeight = parent.clientHeight;
var parentSHeight = parent.scrollHeight;
if (parentSHeight > parentCHeight) {
var nodeHeight = node.clientHeight;
var nodeOffset = node.offsetTop;
var scrollOffset = nodeOffset + (nodeHeight / 2) - (parentCHeight / 2);
parent.scrollTop = scrollOffset;
}
if (parent.parent) {
scrollIntoView(parent);
}
}
This worked for me
document.getElementById('divElem').scrollIntoView();
Answer posted here - same solution to your problem.
Edit: the JQuery answer is very nice if you want a smooth scroll - I hadn't seen that in action before.
Why not a named anchor?
The property you need is location.hash. For example:
location.hash = 'top'; //would jump to named anchor "top
I don't know how to do the nice scroll animation without the use of dojo or some toolkit like that, but if you just need it to jump to an anchor, location.hash should do it.
(tested on FF3 and Safari 3.1.2)
I can't add a comment to futtta's reply above, but for a smoother scroll use:
onClick="document.getElementById('more').scrollIntoView({block: 'start', behavior: 'smooth'});"
<button onClick="scrollIntoView()"></button>
<br>
<div id="scroll-to"></div>
function scrollIntoView() {
document.getElementById('scroll-to').scrollIntoView({
behavior: 'smooth'
});
}
The scrollIntoView method accepts scroll-Options to animate the scroll.
With smooth scroll
document.getElementById('scroll-to').scrollIntoView({
behavior: 'smooth'
});
No animation
document.getElementById('scroll-to').scrollIntoView();
There is a jQuery plugin for the general case of scrolling to a DOM element, but if performance is an issue (and when is it not?), I would suggest doing it manually. This involves two steps:
Finding the position of the element you are scrolling to.
Scrolling to that position.
quirksmode gives a good explanation of the mechanism behind the former. Here's my preferred solution:
function absoluteOffset(elem) {
return elem.offsetParent && elem.offsetTop + absoluteOffset(elem.offsetParent);
}
It uses casting from null to 0, which isn't proper etiquette in some circles, but I like it :) The second part uses window.scroll. So the rest of the solution is:
function scrollToElement(elem) {
window.scroll(0, absoluteOffset(elem));
}
Voila!
As stated already, Element.scrollIntoView() is a good answer. Since the question says "I have a link on a long HTML page..." I want to mention a relevant detail. If this is done through a functional link it may not produce the desired effect of scrolling to the target div. For example:
HTML:
<a id="link1" href="#">Scroll With Link</a>
JavaScript:
const link = document.getElementById("link1");
link.onclick = showBox12;
function showBox12()
{
const box = document.getElementById("box12");
box.scrollIntoView();
console.log("Showing Box:" + box);
}
Clicking on Scroll With Link will show the message on the console, but it would seem to have no effect because the # will bring the page back to the top. Interestingly, if using href="" one might actually see the page scroll to the div and jump back to the top.
One solution is to use the standard JavaScript to properly disable the link:
<a id="link1" href="javascript:void(0);">Scroll With Link</a>
Now it will go to box12 and stay there.
I use a lightweight javascript plugin that I found works across devices, browsers and operating systems: zenscroll
scrollTop (IIRC) is where in the document the top of the page is scrolled to. scrollTo scrolls the page so that the top of the page is where you specify.
What you need here is some Javascript manipulated styles. Say if you wanted the div off-screen and scroll in from the right you would set the left attribute of the div to the width of the page and then decrease it by a set amount every few seconds until it is where you want.
This should point you in the right direction.
Additional: I'm sorry, I thought you wanted a separate div to 'pop out' from somewhere (sort of like this site does sometimes), and not move the entire page to a section. Proper use of anchors would achieve that effect.
I personally found Josh's jQuery-based answer above to be the best I saw, and worked perfectly for my application... of course, I was already using jQuery... I certainly wouldn't have included the whole jQ library just for that one purpose.
Cheers!
EDIT: OK... so mere seconds after posting this, I saw another answer just below mine (not sure if still below me after an edit) that said to use:
document.getElementById('your_element_ID_here').scrollIntoView();
This works perfectly and in so much less code than the jQuery version! I had no idea that there was a built-in function in JS called .scrollIntoView(), but there it is! So, if you want the fancy animation, go jQuery. Quick n' dirty... use this one!
For smooth scroll this code is useful
$('a[href*=#scrollToDivId]').click(function() {
if (location.pathname.replace(/^\//,'') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname) {
var target = $(this.hash);
target = target.length ? target : $('[name=' + this.hash.slice(1) +']');
var head_height = $('.header').outerHeight(); // if page has any sticky header get the header height else use 0 here
if (target.length) {
$('html,body').animate({
scrollTop: target.offset().top - head_height
}, 1000);
return false;
}
}
});
Correct me if I'm wrong but I'm reading the question again and again and still think that Angus McCoteup was asking how to set an element to be position: fixed.
Angus McCoteup, check out http://www.cssplay.co.uk/layouts/fixed.html - if you want your DIV to behave like a menu there, have a look at a CSS there

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