jQuery .stop() isn't stopping animation completely - javascript

I think the easiest way to demonstrate my problem is to make a short codepen.
(Sorry I couldn't make a snippet. I copied the exact same code from codepen to the SO snippet, but it didn't perform the same way.)
But lets get to the problem:
So as you can see on my codepen, the "most visible" div gets centered after one second without scrolling.
Scroll to the very bottom and the footer should appear and it's not centering the previous div. I did that with that code:
if ($(window).scrollTop() >= $(document).height() - $(window).height() - 20) {
$("footer").addClass("footerVis");
$("html, body").stop(true);
} else {
$("footer").removeClass("footerVis");
}
I'm not sure if there would have been a better way to do that, but I just used .stop() to stop the scrolling animation to the previous div. However it works, but like every second it scrolls a bit up.
I guess that's because of the setTimeout(function() {...}, 1000) earlier in the JS to start the scrolling animation after one second. I can't explain why it scrolls a bit up every second tho...
Does anyone know how I could fix this? Thanks for your help in advance!

Related

Run jQuery/Javascript Function w/GSAP only once?

I have a function that scrolls down/snaps to a div after the user starts to scroll (to avoid them having to manually scroll down to where the main content starts). I have used some GSAP to achieve this, however I don't think that will make much difference with the solution to this problem. However, while this function does exactly what I'd like, It won't then allow the user to scroll back up. It just glitches a little bit, as if I'm fighting with the function to scroll back up. I've tried a variety of answers from all the "run only once questions" on here, but none seem to work in this situation.
I want to basically kill the function after the first time it is initiated, or to tweak the function to only work on the first scroll at the top of the page (though I appreciate this would be much more complicated).
Thank you in advance of any help.
JS:
$(window).scroll(function () {
function headScrollToDiv() {
var dHeight = $(window).height();
if (dHeight >= $(this).scrollTop()) {
gsap.to(window, 0.4, { scrollTo: ".buffer" });
}
}
headScrollToDiv();
});

Scroll snapping to a page section

So I have two sections of content near the top of my page and I’d like for users who have scrolled down to near the top of the second section to get “scroll snapped” to the top of the second one once they have stopped scrolling.
I think it should be possible using jQuery but I haven’t been able to figure it out. Here are my examples:
Without my attempt: http://codepen.io/jifarris/pen/gaVgBp
With my broken attempt: http://codepen.io/jifarris/pen/gaVgQp
Basically I can’t figure out how to make it try scrolling to the spot only once, after scrolling has stopped. It’s kind of just freaking out.
I love how the recently introduced scroll snap points CSS feature handles scroll snapping and I’d almost prefer to use it – for the browsers that support it, at least – but it seems like it only works for items that take up 100% of the viewport height or width, and it seems like it’s for scrolling within an element, not the page itself.
The top section has a fixed height, so this really can be handled with pixel numbers.
And for reference, here’s the heart of the code from my attempt:
$(function() {
$(document).on('scroll', function() {
var top = $(document).scrollTop();
if (top > 255 && top < 455) {
$('html, body').animate({scrollTop: '356'}, 500);
$('body').addClass('hotzone');
} else {
$('body').removeClass('hotzone');
}
});
});
KQI's answer contains most of the steps required to create a well functioning section-scroll for use in your application/webpage.
However, if you'd just want to experiment yourself, developing your script further, the first thing you'll have to do is add a timeout handler. Otherwise your logic, and therefor scrollAnimation, will trigger every single pixel scrolled and create a buggy bouncing effect.
I have provided a working example based on your script here:
http://codepen.io/anon/pen/QjepRZ?editors=001
$(function() {
var timeout;
$(document).on('scroll', function() {
clearTimeout(timeout);
timeout = setTimeout(function() {
var top = $(document).scrollTop();
if (top > 255 && top < 455) {
$('body').animate({
scrollTop: '356'
}, 500);
$('body').addClass('hotzone');
} else {
$('body').removeClass('hotzone');
}
}, 50);
});
});
Good luck!
All right, there are couple of things you gonna have to deal with to get a good result: which are performance, call stack queue, easing.
Performance wise you should drop jQuery animate and use VelocityJs which gives a smoother transition, better frame per second (fps) to avoid screen glitches especially on mobiles.
Call stack: you should wrap whatever logic you have to animate the scrolltop with 'debounce' function, set the delay for let say 500mm and check the scrolling behavior. Just so you know, the 'scroll' listener your using is firing on each pixel change and your script will go crazy and erratic. (It is just gonna be a moment of so many calc at the same time. Debounce will fix that for you)
Easing: make the transition looks cool not just dry snappy movement.
Remember, 'easing' with Velocity starts with 'mina.' i.e.
'Mina.easingFnName'
Finally, your logic could be right, i am in my phone now cannot debug it but try to simplify it and work with a single problem at once, be like i.e.
If ( top > 380 ) // debounce(...)

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.

How to slowly move header while user scrolls the page?

I want to achieve the effect that is used on this Header on this example website:
http://anchorage-theme.pixelunion.net/
You will notice that as you scroll the page, the header slowly moves upward until it disappears from view. I want to achieve this same effect. I believe it will need some JS and CSS positioning but still have no clue how to achieve this. Is this done with parallax scrolling?
Would appreciate if someone could give me a quick example of the code used to do this with a element. So I can then use it on my own site.
Cheers.
the $(window).scroll(function () {...}) is the one you need here
$(document).scrollTop() is the amount of scrolled distance from the top
Use this:
$(window).scroll(function(){
if ($(this).scrollTop() > x){ // x should be from where you want this to happen from top//
//make CSS changes here
}
else{
//back to default styles
}
});

Animate a div after scrolling away from the top of the webpage

I'm currently trying to make a div appear from behind another div after the user scrolls away from the top of the page.
I'm hoping to do this using animate so that it slides out. Like this...
http://jsfiddle.net/xaYTt/99/
But I can't figure out how to make the red box stay behind the blue box until the user scrolls away from the top of the page.
I also need to reverse this when the user scrolls back up to the top of the page, so the red box slides back under the blue box again.
Can anyone help me out?
This is not the most elegant solution, but it works nonetheless.
http://jsfiddle.net/37LZ5/
Components:
Use $(document).scroll as a trigger to know when scrolling
Use scrollTop() to know how far we're scrolling (0 = top)
Remember state to make sure animation doesn't get triggered a zillion times (var away)
Use .stop() to prevent weird behaviour when halfway through one animation, another animation gets triggered
I think you are looking for this take a look at this demo
Working demo
Code
$(document).ready(function(){
//$('#bottom-box').animate({'margin-top': '200px'}, 1500);
$('body').hover(function(){
$('#bottom-box').animate({'margin-top': '200px'}, 1500);
}, function(){
$('#bottom-box').animate({'margin-top': '50px'}, 1500);
});
});
If my understanding about your question is correct, this is what you are looking for
Since you said, "User scrolls away from the top of the page", I added a div to be at the top of the page.
var isAlreadyOut=false;
$("#divPageTop").mouseover(function(){
if( isAlreadyOut==true)
{
$('#bottom-box').animate({'margin-top': '60px'}, 1500);
isAlreadyOut=false;
}
else
{
$('#bottom-box').animate({'margin-top': '200px'}, 1500);
isAlreadyOut=true;
}
});
Here is the jsfiddle version
http://jsfiddle.net/xaYTt/103/
I did something with jsFiddle that might be what you are after, if I understood your question correctly.
Basically, the red box will animate when you scroll the window more than the distance of the blue box.
Not 100%, just a quick mock up to see if that's what you want.
(When you scroll, click on the scroll bar arrows for more accurate results)
Demo here: http://jsfiddle.net/peduarte/xaYTt/104/

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