I am wanting to add an offset from the top and smooth scroll to the following function,
The functionality is on one button thats fixed and follows the user down the page. This button has to be able to scroll through numerous anchors and then go back to the first one, with an offset ideally of 105px from the top. trawled the net for hours for help and dont have the jquery know how myself to fix this, any help??
Similar example here - http://www.google.com/nexus/7/ (button in bottom right)
<script>
var max = 6;
function goToNext() {
var hash = String(document.location.hash);
if (hash && hash.indexOf(/anchor/)) {
var newh = Number(hash.replace("#anchor",""));
(newh > max-1) ? newh = 0 : void(null);
document.location.hash = "#anchor" + String(newh+1);
} else {
document.location.hash = "#anchor1";
}
}
</script>
<div id="anchor1"></div>
<div id="anchor2"></div>
<div id="anchor3"></div>
<div id="anchor4"></div>
<div id="anchor5"></div>
<div id="anchor6"></div>
You can make it scroll smoothly to the element using animate({scrollTop:value},delay).
$('document').ready(function () {
//on DOM ready change location.hash to 'anchor1'
window.location.hash = 'anchor1';
//GO TO NEXT click event:
$('a').click(function (e) {
//preventing the default <a> click (href="#")
e.preventDefault();
//get the current hash to determine the current <div> id
var hash = window.location.hash,
//find the (next) immediate following sibling of the current <div>
$next = $(hash).next('div');
//check if this next <div> sibling exist
if ($next.length) {
var id = $next.attr('id'),
nextOffsetTop = $next.offset().top;
//animate scrolling and set the new hash
$('body, html').animate({scrollTop: nextOffsetTop}, 'slow');
window.location.hash = id;
}else{
//else if the next <div> sibling does not exist move to the first anchor
var first = '#anchor1';
$('body, html').animate({scrollTop: $(first).offset().top},'slow');
window.location.hash = first;
}
});
})
See this jsfiddle.
Then comes the flickering. Actually it does not flicker but somewhat jerky, if you look closely into the code above. I am setting the animate(scrollTop) first, then changing the hash window.location.hash = id. Now when the animate starts scrolling and suddenly we are changing the hash it tends to jump directly to the next <div> (this is the default haschange event) but pulled back by the animate() and that causes the scrolling to be jerky.
We cannot just stop the default propagation of the haschange event, there may be a solution to do that but cannot guarantee that it would work on all browsers, each browser has different behaviour when it comes to the haschange event. But thanks to #Andy E solution on that SO post you've provided, we don't need to stop the haschange propagation. We can just simply change the hash first, reset it to last scrollTop() position then animate scrolling at will!
//get the current scrollTop value
var st = $(window).scrollTop();
//change the hash
window.location.hash = id;
//reset the scrollTop
$(window).scrollTop(st);
//animate scrolling
$('body, html').animate({scrollTop: nextOffsetTop}, 'slow');
Check this updated jsfiddle.
Now let's talk about HTML5 History API. The reason I didn't introduced this at first because it is implemented differently across HTML5 (especially IE) browsers and has no fallback for HTML4 browsers, making this method somehow inconsistent. But you can get this done properly using a plugin I guess.
Here's how you can do it using history.pushState():
if ($next.length) {
var id = $next.attr('id'),
nextOffsetTop = $next.offset().top;
history.pushState({state:id}, id, '#'+id);
$('body, html').animate({scrollTop: nextOffsetTop - 105}, 'slow');
}
See this jsfiddle.
That's it. Cheers!
Related
I'm trying to create a simple scroll effect where the page header hides when the page scrolls down and reappears on scroll up. The HTML:
<header class="siteHeader">...</header>
...is hidden by applying the CSS class "siteHeader--up."
I'm using jQuery. Here is my code:
$(function () {
var $siteHeader = $('.siteHeader');
var $window = $(window);
// to determine scroll direction. initializes to 0 on page load
var scrollReference = 0;
function fixedHeader () {
var scrollPosition = $window.scrollTop();
// if page is scrolling down, apply the CSS class
if (scrollPosition > scrollReference)
{
$siteHeader.addClass('siteHeader--up');
}
// otherwise, page is scrolling up. Remove the class
else
{
$siteHeader.removeClass('siteHeader--up');
}
// update reference point to equal where user stopped scrolling
scrollReference = scrollPosition
}
$window.scroll(function () {
fixedHeader();
});
});
This works fine for the most part. The problem is when I scroll down the page and then refresh the page. Somehow the scroll function is being triggered. The header will be visible for a moment and then hide (as though the page thinks it's being scrolled down). The function is being triggered on page load (confirmed with a console.log), but I don't understand why, because it's only supposed to fire on scroll.
Can someone help me understand what's going on and how I can prevent it?
Thanks!
That is the expected behavior. When the page is refreshed, the browser remembers the scroll position and it scrolls the page to that position, later on the scroll event is fired.
I think that this could be a workaround to solve your problem:
When the jQuery scroll event is fired you can get the timeStamp property and if this timeStamp is very close to the window.onload timeStamp, surely it can't be an event triggered by the user:
I've used a value of 50 milliseconds, test if it is sufficient, I think that it is.
var startTime = false;
$(function () {
var $siteHeader = $('.siteHeader');
var $window = $(window);
// to determine scroll direction. initializes to 0 on page load
var scrollReference = 0;
function fixedHeader () {
var scrollPosition = $window.scrollTop();
// if page is scrolling down, apply the CSS class
if (scrollPosition > scrollReference)
{
$siteHeader.addClass('siteHeader--up');
}
// otherwise, page is scrolling up. Remove the class
else
{
$siteHeader.removeClass('siteHeader--up');
}
// update reference point to equal where user stopped scrolling
scrollReference = scrollPosition
}
$window.on("load", function (evt) {
startTime = evt.timeStamp;
});
$window.on("scroll", function (evt) {
if(!startTime || evt.timeStamp - startTime < 50) return;
fixedHeader();
});
});
Try Loading the function on window load as well as in the scroll function:
$window.load(function(){
fixedHeader();
});
Or on document ready maybe:
$(document).ready(function () {
fixedHeader();
});
This should trigger and reset the values in the Variables you made and therefore determine whether to set the header to fixed or not, regardless of the scroll position.
Let me know if it works because i'm kinda curious too :)
I'm pretty new with Jquery. I would like that my animations with Wow.js could run more than once time. For instance: i scroll to the bottom of my page and see all the animations, and if i scroll back to the top i see again the animations like when you scroll down. I hope that I explained myself. I have already seen many websites that repeats the animations on theirs pages but unfortunately I don't remember them and I can't provide a link.
I have already tried this:
$(window).scroll(function(){
new WOW().init();
}
But it repeat the animations also if you scroll a little and it's pretty ugly to see. I try to explain me better: I have a with my animation and if it is focused the animation is triggered, then i scroll down to another div and the previous div is no more visible(not in the window viewport), then again i scroll back to my div with animation and the animation is triggered again.
I'm sorry for this messy question but I really don't know how to explain it.
Thanks in advance!
This example by Benoît Boucart shows how the animation can be "reset" when the user scrolls out of view and back in. The key here is the second function that removes the animation css class when the element scrolls out of view. I wish WOW.js would implement this, but they've indicated that they don't plan to.
http://codepen.io/benske/pen/yJoqz
Snippet:
// Showed...
$(".revealOnScroll:not(.animated)").each(function () {
var $this = $(this),
offsetTop = $this.offset().top;
if (scrolled + win_height_padded > offsetTop) {
if ($this.data('timeout')) {
window.setTimeout(function(){
$this.addClass('animated ' + $this.data('animation'));
}, parseInt($this.data('timeout'),10));
} else {
$this.addClass('animated ' + $this.data('animation'));
}
}
});
// Hidden...
$(".revealOnScroll.animated").each(function (index) {
var $this = $(this),
offsetTop = $this.offset().top;
if (scrolled + win_height_padded < offsetTop) {
$(this).removeClass('animated fadeInUp flipInX lightSpeedIn')
}
});
If a user wants to repeat the animation on both the events i.e.
onScrollUp
onScrollDown
then this will be a good solution for it:
First create an addBox function, it will help to push new elements into the WOW boxes array.
WOW.prototype.addBox = function(element){
this.boxes.push(element);
};
Then use jQuery and scrollspy plugin that helps to detect which element is out of the view and then push WOW as:
$('.wow').on('scrollSpy:exit',function(){
var element = $(this);
element.css({
'visibility' : 'hidden',
'animation-name' : 'none'
}).removeClass('animated');
wow.addBox(this);
});
Solution Courtesy: ugurerkan
Answer by #vivekk is correct I m just adding a working example so that people can easily get this
see the Demo fiddle
<script>
// Repeat demo content
var $body = $('body');
var $box = $('.box');
for (var i = 0; i < 20; i++) {
$box.clone().appendTo($body);
}
// Helper function for add element box list in WOW
WOW.prototype.addBox = function(element) {
this.boxes.push(element);
};
// Init WOW.js and get instance
var wow = new WOW();
wow.init();
// Attach scrollSpy to .wow elements for detect view exit events,
// then reset elements and add again for animation
$('.wow').on('scrollSpy:exit', function() {
$(this).css({
'visibility': 'hidden',
'animation-name': 'none'
}).removeClass('animated');
wow.addBox(this);
}).scrollSpy();
</script>
I am building a full page slider that keeps the native scrollbar and allows the user to either free scroll, use the mouse wheel or navigation dots (on the left) to switch to a slide.
Once the user is on the last slide and tries to scroll down further, the whole slider moves up to reveal a simple scrollable section. If the user scrolls down and then tries to go back up, then this new section moves out of the way again and returns the slider back into view.
Fiddle: http://jsfiddle.net/3odc8zmx/
The parts I'm struggling with:
Only the first two navigation dots work. The third one DOES WORK if you area looking at the first slide. But doesn't do anything, if you are on slide 2. Note: the purple one is a short-cut to the second section of the page and not related to the slider.
When moving to the last slide (via the dots, if you're on the first slide) it causes the code to make the whole slider move upwards as it sees this as the user has slid past the last slide as per the description above. I have tried to combat this using a variable called listen to stop the scroll event listening when using the showSlide method... but it seems to be true even though I set it to false, and only reset it to true again after the animation...
When scrolling down using the mouse wheel, I can get to the second section and back up, but not to the first third section. I'm wondering if I could use the showSlide method to better handle this instead of the current dirty next and prev functions I have implemented.
Note: If the user has free-scrolled, when they use the mouse-wheel, I want the slider to snap to the nearest slide to correct itself... Any suggestions for how I could do this?
Can anyone offer some help?
Here's the JS:
var listen = true;
function nextSlide()
{
$('#section1').stop(true,false).animate({
scrollTop: $('#section1').scrollTop() + $(window).height()
});
}
function prevSlide()
{
$('#section1').stop(true,false).animate({
scrollTop: -$('#section1').scrollTop() + $(window).height()
});
}
function showSlide(index)
{
var offset = $('#section1 div').eq(index).offset();
offset = offset.top;
if(offset){
listen = false;
$('.slide-dot').removeClass('active');
$('.slide-dot').eq(index).addClass('active');
$('#section1').stop(true,false).animate({
scrollTop: offset
}, 500, function(){
listen = true;
});
} else {
alert('error');
}
}
$(document).ready(function(){
var fullHeight = 0;
$('#section1 div').each(function(){
fullHeight = fullHeight + $(this).height();
});
var lastScrollTop1 = 0;
$('#section1').on('scroll', function(e){
var st = $(this).scrollTop();
if (st > lastScrollTop1){
if( $('#section1').scrollTop() + $(window).height() == fullHeight) {
if(listen){
$('body').addClass('shifted');
}
}
}
lastScrollTop1 = st;
});
$('#section1').on('mousewheel', function(e){
e.preventDefault();
var st = $(this).scrollTop();
if (st > lastScrollTop1){
nextSlide();
} else {
prevSlide();
}
});
var lastScrollTop2 = 0;
$('#section2').on('scroll', function(e){
var st = $(this).scrollTop();
if (st > lastScrollTop1){
} else {
if( st == 0 ){
$('body').removeClass('shifted');
}
}
lastScrollTop1 = st;
});
$('.slide-dots').css({'margin-top':-$('.slide-dots').height() / 2});
$('.slide-dot').first().addClass('active');
$(document).on('click', '.slide-dot', function(e){
e.preventDefault();
showSlide( $(this).index() );
});
$(document).on('click', '.slide-dot-fake', function(e){
e.preventDefault();
$('body').addClass('shifted');
});
});
And for those wondering why I'm not using something like fullPage.js, it's because it can't handle the way I want to transition between the two areas and have two scrollbars (one for each area).
You can use:
e.originalEvent.wheelDelta
instead of:
st > lastScrollTop1
in the mousewheel event for your third problem to check if the user has scrolled up or down. And also change the +/- in prevSlide. I used dm4web's fiddle for your first problem. And I used:
scrollTop: offset - 1
instead of:
scrollTop: offset
for your second problem, because when the scroll reaches to the last pixel of the third element, it automatically goes to the next section, so 1 pixel is enough for it not to.
Here's the fiddle: http://jsfiddle.net/3odc8zmx/3/
As suggested by #chdltest, you could do it by using fullPage.js.
Here's an example. Go to the last section.
Code used for the example:
Javascript
$('#fullpage').fullpage({
sectionsColor: ['yellow', 'orange', '#C0C0C0', '#ADD8E6'],
scrollOverflow: true,
scrollBar: true,
afterLoad: function (anchor, index) {
//hiding the main scroll bar
if (index == 4) {
$('body, html').css('overflow', 'hidden');
}
//showing the main scroll bar
if (index == 3) {
$('body, html').css('overflow', 'visible');
}
}
});
CSS (in case you prefer to use the normal style for it)
/* Normal style scroll bar
* --------------------------------------- */
.slimScrollBar {
display: none !important;
}
.fp-scrollable {
overflow: auto !important;
}
Advantages of using fullPage.js instead to your own code:
Strongly tested in different devices and browsers. (IE, Opera, Safari, Chrome, Firefox..)
Prevent problems with trackpads, Apple laptops trackpads or Apple Magic Mouse.
Old browser's compatibility, such as IE 8, Opera 12...
Touch devices compatibility (IE Windows Phone, Android, Apple iOS, touch desktops...)
It provides many other useful options and callbacks.
I want a nav to highlight (or something similar) once a user clicks on it AND when a user scrolls to the corresponding section.
However, on my computer when one clicks on any of the nav events after3, only nav event 3 changes. I'm guessing this is because after one clicks on 4 or 5, the scroll bar is already at the bottom of the page, so 4 and 5 never reach the top. The only div at the top is post 3, so my code highlights nav event 3 and ignores the click.
Is there any way I can fix this? Ive tried if statements (only highlight nav event if it's at the top AND the scrollbar isn't at the bottom or the top isn't the last item).
Here is a more accurate fiddle, using a fix below showing what I am talking about. The fix now highlights on scroll, but if you click option 5, it will not highlight.
$('.option').children('a').click(function() {
$('.option').css('background-color', '#CCCCCC;');
$(this).css('background-color', 'red');
var postId = $($(this).attr('href'));
var postLocation = postId.offset().top;
$(window).scrollTop(postLocation);
});
$(window).scroll(function() {
var scrollBar = $(this).scrollTop();
var allPosts = [];
var post = $('.content').offset();
var lastPost = allPosts.legnth-1
var windowHeight = $(window).height();
var bottomScroll = windowHeight-scrollBar;
$(".content").each(function(){
allPosts.push($(this).attr('id'));
});
i = 0;
for(i in allPosts){
var currentPost = "#"+allPosts[i];
var postPosition = $(currentPost).offset().top;
if (scrollBar >= postPosition){
$('.option').css('background-color', '#CCCCCC');
$('#nav'+allPosts[i]).css('background-color', 'red');
};
};
});
I think you've overdone your scroll() handler, to keep it simple you just needs to check if the scrollbar/scrollTop reaches the '.contents' offset top value but should not be greater than its offset().top plus its height().
$(window).scroll(function () {
var scrollBar = $(this).scrollTop();
$(".content").each(function (index) {
var elTop = $(this).offset().top;
var elHeight = $(this).height();
if (scrollBar >= elTop - 5 && scrollBar < elTop + elHeight) {
/* $(this) '.content' is the active on the vewport,
get its index to target the corresponding navigation '.option',
like this - $('.Nav li').eq(index)
*/
}
});
});
And you actually don't need to set $(window).scrollTop(postLocation); because of the default <a> tag anchoring on click, you can omit that one and it will work fine. However if you are looking to animate you need first to prevent this default behavior:
$('.option').children('a').click(function (e) {
e.preventDefault();
var postId = $($(this).attr('href'));
var postLocation = postId.offset().top;
$('html, body').animate({scrollTop:postLocation},'slow');
});
See the demo.
What you are trying to implement from scratch, although commendable, has already been done by the nice folks at Bootstrap. It is called a Scrollspy and all you need to do to implement it is include Bootstrap js and css (you also need jquery but you already have that) and make some minor changes to your html.
Scrollspy implementation steps.
And here is a demonstration. Notice only one line of js. :D
$('body').scrollspy({ target: '.navbar-example' });
I have an accordion element, and I need to have different panes expand on hashchange. The code I made, expands it but it doesn't scroll the the targeted div, and page never ends loading.
function hashChange() {
if (window.location.hash === '#senior-backend') {
$('#senior-backend, #backend-developer, #senior-frontend, #frontend, #dev-ops').hide(50);
$('#senior-backend').show(50);
$('#job-posts').removeClass().addClass('beige-bg');
$('#job-posts-top').removeClass().addClass('beige-spikes');
}
}
window.onhashchange = hashChange;
Could you please point out what am I doing wrong.
Thanks
You need to scroll the site using animate once you detect a change in the hash, for example:
var dest = $('#yourSelector').position();
var dtop = dest.top;
$('html, body').animate({
scrollTop: dtop
});
Living demo: http://jsfiddle.net/LZbK8/