helloi want to make a sticky block using this script
$(window).scroll(function() {
var sb_m = 80; /* top and bottom padding */
var mb = 300; /* footer height with a margin */
var st = $(window).scrollTop();
var sb = $(".loginform");
var sbi = $(".loginform #loginform");
var sb_ot = sb.offset().top;
var sbi_ot = sbi.offset().top;
var sb_h = sb.height();
if(sb_h + $(document).scrollTop() + sb_m + mb < $(document).height()) {
if(st > sb_ot) {
var h = Math.round(st - sb_ot) + sb_m;
sb.css({"paddingTop" : h});
}
else {
sb.css({"paddingTop" : 0});
}
}
});
on naked HTML all work fine
if add a script to site (use wordpress) appears an infinite scroll
here can see problem
problem appears if add an element to footer through widgets
please tell me what is problem?
Honestly it's not ideal to work with padding-top, you should use top (with the element set as position:relative or absolute);
If you don't care about supporting IE, the easiest way is to use position:sticky; which does all the work for you: https://developer.mozilla.org/en-US/docs/Web/CSS/position
If you prefer to do it yourself, I'd suggest working this way:
store in variables the current offset().top and .left of the soon-to-be sticky element, outside any onScroll handlers.
When this condition is true:
$(window.scrollTop() >= theElementOffsetTopValueYouStored)
set the element as position: fixed and set the left: and top: properties of the element that should become sticky with the values you stored before. Then add your condition to make sure it stops when it reaches the end of the document, checking if element.offset().top + element.height > document.height
Please consider this is from memory, you might need to tweak a few things here and there to make it work properly.
I have a html div element that scrolls with the page but I would like it to become fixed once it reaches 50px from the top of the screen...
How is this done?
My div id is #box
Thanks!
-Ina
If you want it to be fixed at the top of the page at some distance from the top, you can check the top offset of the element and change the class when it reach the distance you want.
Here is the jquery code for your reference
jQuery(document).scroll(function() {
var documentTop = jQuery(document).scrollTop();
console.log('this is current top of your document' + documentTop );
//box top is 891
if (documentTop > 841) {
//change the value of the css at this point
jQuery("#box").addClass("stayfix");
}
else
{
jQuery("#box").removeClass("stayfix");
}
});
You need to be more specific about what have you done so far. For eg, how did you make the div element to scrolls inside the page. using css or js/jquery animation features?That will help us to give more specific answer.
**Edited According to your fiddle.
They are right, this question is duplicate. Here is a code I made with answers from the forum.
var box_top = $("#box").offset().top;
$(window).scroll(function (event) {
if ($(window).scrollTop() >= (box_top - 50)) {
$("#box").css({position:"fixed",top:"50px"});
} else {
$("#box").css({position:"relative"});
}
});
Hope it helps anyway.
https://jsfiddle.net/ay54msd5/1/
Try something like this. It's a solution using jquery (hopefully not a problem) that checks the scrollHeight of the page every time the page scrolls. If the scrollHeight is greater than a certain threshold, the element becomes fixed. If not, the element is positioned relatively (but you can do whatever you want in that case.
$(document).ready(function() {
var navFixed = false;
var $box = $("#box");
var topHeight = 50;
$(document).scroll(function() {
if ($(document).scrollTop() >= topHeight && !navFixed) {
$box.css("position", "fixed");
navFixed = true;
}
else if ($(document).scrollTop() < topHeight && navFixed) {
$box.css("position", "relative");
navFixed = false;
}
});
});
You would have to write some additional CSS targeting the #box element that tells it what coordinates you'd like it to be fixed to.
I am trying to implement synchronized scrolling for two DIV with the following code.
DEMO
$(document).ready(function() {
$("#div1").scroll(function () {
$("#div2").scrollTop($("#div1").scrollTop());
});
$("#div2").scroll(function () {
$("#div1").scrollTop($("#div2").scrollTop());
});
});
#div1 and #div2 is having the very same content but different sizes, say
#div1 {
height : 800px;
width: 600px;
}
#div1 {
height : 400px;
width: 200px;
}
With this code, I am facing two issues.
1) Scrolling is not well synchronized, since the divs are of different sizes. I know, this is because, I am directly setting the scrollTop value. I need to find the percentage of scrolled content and calculate corresponding scrollTop value for the other div. I am not sure, how to find the actual height and current scroll position.
2) This issue is only found in firefox. In firefox, scrolling is not smooth as in other browsers. I think this because the above code is creating a infinite loop of scroll events.
I am not sure, why this is only happening with firefox. Is there any way to find the source of scroll event, so that I can resolve this issue.
Any help would be greatly appreciated.
You can use element.scrollTop / (element.scrollHeight - element.offsetHeight) to get the percentage (it'll be a value between 0 and 1). So you can multiply the other element's (.scrollHeight - .offsetHeight) by this value for proportional scrolling.
To avoid triggering the listeners in a loop you could temporarily unbind the listener, set the scrollTop and rebind again.
var $divs = $('#div1, #div2');
var sync = function(e){
var $other = $divs.not(this).off('scroll'), other = $other.get(0);
var percentage = this.scrollTop / (this.scrollHeight - this.offsetHeight);
other.scrollTop = percentage * (other.scrollHeight - other.offsetHeight);
// Firefox workaround. Rebinding without delay isn't enough.
setTimeout( function(){ $other.on('scroll', sync ); },10);
}
$divs.on( 'scroll', sync);
http://jsfiddle.net/b75KZ/5/
Runs like clockwork (see DEMO)
$(document).ready(function(){
var master = "div1"; // this is id div
var slave = "div2"; // this is other id div
var master_tmp;
var slave_tmp;
var timer;
var sync = function ()
{
if($(this).attr('id') == slave)
{
master_tmp = master;
slave_tmp = slave;
master = slave;
slave = master_tmp;
}
$("#" + slave).unbind("scroll");
var percentage = this.scrollTop / (this.scrollHeight - this.offsetHeight);
var x = percentage * ($("#" + slave).get(0).scrollHeight - $("#" + slave).get(0).offsetHeight);
$("#" + slave).scrollTop(x);
if(typeof(timer) !== 'undefind')
clearTimeout(timer);
timer = setTimeout(function(){ $("#" + slave).scroll(sync) }, 200)
}
$('#' + master + ', #' + slave).scroll(sync);
});
This is what I'm using. Just call the syncScroll(...) function with the two elements you want to synchronize. I found pawel's solution had issues with continuing to slowly scroll after the mouse or trackpad was actually done with the operation.
See working example here.
// Sync up our elements.
syncScroll($('.scroll-elem-1'), $('.scroll-elem-2'));
/***
* Synchronize Scroll
* Synchronizes the vertical scrolling of two elements.
* The elements can have different content heights.
*
* #param $el1 {Object}
* Native DOM element or jQuery selector.
* First element to sync.
* #param $el2 {Object}
* Native DOM element or jQuery selector.
* Second element to sync.
*/
function syncScroll(el1, el2) {
var $el1 = $(el1);
var $el2 = $(el2);
// Lets us know when a scroll is organic
// or forced from the synced element.
var forcedScroll = false;
// Catch our elements' scroll events and
// syncronize the related element.
$el1.scroll(function() { performScroll($el1, $el2); });
$el2.scroll(function() { performScroll($el2, $el1); });
// Perform the scroll of the synced element
// based on the scrolled element.
function performScroll($scrolled, $toScroll) {
if (forcedScroll) return (forcedScroll = false);
var percent = ($scrolled.scrollTop() /
($scrolled[0].scrollHeight - $scrolled.outerHeight())) * 100;
setScrollTopFromPercent($toScroll, percent);
}
// Scroll to a position in the given
// element based on a percent.
function setScrollTopFromPercent($el, percent) {
var scrollTopPos = (percent / 100) *
($el[0].scrollHeight - $el.outerHeight());
forcedScroll = true;
$el.scrollTop(scrollTopPos);
}
}
If the divs are of equal sizes then this code below is a simple way to scroll them synchronously:
scroll_all_blocks: function(e) {
var scrollLeft = $(e.target)[0].scrollLeft;
var len = $('.scroll_class').length;
for (var i = 0; i < len; i++)
{
$('.scroll_class')[i].scrollLeft = scrollLeft;
}
}
Here im using horizontal scroll, but you can use scrollTop here instead. This function is call on scroll event on the div, so the e will have access to the event object.
Secondly, you can simply have the ratio of corresponding sizes of the divs calculated to apply in this line $('.scroll_class')[i].scrollLeft = scrollLeft;
I solved the sync scrolling loop problem by setting the scroll percentage to fixed-point notation: percent.toFixed(0), with 0 as the parameter. This prevents mismatched fractional scrolling heights between the two synced elements, which are constantly trying to "catch up" with each other. This code will let them catch up after at most a single extra step (i.e., the second element may continue to scroll an extra pixel after the user stops scrolling). Not a perfect solution or the most sophisticated, but certainly the simplest I could find.
var left = document.getElementById('left');
var right = document.getElementById('right');
var el2;
var percentage = function(el) { return (el.scrollTop / (el.scrollHeight - el.offsetHeight)) };
function syncScroll(el1) {
el1.getAttribute('id') === 'left' ? el2 = right : el2 = left;
el2.scrollTo( 0, (percentage(el1) * (el2.scrollHeight - el2.offsetHeight)).toFixed(0) ); // toFixed(0) prevents scrolling feedback loop
}
document.getElementById('left').addEventListener('scroll',function() {
syncScroll(this);
});
document.getElementById('right').addEventListener('scroll',function() {
syncScroll(this);
});
I like pawel's clean solution but it lacks something I need and has a strange scrolling bug where it continues to scroll and my plugin will work on multiple containers not just two.
http://www.xtf.dk/2015/12/jquery-plugin-synchronize-scroll.html
Example & demo: http://trunk.xtf.dk/Project/ScrollSync/
Plugin: http://trunk.xtf.dk/Project/ScrollSync/jquery.scrollSync.js
$('.scrollable').scrollSync();
If you don't want proportional scrolling, but rather to scroll an equal amount of pixels on each field, you could add the value of change to the current value of the field you're binding the scroll-event to.
Let's say that #left is the small field, and #right is the bigger field.
var oldRst = 0;
$('#right').on('scroll', function () {
l = $('#left');
var lst = l.scrollTop();
var rst = $(this).scrollTop();
l.scrollTop(lst+(rst-oldRst)); // <-- like this
oldRst = rst;
});
https://jsfiddle.net/vuvgc0a8/1/
By adding the value of change, and not just setting it equal to #right's scrollTop(), you can scroll up or down in the small field, regardless of its scrollTop() being less than the bigger field. An example of this is a user page on Facebook.
This is what I needed when I came here, so I thought I'd share.
From the pawel solution (first answer).
For the horizzontal synchronized scrolling using jQuery this is the solution:
var $divs = $('#div1, #div2'); //only 2 divs
var sync = function(e){
var $other = $divs.not(this).off('scroll');
var other = $other.get(0);
var percentage = this.scrollLeft / (this.scrollWidth - this.offsetWidth);
other.scrollLeft = percentage * (other.scrollWidth - other.offsetWidth);
setTimeout( function(){ $other.on('scroll', sync ); },10);
}
$divs.on('scroll', sync);
JSFiddle
An other solution for multiple horizontally synchronized divs is this, but it works for divs with same width.
var $divs = $('#div1, #div2, #div3'); //multiple divs
var sync = function (e) {
var me = $(this);
var $other = $divs.not(me).off('scroll');
$divs.not(me).each(function (index) {
$(this).scrollLeft(me.scrollLeft());
});
setTimeout(function () {
$other.on('scroll', sync);
}, 10);
}
$divs.on('scroll', sync);
NB: Only for divs with same width
JSFiddle
I have a scrolling div containing list items. I have this boilerplate scroll event defined
$("#scrollingDiv").scroll(function(e) {
});
Inside of this scroll event function, how can I figure out which elements are at the top and bottom of the currently visible area?
You could try computing the positions of the list items with respect to the scrolling <div> and then scan the positions to see which ones match up with the scrollTop of the <div>.
Something like this perhaps:
var base = $('#scrollingDiv').offset().top;
var offs = [ ];
$('li').each(function() {
var $this = $(this);
offs.push({
offset: $this.offset().top - base,
height: $this.height()
});
});
$("#scrollingDiv").scroll(function() {
var y = this.scrollTop;
for(var i = 0; i < offs.length; ++i) {
if(y < offs[i].offset
|| y > offs[i].offset + offs[i].height)
continue;
// Entry i is at the top so do things to it.
return;
}
});
Live version (open your console please): http://jsfiddle.net/ambiguous/yHH7C/
You'd probably want to play with the fuzziness of the if to get something that works sensibly (1px visible hardly makes an element the top one) but the basic idea should be clear enough. Mixing in the height of #scrollingDiv will let you see which <li> is at the bottom.
If you have a lot of list items, then a linear search might not be what you want but you should be able to solve that without too much effort.
We have code like:
<body>
<div class="blocks">some text here</div>
<div class="end"></div>
</body>
Text can fit in current browser visible part or not.
How to detect, does the block is in visible part of browser window?
I mean, if resoution is 1024x768 and .block height bigger than 768, then .end is invisible.
we should detect this on window.ready and also on browser window change.
if block is visible, then run some function.
Any help is appreciated.
Something like this:
$.fn.viewport = (function() {
var vp = function(el, opts){
this.el = $(el);
this.opts = opts;
this.bind(); // bind resize and scroll
this.change(); // init change
};
vp.prototype = {
bind: function(){
$(window).bind('resize scroll',
$.proxy(this.change, this));
},
change: function(e){
var p = this.el.position(),
o = this.el.offset(),
d = { w: this.el.width() +o.left, h: this.el.height()+o.top },
win = $(window),
winD = {w:win.width() + win.scrollLeft(), h:win.height()+win.scrollTop()};
if(d.w <= winD.w && d.h <= winD.h){
console.log('inview');
} else {
console.log('out of view');
this.opts.outOfView.call(this);
}
}
};
return function(opts){
return $(this).each(function(){
$(this).data('vp', new vp(this, opts));
});
};
})();
And use like this:
$('#el').viewport({
outOfView: function(){
alert('out of view');
}
});
First grab the window dimensions.
var windowSize = {width: $(window).width(), height: $(window).height() + $(window).scrollTop()};
Next grab the div position in relation to the document:
var position = $('.block').offset()
Then make your if's:
if(position.top > windowSize.height){ /* here we go */ }
You might want to also grab div dimensions in case there is a possibility it will be out of bounds on the top or left side.
You could make it into a function that returns a boolean value and then call it on the window.resize and document.ready events.
EDIT: Added scrollTop to account for scrolling.
As a quick answer you'll have to do some computation on load (psuedocode assumes jQuery).
Find the window height $(window).outerHeight(true)
Find the offset of the ".end" element $(".end").offset()
Find the scroll distance of the window $(window).scrollTop()
Calculate! It should roughly be:
if ((step1 + step3) > step2) {
//do stuff here
}
Note that that does not check if you are scrolled past the ".end" element. I didn't verify this one, so hopefully I'm not missing something big.
Get the offsetTop and offsetLeft attributes of the element
Get the width of the element in question
Get the width of screen
Do the relevant maths and see if the element is in the viewport or now.
in jQuery you can do something like
$("#element").attr("offsetTop")
EDIT:
Simple and Effective: http://jsfiddle.net/hPjbh/