I'm using the following pen by Bramus to animate(FadeInUp) divs when entering the viewport. However currently the div only starts fading in when the div is completely in the viewport. What I need is the flexibility to start the animation when a div is a certain pixels inside the viewport. For example it will start the animation FadeInUp when the div is 100 pixels in the viewport. How can I do this with the current code/pen I'm using (see code below)?
Is this also possible with percentages? F.e. when a div is 20% in viewport the animation starts?
Thanks.
jQuery(function($) {
// Function which adds the 'animated' class to any '.animatable' in view
var doAnimations = function() {
// Calc current offset and get all animatables
var offset = $(window).scrollTop() + $(window).height(),
$animatables = $('.animatable');
// Check all animatables and animate them if necessary
$animatables.each(function(i) {
var $animatable = $(this);
if (($animatable.offset().top + $animatable.height() - 20) < offset) {
$animatable.removeClass('animatable').addClass('animated');
}
});
};
// Hook doAnimations on scroll, and trigger a scroll
$(window).on('scroll', doAnimations);
$(window).trigger('scroll');
});
Offsetting is already foreseen in the code. Tweak the value of 20 in this line:
if (($animatable.offset().top + $animatable.height() - 20) < offset) {
You might also need to change the - sign to a + to suit your needs.
Related
The code:
http://codepen.io/anon/pen/EjrpMM
So, i'm working on an interesting problem. I am working with a 2000px HTML document, that has a modal placed ontop of it.
The width of the div lightbox is 80%, and it's sitting positioned fixed.
The goal is, when scrolling down the page, to control the width of the div based on the scroll position. At the bottom of the page, it's only a third in size.
I've had trouble figuring out the proper equation or formula for this, and was seeking help.
Currently, I've been trying to look at the window.pageYOffset, to add 2.5% to the div while increasing, and minus 2.5% when scrolling back up, to bring it back to it's 80% width.
However, something isn't working right. I was seeing if the community had any ideas to help solve the problem.
I'm not using any frameworks for this.
Here's my javascript:
var lightBox = document.getElementById('lightBox'),
count = 80,
num = window.pageYOffset;
document.addEventListener('scroll', function(e) {
var offset = window.pageYOffset;
num >= offset ? count += 2.5 : count -= 2.5;
num = offset;
lightBox.style.width = count + '%';
});
View the code here, in this codepen
http://codepen.io/anon/pen/EjrpMM
Thank you!
You just have to change
+= 2.5 and -=2.5 to += 0.7 and -= 0.7
When I checked your code I did this and it worked.
Scroll event fired once on scroll independently on how much you've scrolled. E.g. if you've scrolled 1px scrollbar, or scrolled 100px using mousewheel scroll event will be fired once.
So if you need stable results you will need to calculate your div width depending on scroll position (window.pageYOffset).
Check this codepen fork. I've assumed that in the end of page div width should be 50%.
Core part is:
var lightBox = document.getElementById('lightBox');
var upperBound = 80;
var lowerBound = 50;
var tickValue = (upperBound - lowerBound) / window.innerHeight;
document.addEventListener('scroll', function(e) {
var offset = window.pageYOffset;
var count = upperBound - offset * tickValue;
lightBox.style.width = count + '%';
});
Important note: for crossbrowser way to get innerHeight you can check this answer
This is a simple equation. Let f : scroll |-> f(scroll) be the function that gives you the width of your div. You want f(0) = 0.8, f(2000)= 1/3.
Let's say you want the progression to be linear so f(scroll) = a*scroll + b, you can easily deduce that b = 0.8 and a = (1/3 - 0.8)/2000 = -0.000233. Now for any scroll value, you can find the width of your div.
Now you can change the values when you want, f(scroll) = (minWidth-maxWidth)/pageLength * scroll + maxWidth.
Trying to accomplish something like on this website:
http://www.strangelove.nl/cases/kpmg-meijburg
The part where the responsive design is showcased, the image inside the devices start to scroll when a visitor scrolls past that point. I've tried to replicate it and I see a .js in the footer which is probably contributing. For now I have the css and html working on my test page.
Any help is gladly appreciated.
Strangelove is using their own Kubrick-js, which is available here: Kubrick-js
If you just want to have the 'images scrolling inside of frame while scrolling by'-effect, you can do it like this:
$(window).scroll(function() {
var animStart = 0, // the point where the animation starts
animEnd = 500, // the point, where the animation ends
scrollStartPos = 0, // the position your inside scrolling element starts
scrollEndPos = -300, // the position your inside scrolling element should end
winPosY = window.pageYOffset, // the scroll distance from top of document
scrollElement = $('.picture'); // the element to scroll
if(winPosY > animStart && winPosY < animEnd) {
// how far through the animation are we?
var howFar = (winPosY - animStart) / (animEnd - animStart),
scrollPos = Math.round(scrollStartPos + howFar * (scrollEndPos - scrollStartPos));
scrollElement.css('top', scrollPos + 'px');
$('.show-stats').html('How far: ' + howFar + '<br>scroll Position: ' + scrollPos);
}
});
Here is a fiddle for it: Fiddle
hope that helps.
I'm trying to get an div to animate 0% - 100% relative to the percentage scrolled of an element.
Now I've set up a few variables, but I'm having trouble trying to calculate the height of one by percentage.
We can set the starting width quite easily and detect the scroll easily enough too, as can we get the height of the element that'll trigger the animation, I just can't get it as a percentage.
If I can figure out how to return the percent of conheight scrolled then this should be easy.
$(window).scroll(function() {
// calculate the percentage the user has scrolled down the page
var scrollPercent = ($(window).scrollTop() / $(document).height()) * 100;
$('.bar-long').css('width', scrollPercent +"%" );
});
Here's a jsfiddle, http://jsfiddle.net/SnJXQ/
This is animating bar-long based on the percent scrolled of the body element.
Animates from 0% - 100% (well, it doesn't really, but I can't figure out why).
What I'd like to do is get scroll percent of the .post div, then animate bar-long relative to that.
ie. Scrolled 10% of .post, .bar-long is 10% width, scrolled 70% of .post, .bar-long is 70% width.
Demo
Your problem is the same as How to get horizontal scrolling percentage of an HTML element in JavaScript?, but vertically.
Then, to get the vertically scrolled percentage, use
/* JS */ var scrollPercentage = 100 * containeR.scrollTop / (containeR.scrollHeight-containeR.clientHeight);
/*jQuery*/ var scrollPercent = 100 * $(containeR).scrollTop() / ($(containeD).height() - $(containeR).height());
In your case, containeR = window; containeD = document:
var scrollPercent = 100 * $(window).scrollTop() / ($(document).height() - $(window).height());
Ok I see what you are trying to achieve....in fact I just did something very similar. Most solutions I found out there also were only for full page examples with window or document properties. Instead I needed this in a specific div which in my case was actually used to update the horizontal position of another div.
First, you are going to want the scroll event attached to your $('.post')
Next, the height of the $('.content') is going to equal your actual Scroll Height
Lastly, apply your percentage formula : (Y / (scrollHeight - postHeight)) * 100 = scrollPercent
So instead of using document or window attributes your code should be as follows:
$('.post').scroll(function() {
var currY = $(this).scrollTop();
var postHeight = $(this).height();
var scrollHeight = $('.content').height();
var scrollPercent = (currY / (scrollHeight - postHeight)) * 100;
});
You can find the fiddle here: JS Fiddle For Div Scroll Percentage
The current project where I have implemented this is located here: Vertical Scroll Drives Horizontal Position
I hope this solves your problem :)
Let's say you want to keep track of the scroll of some document found in some IFrame in your page.
object.addEventListener("scroll", documentEventListener, false);
Then your event listener should look like this:
function documentEventListener(){
var currentDocument = this;
var docsWindow = $(currentDocument.defaultView); // This is the window holding the document
var docsWindowHeight = docsWindow.height(); // The viewport of the wrapper window
var scrollTop = $(currentDocument).scrollTop(); // How much we scrolled already, in the viewport
var docHeight = $(currentDocument).height(); // This is the full document height.
var howMuchMoreWeCanScrollDown = docHeight - (docsWindowHeight + scrollTop);
var percentViewed = 100.0 * (1 - howMuchMoreWeCanScrollDown / docHeight);
console.log("More to scroll: "+howMuchMoreWeCanScrollDown+"pixels. Percent Viewed: "+percentViewed+"%");
}
I've been working on a scroll to top function for my website, and that part of it works fine. My problem is however that I have a fixed div that is overlapping my footer when it hits the bottom of the page.
Here is the function that I have working.
$(document).scroll(function (e) {
if (document.body.scrollTop >= 800) {
$('#beamUp').show(1000);
} else {
$('#beamUp').hide(1000);
return false;
}
});
Is there somehow I could detect when I hit that part of the page and stop the div from moving past that.Help is much appreciated!
jsFiddle: http://jsfiddle.net/zazvorniki/RTDpw/
Just get the height of the page, minus the height of the div in question, as well as the footer... make sure the top is never greater than that value... you'll also need an onresize event handler re-evaluate that value.
looking at your jsfiddle... here are my edits
In your scroll listener, I am checking for the position of the page, and adjusting the bottom position of the floater appropriately. I also set the initial display:none, so you don't need to call .hide() in your initial script. In addition, resizing the window has the effect of scrolling for your use, so I changed the listener for both events.
$(document).on('scroll resize', function (e) {
var viewHeight = $(window).height();
var viewTop = $(window).scrollTop();
var footerTop = $("footer").offset().top;
var baseline = (viewHeight + viewTop) - footerTop;
var bu = $("#beamUp").css({bottom: (baseline < 0 ? 0 : baseline) + 'px'});
if (viewTop >= 50) {
bu.show(1000);
} else {
bu.hide(1000);
}
});
I have an HTML document with images in a grid format using <ul><li><img.... The browser window has both vertical & horizontal scrolling.
Question:
When I click on an image <img>, how then do I get the whole document to scroll to a position where the image I just clicked on is top:20px; left:20px ?
I've had a browse on here for similar posts...although I'm quite new to JavaScript, and want to understand how this is achieved for myself.
There's a DOM method called scrollIntoView, which is supported by all major browsers, that will align an element with the top/left of the viewport (or as close as possible).
$("#myImage")[0].scrollIntoView();
On supported browsers, you can provide options:
$("#myImage")[0].scrollIntoView({
behavior: "smooth", // or "auto" or "instant"
block: "start" // or "end"
});
Alternatively, if all the elements have unique IDs, you can just change the hash property of the location object for back/forward button support:
$(document).delegate("img", function (e) {
if (e.target.id)
window.location.hash = e.target.id;
});
After that, just adjust the scrollTop/scrollLeft properties by -20:
document.body.scrollLeft -= 20;
document.body.scrollTop -= 20;
Since you want to know how it works, I'll explain it step-by-step.
First you want to bind a function as the image's click handler:
$('#someImage').click(function () {
// Code to do scrolling happens here
});
That will apply the click handler to an image with id="someImage". If you want to do this to all images, replace '#someImage' with 'img'.
Now for the actual scrolling code:
Get the image offsets (relative to the document):
var offset = $(this).offset(); // Contains .top and .left
Subtract 20 from top and left:
offset.left -= 20;
offset.top -= 20;
Now animate the scroll-top and scroll-left CSS properties of <body> and <html>:
$('html, body').animate({
scrollTop: offset.top,
scrollLeft: offset.left
});
Simplest solution I have seen
var offset = $("#target-element").offset();
$('html, body').animate({
scrollTop: offset.top,
scrollLeft: offset.left
}, 1000);
Tutorial Here
There are methods to scroll element directly into the view, but if you want to scroll to a point relative from an element, you have to do it manually:
Inside the click handler, get the position of the element relative to the document, subtract 20 and use window.scrollTo:
var pos = $(this).offset();
var top = pos.top - 20;
var left = pos.left - 20;
window.scrollTo((left < 0 ? 0 : left), (top < 0 ? 0 : top));
Have a look at the jQuery.scrollTo plugin. Here's a demo.
This plugin has a lot of options that go beyond what native scrollIntoView offers you. For instance, you can set the scrolling to be smooth, and then set a callback for when the scrolling finishes.
You can also have a look at all the JQuery plugins tagged with "scroll".
Here's a quick jQuery plugin to map the built in browser functionality nicely:
$.fn.ensureVisible = function () { $(this).each(function () { $(this)[0].scrollIntoView(); }); };
...
$('.my-elements').ensureVisible();
After trial and error I came up with this function, works with iframe too.
function bringElIntoView(el) {
var elOffset = el.offset();
var $window = $(window);
var windowScrollBottom = $window.scrollTop() + $window.height();
var scrollToPos = -1;
if (elOffset.top < $window.scrollTop()) // element is hidden in the top
scrollToPos = elOffset.top;
else if (elOffset.top + el.height() > windowScrollBottom) // element is hidden in the bottom
scrollToPos = $window.scrollTop() + (elOffset.top + el.height() - windowScrollBottom);
if (scrollToPos !== -1)
$('html, body').animate({ scrollTop: scrollToPos });
}
My UI has a vertical scrolling list of thumbs within a thumbbar
The goal was to make the current thumb right in the center of the thumbbar.
I started from the approved answer, but found that there were a few tweaks to truly center the current thumb. hope this helps someone else.
markup:
<ul id='thumbbar'>
<li id='thumbbar-123'></li>
<li id='thumbbar-124'></li>
<li id='thumbbar-125'></li>
</ul>
jquery:
// scroll the current thumb bar thumb into view
heightbar = $('#thumbbar').height();
heightthumb = $('#thumbbar-' + pageid).height();
offsetbar = $('#thumbbar').scrollTop();
$('#thumbbar').animate({
scrollTop: offsetthumb.top - heightbar / 2 - offsetbar - 20
});
Just a tip. Works on firefox only
Element.scrollIntoView();
Simple 2 steps for scrolling down to end or bottom.
Step1: get the full height of scrollable(conversation) div.
Step2: apply scrollTop on that scrollable(conversation) div using the value
obtained in step1.
var fullHeight = $('#conversation')[0].scrollHeight;
$('#conversation').scrollTop(fullHeight);
Above steps must be applied for every append on the conversation div.
After trying to find a solution that handled every circumstance (options for animating the scroll, padding around the object once it scrolls into view, works even in obscure circumstances such as in an iframe), I finally ended up writing my own solution to this. Since it seems to work when many other solutions failed, I thought I'd share it:
function scrollIntoViewIfNeeded($target, options) {
var options = options ? options : {},
$win = $($target[0].ownerDocument.defaultView), //get the window object of the $target, don't use "window" because the element could possibly be in a different iframe than the one calling the function
$container = options.$container ? options.$container : $win,
padding = options.padding ? options.padding : 20,
elemTop = $target.offset().top,
elemHeight = $target.outerHeight(),
containerTop = $container.scrollTop(),
//Everything past this point is used only to get the container's visible height, which is needed to do this accurately
containerHeight = $container.outerHeight(),
winTop = $win.scrollTop(),
winBot = winTop + $win.height(),
containerVisibleTop = containerTop < winTop ? winTop : containerTop,
containerVisibleBottom = containerTop + containerHeight > winBot ? winBot : containerTop + containerHeight,
containerVisibleHeight = containerVisibleBottom - containerVisibleTop;
if (elemTop < containerTop) {
//scroll up
if (options.instant) {
$container.scrollTop(elemTop - padding);
} else {
$container.animate({scrollTop: elemTop - padding}, options.animationOptions);
}
} else if (elemTop + elemHeight > containerTop + containerVisibleHeight) {
//scroll down
if (options.instant) {
$container.scrollTop(elemTop + elemHeight - containerVisibleHeight + padding);
} else {
$container.animate({scrollTop: elemTop + elemHeight - containerVisibleHeight + padding}, options.animationOptions);
}
}
}
$target is a jQuery object containing the object you wish to scroll into view if needed.
options (optional) can contain the following options passed in an object:
options.$container - a jQuery object pointing to the containing element of $target (in other words, the element in the dom with the scrollbars). Defaults to the window that contains the $target element and is smart enough to select an iframe window. Remember to include the $ in the property name.
options.padding - the padding in pixels to add above or below the object when it is scrolled into view. This way it is not right against the edge of the window. Defaults to 20.
options.instant - if set to true, jQuery animate will not be used and the scroll will instantly pop to the correct location. Defaults to false.
options.animationOptions - any jQuery options you wish to pass to the jQuery animate function (see http://api.jquery.com/animate/). With this, you can change the duration of the animation or have a callback function executed when the scrolling is complete. This only works if options.instant is set to false. If you need to have an instant animation but with a callback, set options.animationOptions.duration = 0 instead of using options.instant = true.