We Keep Coding

How do I animate things on scroll?

This theme demo on themeforest has neat animations including for example showing text when the users scrolls down, or making icons appear from the sides.
I'm guessing CSS3 and JavaScript, possibly with jQuery or a framework specialized in animations would be used for this, but I have no idea where to start learning how to accomplish these kinds of animations.
Where do I start?

Checkout WowJS.
And try going through their source code if you're curious about it works under the hood.
Otherwise its a pretty good library to get started with scroll animations.

Basically animations that are triggered by scrolling actions are Javascript / jQuery stuff (not CSS). There's a nice JS plugin which you can take a look at which helps to do all that: Scrollmagic, to be found here

If you are using Wordpress, chances are you can buy a theme that includes very nice animations ready for use with a few options (say how fast it should occur or such) - similarly there are many neat animations on codepen and similar sites so maybe if you search long enough you could find and copy what you want.
However, if you really want to learn how to do that yourself, there's no short cuts and you have to start with understanding JavaScript and the capabilities of CSS3 animations and deeply, so you know which can do what.
CSS Transitions, CSS Animations, Simple JS animations
These are all w3school tutorials but there are many other resources out there. Start with something simple and work your way up.
Since you mentioned the behavior on scroll, the relevant JavaScript is
object.addEventListener("scroll", myScript);
Here's a simple use case to start.

Well there are lots of ways to do it, but jQuery works nicely.
You may find this and this helpful.
$(window).scroll(function () {
if($('body').scrollTop() > 110) {
$('.box').css({
'width': '50px',
'height': '50px',
'background': 'coral'
});
} else {
$('.box').css({
'width': '100px',
'height': '100px',
'background': 'red'
});
}
});
body {
padding-top: 175px;
background: whitesmoke;
height: 600px;
}
.box {
margin-top: 150px;
background: red;
width: 100px;
height: 100px;
margin: 0 auto;
transition: all .6s ease;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="box">
</div>

Standardize image into div

I'm working with Bootstrap and I want to put some photos into my div and I want them to be all at the same size ("standardize").
If they're too big (and they will always be) I want to resize them to fit in my div and crop them if necessary.
For the moment her is what I do :
I've tried to change the style of the image in jQuery in a function:
• If the height is bigger than the width, I switch the style to max-width:100% and height auto.
• Inversement if the width is bigger than the height.
But I'm still new to jQuery and I am probably doing something wrong; can someone light my lantern please?
Here is my jQuery
$(document).ready(function(){
photoResize();
$(window).resize(function(){
photoResize();
});
});
function photoResize(){
image_w = $('img').width();
image_h = $('img').height();
if(image_h > image_w)
{
$('img').css("max-width","100%");
$('img').height("auto");
}
else if(image_w > image_h)
{
$('img').css("max-height","100%");
$('img').width("auto");
}
}
And here is a Fiddle for a better view : https://jsfiddle.net/Baldrani/DTcHh/9801/

Simplicity
I do this quite often in the CMS we use at work for galleries etc. The method I use involves a jQuery library called imgLiquid.js.
This will turn an inline image into a background image on the parent div. It's good because you can achieve your desired effect. It will crop the image (as it technically becomes a background image) and will apply background-size: cover; and background-position: center center; as inline styles.
You can find the plugin here
To initialize the plugin you just need:
$(".myele").imgLiquid();
Overheads
The plugin is very small (roughly around 5.106 KB) so you don't need to worry about adding weight to the page. It really it the most simple method I've come across (bar using thumbnails generated from the sever-side - see note at the bottom).
Cue CSS
I've tested this thoroughly and found it gives excellent results. You may then ask... what happens to my parent divs (as technically the plugin hides the img element - which therefore means the parent element doesn't know what height to make itself).
An easy method to make things work responsively, or not:
.myelement:before{
content: "";
padding-top: 50%;
display: block;
}
This CSS will give your heights back to the wrapping element. So if you wanted certain proportions you could use this math:
h / w * 100 = your percentage for the padding-top.
Working Example
Small note
Technically if I had the control I'd advise just using thumbnails.. I assume you're using some sort of system that could technically just render cut down versions of the images? The reason I use this method — and suggested it — is that I don't have control over the CMS and I'm assuming you just want to manage the code that's being produced as it's not stated.

if you want to make your images the same size then you dont need any javascript or calculations, why not just set it in css?
.someUniqueContainer img{
width:300px;
height:300px; // or what ever height you want
}
I'm guessing that in reality you actually want to crop all your images to a set width/height. if that's the case you'll need a serverside script for that.
where are the images coming from? it would be easyer to just edit them. if they are coming from a user then you would resize/crop on the server on file upload

There were several mistakes in your code.
Please look at this jsfiddle, please see https://jsfiddle.net/DTcHh/9796/
$(document).ready(function () {
photoResize();
$(window).resize(function () {
photoResize();
});
});
function photoResize() {
image_w = $('img').width();
image_h = $('img').height();
if (image_h > image_w) {
$('img').css("max-width", "100%");
$('img').height("auto");
} else if (image_w > image_h) {
$('img').css("max-height", "100%");
$('img').width("auto");
}
}

sth like this?, although this is pure css, not jquery included, might not be suit in your case..
body {
margin-top:20px
}
.col-xs-3 {
margin: 5px 0;
width: 500px;
height:120px
}
.col-xs-3 > div {
width: 100%;
height: 120px;
background-repeat: no-repeat;
background-position: center;
background-size: cover;
}
JsFiddle

scrollr.js animation happens on element only with position fixed

Hey guys i am new to Jquery and i was trying integrating the scrollr.js plugin in my website and came across the a difficulty , i have the following HTML :
<div data-0="background-color:rgb(0,0,255);transform:rotate(0deg);" data-500="background-color:rgb(255,0,0);transform:rotate(360deg);" class="block"></div>
and the following CSS :
.block {
height: 200px;
width: 200px;
position: relative;
}
Fiddle here.
now with the above CSS , the animations don;t work , scrollr.js does't work , but when i apply the following CSS :
.block {
height: 200px;
width: 200px;
position: fixed;
top:20px;
}
The animations and everything works fine .
fiddle here.
i don't always want the position on my element to be fixed . how do i get the animations to work, without taking out the element from the normal flow of the document ??
I saw this demo on scrollr.js .
But still can't get why my example does't work. , If somebody could explain why my example is not working . it would be of great help .
Thanks .
Alexander.

Your first animation does work. You probably don't see it because it starts animating as soon as you start scrolling and when you scroll to the image, animation is already done. Try making your screen height bigger, or remove some text at the beginning.
If you want animation to start when the item actually appears on the screen, take a look at documentation.
Try to change data-0 to data-bottom-top and data-500 to data-center.

Change div height onclick with animation

I'm trying to make a gallery using divs that change their height when you click on them. Ideally, this would include animation to smoothly expand the div's height. There will be several of each div on each page, so it needs to just expand that section.
It's actually supposed to turn out something like the news section on this page: http://runescape.com/
I'd like to do it with JavaScript/jQuery if possible.

$('div').click(function(){
$(this).animate({height:'300'})
})
Check working example at http://jsfiddle.net/tJugd/

Here's the code I ended up using:
JS:
document.getElementById("box").addEventListener("click", function() {
this.classList.toggle("is-active");
});
CSS:
#box {
background: red;
height: 100px;
transition: height 300ms;
width: 100px;
}
#box.is-active {
height: 300px;
}
HTML:
<div id="box"></div>
Fiddle:
https://jsfiddle.net/cp7uf8fg/

try
$('div').toggle(function(){
$(this).animate({'height': '100px'}, 100);
}, function(){
$(this).animate({'height': '80px'}, 100);
});
DEMO

jQuery rules. Check this out.
http://api.jquery.com/resize/

The complete solution:
Both spacer DIV and Margin or Padding on content DIV works but best to still have a spacer DIV.
Responsive design can be then applied to it in your CSS file.
This is mutch better as with JAVA the screen would flicker!
If you use a grid system there will be a media query part there you need to include your settings.
I use a little spacer on HD screen while its increasing till mobile screen!
Still if you have breadcrumb in header multiple lines can be tricky, so best to have a java but deferred for speed resons.
Note that animation is for getting rid of flickering of screen.
This java then would only fire if breadcrumb is very long otherwise single CSS applied via the grid and no flickering at all.
Even if java fired its doing its work via an elegant animation
var header_height = $('#fixed_header_div').height();
var spacer_height = $('#header_spacer').height() + 5;
if (header_height > spacer_height) {
$('#header_spacer').animate({height:header_height});
};
Note that I have applied a 5px tolerance margin!
Ho this helps :-)

I know this is old, but if anyone seems to find their way here. #JacobTheDev answer is great and has no jQuery! I have added a little more for use cases where the event is not being assigned at the same point your toggling the css class.
HTML
<div id='item' onclick='handleToggle()'> </div>
JS
handleToggle(event){
document.getElementById(event.target.id).classList.toggle('active')
}
CSS
#item {
height: 20px;
transition: 1s;
}
.active {
height: 100px;
}

jQuery code for sliding div (accordion)

I am looking for some good jQuery, XHTML & CSS code to achieve the effect as seen in the following image:
http://i48.tinypic.com/a3o4sn.jpg
Obviously this is a static image, what is supposed to happen is the text and the transparent background is hidden, and when you put your mouse over the image it slides up into view and down again onmouseout.
I think this is an accordion, can anyone point me in the right direction (or maybe you've seen another site that does this)?

Your may be interested in this great resource: Sliding Boxes and captions
DEMO

I've recently used a jquery plugin that does something quite similar.
You may find the plugin does all you need, or look at the source to see how the slide-in effect is achieved (although, of course, there's more than one way to do just about anything).
The plug-in is called Showcase
Its home page has more info and demo and tutorials
Finally, as an added demo, here's the site where I used it.
HTH

My approach to this effect is to have a div with overflow: hidden and the transparent black div with a top margin that puts it "outside" the container." Using .hover() you can tell the black div to slide up when the mouse is over the container div, and to slide away again when the mouse leaves.
Markup:
<div id='container'>
<div id='slider'>Some Text</div>
</div>
Styles:
div#container {
height: 100px;
width: 100px;
overflow: hidden;
}
div#slider {
width: 100px;
height: 40px;
margin-top: 100px;
background: black;
}
And your script:
$('#container').hover (
function () {
$('#slider').css('margin-top', '60px'),
$('#slider').css('margin-top', '100px');
);
I forget if you have to put the 60px in quotes or not, or if you have to pass 60 as an int, play around with it, but hopefully this gets you started.