Develop Reference

Scale div inside another div with overflow scroll and center

I'm coding a very tiny small feature, but I'm having problems with the scroll. I need to do a zoom of a div scaling with css:
transform: scale(X,Y)
But my problem is that I don't have a correct left and top scroll in the parent div. I need to know how to calculate the new left and top each time the user press the button "More zoom", I could use translate css property if it is mandatory.
I can use jQuery, but I think this is just a math problem :)
One detail: I need that the image grow from the center.
Picture:
Here is the fiddle:
Fiddle example

i believe you need to mind transform-origin too:
// get element references
var foo = document.querySelector('#foo');
var bar = document.querySelector('#bar');
// fit bar into foo
// the third options argument is optional, see the README for defaults
// https://github.com/soulwire/fit.js
var zoom = 1;
var trans = 50;
var moreZoom = document.querySelector('#moreZoom');
moreZoom.onclick = function(e){
console.log(foo);
bar.style.transform = 'scale(' + (zoom + 0.1) + ',' + (zoom + 0.1) + ')';
zoom = (zoom + 0.1);
bar.style.transformOrigin = (50 / zoom) +'px ' +(50 / zoom )+'px';
}
#foo {
background: #36D7B7;
height: 200px;
width: 400px;
padding: 50px;
overflow: auto;
}
#bar {
background-image: url('http://www.space.com/images/i/000/028/001/original/wing-small-magellanic-cloud-galaxy-1920.jpg?interpolation=lanczos-none&fit=around%7C1440:900&crop=1440:900;*,*');
background-size:cover;
height: 100%;
transform:scale(1);
width: 100%;
}
<script src="https://rawgithub.com/soulwire/fit.js/master/fit.js"></script>
<button id="moreZoom">
More Zoom
</button>
<div id="foo">
<div
http://jsfiddle.net/as20h6t4/5/

slide image from left to right and reverse back again

I am trying to slide image from left to right and after a set point it should again slide in reverse direction. This is my code somehow its not working as i am going wrong somewhere in the if statement.
(function($) {
var x = 0;
var y = 0;
//cache a reference to the banner
var banner = $("#banner");
// set initial banner background position
banner.css('backgroundPosition', x + 'px' + ' ' + y + 'px');
// scroll up background position every 90 milliseconds
window.setInterval(function() {
banner.css("backgroundPosition", x + 'px' + ' ' + y + 'px');
x++;
//x--;
//if you need to scroll image horizontally -
// uncomment x and comment y
}, 90);
if ($(banner.offset().left > 40) {
banner.css("backgroundPosition", "0px 0px ");
}
})(jQuery);
div#banner {
width: 960px;
height: 200px;
margin: auto;
background: url(http://cdn-careers.sstatic.net/careers/gethired/img/companypageadfallback-leaderboard-2.png?v=59b591051ad7) no-repeat 0 0;
}
div#banner p {
font: 15px Arial, Helvetica, sans-serif;
color: white;
position: relative;
left: 20px;
top: 120px;
width: 305px;
padding: 20px;
background: black;
text-align: center;
text-transform: uppercase;
letter-spacing: 20px;
zoom: 1;
filter: alpha(opacity=50);
opacity: 0.5;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="banner"></div>

Firstly, you are using a IIFE (Immediately Invoked Function Expression) instead of a DOM ready handler. This code will only work if placed after the elements it references.
Use this shortcut for DOM ready that also provides a locally scoped $
jQuery(function ($) {...});
You also have a missing closing paren (or really a redundant $( as it is already a jQuery object):
JSFiddle: http://jsfiddle.net/g0gn4osy/7/
You also need to have a delta value that changes the direction when you hit a bound value. I sped up your timing to show this:
jQuery(function ($) {
var delta = 1;
var y = 0;
//cache a reference to the banner
var $banner = $("#banner");
// set initial banner background position
$banner.css('background-position', '0px' + ' ' + y + 'px');
// scroll up background position every 90 milliseconds
window.setInterval(function () {
var position = parseInt($banner.css('background-position'));
if (position >= 40 || position < 0) {
delta = -delta;
}
position += delta;
$banner.css("background-position", position + 'px' + ' ' + y + 'px');
}, 10);
});
Notes:
You also had backgroundPosition instead of background-position for the CSS property. I prefer to use the values that match the css properties (personal choice only for maintenance).
To avoid the redundant $() issue, I recommend you prefix jQuery variables with $. e.g. $banner in this case. Then it becomes obvious you are dealing with a jQuery object.
I tend to use the current position of an element, rather than keep a global var running. This allows for external influences to change the position and still work. Have removed x and just use position.

Inspired and modelled on Gone Coding's answer.
I have expanded his example to take into account the image width and the view pane DIV width.
It now scrolls to image end and then back. You never scroll off the canvas or past a visible part of the image. It doesn't jerk or rock, just switches direction.
With awareness of the viewing box width you can easily adjust the width of div#banner to fit the display space and the code adjusts. Just remember to set the background image width imgW var.
I have also added:
Visual indicator for testing with a current position and scroll direction. (With -1 is scrolling left, +1 is scrolling right),
Image start position in px. (A minus number or Zero. With 0 is start image at left, Minus number is start image part way through i.e image pre-scrolled left)
Image start vertical position in px (to vertically pull image up/down. Useful if view pane height shorter than image height and you want to tweak what is seen)
Things to do:
Change image URL (background: url(IMAGENAMEHERE) no-repeat 0 0;)
Insert image width (var imgW = #PIXELWIDTH#;)
Play with WIDTH: and HEIGHT: of view pane (div#banner)
Enjoy.
Fiddle
Have a play http://jsfiddle.net/Lm5yk46h/
Image credit Mark Higgins | Dreamstime.com Image source for purchase
Javascript
jQuery(function ($) {
var delta = 1;
var imgW = 3000;//width of image px
var imgY = 0;//to shift image view vertically px (Minus or zero)
//cache ref to #banner
var $banner = $("#banner");
var viewpaneW = $banner.width();
var endpos = (imgW - viewpaneW);
var startpos = 0;//0 or negative number
// set initial banner background position
$banner.css('background-position', startpos + 'px' + ' ' + imgY + 'px');
// scroll background position every 20ms
window.setInterval(function () {
var position = parseInt($banner.css('background-position'));
// minus is left, plus is right
if (position >= 0 ) delta = -delta;//go left
if (position < (-1*endpos)) delta = (-1*delta);//go right
position += delta;//increment posn
$banner.css("background-position", position + 'px' + ' ' + imgY + 'px');
$("#indicator").text('Posn:' + position + ' | direction: ' + delta);
}, 20);
});
CSS
div#canvas {
background-color: #999;
width: 100%;
height: 400px;
margin:0;padding:10px;
}
div#banner {
width: 460px;
height: 300px;
margin: 10px;
background: url(https://digido.net/eg/newcastle-beach-3000x300.jpg) no-repeat 0 0;
}
div#banner p {
font: 13px Arial, Helvetica, sans-serif;
color: white;
position: relative;
left: 0;
top: 310px;
width: 99%;
padding: 10px;
background: black;
text-align: center;
text-transform: uppercase;
letter-spacing: 8px;
zoom: 1;
filter: alpha(opacity=50);
opacity: 0.5;
}
HTML
<div id="canvas">
<div id="banner">
<p id="indicator">Hit run</p>
</div>
</div>

Just put the if condition inside the setInterval. And check the syntax error. The if doesn't have a closing }:
// scroll up background position every 90 milliseconds
window.setInterval(function() {
banner.css("backgroundPosition", x + 'px' + ' ' + y + 'px');
x++;
//x--;
if (banner.offset().left > 40) {
banner.css("backgroundPosition", "0px 0px ");
}
}, 90);

Your "if" should be like this:
if ($(banner).offset().left > 40) {
banner.css("backgroundPosition", "0px 0px ");
}
https://jsfiddle.net/wc4b2g97/

your if should be inserted inside your setInterval handler, so it would get evaluated every 90 milliseconds (thank you for correcting me).
Actually, your if is evaluted only the first time, when your javascript file is parse.
Add it into your setInterval and it should work as expected

Animate div when the scrollbar reaches certain position

My website at the moment has three sections in a single scroll layout. With a Heading for two sections: About & Contact (these are div boxes) that animate when you scroll to the bottom of the page. What I'm trying to achieve is having the animation take place when the user scrolls down and hits the bottom of each (div box) section as opposed to the bottom of the website.
I believe I need to implement the .offset() function but unsure if that is correct?
Any help would be greatly appreciated.
CSS
.header {
display: none;
position: relative;
left: 0px;
right: 0px;
top: 500px;
height: 80px;
width: 100%;
background:red;
color: #fff;
text-align: center;
}
JS
var header = $('.header'),
extra = 10; // In case you want to trigger it a bit sooner than exactly at the bottom.
header.css({ opacity: '0', display: 'block' });
$(window).scroll(function() {
var scrolledLength = ( $(window).height() +extra) + $(window).scrollTop(),
documentHeight = $(document).height();
console.log( 'Scroll length: ' + scrolledLength + ' Document height: ' + documentHeight )
if( scrolledLength >= documentHeight ) {
header
.addClass('top')
.stop().animate({ top: '20', opacity: '1' }, 800);
}
else if ( scrolledLength <= documentHeight && header.hasClass('top') ) {
header
.removeClass('top')
.stop().animate({ top: '500', opacity: '0' }, 800);
}
});
Fiddle - http://jsfiddle.net/SFPpf/480/

Looks like position() would be better in this case. The position method is relative to the document whereas offset is relative to the parent element. It returns an object with the properties "top" and "left". It can only return the position of one element at a time, so for the first div, you would need to use first() and eq() to get a specific one.
The bottom of a .fillWindow will be its vertical position + its height.
var $fillWindow = $(".fillWindow").first(), // or eq() for others
position = $fillWindow.position(),
height = $fillWindow.height();
//bottom = position.top + height;
scrollTop() can now be used to check when the user scrolls past the .fillWindow.
if ( $(window).scrollTop() >= position.top ) {
// do the animation here
} else {
// do something else
}
Edit: I just caught my mistake. It should be $(window).scrollTop(). You should also just test for scrollTop being at the top of the .fillWindow.

How to correctly resize an element by dragging?

I have two divs serving as two panels one to the left and one to the right.
They take 70% and 30% of the area.
I have a separator between them.
When I drag the separator to the left or right, I want that to remain as the position of the separator. i.e., I should be able to dynamically resize the left and right divs by dragging.
Here is the code I have:
http://jsbin.com/witicozi/1/edit
HTML:
<!DOCTYPE html>
<html>
<head>
<body>
<div style='height: 100px'>
<div id='left'>...</div>
<div id='separator'></div>
<div id='right'>...</div>
</div>
</body>
</html>
CSS:
#left {
float: left;
width: 70%;
height: 100%;
overflow: auto;
}
#separator {
float: left;
width: 3px;
height: 100%;
background-color: gray;
cursor: col-resize;
}
#right {
height: 100%;
overflow: auto;
}
JavaScript:
document.querySelector('#separator').addEventListener('drag', function (event) {
var newX = event.clientX;
var totalWidth = document.querySelector('#left').offsetWidth;
document.querySelector('#left').style.width = ((newX / totalWidth) * 100) + '%';
});
The problems:
The resizing happens, but the separator jumps around randomly. It even falls down many times. I have no idea what's happening.
The mouse cursor changes to a hand when the dragging begins. I want it to remain a col-resize.
It is very hard to drag.
No JQuery please.

If you use console.log(event), it shows that event.clientX doesn't return exactly what you are looking for. The following JavaScript worked for me in chrome.
document.getElementById('separator').addEventListener('drag', function(event) {
var left = document.getElementById('left');
var newX = event.offsetX + left.offsetWidth;
left.style.width = newX + 'px';
});
The event.offsetX value that it is returning is the location (in px) of the upper left hand corner of the left div. This will give you the same result but using percentages so that when the resize the window the columns adjust:
document.getElementById('separator').addEventListener('drag', function(event) {
var left = document.getElementById('left');
var newX = event.offsetX + left.offsetWidth;
left.style.width = (newX / window.innerWidth * 100) + '%';
});

Taking a bit of a different approach: rather than using the drag and drop functionality, I used some coupled mouse down and mouse up listeners. This has better cross-browser compatibility (at least as far as my testing goes) and it has the added benefit of being able to easily control the cursor.
var resize = function(event) {
var newX = event.clientX;
document.getElementById('left').style.width = (newX / window.innerWidth * 100) + '%';
};
document.getElementById('separator').addEventListener('mousedown', function(event) {
document.addEventListener('mousemove', resize);
document.body.style.cursor = 'col-resize';
});
document.addEventListener('mouseup', function(event) {
document.removeEventListener('mousemove', resize);
document.body.style.cursor = '';
});

Sticky Footer and Animation

I found this jsfiddle here at stackoverflow, but the solution provided by the person is very jumpy. http://jsfiddle.net/BramVanroy/ZVzEe/ I need something very smooth.
var secondary = $("#secondary-footer");
secondary.hide().addClass("fixed").fadeIn("fast");
$(window).scroll(function() {
if (secondary.offset().top >= ($(document).height() - 350)) {
secondary.removeClass("fixed");
}
else if(secondary + ":not('.fixed')") {
secondary.addClass("fixed");
}
});
How I need the sticky footer to work is for it to show the footer as a narrow bar at the bottom of the page while still scrolling through the content. Once the bottom of the page is reached with the scrollbar, the footer will expand in height.
The jsfiddle provided is very close to how I need this to work, but I need something very smooth. And another note, the height of the fully expanded footer is not fixed. Thanks to everyone for your help.

demo
jQuery
var secondary = $("#secondary-footer");
secondary.hide().addClass("fixed").fadeIn("fast");
$(window).scroll(function() {
var scrollBottom = $(window).scrollTop() + $(window).height();
$("#content").css("bottom",secondary.height());
var maxHeight = 350; // set maximum height of the footer here
var minHeight = 120; // set the minimum height of the footer here
secondary.height(maxHeight - ($(document).height() - scrollBottom));
if (secondary.height() <= minHeight) secondary.height(minHeight);
});
CSS
#content {
width: 90%;
margin: 0 auto;
padding: 0.5em;
background: #dedede;
position:relative; /* added this */
}
#secondary-footer {
width: 100%;
height: 120px;
background: #666;
position: fixed;
bottom: 0;
left: 0;
}
/* removed #secondary-footer.fixed and merged content with #secondary-footer */

Another solution: http://jsfiddle.net/27rNu/
jQuery
$(document).ready(function() {
var secondary = $("#secondary-footer");
secondary.addClass("fixed");
var windowH = $('#wrapper').outerHeight(true);
$(window).scroll(function() {
var scrollVal = $(this).scrollTop();
if (scrollVal < (windowH - 350 * 2)) {
secondary.addClass("fixed");
}
else {
secondary.removeClass("fixed");
}
});
});
I also added a "wrapper" div around the whole html.