Cross browser div center alignment using CSS - javascript

What is the easiest way to align a div whose position is relative horizontally and vertically using CSS ? The width and the height of the div is unknown, i.e. it should work for every div dimension and in all major browsers. I mean center alignment.
I thought to make the horizontal alignment using:
margin-left: auto;
margin-right: auto;
like I did here.
Is this a good cross browser solution for horizontal alignment ?
How could I do the vertical alignment ?

Horizontal centering is only possible if the element's width is known, else the browser cannot figure where to start and end.
#content {
width: 300px;
margin: 0 auto;
}
This is perfectly crossbrowser compatible.
Vertical centering is only possible if the element is positioned absolutely and has a known height. The absolute positioning would however break margin: 0 auto; so you need to approach this differently. You need to set its top and left to 50% and the margin-top and margin-left to the negative half of its width and height respectively.
Here's a copy'n'paste'n'runnable example:
<!doctype html>
<html lang="en">
<head>
<title>SO question 2935404</title>
</head>
<style>
#content {
position: absolute;
width: 300px;
height: 200px;
top: 50%;
left: 50%;
margin-left: -150px; /* Negative half of width. */
margin-top: -100px; /* Negative half of height. */
border: 1px solid #000;
}
</style>
<body>
<div id="content">
content
</div>
</body>
</html>
That said, vertical centering is usually seldom applied in real world.
If the width and height are really unknown beforehand, then you'll need to grab Javascript/jQuery to set the margin-left and margin-top values and live with the fact that client will see the div quickly be shifted during page load, which might cause a "wtf?" experience.

"Vertical centering is only possible if the element is positioned absolutely and has a known height." – This statement is not exactly correct.
You can try and use display:inline-block; and its possibility to be aligned vertically within its parent's box. This technique allows you to align element without knowing its height and width, although it requires you to know parent's height, at the least.
If your HTML is this;
<div id="container">
<div id="aligned-middle" class="inline-block">Middleman</div>
<div class="strut inline-block"> </div>
</div>
And your CSS is:
#container {
/* essential for alignment */
height:300px;
line-height:300px;
text-align:center;
/* decoration */
background:#eee;
}
#aligned-middle {
/* essential for alignment */
vertical-align:middle;
/* decoration */
background:#ccc;
/* perhaps, reapply inherited values, so your content is styled properly */
line-height:1.5;
text-align:left;
}
/* this block makes all the "magic", according to http://www.w3.org/TR/CSS2/visudet.html#propdef-vertical-align specification: "The baseline of an 'inline-block' is the baseline of its last line box in the normal flow, unless it has either no in-flow line boxes or if its 'overflow' property has a computed value other than 'visible', in which case the baseline is the bottom margin edge." */
#container .strut {
/* parent's height */
height:300px;
}
.inline-block {
display:inline-block;
*display:inline;/* for IE < 8 */
*zoom:1;/* for IE < 8 */
}
Then #aligned-middle will be centered within #container. This is the simplest use of this technique, but it's a nice one to be familiar with.
Rules marked with "/* for IE < 8 */" should be placed in a separate stylsheet, via use of conditional comments.
You can view a working example of this here: http://jsfiddle.net/UXKcA/3/
edit: (this particular snippet tested in ie6 and ff3.6, but I use this a lot, it's pretty cross-browser. if you would need support for ff < 3, you would also need to add display:-moz-inline-stack; under display:inline-block; within .inline-block rule.)

Check this Demo jsFiddle
Set following two things
HTML align attribute value center
CSS margin-left and margin-right properties value set auto
CSS
<style type="text/css">
#setcenter{
margin-left: auto;
margin-right: auto;
// margin: 0px auto; shorthand property
}
</style>
HTML
<div align="center" id="setcenter">
This is some text!
</div>

"If the width and height are really unknown beforehand, then you'll
need to grab Javascript/jQuery to set the margin-left and margin-top
values and live with the fact that client will see the div quickly be
shifted during page load, which might cause a "wtf?" experience."
You could .hide() the div when the DOM is ready, wait for the page to load, set the div margin-left and margin-top values, and .show() the div again.
$(function(){
$("#content").hide();
)};
$(window).bind("load", function() {
$("#content").getDimSetMargins();
$("#content").show();
});

Related

Vertical Alignment

Please take a look at this: http://sources.freehosting.bg/landing.html
I am trying to vertically align #content so it looks good on larger (1920x1200) and smaller (1024x768) resolutions. By that I mean it does not have a scrollbar.
As you see there is plenty of free space so a scrollbar is unneeded.
The only solution I came up with is to calculate the height of #content with JS and to set a padding, but I realize it is the lamest possible solution.
Please advise me on how to achieve that.
See if this fiddle is what you are looking for. Simple solution IMO.
It works by forcing the containing div to behave as a table-cell, and making use of the vertical-align: middle style. It doesn't require you to know the heights of any elements at all.
Code used in the fiddle are below.
HTML:
<div class="a">
text inside div a
<div class="b">
text inside div b
</div>
</div>
The important styles are:
display: table-cell
vertical-align: middle
The rest are only there for demonstration. CSS:
div.a {
border: 1px solid red;
}
div.b {
border: 1px solid blue;
height: 200px;
display:table-cell;
vertical-align:middle;
}
If your content height is fixed put a div before the content
<div id="distance"></div>
<div id="content">
Vertically centered :D
</div>
and style it like:
html, body {
height:100%;
margin:0;
padding:0;
}
div#distance {
width:1px;
height:50%;
margin-bottom:-300px; /* half of website height */
float:left;
}
div#content {
text-align:left;
margin:auto;
position: relative;
width: 950px;
height: 600px;
clear: left;
}
​
The only way I know of that works using pure CSS, no JS and no hacks requires you to know the height of the thing you're trying to position:
<html>
<head>
<style type="text/css">
/* Give your document height */
body, #content {
height: 100%;
}
/* Give your element height */
.thing {
width: 20px;
height: 300px;
background: #000;
}
/* Position thing */
#content .thing {
position: absolute;
top: 50%;
margin-top: -150px; /* half the height of the thing */
}
</style>
</head>
<body>
<div id="content">
<div class="thing"></div>
</div>
</body>
</html>
EDIT: Updated height of item, container id. Still works just fine.
There is one way to do this without javascript and without knowing the height of the content - but purists will not like it. Then again, sometimes it doesn't matter if it's not approved by the trendy people. Sometimes all you need is to get the job done because you boss wants it that way.
And the solution is: use a table (told you purists wouldn't like it). Do layout the old school way and abuse the fact that HTML specifies lots of capabilities to tables.
A table cell is the only HTML element that has a vertical alignment attribute that does what most people expect it to do. Just give the table 100% width and height (so that is expands with the window size) and use cell alignment to position the content you want.
I've only ever had to use this trick once and it still makes me feel dirty* but when you really need it it works better than anything else.
*note: I'm a purist myself but understand that sometimes a man's got to do what a man's got to do.

Overlaying one div over another, but not knowing the size of the div

I'm trying to lay one div over another. This is really simple if you know the dimensions of the div.
Solved here:
How to overlay one div over another div
So, here is my HTML:
<div class="container">
<div class="overlay"></div>
<div class="content"></div>
</div>
In my case, I don't know the exact dimensions of the "content" or "container" div. This is because I don't have control over any of the content in the div (we are making our app extensible for 3rd party developers).
See my example on jsFiddle
The overlay should cover the content entirely. Width 100% and Height 100%. However, this does not work because in my example I positioned the overlay absolutely.
One solution is to use JavaScript to get the size of the content div and then set the size of the overlay. I don't like this solution much since if image sizes are not specified, you need to wait until images are loaded and recalculate the size of the div.
Is there any way of solving this problem in CSS?
You could set the position to absolute and then set all 4 positioning values to 0px which will make the box expand. See a demo here: http://jsfiddle.net/6g6dy/
This way you dont have to worry about recalculating things if you want padding on the overlay or the container (like you would if you used actual height and width values), because its always going to be adjusted to the outer dimensions of the box.
It's not possible to do this because:
The overlay is not contained by anything to restrict it's size (since there is no height/width applied to the container).
The size of the content div can change as content loads (since it has no fixed width/height).
I solved this by using JavaScript*. Eg.
function resizeOverlay() {
$('.overlay').css({
width: $('.content').width()
height: $('.content').height()
});
}
$('.content').find('img').on('load', resizeOverlay);
*Code not tested.
Hey are you looking like this : http://tinkerbin.com/Vc4RkGgQ
CSS
.container {
position:relative;
background:blue;
color:white;
}
.content {
position:absolute;
top:0;
left:15px;
background:red;
color:yellow;
}
I do not know what you are exactly trying to do but this might work:
container must be relative: anything from static
overlay and content are absolute :move top/left in first non static parent; no flow.
Give same top/left to be on top and higher z-index for upper element.
See this demo: http://jsfiddle.net/rathoreahsan/kEsbx/
Are you trying to do as mentioned in above Demo?
CSS:
#container {
position: relative;
}
.overlay,
.content{
display:block;
position: absolute;
top: 0;
left: 0;
}
.overlay{
z-index: 10;
background: #ccc;
}
You can indeed do this without JavaScript. Your problem is that #container element has 100% width relative to the whole page. To fix this you can:
a) position it absolutely,
#container {
position: absolute;
}
b) make it float or
#container {
float: left;
}
c) make it display as table cell
#container {
display: table-cell;
}
One of the above is enough, you don't need to apply all. Also you should not position .content absolutely as this will prevent #container to have the same width/height.
If you are worried about images loading after the height is set you can go ahead and set the dimensions of the image in the containing div and use the padding-bottom hack. This way when the browsers paints over the page it knows how big the image will be before it loads.

Overflow scroll on y axis with fixed height

I have an apparently easy problem which is:
<div class="container">
<div class="a"></div>
<div class="b"></div>
<div class="c"></div>
</div>​
I have 3 divs inside a container: A and B have fixed heights. C must have an extendable height, it extends along with the container height. If the content inside C are too big, I'd like C to scroll but to keep A and B in the same place.
Code in: http://jsfiddle.net/V2c9G/
I'm not able to do it.
I tried:
<div class="container">
<div class="a"></div>
<div class="b"></div>
<div class="xxx" style="overflow-y:scroll">
<div class="c"></div>
</div>
</div>​
without success. The container div it's supposed to resize along the browser.
A complex example would be http://www.sencha.com/examples/#overview (I'm talking about the layout, make the browser smaller and you will see scrolls apperaring hile the headers keeps fixed) but it's not a solution since it uses JS to recalculate the heights.
Any idea?
Edit 3:
This is my recommended solution, which uses CSS from the Edit 2 below as a fallback, but uses JavaScript to resize your divs appropriately onload and when your window size changes. The CSS solution provides a decent starting point if the client has JavaScript disabled, and the JavaScript is such that it really shouldn't affect the performance of the page, so I see no reason not to use JavaScript to perfect what you want to see. A working fiddle can be seen here. Also, here is the appropriate JavaScript code:
var resizeDiv = function(){
document.getElementById('c').style.height = getWindowHeight() - 64 + 'px';
};
//Framework code
var getWindowHeight = function(){
if (window.innerHeight) {
return window.innerHeight;
}
if (document.body && document.body.offsetHeight) {
return document.body.offsetHeight;
}
if (document.compatMode=='CSS1Compat' &&
document.documentElement &&
document.documentElement.offsetHeight ) {
return document.documentElement.offsetHeight;
}
return 740;//provide a default height as a fallback
};
//resize on pageload
window.onresize = resizeDiv;
setTimeout(resizeDiv);
I think you need to adjust the absolute height on your third div to take up the rest of the space (either absolutely or with percentages), set overflow to hidden on the parent div, and let the content in the third inner div determine whether to show the scrollbar or not. Here's an updated fiddle using the absolute height method.
Edit:
From your "Imagine the container is the browser" comment (which to me means the scrollbar should be on the container), all you'd really have to do is set the overflow to 'scroll' and height in the third div to 'auto'. Here's an updated fiddle for that.
Edit #2:
According to your comment on this question, it sounds like you need to go with the percentage method. The most straightforward would be to make the height of a, b, and c a percentage (I had to tweak the margins to get it to fit for all zooms). Unfortunately with this method, the top components will not be fixed, and it sounds like you may be displaying static content there that would look funky. Thus, another option is to pick a minimum supported size for your browser window and adjust the percentage of the third element so that it just fits. Here's a fiddle for that. However, the downside there is that you'll have more empty space at the bottom of the page the bigger the height of the window, and you'll have 2 scrollbars below a certain height. To really do this properly with the fixed sized divs at the top, you'll need to add an event listener to the window.resize method and resize your third div when that happens appropriately based on the new size of the window.
Note: It is times like this where I wish the W3C would approve percentages plus pixels for their height, width, and other sizing properties!
I think you might be searching for something like this: http://jsfiddle.net/QsLFt/.
However, I'm not sure how to get rid of the divs hiding the scrollbar, the easiest solution would probably be to set it a fixed width?
You need to apply overflow-y:scroll in .container
See this,
http://jsfiddle.net/v4ZtN/
Edit (after comments):
Css:
.container{
background-color: red;
width: 90%;
margin: 0 auto;
height:220px;
}
.a{
background-color: yellow;
height: 30px;
margin: 2px;
}
.b{
background-color: blue;
height: 30px;
margin: 2px;
}
.c{
background-color: green;
overflow-y: scroll;
height:inherit;
}
Html:
<div class="container">
<div class="a"></div>
<div class="b"></div>
<div class="c"><img src="http://www.boingboing.net/images/_documents_anemone_images_anemone850-1.jpg" alt=""/></div>
</div>
Edit:2 (after comments)
Change .c style with this.
.c{
background-color: green;
overflow-y: scroll;
height:100%;
}
Check this fiddle:
http://jsfiddle.net/XM4gH/6/
div only show scroll when you put some data in it, here is the result;
jsfiddle
Based on what's currently up on your jsFiddle, I think you can simply add this to the style declarations for your .container class:
overflow:hidden;
You'll have to actually add content to the .c div to see any scrolling however.
did this anser is match to your request ? enter link description here
.container{
background-color: red;
width: 90%;
margin: 0 auto;
height: 315px;
}
.a{
background-color: yellow;
height: 30px;
margin: 2px;
width: 90%;
}
.b{
background-color: blue;
height: 30px;
margin: 2px;
width: 90%;
}
.c{
background-color: green;
height: 250px;
margin: 2px;
width: 90%;
overflow-y: scroll;
}
​
It's hard to tell exactly what you are trying to do based on the question, but if this is the desired result, these are the problems I discovered in your code:
You needed to hide overflow on the red box, so the green box does not extend beyond the container
In the green box, if there is enough data to extend, you want a scroll bar. This was working, but the height you had set specifically (250px) was enough to extend out of the container. You want a specific height here, the number is whatever is remaining in the container. I got 132px. Then with the overflow scroll applied, anything that extends beyond this height will be scrollable.

Size of div depending on size of another div

I got a div which contains 2 other divs. They are vertically aligned. Now, the lower div is changing its size via javascript. What I want now is that the upper div is changing its size depending on the other divs size. Is there a way to do this with css style only, without using js?
UPDATE: The outer div has a fixed size.
<div>
<div> childdiv 1</div>
<div> childdiv 2</div>
</div>
UPDATE: Ok I didnt make this clear enough, the lower box is changing its height in top direction. And the upper div should then decrease its height.
You could use display:table and display:table-row to change the height of the upper div accordingly, so that the total height matches the fixed height of the container:
#outer{
display:table;
height:200px;
width:200px;
}
#inner1{
background-color:red;
display:table-row;
}
#inner2{
background-color:green;
display:table-row;
height:30px;
}
You'll find an example here: http://jsfiddle.net/bRg6m/
Is this what you want?
Added: Note that this doesn't work in IE7 or older. You'll have to use a Javascript solution if you want to support those browsers.
I'm not sure I understand your question.
I made an example here where the upper div is changing its width depending on the lower divs size. Is that what you needed?
http://jsfiddle.net/8fwXR/
HTML
<div id="wrapper">
<div id="box1"></div>
<div id="box2"></div>
</div>
CSS
#wrapper {
float: left;
}
#box1 {
background: red;
height: 100px;
width: 100%;
}
#box2 {
background: green;
height: 100px;
width: 400px;
}
Possibly this is what I meant:
document.getElementById("upperDiv").style.width = document.getElementById("bottomDiv").style.width
Really depends on your setup. The easiest way by far would be to just apply the javascript code to both DIVs at the same time.
Setting the width of the first DIV to be 100% should cause it to resize the width to match the second DIV (as the resize will force the parent DIV to increase in width too), but you will have a problem when trying to get the height to match, as with pure CSS the first DIV will have no reference to recalculate its own height to match.
Example Here
Alternatively, instead of making the second DIV resize you could resize the parent DIV and have both children set with CSS as follows:
width:100%;
height:50%;

Force <div></div> to the bottom of the web page centered

I have a <div>...</div> section in my HTML that is basically like a toolbar.
Is there a way I could force that section to the bottom of the web page (the document, not the viewport) and center it?
I think what you're looking for is this: http://ryanfait.com/sticky-footer/
It's an elegant, CSS only solution!
I use it and it works perfect with all kinds of layouts in all browsers! As far as I'm concerned it is the only elegant solution which works with all browsers and layouts.
#Josh: No it isn't and that's what Blankman wants, he wants a footer that sticks to the bottom of the document, not of the viewport (browser window). So if the content is shorter than the browser window, the footer sticks to the lower end of the window, if the content is longer, the footer goes down and is not visible until you scroll down.
Twitter Bootstrap implementation
I've seen a lot of people asking how this can be combined with Twitter Bootstrap. While it's easy to figure out, here are some snippets that should help.
// _sticky-footer.scss SASS partial for a Ryan Fait style sticky footer
html, body {
height: 100%;
}
.wrapper {
min-height: 100%;
height: auto !important;
height: 100%;
margin: 0 auto -1*($footerHeight + 2); /* + 2 for the two 1px borders */
}
.push {
height: $footerHeight;
}
.wrapper > .container {
padding-top: $navbarHeight + $gridGutterWidth;
}
#media (max-width: 480px) {
.push {
height: $topFooterHeight !important;
}
.wrapper {
margin: 0 auto -1*($topFooterHeight + 2) !important;
}
}
And the rough markup body:
<body>
<div class="navbar navbar-fixed-top">
// navbar content
</div>
<div class="wrapper">
<div class="container">
// main content with your grids, etc.
</div>
<div class="push"><!--//--></div>
</div>
<footer class="footer">
// footer content
</footer>
</body>
If I understand you correctly, you want the toolbar to always be visible, regardless of the vertical scroll position. If that is correct, I would recommend the following CSS...
body {
margin:0;
padding:0;
z-index:0;
}
#toolbar {
background:#ddd;
border-top:solid 1px #666;
bottom:0;
height:15px;
padding:5px;
position:fixed;
width:100%;
z-index:1000;
}
I just want to be clear on what your saying here:
bottom of the web page (the
document, not the viewport)
Naturally, a div will be at the bottom of the "document", depending on your layout.
If it's not going to the bottom of a document, or not paying attention to how tall your columns are, is it because your floating? Clear: both; would be in order to solve that.
The sticky footers are what I think your looking for, but when you say document, and not the viewport, I get a bit confused. Sticky footers typically do this: Watch for short pages, and if its shorter than the view port, the sticky footer tacks the footer div to the bottom.
Here's some sticky footers (there's gajillions of em, but this is in order of my favorites):
http://www.cssstickyfooter.com/
http://css-tricks.com/sticky-footer/
http://ryanfait.com/sticky-footer/ (listed previously)
http://brassblogs.com/blog/sticky-footer
http://alistapart.com/ (theres one there I just can't find it)
Maybe if you gave a quick illustration or were a bit more specific on what you want? Hope this helps :D
-Ken
Try this: Fixed footers without Javascript. I don't know if it will be a perfect fit, but I think it's close enough.
You can just give the div a:
clear:both; text-align:center;
and put the div as the last element before the closing body statement. That would force it to be the last element without anything next to it.
Your best bet is to use javascript to determine the size of your page. You can get the height with window.innerHeight with non-IE browsers and document.documentElement.clientHeight with IE. With that value you should be able to absolutely position your element on the page setting top to that value minus the height of your div. If the height of your div is variable you will need to check the div's offsetHeight property to get the real height.
For centering use the following example:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style>
.wrapper
{
width: 100%;
padding-left: 50%;
}
.test
{
width: 400px;
margin-left: -200px;
border: 1px solid black;
padding-left: -200px;
}
</style>
</head>
<div class="wrapper">
<div class="test">This is a test</div>
</div>
</html>
You have a wrapper div around the div you want centered. The wrapper div has a width of 100% the inner div has a width set to whatever you want it to be. Give the wrapper div a left padding of 50% and the inner div a negative left margin equal to half of its width.

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