Dead Centered Div - javascript

How is it possible to center a div both horizontally and vertically with respect to the screen, not the page. So that when the user scrolls down a long page, the div remains horizontally and vertically centered?

Here's a pure CSS solution, note the percentages and negative margins.
http://jsfiddle.net/R7Xy2/
div {
position: fixed;
width: 200px;
height: 200px;
top: 50%;
left: 50%;
margin-left: -100px;
margin-top: -100px;
}

Here is your code
http://www.geekdaily.net/2007/07/04/javascript-cross-browser-window-size-and-centering/
just attach this event to window.onscroll. No need to use jQuery, try this
function addEvent(obj,ev,fn) {
if(obj.addEventListener) obj.addEventListener(ev,fn,false);
else if(obj.attachEvent) obj.attachEvent("on"+ev,fn);
}
addEvent(window,"scroll",yourfunction);
good luck

You may also try the following:
HTML markup:
<div class="classname">text here</div>
CSS:
.classname {
position:absolute;
left:50%;
top:50%;
padding:10px;
border:1px solid #ccc;
}
The border and padding can be changed or removed on the basis of requirement. Also, make sure that the parent container must be positioned relatively, i.e. it should have position:relative.

CSS for the <div>:
position: absolute
left : (centerofpagepixel.x - (width of div /2));
top : (centerofpagepixel.y - (height of div/2));
Set the above using jQuery on the <div>.
You can calculate the centerofpagepixel.x and y using jQuery again. Probably get the width/height of the screen and divide them by 2.

Related

Moving a CSS Element Vertically Without JS

Is there anyway I can make an HTML div move down while scrolling instead of moving up without using javascript? I know you can use window.onscroll = function() { } and have that move the position of an object while scrolling, but is there anyway I can move an object down with just CSS and HTML?
I think you want to retain your div on the viewport while scrolling down.
There are 2 ways for it.
Make the element position fixed and apply positioning to that element.
Make parent element position relative and make your div position sticky and apply positioning.
Positioning means adding any one of the top, right, bottom, and left properties.
.parent {
height: 1200px;
width: auto;
position: relative;
}
.floating {
position: sticky;
top: 10px;
width: 100%;
height: 60px;
background: black;
color: white;
}
<div class="parent">
<p>Hi this is parent</p>
<div class="floating">
This is floating element
</div>
</div>

Overlaying divs on responsive parent div with background image

What I'm trying to achieve is a div container that is responsive but the ability to overlay highlight fields that will stay in the same place based on the parent div. I want to be able to highlight certain areas of text or form fields but have the form be responsive. Here's a link to an example: http://www.codeply.com/go/nufYSSEMir
As you can see the highlight div is position: absolute; so obviously it's going to stay exactly where it's at. I've tried using percents as top and left values but it doesn't scale with the background image. I have a feeling that my two options are to either have the width as a static value and set the meta viewport to scale to the window size, or get crazy with some JS and maybe jQuery.
Thanks in advance for any and all suggestions.
As said by divix, you need to set position : relative to the parent div.
This will tell the browser that your highlight's position : absolute is absolute in reference to outerContainer.
Basically any position:absolute will look at the first parent that has a position set (whether it's relative, fixed, absolute etc) to calculate top|right|bottom|left offset. If you don't have any parent that has a position set, it will just take the body as a reference
Edit: In order the get the right responsivness try this :
body {
background-color:#ddd;
}
#outerContainer {
background: transparent url("http://scontent-ord1-1.xx.fbcdn.net/hphotos-xpl1/t31.0-8/s960x960/12605534_504076036438839_6108375615162000201_o.jpg") no-repeat scroll center top / 100% auto;
height: 960px;
margin: 0 auto;
max-width: 742px;
width: 100%;
position: relative;
}
#media only screen AND (max-width:742px){
#outerContainer {
height:0;
padding-top:129.5%;
}
}
#innerContainer {
background-color: rgba(0, 255, 0, 0.5);
border: 1px solid #000;
height: 8%;
left: 12%;
position: absolute;
top: 14%;
width: 30%;
}
Simply add position: relative; to the #outerContainer, it works for me.

How to make a fixed div/nav resize with the div it's inside of?

I'm pretty fresh to web development and cannot figure this one out. Appreciate any help!
On re-size the fixed div moves out of the container instead of re-sizing. The site I'm working on has the nav as the fixed section and is inside of the main container.
Any help is appreciated. Thanks!
<div class="container">
<div class="fixed"></div>
</div>
.container {
border: 1px solid;
max-width: 600px;
width: 100%;
min-height: 1600px;
}
.fixed {
max-width: 600px;
width: 100%;
height: 50px;
border: 1px solid green;
position: fixed;
}
http://jsfiddle.net/KqvQr/
When you specify position as fixed the Element, even thought it is inside a parent container, It won't behave as a child of a parent container. It won't adjust his width according to the parent width. But I can give you a solution where when user resize the page the fixed element also get resize yet it is a position fixed
.fixed {
height: 50px;
border: 1px solid green;
position: fixed;
right:0;
left:0;
}
Don't specify widths for the container. instead of that specify left and right values. so then when page is resizing css only check for the left and right margin values. by keeping those values it will adjust its inner width always.
Here is the working fiddle http://jsfiddle.net/KqvQr/5/
I don't think you can achieve what you want if you stick with that constraints. Your width and max-width will work as expected if you change your position to relative instead of fixed..
Check out this Fiddle

Floating menu bar using HTML/CSS?

wondered if any one knew of a way of creating a floating menu bar that sticks to a point on a page until the browser window gets far enough down the page and unsticks it and then the menu bar begins to scroll along with it. The effect I want is the exact same as this http://www.jtricks.com/javascript/navigation/floating.html javascript menu. However, I really want to do this with CSS. I am aware I can make the div Absolutely positioned and it will move down the page, I tried making one DIV relative positioned (parent div) and then another div inside this which was absolute positioned, but I could not get this to work. Does any one know how to make this work with CSS or does it need to be JS?
Thanks in advance.
Jon.
I believe using javascript is the only solution to get the effect you described. Here's a quick demo of a banner that starts in a absolute position and goes to fixed when the user scrolls.
<div style="height:1000px;width:500px;">
<div id="floatbar" style="background:gray;
width:200px;
height:40px;
position:absolute;
left:0;top:200px;">
</div>
</div>
$(window).scroll(function(){
if ($(window).scrollTop() >= 200)
{
$("#floatbar").css({position:'fixed',left:'0',top:'0'});
}
else
{
$("#floatbar").css({position:'absolute',left:'0',top:'200px'});
}
});
well if you do NOT need the animation, than just use
position: fixed;
in the css.
if you want it animated you need to use javascript.
for example in jquery:
$(window).scroll(function(){
$('#menu').css({
right: 0,
top: 0
})
})
Well you can't do it with absolute positioned div inside of a relative. Fixed position is basically an absolute positioned div, positioned relatively to the window. I'd say you definately need javascript here.
This should be rather easy with a fixed sidebar, and a floating content section. Try something like this...
#container {
width: 960px;
margin: 0 auto;
overflow: hidden;
position: relative;
}
#sidenav {
width: 300px;
position: fixed; /*--Fix the sidenav to stay in one spot--*/
float: left; /*--Keeps sidenav into place when Fixed positioning fails--*/
}
#content {
float: right; /*--Keeps content to the right side--*/
width: 620px;
padding: 0 20px 20px;
}
This is old post but CSS has changed a lot since then, we can do a floating menu with plain CSS. See sample code below. Credit to https://www.quackit.com/css/codes/css_floating_menu.cfm
main {
margin-bottom: 200%;
}
.floating-menu {
font-family: sans-serif;
background: yellowgreen;
padding: 5px;;
width: 130px;
z-index: 100;
position: fixed;
right: 0px;/* You can change float left/right */
}
.floating-menu a,
.floating-menu h3 {
font-size: 0.9em;
display: block;
margin: 0 0.5em;
color: white;
}
<!DOCTYPE html>
<title>Example</title>
<main>
<p>Scroll down and watch the menu remain fixed in the same position, as though it was floating.</p>
<nav class="floating-menu">
<h3>Floating Menu</h3>
CSS
HTML
Database
</nav>
</main>
I believe it needs to be JS. I can imagine it can be rather simple with jQuery and I really cannot think of any way to achieve this only with CSS. I'll try to think about it, but I doubt I'll find a solution.

How do I keep a div in the center of the page?

I'm using jQuery to create a "dialog" that should pop up on top of the page and in the center of the page (vertically and horizontally). How should I go about making it stay in the center of the page (even when the user resizes or scrolls?)
I would use
position: fixed;
top: 50%;
left: 50%;
margin-left: -(dialogwidth/2);
margin-top: -(dialogheight/2);
but with this solution and a browsers viewport-size of less than your dialog is, parts of the dialog will be unreachable on top and left sides because they are outside the viewport.
So you have to decide if it's suitable for your dialogs size.
(CSS doesn't know how to calculate, yet. So the little math over there has to be done by you, right now. Therefore your dialog has to be a fixed size which you have to know.)
Edit:
Oh yes, if you want to serve your dialog for the IE6 too, you should do something like this:
#dialog { position: absolute; }
#dialog[id] { position: fixed; }
Since IE6 is not capable of fixed positions and also not capable of attribute-selectors, the IE6 will be the only one who has the position set to absolute. (This will only affect with scrolling behaviour. absolute stays on its place in page and fixed stays on its place in the browser. The rest is similar.)
Check out Infinity Web Design's piece on this.
#mydiv {
background-color:#F3F3F3;
border:1px solid #CCCCCC;
height:18em;
left:50%;
margin-left:-15em;
margin-top:-9em;
position:absolute;
top:50%;
width:30em;
}
This is the CSS they use, and I've tested it out in multiple browsers.
You'll note that the left margin is negative half the width and the top margin is negative half the height. This takes care of the centering, more or less, with absolutely positioning it at 50% top and left.
To put a div horizontally in the middle I always put margin: 0 auto. But it cannot be a floating element and in IE I always needed to put a div around and then give it the property text-align: center, so that the inside div is centered horizontally.
If you know the element's offset dimensions (width/height + padding), you can use this CSS:
elementContainerSelector {
position: fixed; /* You'll of course need to handle browsers that don't support fixed positioning */
top: 0;
left: 0;
width: 100%;
height: 100%;
}
elementSelector {
position: absolute;
top: 50%;
left: 50%;
margin: -[half of offset height]px 0 0 -[half of offset width]px;
}
Hurix's answer works too, and bear in mind the caveats in that answer as well.
Keep margin-left:auto and margin-right:auto

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