CSS/JS content scroll UP instead of down - javascript

I'm building a site with the navigation bar stretching across the entire site and it's fixed.
Under the navigation bar there is an image, a background image, which is set as a cover. And under the image is the main content.
When you scroll down, the navigation bar covers the image from top to bottom and the main content is now visible, effectively scrolling in a downwards fashion. I would like to "reverse" it. So the navigation is still fixed with the cover image under it but this time, when you scroll down the main content comes up and covers the image from bottom to top. So when you scroll down, the main content scrolls up.
Let's say my image has a 1 at the top and a 2 at the bottom. So, normally when you scroll down the navigation bar covers the image from top to bottom the 1 will disappear and the 2 will be visible until that is also covered. The effect I'm looking for would make the 2 disappear and the 1 would remain in the same place until it is covered by the main content.
I looked into parallax but I'm not sure if that's the right thing to go with. And I have no idea how to do achieve this effect.
Hopefully you'll understand what I'm trying to do here. If you need any more info then just let me know.
Thanks in advance.
EDIT
The effect can be seen on the abduzeedo frontpage

You need the image to be "attached" to the background ?
If so, cannot you just fix it to the background ?
body {
background-attachment:fixed;
}
Source: http://www.w3schools.com/cssref/pr_background-attachment.asp
https://developer.mozilla.org/en-US/docs/Web/CSS/background-attachment
Note: Be careful using W3Schools, their information is often incorrect, see here.

Here's an example with an img element.
Demo
code view
The basic HTML layout:
<nav></nav>
<img src="/image.ext" class="scrollup" />
<div class="main"></div>
Your nav will be positioned fixed, as you said. The image also needs fixed positioning. We set its z-index to -1 to make sure it's covered up.
img {
position: fixed;
width: 100%;
z-index: -1;
top: 20px; left: 0;
}
The main element is positioned relatively. Because our nav and image both have fixed positioning, the top value is relative to the top of the viewport. 100% means that .main starts as soon as we start scrolling.
.main {
background: white;
position: relative;
top: 100%;
}

Related

Side by side fixed divs - one is overriding the other

http://codepen.io/justinturner/pen/VjyWJE
The linked codepen has a fixed header div.
I'm using javascript to add a menu div on the left when the hamburger icon is clicked. This is also a fixed div.
When the menu div is added, the header div seems to revert to relative positioning, and jumps to the top of the main content div. Scroll down just a hair and then click the hamburger, you'll see what I mean.
What issue am I running into here? When a user clicks the hamburger, I want the header to remain fixed and translate directly to the right like the rest of the content.
<em>too much code to paste</em>
According to the spec and other similar questions here on SO, fixed elements and translates don't "play" well together.
As a workaround you could:
1) Use transitions (eg. on the left property) instead of transform (translateX)
2) Remove the position:fixed button from the container which uses transforms
Following the first suggestions from above (using left instead of translateX), edit your code to the following and the issue should no longer persist.
.o-wrapper.has-push-left {
left: 300px;
}
.o-wrapper {
position: relative;
transition: left 0.3s;
}
#header-wrapper {
transition: left 0.3s;
}
.has-push-left #header-wrapper {
left: 300px;
}
DEMO

CSS: Unable to position elements correctly below a sticky navigation bar

I created a website with enough text, so that you are able to scroll (http://jsfiddle.net/o0emtyug/1/). On the right side I added some buttons for special functions on my website, which are positioned fixed and have a spacing using CSS top:XXpx;. Furthermore I placed the buttons within my menu bar div container nav-primary.
Using my JQuery script sticky-nav.js the menu bar is always visible on my page, even if I scroll down the page. So if I scroll down the page my menu bar stays on top of the page.
What I want to achieve:
I want my buttons to keep the same distance height from the menu bar all over the time. For this I will need to remove the CSS code top:XXpx;. If I do this, my buttons disappear. I tried changing top to margin-top but this did not solve my problem.
Anyone able to tell me what I need to do in order to arrange the buttons exactly below the menu bar, with the same distant height when scrolling?
I've added a test button with Absolute positioning in the nav bar, so it doesen't seem to be in the container, but inherits its position:
#test {
position: absolute;
right: 0px;
top: 100px;
}
Here the Fiddle
Remember that Absolute positioning is relative to the Body or the first container that have a specific position. In this case, top:100px is relative to .nav-primary, that has position: relative.

Full background image initially fixed, then scrolls when DIV content ends

I'm trying to figure out how to have a full background image (background-size: cover) be fixed initially (the text over the image scrolls while the image stays put), but, at the moment when the user scrolls down to the end of the content (like a tall block of text), the background then scrolls up revealing a new section/div below.
For example:
<section id="top-section-with-fixed-bg">
<div class="tall-content-1500px">
<p>Text that's really tall</p>
</div>
</section>
<section id="next-section">
...
</section>
But, again, the background image is fixed until the user has scrolled down 1500px and the content for that section/div is done. At that point, the user continues to scroll and the background image scrolls up.
Not, as with parallax solutions, with the background image being covered by the next section. But the background image going up with the scroll.
I'm thinking this takes some javascript, jQuery fixing, but I'm still a bit novice with it. I'm a designer just wanting a site to look and act this certain way. I'm guessing I have to recognize the height of the content, where that ends, and then either tell the CSS to switch from fixed to scroll (without effecting the position of the image), or having the js move the image up with the scroll action.
Update: Here's a quickly tossed together jsfiddle
UPDATED UPDATE:
I think I've found the solution!
With the pointers provided in responses here, then some digging around, I have it kind of working.
I started with trying to figure out how to detect the window height. I plug that into the text/content DIV, using that value for the DIVs height. This is important, to set the container for the text to the height of the user's window, not to a specific height. Then, I set that DIV to overflow: auto (and hide the scrollbar, for aesthetics). That allowed me to set a trigger so when the end of the content in that DIV is reached, the background-attachment is changed from fixed to scroll.
And, voila! It's not perfect, and I'm sure some real javascript/jQuery experts will right my wrongs on it, but I like how far I've gotten with this so far.
I realize that the swtich from fixed to scroll is probably unnecessary. At the moment, when the switch happens, the image jumps a little to adjust to the window size and its own position, now being set to scroll. If I set the CSS originally to fixed, and make sure the content of the DIV (using padding wisely) to cover the window, as the user scrolls with the mouse the correct action will occur: text scrolls until there is no more text, then the image scrolls up.
Check it out and look forward to help and comments.
jsfiddle
have you set background-attachment:fixed;? This makes background images 'move' with the browser scroll. Be careful when it comes to devices though as this method can cause 'laggy looking sites' because there's too much render for the device (depending on image).
I personally target 'large' and 'modern' browsers with this:
#media query and (max-width:600px){
.top-section-with-fixed-bg{background-attachment:fixed;}
}
EDIT:
sorry I didn't fully understand the question. Here's some CSS to get you going
window.addEventListener('scroll',function(){
//document.body.scrollTop would be the windows scroll position.
if(document.body.scrollTop==1500px)
document.getElementById('top-section-with-fixed-bg').style.backgroundAttachment='static';
}else document.getElementById('top-section-with-fixed-bg').style.backgroundAttachment='fixed';
});
I'm very sorry but this is very basic. I'm about to finish work. The function could use a bit of sprucing up a bit like making it dynamic. This is also only native JS. So it's not all that fancy but you get the idea. When the document.body.scrollTop is at the bottom of your element. Which I'm guessing is 1500px tall? IF not use offsetHeight(). That'll give you the complete height of the element including padding and margins and I think borders as well?
I'd set your background images to background-position: fixed; then put the next background image at the bottom of the text so it overlays on top of the first div. Problem is you can't have the nice <section> structure you had going before.
<style type="text/css">
.section-with-fixed-bg {
min-height: 100%;
background-size: cover;
background-attachment: fixed;
background-repeat: no-repeat;
background-position: center center;
}
#bg-1 {
background-image: url("./background-1.jpg");
}
#bg-2 {
background-image: url("./background-2.jpg");
}
#bg-2 {
background-image: url("./background-3.jpg");
}
</style>
...
<body>
<div id="bg-1" class="section-with-fixed-bg">
<p>Text that's really tall</p>
<div id="bg-2" class="section-with-fixed-bg">
<p>Next section of text that's really tall.</p>
<div id="bg-3" class="section-with-fixed-bg">
<p>Next section of text that's really tall.</p>
</div>
</div>
</div>
I haven't tested this but it should cause the new image to overlap the old one, at least in theory.

page not redrawing on horizontal scroll

When I shrink the width of my browser window (Firefox v26) so that only 1/2 of my home page is shown, the horizontal scrollbar appears on the bottom of the browser, which is fine.
But if I scroll the page to see its right half -- that right half is blank. In other words, after horizontally scrolling to the right (which moves the page's content leftward, obviously) -- the right side of the page does not redraw. It stays blank. Even if I hit the refresh on the browser URL bar.
I looked around and saw several posts. This one seemed to be exactly the same problem (only difference was, theirs involved the vertical scrollbar).
So I took the suggestion there -- which was to set my outermost content div (called wholePageDiv in the code below) and also my outerDiv to 'min-width: 100%" but this changed nothing.
Here's the very simple code:
<html>
<body>
<div id="wholePageDiv" class="wholePageDivForCentering">
<div id="outerDiv" style="margin: 0; margin-top: 10px; min-width: 100%;
display: inline-block; overflow: hidden">
(not shown: a bunch of divs with text)
</div>
</div>
</body>
<html>
Here is the wholePageDivForCentering CSS class, with the change made per that SO post I read:
.wholePageDivForCentering
{
/* width: 100%; */
min-width: 100%;
/* height: 100%; */
min-height: 100%;
white-space: nowrap;
margin: 0 auto;
}
I have looked at other websites to see if they exhibit the same "right side of scrolled page does not redraw" problem. On other websites I tested, I shrink the browser to 1/2 the width needed to show the whole page, then I scroll to see the right 1/2 of the page -- all other websites I check are successfully redrawing the right-side content as I scroll.
Do I have a CSS style problem above?
EDIT: I hit F12 in my browser and use the 'Inspector' tool and I clearly see that the only visible content is within the wholePageDiv and this div is not expanding at all, to the right, as I scroll to the right -- the Inspector shows that for whatever reason my outermost wholePageDiv is remaining the same fixed size as the viewport, and when I scroll to the right, this viewport outline as shown by the Inspector simply shifts leftward and does not expand on the right side to accommodate moving the scrollbar to the right.
I have added your html and css in a fiddle and it scrolls fine for me. The text of the div is displayed with no issues: http://jsfiddle.net/micahSan/UucLB/3/
same code as the OP
Can you replicate your problem in a fiddle so we can all see it?
I solved this (for now) by either hard-coding the div's width, or by programmatically increasing the div's width as the width of the browser window/document was changed. Hopefully will find a less kludgy solution later.

How can I add a scroll bar to a fixed sidebar that only appears on hover

I'm working on a site where I made the sidebar to be fixed on the left and extended to the full height of the page using this CSS:
sidebar {
position: fixed;
top: 0;
bottom: 0;
}
And that works fine to keep the sidebar in place, but the problem is when the page is re-sized to a smaller height, you can only see the stuff at the top of the sidebar and there's no way to see the stuff at the bottom of the sidebar.
Now, I know I can add a scroll bar using overflow-y: scroll; but what I'm trying to do is have a scroll bar that only appears when the content on the sidebar exceeds the height of the window and only appears on hover. I also want the scroll bar to have some style to it, similar to the sidebar on TheNextWeb or the Facebook chat sidebar.
I know I need some JavaScript to do this, but my skills in JavaScript are very limited so I appreciate any help on this.
overflow-y: auto should work:
For styling you should probably search for a good scrollbar-replacement, as scrollbar-styling only works in webkit (http://css-tricks.com/custom-scrollbars-in-webkit/). It's not a trivial thing to do, but fortunately there are some plugins:
http://cubiq.org/iscroll-4
http://jscrollpane.kelvinluck.com/
http://www.yuiazu.net/perfect-scrollbar/
Just to mention a few.
EDIT:
Thanks to sheba, I made some modfications:
.sidebar:hover{
overflow-y: scroll;
}
http://codepen.io/johannesjo/pen/GcLFn

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