Prevent fixed sidebar menu to scroll over footer - javascript

Hi is there a simple way to prevent a fixed sidebar som scrolling over a footer or a specific element? I've tried changing it from fixed to absolute depending on different viewport height but my application is nested in a lot of position relative elements so I haven't managed to get it to work yet.
Here is a code example: https://codesandbox.io/s/fixed-sidebar-7gvpf?file=/src/index.js
Ask if I need to clarify anything.
Thanks beforehand,
Erik

Because the element is fixed and therefore outside the normal page flow you can z-index to specify if an element is above or below another.
In your case you can use it like this with z-index: -1; so it wil be positioned behind the element.
const SideBar = styled("div")`
background-color: green;
height: calc(100vh);
width: 50px;
position: fixed;
z-index: -1;
`;
If this causes the sidebar to disappear behind everything you also can set the z-index on the footer with position: relative; to get it to work. like the following CSS:
const Footer = styled("div")`
background-color: blue;
height: 200px;
position: relative;
z-index: 1;
`;
Here is an MDN article on z-indexes if you want to know more
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Positioning/Understanding_z_index/Adding_z-index

Related

Absolute and Fixed Positioning bug on Firefox?

What should be a super simple one here, but its getting me to scratch my head. I have a div with an H1 and P tag that is overlaid on top of a Three.JS 360° video viewer on this website: http://gloriouslabs.com/#page-5
Right now the code for that div is:
.video_tag {
position: absolute;
z-index: 100;
top: 15%;
left: 5%;
width: 230px;}
Works fantastically on Chrome with the position tag rendering it in reference to the top of the screen. However on Firefox, the div renders itself from the top of the PAGE, not the SCREEN (on Firefox you can see the .video_tag div appear on the top of the screen at http://gloriouslabs.com/)
Any ideas why it's acting like that? The same bug happens on both absolute and fixed position.
Cheers!
I opened your page in firefox's inspect and added this position: relative;:
#holder {
height: 100%;
width: 100%;
position: relative;
}
It is working, but I didnt test back in chrome
Set your container to relative positioning
#holder {
position: relative;
}
If this is not the right container then set it on the one you need

stick scrollable div to bottom of screen

I've got a cordova app using jquery, jquery-mobile, iscroll and iscrollview
I'm not exactly committed to any of these tools.
I've got the jquery-mobile header/footer stuck to the top and bottom of the screen just fine.
I have a scrollable div between the header and footer. It will contain variable amounts of data. Sometimes the data will be less than the height of the div and sometimes it will be greater (hence the scrolling)
Here's the tricky part. I want to stick the bottom of the scrollable div to the top of the footer. When I add stuff to the div i want the most recently added closest to the top of the footer so the top of the scrollable div looks like its growing upwards towards the bottom of the header as data is added.
Once the top of the scrollable div is fille by its content then i want to be able to scroll it.
Has anyone been able to achieve something like this?
Here's a neat little trick for you.
<div class="header"></div>
<div class="content"></div>
<div class="footer"></div>
Now the CSS
div {
width: 100%;
}
.header {
position: absolute;
top: 0px;
left: 0px;
height: 50px;
}
.footer {
position: absolute;
bottom: 0px;
left: 0px;
height: 100px;
}
/* the magic */
.content {
position: absolute;
top: 50px; /* matches height of header */
bottom: 100px; /* matches height of footer */
left: 0px;
overflow: scroll;
}
The neat thing about forcing .content to have both a top and a bottom is that it stretches the div so that it's always the proper height. IF you specified height on it, it wouldn't work, but because the height is determined by the top/bottom property, it's dynamic. I think this gets you to where you want to be.
Here's a fiddle
Edit: Here's what it looks like with content
Edit 2 - forcing content to grow from the bottom.
I'm not sure this is a good idea, and I'm not sure I would ever seriously recommend doing things this way. However, using vertical-align it's possible to force content to grow from the bottom. I suspect that it would be better to just set a margin with javascript that shrunk as content grew, but... maybe not. With all that said, here's one way to do things with CSS.
This requires a little bit of restructuring of the content div.
<div class="content">
<span class="margin"></span>
<span class="inner"></span>
</div>
And a little bit more CSS
span.left-margin {
height: 98%;
width: 0px;
display: inline-block;
}
span.inner {
width: 99%;
background-color: white;
display: inline-block;
vertical-align: bottom;
}
It looks like this with a little content
It looks like this with a lot of content
If you want the scroll bar to stick to the bottom as content comes in, you'll need to do some javascript (easy to google it).
I'm not completely happy with doing things this way because if you set height 100% or width 100%, the content div gets a scrollbar automatically from the beginning. However... it looks pretty good and should work in most (if not all) browsers.

Make a div stick to the left when scrolling

So I am trying to create a left-sided nav bar, but after scrolling I can't get it to correctly stay to the left.
I have tried using:
position: fixed;
and
position: absolute;
However it cuts the width of the DIV down completely.
To get a view of what I'm working with go to: http://198.50.242.77/YouBB/
I'd prefer to use strictly CSS only but if I must use JS I'll use it.
Thanks!
position: fixed is what you want. This causes the element to be removed from the flow entirely and stay in the same position even after scrolling the page.
position: absolute is similar, but it only removes an element from the flow. Scrolling a containing div (or in this case, the whole page) will still cause it to move.
I opened up your web page in Chrome, and changed the styles for #navigation to:
background: white;
height: 100%;
text-align: center;
position: fixed;
width: 18.72%;
This does what you want. You will just need to position the rest of the content to the right.

Best way to size an element to the size of another element

I am using an old CSS trick to get a semi-transparent background for some content, without the content appearing semi-transparent. Here is the HMTL:
<div id="frame">
<div id="opacityFrame">
</div>
<div id="contentFrame">
<div>
<!-- Main Site Content Here -->
</div>
</div>
</div>
Here is the corresponding CSS:
#frame
{
width: 90%;
margin: auto;
position: relative;
z-index: 0;
}
#opacityFrame
{
background: #00ff00;
opacity: .15;
top: 0;
left: 0;
position: absolute;
width: 100%;
height: 100%;
z-index: 1;
}
#contentFrame
{
top: 0;
left: 0;
position: absolute;
height: 100%;
width: 100%;
z-index: 1;
}
My problem is that because #frame is position: relative, it's height does not dynamically expand with its content. Both #opacityFrame and #contentFrame are set to 100% height and width and they appropriately expand to fill #frame which is great. The issue is that I need #frame's height to grow with the contents of the child DIV of #contentFrame because that DIV's height dynamically adjusts with the content placed in it.
I ended up having to create a jQuery function:
function resizeFrame()
{
$('#frame').height($('#contentFrame > div').height());
}
NOTE: The reason there is a child DIV of #contentFrame is because #contentFrame's height always reads as zero for some weird reason. I'm assuming it has to do with its position being absolute.
This code works great and accurately resizes #frame's height to the height of the child DIV of #contentFrame. However, I do a lot of ajax that changes the content within that DIV. One solution would be to call resizeFrame() with EVERY ajax event but it just seems so tedious. Is there an event or something I can tie to that would execute this function without my explicitly having to call it? I tried the following events but they didn't seem to work; maybe I did them wrong.
$('#subFrame > div').resize()
$('#subFrame > div').change()
Neither of these seemed to fire when the contents of the child DIV were modified. Maybe I'm going about this the wrong way? I do not want to use transparent images for the background.
Try taking position: absolute off of the contentFrame but leaving it on the opacityFrame. That should cause it's parent to resize, and the opacityFrame to still overlay everything.
do you have to use opacity? If it's a solid color, consider RGBA or if it's not solid, consider a semi-transparent PNG. That way you can nest them.

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.

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