Hide element "beneath" div of lower z-index - javascript

Two fiddles. The first, showing everything working as I want: http://jsfiddle.net/3SWwD
The second, showing the problem as it exists on the site I'm trying to deploy the effect on: http://jsfiddle.net/3SWwD/1/
Those fiddles describe everything this code does, but for thoroughness:
I have two container divs bumped up to one another, the first of which contains an imagel which I have simplified to <div id="image"> for this example.
<div id="container">
<div id="image"></div>
</div>
<div id="never_cover_me">
</div>
They are styled as follows, and theses styles will exhibit the issue, which I'll explain when I show the js.
#container{
height: 400px;
width: 400px;
background: blue;
position: relative;
z-index: 200;
}
#image{
height: 200px;
width: 200px;
background: red;
position: relative;
top: 200px;
left: 100px;
z-index: 50;
}
#never_cover_me {
position: relative;
height: 400px;
width: 400px;
background: yellow;
z-index: 100;
}
Lastly, some Jquery/JS moves the image down, thus into the space of #never_cover_me. If all was well in the world, #image would be covered by #never_cover_me while it was moved down, but since #container has a higher z-index than #never_cover_me, obviously that isn't the case and the image is instead drawn over #never_cover_me.
$(document).ready(function(){
setInterval(
function(){
$('#image').animate({top: '+=200px'}, "slow", function(){
$('#image').delay(1000).animate({top: '-=200px'}, "slow")
});
},3000
);
});
For various reasons, #container MUST have a higher z-index than #never_cover_me. Semantically, I would prefer if #image stays within #container.
Ideas?

The #container:
z-index: 200;
is above #never_cover_me:
z-index: 100;
Therefore, it is causing the issue you are experiencing. Here is more information on stacking order and how descendants are affected.
https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Understanding_z_index/Stacking_and_float
You shouldn't really try to use other elements to hide your content. A better solution would be to set overflow:hidden; on #container because the effect you are going for is "hide this when the block is outside the current element."

It was as easy as adding overflow:hidden to #container.
Fiddle: http://jsfiddle.net/3SWwD/2/

Related

Dynamic placeholder height

So I have a list with a position: fixed button in the bottom of the viewport. Because this button is position: fixed the last element of the list and part of the second last appear beneath the button, so the user can't see them properly.
What I tried so far:
adding a padding-bottom to the container with the height of the button. Issue with this approach: in different languages the height of the button is different, so it's good in only a couple of scenarios.
making the button position: sticky instead of fixed. Issue with this approach: the list is in a overflow-y: scroll container, so this approach does not work in iOS. Again, only good in a couple of scenarios.
adding a div after the list and controlling its height with javascript. Issue with this approach: does the job, but it's not very elegant.
Does anyone know of a better approach other than my third one? When I started with this I thought I might have to use JS for it, but position: sticky gave me hope that it would be possible with only CSS.
Since your list is fixed, this is an example of what I do for buttons on the bottom of my screen. Although it would be nice if you showed an example of your problem, cause it's hard to tell.
Obviously, you'll have to edit the text's positioning if you wanted, but the principle is what matters, and everything is responsive. Each individual <li> element is 10% high and 20% wide no matter the size of the screen.
CSS:
<style>
ul { position: fixed; width: 100%; height: 10%; bottom: 0%; left: 0%; background-color: deepskyblue; list-style-type: none; margin: 0; }
li { position: absolute; }
.a { width: 20%; height: 100%; background-color: red; left: 0%; }
.b { width: 20%; height: 100%; background-color: orange; left: 20%; }
.c { width: 20%; height: 100%; background-color: yellow; left: 40%; }
</style>
HTML:
<ul>
<li class="a">AAA</li>
<li class="b">BBB</li>
<li class="c">CCC</li>
</ul>

Div dissappears when Dragging from one div to another with scroll overflow using jquery

I have two "DIV"s, one on the left and one on the right. The right one has draggable elements and the left one has a droppable container. Both DIV's have the CSS attribute overflow: auto, which is essential in my implementation because I need a scroll to appear in each div when either DIV overflows.
The issue is, when I drag the element in the right DIV, and move it to the left, it disappears after the edge of the DIV.
This is a sample of what I'm trying to do.
<!DOCTYPE html>
<html>
<head>
<title>Practice</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
<script>
$(function() {
for (var i = 1; i <= 20; i++) {
$('#right').append($('<div></div>')
.addClass('item')
.html(i));
}
$(".item").draggable({
cursor: "move",
revert: "invalid"
});
$("#bin").droppable({
drop: function(event, ui) {
var mydiv = $(ui.draggable);
$("#bin").html("Dropped");
}
});
});
</script>
<style>
#left {
border: 2px solid black;
position: fixed;
width: 49%;
height: 98%;
overflow: auto;
}
#right {
border: 2px solid black;
position: fixed;
left: 52%;
top: 2%;
width: 46%;
height: 98%;
overflow: auto;
}
#bin {
border: 2px solid black;
position: relative;
left: 12%;
top: 5%;
width: 75%;
height: 75%;
}
.item {
border: 2px solid black;
left: 12%;
top: 5%;
width: 15%;
height: 5%;
}
</style>
</head>
<body>
<div id="left">
<div id="bin">
</div>
</div>
<div id="right">
</div>
</body>
</html>
You need to remove the overflow:auto in your CSS. You will then see the item will be visible when dragging between the divs then.
In order to accomplish the functionality you'd like, you need an outer div wrapping the two container boxes. You'd set an fixed height on the outer div, then use overflow-y:scroll to get your functionality.
You can do as others have suggested, but I've always found the best way to accomplish this is to set the draggable item to position:fixed
see for example:
https://jsfiddle.net/gregborbonus/tzz0927p/1/
For me personally, this allowed a lot more flexibility, but I also did a lot of work with responsive designs and such to make it work right.
I've edited to include overlapping div's. Added a few functions to make it more visible, like random Color, and an on hover and hover out event to make it possible to see and click each box.
https://jsfiddle.net/gregborbonus/tzz0927p/3/
With 100 and added a scroll function to make the scroll smooth. Also added a quick snippet so that the elements would only appear within the containing box.
This is different from your code, it uses 2 containers, rightc for the main container(the one that scrolls) and right for the container of all the elements. The rest is commented in the code.
https://jsfiddle.net/gregborbonus/tzz0927p/13/
so, something I realized was that the elements would still overlap the page on page load.
So, to show this working with an even shorter div and changed to compensate for onload:
https://jsfiddle.net/gregborbonus/tzz0927p/15/

CSS: Performance wise, better to use calc or position absolute

I have a container div with fixed height. Inside two divs, the top height: 50px and the other one must fill the empty space but allowing internal scroll.
Now I have two options:
#up{
height: 50px;
}
#down{
position: absolute;
top: 50px;
bottom: 0;
}
or:
#up{
height: 50px;
}
#down{
height: calc(100% - 50px);
}
If I have many of these cases inside my window, which one is the best to use performance wise?
This Fiddle
ps. I don't care about old browser support.
I would always work with calc option. Both could look the same but they are not.
When you use position:absolute You are taking the container #down out of the html flow.
This means that if anytime you are going to add more stuff to your project, You will have many problems positioning them.
As an example, if you want to add another container below #down (a footer maybe), in your first option it will be placed overlapping #down container right below your header. In the second option it will be placed where you want it.
One way to fill the space would be to use flexbox.
.container {
display: flex;
flex-direction: column;
height: 200px;
}
#up {
background: yellow;
flex: 0 0 50px;
}
#down {
background: orange;
flex: 1 1 auto;
}
<div class="container">
<div id="up">
up
</div>
<div id="down">
down
</div>
</div>

Hide scroll bar of nested div, but still make it scrollable [duplicate]

This question already has answers here:
Hide scroll bar, but while still being able to scroll
(42 answers)
Closed 8 years ago.
This is a reference that I used, which explains how to make a div scrollable with its scroll bar hidden. The only difference is that I have nested divs. Check my fiddle
HTML:
<div id="main">
<div id="sub-main">
<div id="content">
<div id="item-container">
<div class="item">a</div>
<div class="item">b</div>
<div class="item">c</div>
</div>
</div>
</div>
</div>
CSS:
#main {
width: 500px;
height: 500px;
}
#sub-main {
width: 500px;
height: 500px;
overflow: hidden;
}
#content {
background-color: red;
width: 500px;
height: 500px;
overflow: auto;
}
#item-container {
width: 1500px;
height: 500px;
}
.item {
width: 500px;
height: 500px;
font-size: 25em;
text-align: center;
float: left;
}
Like above, I have a overflowed horizontal div and I want to hide its scroll bar. I have to make it still scrollable because $.scrollTo() wouldn't work otherwise.
UPDATE:
I have read all the answers, but I still have not resolved my problem and don't know what's causing it. This is the live that's having troubles.
Basically, I am trying to follow this almost exactly the same, but there must be some reason that my website isn't working as expected. There are two problems.
When I set overflow: hidden to a parent container of scrollable items, I cannot scroll (native javascript scroll functions do not work too).
I want to scroll just the overflowed container, not the entire window. This can be done by setting a target in $.localScroll({ target: '#projects-content' }) but nothing scrolls when I set the target. If I don't, scrolling works as long as overflow:hidden is not applied.
Again, any help would be greatly appreciated.
HTML:
<div id="projects"> <!-- start of entire projects page -->
<div id="project-sidebar">
<a href="#project-first">
<div class="sidebar-item sidebar-first">first</div>
</a>
<a href="#project-second">
<div class="sidebar-item sidebar-second">second</div>
</a>
<a href="#">
<div class="sidebar-item sidebar-third">third</div>
</a>
</div>
<div id="project-content"> <!-- this must be the scrollable itmes' container, not the entire window -->
<div id="project-first" class="project-item">
<!-- these items should be scrollable -->
<div class="project-subitem" id="first-sub1">
<a href='#first-sub2' class='next'>next</a>
</div>
<div class='project-subitem' id='first-sub2'>
<a href='#first-sub1' class='prev'>prev</a>
</div>
<!-- end of scrollable items -->
</div>
</div> <!-- end of scroll scroll container -->
</div> <!-- end of entire projects page -->
<script>
// FIXME: when I set target, nothing scrolls.
// But I don't want the entire window to scroll
$('#projects').localScroll({
//target: '#project-content',
hash: false
});
</script>
CSS
#project-content {
width: 80%;
height: 100%;
position: relative;
float: left;
}
#project-sidebar {
float: left;
width: 20%;
height: 100%;
}
.project-item {
width: 300%;
height: 100%;
}
.project-subitem {
height: 100%;
width: 33.33%;
position: relative;
float: left;
}
Update:
After I added overflow:scroll to #project-content, the scrolling works as expected. All I need now is making scroll bars disappear in #project-content. I tried adding overflow:hidden to its parent but had no success. I also tried adding it to html, body, but then the entire document refuses to accept any scrolling functions like scrollTop().
Any help will be greatly appreciated!
Theory :
The technique is to use a parent container that is shorter than the child element with scrollbar. This image shows what I mean :
Practice :
In your case, I suggest using absolute positionning and negative bottom value on #project-content so it overflows it's parent container (#projects) at the bottom.
The point is now what negative value? It should be the same value as the with of a scroll but scrollbars are never the same width according to browsers. So I suggest giving a bigger value : -30pxto be sure it is hidden. You will just need to be carefull that you don't have content to close to the bottom that can be hidden on browesers with thin scrollbars.
This is the CSS you should add to your website :
#projects{
position: relative;
}
#project-content{
position: absolute;
top: 0;
left: 20%;
bottom: -30px;
/* remove:
height: 100%;
position: relative;
float: left;
padding-bottom: -15px
/*
}
scollbars take up around 20px so just make you scrollable div 20px taller and 20px wider and your scrollbars will be hidden:
#content {
background-color: red;
width: 520px;
height: 520px;
overflow: auto;
}
Example
It's kind of cheating but could you hide it behind the #content like this DEMO
#content {
background-color: red;
width: 500px;
height: 480px;
overflow: hidden;
}
#item-container {
width: 1500px;
height: 500px;
overflow: scroll;
}
If you know all containers that can be scrollable, you can hide scrollbar with CSS and a little bit of JS. For webkit-based browsers (safari, google chrome, opera) it will be CSS-only solution to set scrollbar width to 0. For IE, Firefox and other non-webkit browsers you should calculate scrollbar width that will be used as negative margin-right for you scrollable content.
To do so you should wrap your content into div with overflow-y:scroll to always show vertical scrollbar and hide this scrollbar with margin-right:-17px and parent overflow:hidden. Example is here. No need to set fixed width, nor height.
This is the way that used in jQuery Scrollbar. Hiding horizontal scrollbar is more complicated and requires to handle content changes to recalculate container height.
I basicly add padding:0 1em 1em 0; to the element where it is supposed to be hidden , this hides both scrollbars if parent has overflow: hidden. tune padding-bottom or only padding-right, if it is to hide only one of them.
1em is average width of scroll bars in most browsers :
http://jsfiddle.net/5GCsJ/912/
The solution to make the content itself with horizontal scroll.
Just increase the height of #main, and #content.
#main {
width: 500px;
height: 520px;
}
#sub-main {
overflow: hidden;
}
#content {
background-color: red;
width: 500px;
height: 520px;
overflow: auto;
}
#item-container {
width: 1500px;
height: 500px;
overflow: hidden;
}
.item {
width: 500px;
height: 500px;
font-size: 25em;
text-align: center;
float: left;
}
Use a script to create custom scrollbars.
http://manos.malihu.gr/jquery-custom-content-scroller/
Then use CSS(or modify script or change script config) to hide the custom scrollbars.
I did this crudely using jQuery and your example
Check this fiddle:
I simply detected the direction of the scroll-wheel and pushed the horiz-scroll bar with jQuery
$(document).ready(function(){
$('#content').bind('mousewheel', function(e){
var curScroll = $("#content").scrollLeft();
if(e.originalEvent.wheelDelta > 0) {
$("#content").scrollLeft(curScroll-500);
} else {
$("#content").scrollLeft(curScroll+500);
}
});
});
It is "crude" because I hard-coded some values like the 500px amount to scroll, you could write some more javascript to detect dynamically how much to scroll. Plus I don't know if the wheelDelta value will be +120 for up and -120 for down, for you and other users.
Also note that the scrolLeft() can be animated.. for smoother transitions.

Prevent scrolling past a certain point

I am trying to make a scrolling carousel, unlike other carousels this one doesn't jump from slide to slide but only allows the user to slowly move through them horizontally at a rate of 50px.
http://codepen.io/anon/pen/pyLfz
Problem is when clicking next, once the number 6 box comes into full view the script should not allow the user to go any further, same for when the number 1 box is in full view and prev link is clicked, the user should not be allowed to scroll back anymore.
Right now I can't figure out how to do that.
HTML:
<div class="carousel">
<div class="slide">
<article class="pod">1</article>
<article class="pod">2</article>
<article class="pod">3</article>
<article class="pod">4</article>
<article class="pod">5</article>
<article class="pod">6</article>
</div>
</div>
Prev
Next
CSS:
.carousel {
position: relative;
border: 1px solid red;
width: 250px;
height: 100px;
overflow: hidden;
}
.carousel .slide {
overflow: hidden;
position: absolute;
width: 600px;
}
.carousel .slide .pod {
width: 100px;
height: 100px;
line-height: 100px;
text-align: center;
background: blue;
box-shadow: 0 0 18px white;
color: #fff;
float: left;
}
jQuery:
$('.next').on('click', function() {
$('.slide').animate({
left: '-=50'
});
});
$('.prev').on('click', function() {
$('.slide').animate({
left: '+=50'
});
});
Your .carousel class need to have the same width at your .pod because you have the .carousel acting as a viewport. Also, change 50px to 100px for your .animate().
Here is my version with the changes suggested:
http://codepen.io/anon/pen/hcewq
EDIT
Sorry. I put the 50px offsets back. I have boundary checks as before but the issue issue is the clicking versus the timing of the animation. So, you need to check if your slider is going past its boundaries and have an animation flag check to see if the previous animation is complete or it will not get the latest offsets.
Here is the update: http://codepen.io/anon/pen/KJBzy
You need to use some math to determine if you're at the end or not.
Here is your pen, forked: http://codepen.io/chrisrockwell/pen/dxqbp
The main part is in the if statement for your next action:
if (Math.abs(slideOffset.left) <= ($slide.width() - $('.carousel').width() - moveBy)) {
$slide.animate({
left: next
});
}
With this structure you are able to easily add .pod's because, in your CSS, you can give .slide a ridiculously large width (10000em, for example) and it will still work. You can also change the width of the .pod's without having to modify anything but the CSS. Finally, you can change the amount it moves by, should you ever need to, by changing just one variable.
To cover all scenarios, you would need to add in more checks, but this should get you started.

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