I'm trying to understand what appears to be unexpected behaviour to me:
I have an element with a max-height of 100% inside a container that also uses a max-height but, unexpectedly, the child overflows the parent:
.container {
background: blue;
padding: 10px;
max-height: 200px;
max-width: 200px;
}
img {
display: block;
max-height: 100%;
max-width: 100%;
}
<div class="container">
<img src="http://placekitten.com/400/500" />
</div>
This is fixed, however, if the parent is given an explicit height:
.container {
background: blue;
padding: 10px;
max-height: 200px;
max-width: 200px;
height: 200px;
}
img {
display: block;
max-height: 100%;
max-width: 100%;
}
<div class="container">
<img src="http://placekitten.com/400/500" />
</div>
Does anyone know why the child would not honour the max-height of its parent in the first example? Why is an explicit height required?
When you specify a percentage for max-height on a child, it is a percentage of the parent's actual height, not the parent's max-height, oddly enough. The same applies to max-width.
So, when you don't specify an explicit height on the parent, then there's no base height for the child's max-height to be calculated from, so max-height computes to none, allowing the child to be as tall as possible. The only other constraint acting on the child now is the max-width of its parent, and since the image itself is taller than it is wide, it overflows the container's height downwards, in order to maintain its aspect ratio while still being as large as possible overall.
When you do specify an explicit height for the parent, then the child knows it has to be at most 100% of that explicit height. That allows it to be constrained to the parent's height (while still maintaining its aspect ratio).
.container {
background: blue;
padding: 10px;
max-height: 200px;
max-width: 200px;
float: left;
margin-right: 20px;
}
.img1 {
display: block;
max-height: 100%;
max-width: 100%;
}
.img2 {
display: block;
max-height: inherit;
max-width: inherit;
}
<!-- example 1 -->
<div class="container">
<img class='img1' src="http://via.placeholder.com/350x450" />
</div>
<!-- example 2 -->
<div class="container">
<img class='img2' src="http://via.placeholder.com/350x450" />
</div>
I played around a little. On a larger image in firefox, I got a good result with using the inherit property value. Will this help you?
.container {
background: blue;
padding: 10px;
max-height: 100px;
max-width: 100px;
text-align:center;
}
img {
max-height: inherit;
max-width: inherit;
}
Instead of going with max-height: 100%/100%, an alternative approach of filling up all the space would be using position: absolute with top/bottom/left/right set to 0.
In other words, the HTML would look like the following:
<div class="flex-content">
<div class="scrollable-content-wrapper">
<div class="scrollable-content">
1, 2, 3
</div>
</div>
</div>
.flex-content {
flex-grow: 1;
position: relative;
width: 100%;
height: 100%;
}
.scrollable-content-wrapper {
position: absolute;
left: 0;
right: 0;
top: 0;
bottom: 0;
overflow: auto;
}
.scrollable-content {
/* Add styling here */
}
Try it below:
.flex-content {
flex-grow: 1;
position: relative;
width: 100%;
height: 100%;
}
.scrollable-content-wrapper {
position: absolute;
left: 0;
right: 0;
top: 0;
bottom: 0;
overflow: auto;
}
html {
height: 50%;
width: 50%;
}
body {
height: 100%;
width: 100%;
}
.parent {
height: 100%;
outline: 1px solid red;
}
<html>
<body>
<div class="parent">
<div class="flex-content">
<div class="scrollable-content-wrapper">
<div class="scrollable-content" id="scrollable">
1, 2, 3
</div>
</div>
</div>
</div>
<button onClick="scrollable.innerText += '\nSome more text'" style="margin-top: 1rem;">Add Line</button>
<p>
The red outline represents the parent. Click above to add a line until overflow occurs to see that the size of the parent is not increased.
</p>
</body>
</html>
I found a solution here:
http://www.sitepoint.com/maintain-image-aspect-ratios-responsive-web-design/
The trick is possible because it exists a relation between WIDTH and PADDING-BOTTOM of an element. So:
parent:
container {
height: 0;
padding-bottom: 66%; /* for a 4:3 container size */
}
child (remove all css related to width, i.e. width:100%):
img {
max-height: 100%;
max-width: 100%;
position: absolute;
display:block;
margin:0 auto; /* center */
left:0; /* center */
right:0; /* center */
}
You can use the property object-fit
.cover {
object-fit: cover;
width: 150px;
height: 100px;
}
Like suggested here
A full explanation of this property by Chris Mills in Dev.Opera
And an even better one in CSS-Tricks
It's supported in
Chrome 31+
Safari 7.1+
Firefox 36+
Opera 26+
Android 4.4.4+
iOS 8+
I just checked that vivaldi and chromium support it as well (no surprise here)
It's currently not supported on IE, but... who cares ? Also, iOS supports object-fit, but not object-position, but it will soon.
Here is a solution for a recently opened question marked as a duplicate of this question. The <img> tag was exceeding the max-height of the parent <div>.
Broken: Fiddle
Working: Fiddle
In this case, adding display:flex to the 2 parent <div> tags was the answer
Maybe someone else can explain the reasons behind your problem but you can solve it by specifying the height of the container and then setting the height of the image to be 100%. It is important that the width of the image appears before the height.
<html>
<head>
<style>
.container {
background: blue;
padding: 10px;
height: 100%;
max-height: 200px;
max-width: 300px;
}
.container img {
width: 100%;
height: 100%
}
</style>
</head>
<body>
<div class="container">
<img src="http://placekitten.com/400/500" />
</div>
</body>
</html>
The closest I can get to this is this example:
http://jsfiddle.net/YRFJQ/1/
or
.container {
background: blue;
border: 10px solid blue;
max-height: 200px;
max-width: 200px;
overflow:hidden;
box-sizing:border-box;
}
img {
display: block;
max-height: 100%;
max-width: 100%;
}
The main problem is that the height takes the percentage of the containers height, so it is looking for an explicitly set height in the parent container, not it's max-height.
The only way round this to some extent I can see is the fiddle above where you can hide the overflow, but then the padding still acts as visible space for the image to flow into, and so replacing with a solid border works instead (and then adding border-box to make it 200px if that's the width you need)
Not sure if this would fit with what you need it for, but the best I can seem to get to.
A good solution is to not use height on the parent and use it just on the child with View Port :
Fiddle Example: https://jsfiddle.net/voan3v13/1/
body, html {
width: 100%;
height: 100%;
}
.parent {
width: 400px;
background: green;
}
.child {
max-height: 40vh;
background: blue;
overflow-y: scroll;
}
Containers will already generally wrap their content nicely. It often doesn't work as well the other way around: children don't fill their ancestors nicely. So, set your width/height values on the inner-most element rather than the outer-most element, and let the outer elements wrap their contents.
.container {
background: blue;
padding: 10px;
}
img {
display: block;
max-height: 200px;
max-width: 200px;
}
http://jsfiddle.net/mpalpha/71Lhcb5q/
.container {
display: flex;
background: blue;
padding: 10px;
max-height: 200px;
max-width: 200px;
}
img {
object-fit: contain;
max-height: 100%;
max-width: 100%;
}
<div class="container">
<img src="http://placekitten.com/400/500" />
</div>
Related
I have seen some web design lessons that always start with a css like this:
body,html {
display: block;
width: 100%;
height: 100%;
padding: 0;
margin: 0;
}
I'm trying to figure out what's the point of declaring attributes like width, height or display for body and html that are, if I'm not wrong, by default in browsers.
I thought it would be to prevent and undefined return or similar when accessing the css with js, but the result is the same when the attributes are defined in the css than when left to default:
console.log($("BODY").css('width')); // Always returns the width of the body
I also thought it could be to start the inheritance in cascade elements, but a div inside the body inherits the value just the same.
Anybody knows a solid reason for this approach? any browser / device issue I have missed? future compatibility? plain pedantry?
I'm kind of curious about it.
I found a good reason to define the html and body width and height to 100%. Say you want to vertically align a relative positioned div, you need to put it into an absolute positioned container:
html,
body {
margin: 0;
padding: 0;
}
#container {
position: absolute;
width: 100%;
height: 100%;
}
#main {
background: lightgrey;
position: relative;
top: 50%;
transform: translateY(-50%);
width: 100px;
height: 100px;
text-align: center;
margin-left: auto;
margin-right: auto;
}
<div id="container">
<div id="main">
<h1>MY DIV</h1>
</div>
</div>
But, setting the body width and height to 100% you get an absolute positioned container that covers the whole window:
html,
body {
margin: 0;
padding: 0;
width: 100%;
height: 100%;
}
#main {
background: lightgrey;
position: relative;
top: 50%;
transform: translateY(-50%);
width: 100px;
height: 100px;
text-align: center;
margin-left: auto;
margin-right: auto;
}
<div id="main">
<h1>MY DIV</h1>
</div>
You get the same result, but it saves you a div element.
I have few thumbnail image of users and their image can be portrait or wide.
I wish the thumbnails to be in a circle without lose the aspect ratio of it.
So I created a container for each image like that:
<div class='container'>
<img src='' ... />
</div>
With this css:
.container {
border-radius: 50%;
overflow: hidden;
position: relative;
width: 50px;
height: 50px;
img {
width: inherit;
}
}
it works fine with portrait images because the image width inherit from the container.
The problem now is to adapt the same to wide images... I should replace the width with height in order to let in work as expected.
There is a better solution of mine?
Or there is a way with Less to achieve at this?
You should leave the width/height unset and set the max-width/max-height to 100%.
img {
max-width: 100%;
max-height: 100%;
}
This will only downscale images though, not upscale.
width: fit-content; height: fit-content;
.container{
width: 50px;
height: 50px;
border: 1px solid black;
border-radius: 50%;
overflow: hidden;
}
.container > img{
object-fit: cover;
width: 100%;
height: 100%;
}
<div class='container'>
<img src='http://searchengineland.com/figz/wp-content/seloads/2015/12/duckduckgo-logo-wordmark4-1920.png' alt='duck power'>
</div>
Here is the code. I want the DIV.fixed-nav (position:fixed) to completely fit its parent DIV.container of which width may change. Is there a pure CSS solution for this?
CSS:
body {
margin: 0;
padding: 0;
}
.container {
border: 1px solid #000000;
margin: 0 auto;
max-width: 600px;
min-width: 400px;
}
.fixed-nav {
background-color: red;
height: 20px;
position: fixed;
width: 100%;
top: 0;
z-index: 99;
}
.content {
background-color: green;
height: 100px;
margin-top: 20px;
}
HTML:
<div class="container">
<div class="fixed-nav">
</div>
<div class="content">
</div>
</div>
Please check the DEMO.
The problem with fixed is that it will always be relative to the browser window. So if you set 100% height on your fixed container it will be 100% of the browser window.
The only way I could think of to achieve this is to use jQuery. Or if you don't need the menu to be fixed and it could be absolute then height 100% will work.
Safari for Windows is not calculating img height correctly within absolutely positioned div. The styling works fine on Chrome and Firefox.
http://jsfiddle.net/Wh2Tr/
HTML:
<div class="image">
<div class="image-inner">
<img src="http://lorempixel.com/400/200" />
</div>
</div>
CSS:
.image {
position: relative;
max-width: 100%;
height: 0;
padding-bottom: 75%;
}
.image-inner {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
z-index: 0;
}
.image img {
width: auto;
max-height: 100%;
margin: 0 auto;
display: block;
}
Caveats:
This is a simplification of the HTML. There are multiple images of varying sizes which need to have the same height (so using width:100%;height:auto; won't work)
This needs to be adaptive/responsive, so I can't set an explicit width or height to the image or container.
Same problem, I've used jquery. I couldn't find any solution till now:
$('.image-inner').css('height','100%').height($('.image-inner').height());
On the class image put height to auto. That should fix it. http://jsfiddle.net/Wh2Tr/1/
.image {
position: relative;
max-width: 100%;
height: auto;
padding-bottom: 75%;
}
Why does height: 100% have no effect on #baz in the following code? How could you fix this when min-height on (some of) the ancestor element(s) is required?
HTML:
<div id="foo">
<div id="bar">
<div id="baz">
foo bar baz
</div>
</div>
</div>
CSS:
div { border: 3px solid red; padding: 5px; }
#foo { height: 300px; }
#bar { min-height: 100%; }
#baz { height: 100%; }
See example at http://jsfiddle.net/pmmyP/
Tested with Chrome 12 and Firefox 4.
Using the following kind of works:
#bar { min-height: 100%; position: relative; }
#baz { position: absolute; top: 0; bottom: 0; left: 0; right: 0; }
But is there another (or better) way?
Example at http://jsfiddle.net/pmmyP/1/
Don't use min-height when you want height
min-height means it can't go smaller. height: 100% means 100% of the parent element's height (which isn't specified and so it defaults to auto I think).
#bar, #baz { height: 100%; box-sizing: border-box; }
The box-sizing is so that they stay inside each other.
http://jsfiddle.net/Zweu7/1/
Explanation of min-height: http://www.dynamicsitesolutions.com/css/height-and-min-height/