Develop Reference

why is child element's width changing when parent's width changes?

I am trying to create a tooltip element that has a min width of 50px and a max width of 200px. I place the tooltip element inside another element so that I can easily control when the tooltip appears or disappears when there is a hover event on the parent.
The problem that I have is that the tooltip element's width appears to be controlled by the parent's width even though I specified that the child(tooltip) has an absolute position.
let p = document.getElementById( 'parent' );
let b = true;
setInterval( ()=> {
b = !b;
let w = 10;
if( b ) {
w = 300;
}
p.style.width = `${w}px`
}, 5000 );
#parent {
background-color: cyan;
width: 100px;
height: 25px;
position: relative;
transition: width 2s;
}
#tooltip {
position: absolute;
top: calc( 100% + 5px );
left: 5px;
min-width: 50px;
max-width: 200px;
background-color: yellow;
padding: 5px;
border: 1px solid black;
}
<div id="parent">
<div id="tooltip">
My long tooltip text that wraps to multiple lines as needed.
</div>
</div>
I would like the tooltip (yellow div) to keep it's size at 200px in this example, but we can see that when the parent changes width, the tooltip width also changes. Why?
Is there a way to fix this problem?
Clarification: In this example: https://codepen.io/anon/pen/ePPWER we see that the tooltip text looks nice on one line. I don't want the tooltip's div to change its width when the parent changes width, because it forces the tooltip text to wrap onto 2 lines which is undesirable.

If we check the specification related to the width of absolutely positioned element we can read this:
'width' and 'right' are 'auto' and 'left' is not 'auto', then the width is shrink-to-fit . Then solve for 'right'
So in your case the width of your element is shrink to fit:
Calculation of the shrink-to-fit width is similar to calculating the
width of a table cell using the automatic table layout algorithm.
Roughly: calculate the preferred width by formatting the content
without breaking lines other than where explicit line breaks occur,
and also calculate the preferred minimum width, e.g., by trying all
possible line breaks. CSS 2.1 does not define the exact algorithm.
Thirdly, calculate the available width: this is found by solving for
'width' after setting 'left' (in case 1) or 'right' (in case 3) to 0.
Then the shrink-to-fit width is: min(max(preferred minimum width,
available width), preferred width).
To make it easy, and without considering the min/max-width, the width of your element will try to fit the content without exceding the width of its parent container (containing block). By adding min/max-width you simply add more constraint.
One idea of fix it to remove positon:relative from the parent element so that it's no more the containing block of the position:absolute element (it will be the initial containing block which is wide enough to avoid the available width constraint).
Then use margin instead of top/left to control the position:
let p = document.getElementById( 'parent' );
let b = true;
setInterval( ()=> {
b = !b;
let w = 10;
if( b ) {
w = 300;
}
p.style.width = `${w}px`
}, 5000 );
#parent {
background-color: cyan;
width: 100px;
height: 25px;
transition: width 2s;
}
#tooltip {
position: absolute;
margin-top: 30px;
min-width: 50px;
max-width: 200px;
background-color: yellow;
padding: 5px;
border: 1px solid black;
}
<div id="parent">
<div id="tooltip">
My long tooltip text that wraps to multiple lines as needed.
</div>
</div>

ID Tooltip is being used under Parent. When parent's width changes, it also suggest that tooltip's total width is changed. Since you have used mix-width and max-width it will expand till it reaches max-width. If you want it to be fixed then simple use width.

It is because the .parent has a position: relative. This will keep all children (position: absolute included) as confined by the parent div.
Not sure if this will work for you because it is pulling the tooltip out of the parent and making it's own with span wrapping the text. Alternatively, you'll need to change the parent from being relative otherwise it'll continually affect the child.
let p = document.getElementById('parent');
let b = true;
setInterval(() => {
b = !b;
let w = 10;
if (b) {
w = 300;
}
p.style.width = `${w}px`
}, 5000);
#parent {
background-color: cyan;
width: 100px;
height: 25px;
transition: width 2s;
position: relative;
}
#root {
position: relative;
}
#tooltip {
width: 100%;
}
#tooltip span {
position: absolute;
top: calc( 100% + 5px);
left: 5px;
min-width: 50px;
max-width: 200px;
background-color: yellow;
padding: 5px;
border: 1px solid black;
}
<div id="root">
<div id="parent"></div>
<div id="tooltip">
<span>My long tooltip text that wraps to multiple lines as needed.</span>
</div>
</div>

AngularJS UI Bootstrap merge two progress bars

I have set up two progress bars in UI Bootstrap, however my goal is to merge them into one, main bar and a secondary one which only is in the form of a vertical bar.
Here is the HTML code for my progress bars:
<div>
<h3 class="inline-block no-margin">Main</h3>
<uib-progressbar value="95"
class="progress-xs no-radius"
type="success"></uib-progressbar>
<h4 class="no-margin">SubCategory</h4>
<uib-progressbar value="50"
class="progress-xs no-radius no-margin"
type="danger"></uib-progressbar>
</div>
My question is how can I merge these two so that the secondary one only appears as a small vertical bar on the main bar?
So that the main bar showing 95% of the bar and the subcategory showing only a vertical bar at 50%.
There is an example similar to this in here called limit lines, but it is another old library.

You can make use of ng-style to update the position of a vertical line div in order to solve this problem. This will allow you to easily set the position and value of the vertical bar. Check out this working example on plunkr.:
HTML
<uib-progressbar animate="false" value=95 type="success"><b>95%</b></uib-progressbar>
<div id="vertical-mark" ng-style="style()"> {{mark}}%</div>
JS
$scope.mark = 50;
$scope.style = function() {
return {
'left': $scope.mark + '%'
}
}
CSS
#vertical-mark {
position:relative;
border-left:1px solid #000;
height:50px;
top:-57px;
}
As an alternative I've also added a similar implementation with a stacked progress-bar.

I haven't tried this out on my own, but it's what came to mind when I saw your question.
You could modify the CSS of the ui-progressbars such that they were overlaid on one another; perhaps with an position:absolute or what have you. This would allow the numerical markers to all sit next to each other like you want.
Next, you could modify the CSS of the bars themselves. Any bars less than the max, perhaps give them a .no-fill class or something. It would be tricky, but that way you can have any bars less than max % to only consist of a border-right property, while the max % bar would be the one with the background and all the normal progress bar styles.
A gotcha that might show up is that you may also have to order the bars' z-index so that the largest value bar sits behind the lesser values and their vertical lines show up.
Good luck!
FINAL UPDATE (with plunkr)
JS
$scope.stacked = [{
value: 55,
type: 'info'
}, {
value: 95,
type: 'success'
}];
HTML
<div class="progress-wrapper">
<uib-progress max="100" ng-repeat="bar in stacked | orderBy:'value':true">
<uib-bar value="bar.value" type="{{bar.type}}">
<span class="marker" ng-hide="bar.value < 5">
{{bar.value}}%
</span>
</uib-bar>
</uib-progress>
</div>
CSS
/* wrapper to help us contain the bars and their positioning */
.progress-wrapper {
position: relative;
padding-top: 30px;
}
/* make all progress bars the same, no bg so they 'stack' */
.progress-wrapper .progress {
width: 100%;
position: absolute;
overflow: visible;
background: none;
}
/* first child is the background bar, give it color */
.progress-wrapper .progress:first-child {
background: #EEE;
}
/* make all bars invisible and with a right, border;
except the last/furthest back bar, give it color only
*/
.progress-wrapper .progress .progress-bar {
background: none;
border-right: solid 2px #FFF;
}
.progress-wrapper .progress:first-child .progress-bar {
background: #0AF;
border-right: none;
}
/* makes sure that markers behave,
otherwise they'll fly away
*/
.progress .progress-bar {
position: relative;
}
/* style for marker element and drop triangle */
.progress .marker {
position: absolute;
padding: 0 2px;
top: -30px;
right: -15px;
color: #FFF;
background: #000;
}
.progress .marker:after {
content: '';
width: 10px;
height: 10px;
background: #000;
position: absolute;
left: 30%;
bottom: -5px;
transform: rotate(45deg);
}

You can make use of stacked progressbar with some custom styles.
<uib-progress><uib-bar ng-repeat="bar in stacked track by $index" value="bar.value" type="{{bar.type}}"><span ng-hide="bar.value < 5">{{bar.value}}%</span></uib-bar></uib-progress>
$scope.stacked = [{
value: 10,
type: 'info'
}, {
value: 35,
type: 'success'
}];
});
Refer progressbar in this https://angular-ui.github.io/bootstrap/
My example is here https://plnkr.co/edit/9qCP1lV40BQ9DYDHvayo?p=preview
I have edited the code in stacked progressbar. Think this helps.
You can add custom styles to this to show the progress value.

Setting a length (height or width) for one element minus the variable length of another, i.e. calc(x - y), where y is unknown

I know we can use calc when lengths are defined:
flex-basis: calc(33.33% - 60px);
left: calc(50% - 25px);
height: calc(100em/5);
But what if a length is variable?
height: calc(100% - <<header with variable height>>);
OR
width: calc(100% - 50px - <<box with variable width>>);
Is there a standard way to do this in CSS?
I know the overall task is possible with flexbox and tables, but I'm wondering if CSS offers a simpler method. Flexbox, tables and simple Javascript are acceptable alternatives.
height demo
width demo

You can use CSS tables:
.wrapper {
display: table;
width: 100%;
margin: 15px 0;
}
.horizontal.wrapper > div {
display: table-cell;
white-space: nowrap; /* Prevent line wrapping */
border: 1px solid;
}
.left { width: 100px } /* Minimum width of 100px */
.center { width: 0; } /* Width given by contents */
.vertical.wrapper { height: 200px; }
.vertical.wrapper > div {
display: table-row;
}
.vertical.wrapper > div > span {
display: table-cell;
border: 1px solid;
}
.top { height: 100px; } /* Minimum heigth of 100px */
.middle { height: 0; } /* Height given by content */
.bottom { height: 100%; } /* As tall as possible */
<div class="horizontal wrapper">
<div class="left">100px wide</div>
<div class="center">Auto width, given by contents</div>
<div class="right">Remaining space</div>
</div>
<div class="vertical wrapper">
<div class="top"><span>100px tall</span></div>
<div class="middle"><span>Auto height, given by contents</span></div>
<div class="bottom"><span>Remaining space</span></div>
</div>
The horizontal case can also be achieved with floats:
#wrapper, .right { overflow: hidden; } /* Establish BFC */
#wrapper > div { border: 1px solid; }
.left, .middle { float: left; }
.left { width: 100px }
<div id="wrapper">
<div class="left">100px</div>
<div class="middle">Auto width, given by contents</div>
<div class="right">Remaining space</div>
</div>

Flexbox can do that.
Support is IE10 and up.
JSfiddle Demo
* {
margin: 0;
padding: 0;
}
html,
body {
height: 100%;
}
#container {
height: 100%;
display: flex;
flex-direction: column;
}
#top {
background-color: lightgreen;
}
#bottom {
background-color: lightblue;
flex: 1;
}
<div id="container">
<div id="top">green box variable height</div>
<div id="bottom">blue box no longer overflows browser window</div>
</div>

I'm looking for something simple and portable. In the same way a CSS
property can be easily applied across documents, I'm looking for
something similar in terms of ease-of-application for this function.
... isolated fix is preferred.
Horizontal:
This can be achieved using CSS only. As you do not prefer a flex layout solution, the next best bet would be a table layout.
A simple CSS snippet which you could drop into your project (and be done with) would look like this:
div.flexh {
display: table; box-sizing: border-box; padding: 0; margin: 0;
}
div.flexh > div {
display: table-cell; width: auto;
box-sizing: border-box; vertical-align: middle;
}
div.flexh > div:first-child {
/* Override your custom styling below */
min-width: 75px; width: 75px; max-width: 75px;
}
div.flexh > div:last-child { width: 100%; }
You can then add your site-specific styling to this base CSS as per site requirements. Like, nowrap etc.
Two apparent advantages of this solution are:
You do not need to change your markup and also do not need to decorate all children with classes. Just apply the class flexh to your parent div and that would be it.
Minimal Markup Required:
<div class="flexh">
<div>...</div>
<div>...</div>
<div>...</div>
</div>
You are not limited to just three columns. You could have as many columns as need be. The first one will have fixed width, the last one will be flexible, and all the columns in-between would get content-based widths.
Demo Fiddle: http://jsfiddle.net/abhitalks/qqq4mq23/
Demo Snippet:
div.flexh {
display: table; box-sizing: border-box; padding: 0; margin: 0;
/* Override your custom styling below */
width: 80%; border: 2px solid black;
border-right: 2px dashed black;
font-size: 1em;
}
div.flexh > div {
display: table-cell; width: auto;
box-sizing: border-box; vertical-align: middle;
/* Override your custom styling below */
background-color: lightgreen; border: 1px solid #ddd;
padding: 15px 5px;
}
div.flexh > div:first-child {
/* Override your custom styling below */
min-width: 75px; width: 75px; max-width: 75px;
background-color: orange;
}
div.flexh > div:last-child {
width: 100%;
/* Override your custom styling below */
background: skyblue;
}
<div class="flexh">
<div>75px Fixed Width</div>
<div>Variable Content Width</div>
<div>Flexible Remaining Width</div>
</div>
<hr/>
<div class="flexh">
<div>75px Fixed Width</div>
<div><img src='//placehold.it/128x48/66c' /></div>
<div>Flexible Remaining Width</div>
</div>
<hr/>
<div class="flexh">
<div>75px Fixed Width</div>
<div>Variable TextWidth</div>
<div>
<img src='//placehold.it/128x48/66c' />
<p>Variable ContentWidth</p>
</div>
<div>Flexible Remaining Width</div>
</div>
Vertical:
This is a bit tricky to achieve without flex layout. A table layout would not work here mainly because, the table-row would not keep a fixed height as required by your use-case. The height on a table-row or table-cell is only an indicative of the minimum height required. If the space is constrained, or the content exceeds the available space, then the cell or row will increase its height depending on the content.
As per the specs here: http://www.w3.org/TR/CSS21/tables.html#height-layout
The height of a 'table-row' element's box is calculated once the user
agent has all the cells in the row available: it is the maximum of the
row's computed 'height', the computed 'height' of each cell in the
row, and the minimum height (MIN) required by the cells...
...the height of a cell box is the minimum height required by the
content
This effect can be seen here: http://jsfiddle.net/abhitalks/6eropud3/
(Resize the window pane and you will see that the first row will increase in height as the content cannot be fit into the specified height, hence defeating the purpose)
Therefore, you can restrict the height indirectly either using inner markup like a div element, or let go of the table-layout and calculate the height for the flexible one. In your use-case, you prefer not to change the markup, hence I am not proposing an inner markup.
The best-bet here would be to use the time-tested model of plain block-level divs with the height of the flexible one to be calculated. As you have already discovered that it is not possible with CSS, you will need a small JavaScript snippet to do that for you.
A simple JavaScript snippet (no jQuery) which you could wrap in a window.load and drop into your project (and be done with) would look like this:
var flexv = document.querySelectorAll('div.flexv');
/* iterate the instances on your page */
[].forEach.call(flexv, function(div) {
var children = [].slice.call(div.children), // get all children
flexChild = children.splice(-1, 1), // get the last child
usedHeight = 0, totalHeight = div.offsetHeight;
children.forEach(function(elem) {
usedHeight += elem.offsetHeight; // aggregate the height
});
/* assign the calculated height on the last child */
flexChild[0].style.height = (totalHeight - usedHeight) + 'px';
});
The CSS snippet is more or less like the horizontal one, sans table layout, which also you could just drop into your project and just add the additional site-specific styling. Minimal markup required remains the same.
Demo Fiddle 2: http://jsfiddle.net/abhitalks/Ltcuxdwf/
Demo Snippet:
document.addEventListener("load", flexit);
function flexit(e) {
var flexv = document.querySelectorAll('div.flexv');
[].forEach.call(flexv, function(div) {
var children = [].slice.call(div.children),
flexChild = children.splice(-1, 1),
usedHeight = 0, totalHeight = div.offsetHeight;
children.forEach(function(elem) {
usedHeight += elem.offsetHeight;
});
flexChild[0].style.height = (totalHeight - usedHeight) + 'px';
});
}
div.flexv {
display: inline-table; box-sizing: border-box; padding: 0; margin: 0;
overflow: hidden;
/* Override your custom styling below */
height: 320px; width: 20%; border: 1px solid black; font-size: 1em;
margin: 8px;
}
div.flexv > div {
display: block; height: auto; box-sizing: border-box;
overflow: hidden;
/* Override your custom styling below */
background-color: lightgreen; border: 1px solid #ddd;
padding: 5px 15px;
}
div.flexv > div:first-child {
/* Override your custom styling below */
min-height: 36px; height: 36px; max-height: 36px;
background-color: orange;
}
div.flexv > div:last-child {
height: 100%;
/* Override your custom styling below */
background: skyblue;
}
<div class="flexv">
<div>36px Fixed Height</div>
<div>Variable Content Height</div>
<div>Flexible Remaining Height</div>
</div>
<div class="flexv">
<div>36px Fixed Height</div>
<div><img src='//placehold.it/64x72/66c' /></div>
<div>Flexible Remaining Height</div>
</div>
<div class="flexv">
<div>36px Fixed Height</div>
<div>Variable Text Height</div>
<div>
<img src='//placehold.it/72x48/66c' />
<p>Variable Content Height</p>
</div>
<div>Flexible Remaining Height</div>
</div>
Note: As pointed out by #LGSon, the display: inline-table used for the demo does not play well with Firefox. This is only for a demo and should be replaced by either block or inline-block as per your use-case.

Updated
As I commented earlier, and besides flex, this is also solvable using display: table and here is a fiddle demo I made showing that.
If a fixed top also were required for the vertical demo, here is an update of my original display:table version: fiddle demo
Sometimes I haven't been able (or didn't want) to use either flex nor tables, and I have, on and off, looked into making use of css calc() and css attr().
Both come short though, as calc() can only use +-*/ and attr() can only return a string value, which can't be computed by calc().
My suggestion, using plain javascript, is based on that these 2 methods, at some point, might be extended so we can make better use of them.
This is how I would like see them work;
width: calc(100% - attr(this.style.left))
but as they don't, and I can't add it to my css either as it wouldn't validate properly (might even break the parsing, who knows) I added a variant as an attribute on the element instead, with some quirks to make it easier to compute.
And in this case (the 2 demos) it looks like this:
//height
<div id="bottom" data-calcattr="top,height,calc(100% - toppx)">...</div>
//width
<div class="box right" data-calcattr="left,width,calc(100% - leftpx)">...</div>
Together with below script, which by no means is fully developed/tested on all property combinations, it does adjust the div's size.
In short, when runned, it take the attribute, split it into an array, take the first item value as from which property to read, the second to which property to set and the third to which the read value gets inserted/replaced and assigned to the property to be set (hmmm, still working on a better way to express this, but hopefully the script is clear enough with whats going on).
Here is a fiddle showing both the height and width demo, integrated, making use of the same script.
function calcattr() {
var els = document.querySelectorAll('[data-calcattr]');
for (i = 0; i < els.length; i++) {
var what = els[i].getAttribute('data-calcattr');
if (what) {
what = what.split(',');
var rect = els[i].getBoundingClientRect();
var parentrect = els[i].parentNode.getBoundingClientRect();
var brd = window.getComputedStyle(els[i].parentNode,null).getPropertyValue('border-' + what[0] + '-width');
what[2] = what[2].replace(what[0],parseInt(rect[what[0]]-parentrect[what[0]]) - parseInt(brd));
els[i].setAttribute("style", what[1] + ":" + what[2]);
}
}
}

IN CSS
Although I've never tried it, I believe that this would work:
.top {
height:13px;
}
.main {
height:calc(100% - var(height));
}
http://www.creativebloq.com/netmag/why-you-need-use-css-variables-91412904
IN SASS
$top_height: 50px
.main {
height: calc(100% - $top_height)
}
Sass Variable in CSS calc() function

In both cases on container css you should put:
#container {
overflow: hidden;
}
But, it will hide the information that overflows the container. I think that is the point, since you put white-space: nowrap; it means that you don't want to change the height, so you have to hide the text that can't fits the container.

amcharts chart insertion in Leaflet control

I'm coding a website in which i insert a chart in the map canvas, exactly as a legend would be inserted:
<>The graph plotter (cf http://www.amcharts.com/tutorials/your-first-chart-with-amcharts/)
function grapher(chartData) {
var chart = new AmCharts.AmSerialChart();
[...]
chart.addGraph(graph);
chart.write('chartdiv');
return chart;
};
<>The leaflet control (cf http://leafletjs.com/examples/choropleth.html)
var courbe = L.control({position: 'bottomleft'});
courbe.onAdd = function (map) {
var div = L.DomUtil.create('div', 'info legend');
div.id = "chartdiv"
div.style = "width: 400px; height: 200px;"
return div;
};
<>
courbe.addTo(map);
grapher(json);
On firefox, everything works fine. And checking the canvas element on firebug shows what desired, that is :
class="width: 400px; height: 200px; overflow: hidden; text-align: left;"
On chrome, the 400px by 200px frame is collapsed, as an empty leaflet control, and analogously :
class="overflow: hidden; text-align: left;"
Has my problem something to deal with this question : amCharts doesn't display chart for initially-hidden divs)
Safari behaves as Chrome. Actually, it only displays correctly with firefox. Why ?

Ok, I simply put the width and height parameters in my customized info css style, as follows :
.info {
padding: 6px 8px;
font: 12px/14px courier;
background: white;
background: rgba(255,255,255,0.8);
box-shadow: 0 0 15px rgba(0,0,0,0.2);
border-radius: 5px;
+ width: 400px;
+ height: 200px;
}

Javascript, HTML5 (canvas) progressbar with update

I'm looking for the best way to do a progress bar (in my case it's a life bar for a game) in an html5 canvas.
I don't know if it's better to use javascript and dom element, or draw this bar directly in the canvas.
I need an update function, for example myBar.updateValue(40), and I need to show the new bar without refresh all the page or all the canvas, of course.
Do you know something like that? An existing script? Thanks!

It’s very easy in HTML/CSS:
<style>
#progress-holder{width:400px;height:20px;background:grey}
#progress{width:0;height:100%;background:black}
</style>
<div id="progress-holder">
<div id="progress"></div>
</div>
<script>
var progress = document.getElementById('progress');
function updateValue(perc) {
progress.style.width = perc+'%';
}
updateValue(40);
</script>
DEMO: http://jsbin.com/EGAzAZEK/1/edit
And animating with CSS: http://jsbin.com/EGAzAZEK/3/edit

HTML:
<div class='progress'>
<div class='progress-bar' data-width='//Enter a percent value here'>
<div class='progress-bar-text'>
Progress: <span class='data-percent'>//This is auto-generated by the script</span>
</div>
</div>
</div>
CSS:
html, body {
margin: 0;
padding: 15px;
width: 100%;
height: 100%;
position: relative;
color: #fff;
}
.progress {
position: relative;
width: 100%;
height: 30px;
}
.progress-bar {
margin-bottom: 5px;
width: 0%;
height: 30px;
position: relative;
background-color: rgb(66, 139, 202);
}
.progress-bar-text {
position: absolute;
top: 0px;
width: 100%;
text-align: center;
/*
Do not change the values below,
unless you want your text to display away from the bar itself. */
line-height: 30px;
vertical-align: middle;
}
jQuery:
$('.progress-bar').each(function (){
var datawidth = $(this).attr('data-width');
$(this).find("span.data-percent").html(datawidth + "%");
$(this).animate({
width: datawidth + "%"
}, 800);
});
Link to JSFiddle
The HTML data-width attribute is used to track the percent the bar should be set to. Change it to your liking.
The jQuery script works with ALL progress bars on your page (See the JSFiddle, so you don't have to copy and paste the same jQuery for every new progress bar.
(Just be sure to keep the structure of the HTML, or change it to your liking).
The div "progress" is just an expander, it can be named whatever your want - without you having to change the jQuery.
EDIT:
If you can use Javascript & HTML, don't use a canvas. Canvas (imho) are good for only 1 thing: Seat bookings for concerts, theaters and alike.