Hover a div with NgClass - html

I am trying to make a hover effect on a div with a Angular ngClass directive. In the template file I have a div element with class "list-item-container' which contains a div with class "list-item" that is iterated with a *ngFor directive. Inside the "list-item" div element I have three divs with class "list-item-column" which are placed horizontally like a table row with inline display. in the div with "list-item" class I have placed a mouseenter and mouseleave event listeners which calls hoverListItem() in my .ts file. the hoverListItem() function changes the value of listItemHovered variable to true or false. In the "list-item" class I have a ngClass directive which triggers a css class 'list-item-highlight' based on the value of listItemHovered boolean value which then changes to background to a different color.
The problem I'm facing is that upon hovering mouse pointer on the "list-item" div all my "list-item" divs are affected instead of the one I am hovering over. How to solve this problem?
.html file
<div class="list-item-container">
<ng-container *ngFor="let opportunity of dealService.opportunities">
<div [ngClass]="{'list-item-highlight': listItemHovered}" class="list-item" (mouseenter)="hoverListItem()"
(mouseleave)="hoverListItem()"
(click)="selectOpportunity(opportunity)">
<div
class="list-item-column">{{opportunity.account?.name === null ? "N/A" : opportunity.account.name}}</div>
<div class="list-item-column">{{opportunity.requirementTitle}}</div>
<div class="list-item-column">{{opportunity.salesValue | number: '1.0-2'}}</div>
</div>
</ng-container>
</div>
.css file
.list-item-container{
overflow: auto;
width: 100%;
max-height: 500px;
}
.list-item{
font-size: 15px;
border-radius: 10px ;
margin-top: 5px;
height: 50px;
background: lightgray;
color: black;
}
.list-item-highlight{
background: #7e00cc;
color: white;
}
.list-item-column{
height: inherit;
vertical-align: center;
display: inline-block;
width: 33.33%;
padding-left: 40px;
}
.ts file
hoverListItem() {
this.listItemHovered = !this.listItemHovered;
}

Right now you're creating and modifying listItemHovered flag inside component context, rather you should maintain a flag for each item level, which could help to easily identify wheather component has been highlighted or not.
[ngClass]="{'list-item-highlight': opportunity.listItemHovered}"
(mouseenter)="hoverListItem(opportunity)"
(mouseleave)="hoverListItem(opportunity)"
Component
hoverListItem(opportunity) {
opportunity.listItemHovered = !opportunity.listItemHovered;
}
Though I'd recommend to use :hover pseudo class if requirement is just to highlight the element on hover. That can be easily doable by changing CSS rule. This way could save several change detection cycle to be ran.
.list-item:hover {
background: #7e00cc;
color: white;
}

I would suggest use a directive to listen to the hover event on the target element and attach the class:
#Directive({
selector: '[hoverDir]'
})
export class HoverOverDirective {
#HostListener('mouseenter') onMouseEnter() {
this.elementRef.nativeElement.class = 'list-item-highlight';
}
#HostListener('mouseleave') onMouseLeave() {
this.elementRef.nativeElement.class = 'list-item-not-highlight';
}
}
Or the easiest way is to make use of CSS pseudo property :hover and use it as below:
.list-item:hover {
background: #7e00cc;
color: white;
}

Related

Show/hide images with only HTML, CSS using CSS variables

Here I'm trying to change the CSS variable's value (visibility) when the button is clicked on (using :focus) to show/hide the images, without using Javascript.
CSS
img {
width: 200px; height: 200px; margin-left: 40px; margin-top: 30px;
}
:root {
--c1-vsb: none; --c2-vsb: none;
}
a.c1-imgs {
visibility: var(--c1-vsb);
}
a.c2-imgs {
visibility: var(--c2-vsb);
}
#C1:focus {
background-color: red;
--c1-vsb: hidden;
}
#C2:focus {
background-color: red;
--c2-vsb: hidden;
}
HTML
<html>
</head>
<body>
<div id="left-panel">
<button class="lp-btn" id="C1">SEAL 1</button><br>
<button class="lp-btn" id="C2">SEAL 2</button><br>
</div>
<div id="right-panel">
<a class="c1-imgs"><img src="https://files.worldwildlife.org/wwfcmsprod/images/HERO_harbor_seal_on_ice/hero_full/87it51b9jx_Harbor_Seal_on_Ice_close_0357_6_11_07.jpg"></a>
<a class="c2-imgs"><img src="https://www-waddensea-worldheritage-org.cdn.gofasterstripes.download/sites/default/files/styles/inline_image_full_width/public/20-11-09_habour%20seals%20report_TTF_5200.JPG?itok=YZs9c_dH"></a>
</div>
</body>
</html>
But for some reasons, when I clicked on the button to set visibility to hidden, the images do not get hidden away.
Previously, I tried hiding the images with css pseudo classes and display:none, z-order... but got stuck. In the end, I thought this should have been the simple way out.
Could you suggest a solution to this problem I'm having? I'm not too sure if this is the correct approach.
Thank you!
When you declare #C1:focus { --c1-vsb: hidden; }, the new value of --c1-vsb only applies to #C1, not the entire HTML document.
As MDN states: "[...] the selector given to the ruleset defines the scope that the custom property can be used in".
With css, you can only Show/hide with mouse handle. You don't change 2 state (Show/Hide) when click into button.

Target a nested div coming from an external component

I am using an imported component which I can't change.
This component has a lot of nested divs.
Somewhere deep in these divs, I need to add a bottom margin to it.
Via Chrome DevTools, I am able to add the margin in one of the divs and achieve the
margin I want. But unable to get it to work when I try to add my css into my scss file.
How can I do this?
const MyComponent = props => {
return (
<div>
{/* This component is not in my control. I can't modify this component*/}
<ImportedComponent/>
</div>
);
};
When I see it in Chrome DevTools, the CSS is something like this.
If I were to add a margin style near the aCssClass or within the block of aCssClass via Chrome,
I get the margin I need. But as said, able to achieve in Chrome DevTools, but not via my scss file.
<div class="my-own-class">
<!-- This is all coming from ImportedComponent, each div has some css class -->
<div>
<div>
<div class="aCssClass anotherClass"> <!-- i want to be able to add my margin here, able to do it but only via Chrome dev tools-->
<div>
<div>
Some data
</div>
</div>
</div>
</div>
</div>
</div>
These are the styles I tried which makes no difference.
.my-own-class {
margin-bottom : 1em;
}
.my-own-class > div:nth-child(3) {
margin-bottom : 22px;
}
.my-own-class body .aCssClass {
margin-bottom: 22px;
}
body .aCssClass {
margin-bottom: 22px;
}
body > .aCssClass {
margin-bottom: 22px;
}
.my-own-class .aCssClass {
margin-bottom: 22px;
}
.my-own-class > .aCssClass {
margin-bottom: 22px;
}
Screenshot
At the highlighted portion, I added margin-bottom 10px under body .sc_marginRight_0 on the right panel which works.
i think it's just a specificity problem, try adding !important and it will work just fine.
.my-own-class .aCssClass {
margin-bottom: 22px !important;
}

Not able to change tab's height, colour in Angular 6

I'm new Angular, CSS and Html.
I have used MatTabsModule(import { MatTabsModule } from '#angular/material/tabs';) to create tabs but I'm able to adjust/change height, background etc. In short I'm not able to override default properties of MatTabsModule's classes. Please help me.
Below is my CSS and Html code. I hope Typescript code is not needed.
HTML: -
<mat-card>
<mat-card-content>
<mat-tab-group class="tab-group" dynamicHeight>
<mat-tab *ngFor="let obj of tags">
<ng-template mat-tab-label>{{ obj.name }}</ng-template>
<div class="tab-content">
{{ obj.name }}
</div>
</mat-tab>
</mat-tab-group>
</mat-card-content>
CSS: -
.tab-group {
border: 1px solid #e8e8e8;
margin-bottom: 30px;
.unicorn-dark-theme & {
border-color: #464646;
}
}
.tab-content {
padding: 16px;
}
mat-card{
padding: 0px;
}
.mat-tab-label .mat-ripple {
min-width: 0;
height: 30px;
}
I'm not able to change height width background colour of these tabs.. :(
You cannot access the styles of child components from your css-file as the ViewEncapsulation.Emulated prevents styles from leaking to the rest of the app (as it should, don't change it).
If you use the ng-deep-selector like this: :host ::ng-deep mat-tab { ... } you can override default material styles that cannot be configured in any other way. I say that because making css leak from a component is considered a bad practice and if possible you should use #Input to pass on styles.
By the way, the :host is there so the styles leak only to this components children and not to the rest of the app
To override default style of angular material elements you need to prefix ::ng-deep in CSS style.
This is how you can control height and width of tabs
::ng-deep .mat-tab-label{
height: 27px !important;
min-height: 0px!important;
margin: 3px!important;
}

CSS: Prevent parent element getting :active pseudoclass when child element is clicked

JSFiddle
When you click the button, you see that :active pseudoclass is triggered for the parent div. Is there a pure CSS (or some JS library) way of :active pseudoclass not toggling on button click?
I tried z-index, position: absolute & fixed and no success.
From the spec:
Selectors doesn't define if the parent of an element that is ‘:active’ or ‘:hover’ is also in that state.
That means it's implementation dependent. If an implementation chose to act this way (as current browsers obviously do), there's nothing in the standard that can change that.
With CSS4, you might be able to do:
.parent:active:not(:has(:active)) {
color: red;
}
but that is neither available nor finalized yet.
If you really want to solve this with CSS only:
If your button is active, add a :before-pseudo-element and with position: absolute; give the :before the same background as the parents.
button:active::before {
content: '';
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
background-color: #eee;
z-index: -1;
}
Now all that is needed is that the parent is :
position: relative;
z-index: 0;
Have a look: http://jsfiddle.net/s0at4w4b/4/
This does not solve the underlying issue, but is a solution for your current problem.
I don't think :has pseudo-class will ever be available in stylesheets. If browsers finally decide to implement it, it will probably be only for JS APIs like querySelector.
However, I have much more hopes for :focus-within, which seems much simpler to implement.
#parent:active:not(:focus-within) {
background-color: red;
}
Of course, it will only prevent :active from being applied to #parent when clicking a focusable element like a button. You can make other elements focusable by adding tabindex = "-1"
Sadly, :focus-within is not widely supported, but you can use a JS polyfill.
#parent {
border: 1px solid black;
width: 300px;
height: 300px;
}
#parent:active:not(.focus-within) {
background-color: red;
}
<script src="https://gist.githubusercontent.com/aFarkas/a7e0d85450f323d5e164/raw/"></script>
<div id="parent">
<button>Click me</button>
<p tabindex="-1">Or me</p>
</div>
Github does not allow hotlinking, so the snippet above might not work unless you copy the polyfill to your server and use it.
Perhaps the simplest way of achieving what you probably really want to do is to put not put the button inside the div you don't want activated.
Here, you have a container div, which contains a background div (the equivalent of the parent div in your original example). The background div has an active state separate from the button's.
.container {
position: relative;
width: 200px;
height: 200px;
}
.background {
position: absolute;
width: 100%;
height: 100%;
border: 1px solid black;
background-color: #eee;
}
.background:active {
background-color: red;
}
button {
position: relative;
}
<div class="container">
<div class="background"></div>
<button>Click me!</button>
</div>
This may or may not work for you, but this is how I achieve it with pure CSS. The only caveat is the dependence of focus-within which isn't supported by IE or Edge.
.parent {
transition: background-color;
}
.parent:active:not(:focus-within) {
background-color: red;
transition-delay: 1ms; // Delay one cycle to allow child to focus
}
What's going on here is, the parent element will get the active state, as will the child that gets clicked. The only difference is that the focus will apply to the child element, but only on the next cycle. To circumvent any animations from while in this 2 step process, apply a 1ms delay. The next cycle, the element will be active, but the focus will be applied to the child. Thus, the parent will not apply the transition. I would imagine animation delay: 1ms would work the same way.
Another alternative is to give the item a tabindex=-1 attribute and use
.parent {
transition: background-color;
}
.parent:active:focus {
background-color: red;
}
The only issue with this is the fact it may change keyboard navigation behavior and relies on some HTML as well. If you do want keyboard navigation use tabindex=0 or any value besides -1. But there's no JS used.
There are some nice polyfills for focus-within that you can use for IE/Edge but that would go outside "CSS Only".
But, we can put both of them together to create this:
.parent {
transition: background-color;
}
.parent[tabindex]:active:focus {
background-color: red;
}
.parent:active:not(:focus):not(:focus-within) {
background-color: red;
transition-delay: 1ms;
}
This works on IE11, Edge, and Chrome.
http://jsfiddle.net/s0at4w4b/42/
here's a jquery solution instead of using the css pseudo class :active
$(document).ready(function() {
$('button').mousedown(function(e){
e.stopPropagation();
console.log('i got clicked');
});
$('div').mousedown(function(e){
$('div').css('background', 'red')
}).mouseup(function(e){
$('div').css('background', '#eee')
});
$(document).mouseup(function(e){
$('div').css('background', '#eee')
});
});
div {
width: 200px;
height: 200px;
background-color: #eee;
border: 1px solid black;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<button>Qlick me</button>
</div>
As far as I know, the the active state will bubble up. So all parent nodes will have an active state.
Therefore, I don't now of a pure CSS solution. You can avoid a javascript solution (which I assume is what you're really after), by altering the markup so that the div that has an active state is no longer a parent of the button. You can make them siblings, for example.
The CSS part of that solution is then fixing the layout so it appears the same now that they are sibilings as what it did when they were parent>child.
Without seeing a fiddle of what you're working with, I can't offer you a more specific solution I'm afraid.
try this
html:
<div class="current" id="current">
<button id="btnclick" >Qlick me</button>
</div>
css script:
div {
width: 200px;
height: 200px;
background-color: #eee;
border: 1px solid black;
}
.current_active{
background-color: red;
}
jquery:
$("#btnclick").click(function(){
$("#current").toggleClass("current_active");
});
JSFiddle
ps: include the jquery library file
The :active pseudo-class applies while an element is being activated by the user. For example, between the times the user presses the mouse button and releases it. On systems with more than one mouse button, :active applies only to the primary or primary activation button (typically the "left" mouse button), and any aliases thereof.
There may be document language or implementation specific limits on which elements can become :active. For example, [HTML5] defines a list of activatable elements.
The parent of an element that matches :active also matches :active.
So there,s no way
Instead of div:active {...} you should code div:active:not(:hover) {...} and the background-color stays untouched.
(old snippet removed)
UPDATE
To keep the main div behaviour intact and a more generic approach I usually create several layers.
Check the snippet below, toggling to green is just to prove that it works while position and abolute are just quick and dirty for now:
#layer-data {
width: 200px;
height: 200px;
background-color: #eee;
border: 1px solid black;
}
#layer-data:active {
background-color: red
}
#layer-btns:active {
background-color: green
}
#layer-btns {
z-index: 1;
position: absolute;
top: 1px;
left: 1px;
background: transparent;
padding: 5px;
width: auto;
height: auto
}
#layer-data {
z-index: 0;
position: absolute;
top: 0;
left: 0;
text-align: center;
line-height: 200px
}
<div id="layer-btns">
<button>Qlick me</button>
<br/>
<button>Qlick me too</button>
<br/>
<button>Qlick me three</button>
</div>
<div id="layer-data">
some data-layer
</div>
There doesn't seem to any CSS way to handle this case. (not sure about CSS4, the way Amit has suggested.) So here is JQuery way.
The idea is you handle mousedown and mouseup events at 3 levels:
the parent div
the button where you don't want the active state propagated to parent div (".btn1" in the example below)
any other children except the button in second condition. (".btn2" in the example below)
JS Fiddle
HTML:
<div>
<button class="btn1">Qlick me1</button>
<button class="btn2">Qlick me2</button>
</div>
JQuery:
$(function(){
$('div').each(function(e){
$(this).mousedown(function(e){
$(this).addClass("activeClass");
}).mouseup(function(e){
$(this).removeClass("activeClass");
});
});
$('div .btn1').each(function(e){
$(this).mousedown(function(e){
e.stopPropagation();
}).mouseup(function(e){
e.stopPropagation();
});
});
$('div :not(.btn1)').each(function(e){
$(this).mousedown(function(e){
$(this).parent().addClass("activeClass");
}).mouseup(function(e){
$(this).parent().removeClass("activeClass");
});
});
});
CSS:
div {
width: 200px;
height: 200px;
background-color: #eee;
border: 1px solid black;
}
.activeClass {
background-color: red;
}
CSS pseudo-elements are incredibly useful -- they allow us to create CSS triangles for tooltips and perform a number of other simple tasks while preventing the need for additional HTML elements. To this point, these pseudo-element CSS properties have been unreachable by JavaScript but now there's a method for getting them!
Check this:
http://davidwalsh.name/pseudo-element
http://davidwalsh.name/ways-css-javascript-interact

Getting element by ID in coffeescript

I'm trying to create a HTML widget:
HTML:
<div>
<h1 class="title" data-bind="title">Title</h1>
<div>
<h1 id = "dc1" class="dc">DC1</h1>
</div>
<div>
<h1 id = "dc2" class="dc">DC2</h1>
</div>
<p class="updated-at" data-bind="updatedAtMessage"></p>
</div>
And I need to be able to set the background color of the id="dc1" and id="dc2" elements dynamically in CoffeeScript. I plan to do this by adding a class with a background color setting:
SCSS:
&.up {
background-color: green;
}
&.down {
background-color: red;
}
.dc {
background-color: orange;
font-size: 30px;
float: left;
width: 50%;
}
So far I have managed to set the whole widget background but not the child elements mentioned above:
I have been using:
CoffeeScript:
$(#node).removeClass('up down')
$('#dc1').removeClass('up down')
$('#dc2').removeClass('up down')
$(#node).addClass('down')
$('#dc1').addClass('down')
$('#dc2').addClass('up')
Note ultimately I will add the classes depending on some data rather than hard coding them to 'up' or 'down' in the coffeescript.
But nothing happends.. Am I getting selecting the id="dc#" elements correctly?
If it helps with context I'm doing this for Dashing
Your SCSS doesn't make sense so I'd guess that your missing an error from the SCSS-to-CSS conversion. An & in SCSS is a reference to the parent selector:
& will be replaced with the parent selector as it appears in the CSS
so have &.up at the top level makes no sense and should generate an error. If we fix the SCSS so that .up and .down apply only to .dc:
.dc {
/* ... */
&.up {
background-color: green;
}
&.down {
background-color: red;
}
}
then everything seems to work just fine.
Demo: http://jsfiddle.net/ambiguous/9y9uywm9/
You can use Sassmeister (and other similar online tools) to see what SCSS thinks of your original SCSS.