How to add arrow in an active navbar class in bootstrap [duplicate] - css

Question

You know how to do this using CSS?
In my navbar I would like to see a transparent triangle to the active link.
If I create a PNG image with a transparent triangle and use it like this:
background: rgba (0,0,0,0.4) url (triangle.png) no-repeat bottom center;
this does not work properly because under my triangle shows the transparent rgba color rgba(0,0,0,0.4) ...
I would like to do this to make a nice effect when scrolling the page. It is possibile?

Answer 1

Demo
You can use the :before and :after pseudo elements to achieve this effect.
<nav>
<ul>
<li class="active">homepage</li>
<li>option2</li>
<li>option3</li>
</ul>
</nav>
nav {
position: fixed;
background-color: rgba(0,0,0,.7);
display: block;
width: 100%;
padding: 10px 0;
color: white;
font-size: 1.5em;
}
ul {
list-style: none;
padding: 0;
margin: 0;
}
ul li {
float: left;
width: auto;
padding: 0 20px;
position: relative;
}
nav li:before,
nav li:after {
content: '';
position: absolute;
bottom: -35px;
left: 0;
right: 0;
height: 5px;
border: 10px transparent solid;
border-top-color: rgba(0,0,0,.7);
border-left-width: 0;
border-right-width: 0;
}
nav li:before {
right: 50%;
}
nav li:after {
left: 50%;
}
nav li.active:before {
border-right-width: 10px;
}
nav li.active:after {
border-left-width: 10px;
}
nav li:last-child:after { /* covers the bottom of the navigation bar all the way to the right */
right: -9999999px;
}
Another solution using links:
<nav>
<ul>
<li>homepage</li>
<li>option2</li>
<li>option3</li>
</ul>
</nav>

Answer 2

write css style for :active class
js. No jQuery and you even get the hover effect for free.
i think this will help you..
same concept but used differently for further reference refer here :
stackoverflow.com/questions/17327076/how-to-create-a-ul-with-a-triangle-for-the-active-row

Answer 3

Will post my solution. It's pretty complicated and though I don't know if there is other simpler way to make li>a nested elements be transparent for the background under ul. This solution uses :before/:after pseudo attributes.
I used this markup (how to avoid helper <i></i>?):
<header>
<ul class="clearfix">
<li><a class="active" href="">HOMEPAGE <i></i></a></li>
<li>CONTACT <i></i></li>
<li>GET OUT <i></i></li>
</ul>
</header>
and CSS:
header li a {
text-align: center;
-moz-box-sizing: border-box;
box-sizing: border-box;
width: 100%;
display: inline-block;
padding: 25px;
color: #FFF;
position: relative;
}
header li a:hover {
background: rgba(255, 255, 255, .2);
}
header li a i:after, header li a i:before {
content:'';
position: absolute;
bottom: 0;
left: 50%;
width: 0;
height: 0;
display: none;
background: url(http://subtlepatterns.com/patterns/escheresque_ste.png);
background-attachment: fixed;
border-top: 15px solid rgba(0, 0, 0, .5);
}
header li a.active i:after, header li a.active i:before {
display: block;
}
header li a:hover i:after, header li a:hover i:before {
display: block;
border-top-color: rgba(255, 255, 255, .1);
}
header li a i:before {
margin-left: -15px;
border-right: 15px solid transparent;
}
header li a i:after {
border-left: 15px solid transparent;
}
Hopefully someone will get inspired one day.
Demo: http://jsfiddle.net/R9pKq/

Answer 4

<figure>
<div><div>
</figure>
css
figure{
width:400px;
height:320px;
background:skyblue url(http://img1.wikia.nocookie.net/__cb20140301204257/disney/images/4/49/Elsa-Anna.jpg);
border:4px solid rgba(0,0,0,.8);
margin:40px auto;
position:relative;
}
figure div{
position:absolute;
bottom:0px;
left:0px;
width:100%;
height:200px;
background:rgba(255,255,255,.1);
}
figure div:before{
content:'';
position:absolute;
width:0px;
height:0px;
left:50%;
top:-40px;
margin-left:-40px;
border-bottom:40px solid rgba(255,255,255,.1);
border-left:40px solid transparent;
border-right:40px solid transparent;
}
Demo
or if you want to apply it to a menu
<menu>
<li><a>Home</a></li>
<li><a>Work</a></li>
<li><a>Projects</a></li>
<li><a>Infos</a></li>
</menu>
css
menu{
margin-top:40px;
}
menu li{
float:left;
list-style:none;
position:relative;
}
menu li{
padding:20px; 40px;
}
menu li:hover:before{
content:'';
position:absolute;
width:0px;
height:0px;
left:50%;
top:-20px;
margin-left:-20px;
border-bottom:20px solid rgba(0,0,0,.8);
border-left:20px solid transparent;
border-right:20px solid transparent;
}
Demo with Hover
to use the active class jst change menu li:hover:before to menu li.active:before