Hover and Click Trigger For CIRCULAR Elements With jQuery

Today we want to share one possible solution to the circle hovering problem. We’ll create a plugin that will take care of the ‘mouseenter’, ‘mouseleave’ and ‘click’ events to be triggered only on the circular shape of the element and not its bounding box.

Applying a :hover pseudo-class to an element is widely known as the classic “hovering” over an element on a web page. A problem that arose with the introduction of the border-radius property is the non-realistic triggering of the hover event when entering the bounding box of the element and not just the actual visible area. This becomes extreme when we create a circle by setting the border-radius of a square to 50% (half of its outer width and height).

Today we want to share one possible solution to the circle hovering problem. We’ll create a plugin that will take care of the ‘mouseenter’, ‘mouseleave’ and ‘click’ events to be triggered only on the circular shape of the element and not its bounding box.

CIRCULAR-Elements-With-jQuery

HOW IT WORKS

In our example, we’ll be creating a circle with some kind of hover effect. The structure will simply be:

<a href="#" id="circle" class="ec-circle">
    <h3>Hovered</h3>
</a>

And the style will be the following:

.ec-circle{
    width: 420px;
    height: 420px;
    -webkit-border-radius: 210px;
    -moz-border-radius: 210px;
    border-radius: 50%;
    text-align: center;
    overflow: hidden;
    font-family:'Kelly Slab', Georgia, serif;
    background: #dda994 url(HoverClickTriggerCircle.jpg) no-repeat center center;
    box-shadow: 
        inset 0 0 1px 230px rgba(0,0,0,0.6),
        inset 0 0 0 7px #d5ad94;
    transition: box-shadow 400ms ease-in-out;
    display: block;
    outline: none;
}

Now, we will define a class for the hover effect but not a dynamic pseudo-class :hover. The idea is to apply this class then with jQuery when we enter the circular area of our element:

.ec-circle-hover{
    box-shadow: 
        inset 0 0 0 0 rgba(0,0,0,0.6),
        inset 0 0 0 20px #c18167,
        0 0 10px rgba(0,0,0,0.3);
}

Only when we have JavaScript disabled, we’ll add the pseudo-class. This style can be found in the noscript.css:

.ec-circle:hover{
    box-shadow: 
        inset 0 0 0 0 rgba(0,0,0,0.6),
        inset 0 0 0 20px #c18167,
        0 0 10px rgba(0,0,0,0.3);
}

THE JAVASCRIPT

We are going to create a simple plugin that basically “redefines” the three events mentioned earlier. We’ll make the events only applicable on the circular shape:

$.CircleEventManager            = function( options, element ) {
    this.$el = $( element );
    this._init( options );
};

$.CircleEventManager.defaults   = {
    onMouseEnter    : function() { return false },
    onMouseLeave    : function() { return false },
    onClick         : function() { return false }
};

$.CircleEventManager.prototype  = {
    _init           : function( options ) {
        this.options = $.extend( true, {}, $.CircleEventManager.defaults, options );
        // set the default cursor on the element
        this.$el.css( 'cursor', 'default' );
        this._initEvents();

    },
    _initEvents     : function() {
       var _self   = this;
       this.$el.on({
           'mouseenter.circlemouse'    : function( event ) {
               var el  = $(event.target),
               circleWidth   = el.outerWidth( true ),
               circleHeight  = el.outerHeight( true ),
               circleLeft    = el.offset().left,
               circleTop     = el.offset().top,
               circlePos     = {
                       x     : circleLeft + circleWidth / 2,
                       y     : circleTop + circleHeight / 2,
                       radius: circleWidth / 2
                   };

                // save cursor type
                var cursor  = 'default';
                if( _self.$el.css('cursor') === 'pointer' || _self.$el.is('a') )
                    cursor = 'pointer';
                el.data( 'cursor', cursor );
                el.on( 'mousemove.circlemouse', function( event ) {
                var distance    = Math.sqrt( Math.pow( event.pageX - circlePos.x, 2 ) + Math.pow( event.pageY - circlePos.y, 2 ) );

                if( !Modernizr.borderradius ) {

                  // inside element / circle
                  el.css( 'cursor', el.data('cursor') ).data( 'inside', true );
                  _self.options.onMouseEnter( _self.$el );

                 }
                 else {

                   if( distance <= circlePos.radius && !el.data('inside') ) {                       // inside element / circle                       el.css( 'cursor', el.data('cursor') ).data( 'inside', true );                       _self.options.onMouseEnter( _self.$el );                                                   }                     else if( distance > circlePos.radius && el.data('inside') ) {

                      // inside element / outside circle
                      el.css( 'cursor', 'default' ).data( 'inside', false );
                      _self.options.onMouseLeave( _self.$el );
                    }
                   }
                }); 
            },
            'mouseleave.circlemouse'    : function( event ) {
              var el  = $(event.target);
              el.off('mousemove');
               if( el.data( 'inside' ) ) {
                  el.data( 'inside', false );
                  _self.options.onMouseLeave( _self.$el );
              }
             },
            'click.circlemouse'         : function( event ) {
              // allow the click only when inside the circle
                var el  = $(event.target);
                if( !el.data( 'inside' ) )
                    return false;
                else
                    _self.options.onClick( _self.$el );
            }
        });         
    },
    destroy             : function() {     
        this.$el.unbind('.circlemouse').removeData('inside').removeData('cursor'); 
    }
}

When we enter with the mouse in the square bounding box of our circle, we bind the ‘mousemove’ event to the element and like that we can track if the distance of the mouse to the center of the element if longer than the radius. If it is, we know that we are not yet hovering the circular area of the element.

hoverTrigger
Once the distance of the mouse is shorter than the radius, we know that we entered the circle and we trigger our custom ‘mouseenter’ event.
We also only allow the click event when the mouse is inside of the circle.
In our example we will then apply our plugin to the regarding element. In our case, we are adding the hover class on ‘mouseenter’ and removing it on ‘mouseleave’.

$('#circle').circlemouse({
    onMouseEnter    : function( el ) {

        el.addClass('ec-circle-hover');

    },
    onMouseLeave    : function( el ) {

        el.removeClass('ec-circle-hover');

    },
    onClick         : function( el ) {

        alert('clicked');

    }
})

Remember that the “normal” pseudo hover class is also defined in the noscript.css which gets applied when JavaScript is disabled.

view demo

Your turn

I hope you enjoyed this article and the techniques I used. Please share your comments and questions below!

Posted by: Dhiraj kumar

An Awesome CSS3 Animated Dropdown Menu

It’s a sure thing that CSS3 features like transitions, animations and transforms can add extra spice to your designs.

In this article you will see how you can build an awesome CSS3 animated dropdown menu with some of these cool features.  This is something I wished to do for a while and I finally made it. I just added support for smartphones / mobile devices and fixed the navigation for iPad and iPhone also.

css3-animated-dropdown-menu-preview

Here’s a quick preview for the CSS3 animated dropdown menu that we’re going to create today:

css3-menu-animation

The HTML

The HTML structure hasn’t changed at all, simple and minimal. Here’s an excerpt:

<ul id="menu">
        <li><a href="#">Home</a></li>
        <li>
                <a href="#">Categories</a>
                <ul>
                        <li><a href="#">CSS</a></li>
                        <li><a href="#">Graphic design</a></li>
                        <li><a href="#">Development tools</a></li>
                        <li><a href="#">Web design</a></li>
                </ul>
        </li>
        <li><a href="#">Work</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">Contact</a></li>
</ul>

The CSS

I revised and improved the styles in order to create this unique CSS3 animated dropdown menu. So, below you can find the commented pieces of styles:

Mini reset

Reset the default ul styles.

#menu, #menu ul {
        margin: 0;
        padding: 0;
        list-style: none;
}

Main level

The #menu is basically the main ul for this menu. CSS3 things like gradientsshadows and rounded corners help us to create the below:

css3-menu-wrapper

#menu {
        width: 960px;
        margin: 60px auto;
        border: 1px solid #222;
        background-color: #111;
        background-image: linear-gradient(#444, #111);
        border-radius: 6px;
        box-shadow: 0 1px 1px #777;
}

Clear floats

Here is Nicolas Gallagher‘s clearing method I’ve been using lately:

#menu:before,
#menu:after {
        content: "";

        display: table;
}

#menu:after {
        clear: both;
}

#menu {
        zoom:1;
}

List elements

css3-menu-elements

Please notice the #menu li:hover > a  selector. This is perhaps the most important CSS trick for this CSS3 dropdown menu.

So, this is how this works: Select an “a” element that is child of a “li” ; the “li” element must be a descendant of the “#menu”. Read more here.

#menu li {
        float: left;
        border-right: 1px solid #222;
        box-shadow: 1px 0 0 #444;
        position: relative;
}

#menu a {
        float: left;
        padding: 12px 30px;
        color: #999;
        text-transform: uppercase;
        font: bold 12px Arial, Helvetica;
        text-decoration: none;
        text-shadow: 0 1px 0 #000;
}

#menu li:hover > a {
        color: #fafafa;
}

*html #menu li a:hover { /* IE6 only */
        color: #fafafa;
}

Submenus

With CSS3 transitons we can animate changes to CSS properties like margin or opacity. This is very cool and I’ve used this for animating the CSS3 sub-menus. The result is great if you ask me:

css3-menu-animation

#menu ul {
        margin: 20px 0 0 0;
        _margin: 0; /*IE6 only*/
        opacity: 0;
        visibility: hidden;
        position: absolute;
        top: 38px;
        left: 0;
        z-index: 1;
        background: #444;
        background: linear-gradient(#444, #111);
        box-shadow: 0 -1px 0 rgba(255,255,255,.3);
        border-radius: 3px;
        transition: all .2s ease-in-out;
}

#menu li:hover > ul {
        opacity: 1;
        visibility: visible;
        margin: 0;
}

#menu ul ul {
        top: 0;
        left: 150px;
        margin: 0 0 0 20px;
        _margin: 0; /*IE6 only*/
        box-shadow: -1px 0 0 rgba(255,255,255,.3);
}

#menu ul li {
        float: none;
        display: block;
        border: 0;
        _line-height: 0; /*IE6 only*/
        box-shadow: 0 1px 0 #111, 0 2px 0 #666;
}

#menu ul li:last-child {
        box-shadow: none;
}

#menu ul a {
        padding: 10px;
        width: 130px;
        _height: 10px; /*IE6 only*/
        display: block;
        white-space: nowrap;
        float: none;
        text-transform: none;
}

#menu ul a:hover {
        background-color: #0186ba;
        background-image: linear-gradient(#04acec, #0186ba);
}

First and last list elements styles

css3-dropdown-first-last-items

#menu ul li:first-child > a {
        border-radius: 3px 3px 0 0;
}

#menu ul li:first-child > a:after {
        content: '';
        position: absolute;
        left: 40px;
        top: -6px;
        border-left: 6px solid transparent;
        border-right: 6px solid transparent;
        border-bottom: 6px solid #444;
}

#menu ul ul li:first-child a:after {
        left: -6px;
        top: 50%;
        margin-top: -6px;
        border-left: 0;
        border-bottom: 6px solid transparent;
        border-top: 6px solid transparent;
        border-right: 6px solid #3b3b3b;
}

#menu ul li:first-child a:hover:after {
        border-bottom-color: #04acec;
}

#menu ul ul li:first-child a:hover:after {
        border-right-color: #0299d3;
        border-bottom-color: transparent;
}

#menu ul li:last-child > a {
        border-radius: 0 0 3px 3px;
}

The jQuery

As you already get used to, IE6 gets some extra attention:

$(function() {
  if ($.browser.msie && $.browser.version.substr(0,1)<7)
  {
        $('li').has('ul').mouseover(function(){
                $(this).children('ul').css('visibility','visible');
                }).mouseout(function(){
                $(this).children('ul').css('visibility','hidden');
                })
  }
});

While the :hover pseudo-class does not work for other elements than anchor, we just need to add this small jQuery snippet to fix it. It’s pretty self-explanatory.

Update: Mobile navigation support

css3-mobile-dropdown

This is something I wished to do for a while and I finally made it. I just added support for mobile devices and fixed the navigation for iPad.

You know how much I love CSS only solutions, but this time we’ll be using some jQuery to enhance this menu. To view the result, you can narrow your browser window or browse it with your smartphone.

The viewport meta tag

To maintain everything at the correct scale, the first thing added is the viewport meta tag:

<meta name="viewport" content="width=device-width, initial-scale=1.0">

Small HTML update

You need to wrap the above HTML structure using something like: <nav id="menu-wrap">. This will be our relative holder for the mobile navigation.

The jQuery add

After page loads, we’ll add the #menu-trigger element which does exactly what you think: will trigger the mobile menu when it will be clicked. Further, in the CSS, you’ll see that this element is displayed using CSS3 media queries.

Another thing here is the iPad device detection. As you can see below, we’ll remove the fancy transition effect and stick to toggling display: none/block. This way, the functionality will be maintained also on the iPad.

/* Mobile */
$('#menu-wrap').prepend('<div id="menu-trigger">Menu</div>');
$("#menu-trigger").on("click", function(){
        $("#menu").slideToggle();
});

// iPad
var isiPad = navigator.userAgent.match(/iPad/i) != null;
if (isiPad) $('#menu ul').addClass('no-transition');

The mobile CSS

Here, the CSS3 media queries do the trick. We’ll add CSS rules to override the initial styles:

#menu-trigger { /* Hide it initially */
        display: none;
}

@media screen and (max-width: 600px) {

        #menu-wrap {
                position: relative;
        }

        #menu-wrap * {
                box-sizing: border-box;
        }

        #menu-trigger {
                display: block; /* Show it now */
                height: 40px;
                line-height: 40px;
                cursor: pointer;
                padding: 0 0 0 35px;
                border: 1px solid #222;
                color: #fafafa;
                font-weight: bold;
                background-color: #111;
                /* Multiple backgrounds here, the first is base64 encoded */
                background: url(data:image/png;base64,iVBOR...) no-repeat 10px center, linear-gradient(#444, #111);
                border-radius: 6px;
                box-shadow: 0 1px 1px #777, 0 1px 0 #666 inset;
        }

        #menu {
                margin: 0; padding: 10px;
                position: absolute;
                top: 40px;
                width: 100%;
                z-index: 1;
                display: none;
                box-shadow: none;
        }

        #menu:after {
                content: '';
                position: absolute;
                left: 25px;
                top: -8px;
                border-left: 8px solid transparent;
                border-right: 8px solid transparent;
                border-bottom: 8px solid #444;
        }       

        #menu ul {
                position: static;
                visibility: visible;
                opacity: 1;
                margin: 0;
                background: none;
                box-shadow: none;
        }

        #menu ul ul {
                margin: 0 0 0 20px !important;
                box-shadow: none;
        }

        #menu li {
                position: static;
                display: block;
                float: none;
                border: 0;
                margin: 5px;
                box-shadow: none;
        }

        #menu ul li{
                margin-left: 20px;
                box-shadow: none;
        }

        #menu a{
                display: block;
                float: none;
                padding: 0;
                color: #999;
        }

        #menu a:hover{
                color: #fafafa;
        }       

        #menu ul a{
                padding: 0;
                width: auto;
        }

        #menu ul a:hover{
                background: none;
        }

        #menu ul li:first-child a:after,
        #menu ul ul li:first-child a:after {
                border: 0;
        }               

}

@media screen and (min-width: 600px) {
        #menu {
                display: block !important;
        }
}       

/* iPad */
.no-transition {
        transition: none;
        opacity: 1;
        visibility: visible;
        display: none;
}

#menu li:hover > .no-transition {
        display: block;
}

view demo

Your turn

I hope you enjoyed this article and the techniques I used. Please share your comments and questions below!

Posted by: Dhiraj kumar