jQuery animate backgroundColor

Question

I am trying to animate a change in backgroundColor using jQuery on mouseover.

I have checked some example and I seem to have it right, it works with other properties

Answer 1

You can use jQuery UI to add this functionality. You can grab just what you need, so if you want to animate color, all you have to include is the following code. I got if from latest jQuery UI (currently 1.8.14)

/******************************************************************************/
/****************************** COLOR ANIMATIONS ******************************/
/******************************************************************************/

// override the animation for color styles
$.each(['backgroundColor', 'borderBottomColor', 'borderLeftColor',
    'borderRightColor', 'borderTopColor', 'borderColor', 'color', 'outlineColor'],
function(i, attr) {
    $.fx.step[attr] = function(fx) {
        if (!fx.colorInit) {
            fx.start = getColor(fx.elem, attr);
            fx.end = getRGB(fx.end);
            fx.colorInit = true;
        }

        fx.elem.style[attr] = 'rgb(' +
            Math.max(Math.min(parseInt((fx.pos * (fx.end[0] - fx.start[0])) + fx.start[0], 10), 255), 0) + ',' +
            Math.max(Math.min(parseInt((fx.pos * (fx.end[1] - fx.start[1])) + fx.start[1], 10), 255), 0) + ',' +
            Math.max(Math.min(parseInt((fx.pos * (fx.end[2] - fx.start[2])) + fx.start[2], 10), 255), 0) + ')';
    };
});

// Color Conversion functions from highlightFade
// By Blair Mitchelmore
// http://jquery.offput.ca/highlightFade/

// Parse strings looking for color tuples [255,255,255]
function getRGB(color) {
        var result;

        // Check if we're already dealing with an array of colors
        if ( color && color.constructor == Array && color.length == 3 )
                return color;

        // Look for rgb(num,num,num)
        if (result = /rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(color))
                return [parseInt(result[1],10), parseInt(result[2],10), parseInt(result[3],10)];

        // Look for rgb(num%,num%,num%)
        if (result = /rgb\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*\)/.exec(color))
                return [parseFloat(result[1])*2.55, parseFloat(result[2])*2.55, parseFloat(result[3])*2.55];

        // Look for #a0b1c2
        if (result = /#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(color))
                return [parseInt(result[1],16), parseInt(result[2],16), parseInt(result[3],16)];

        // Look for #fff
        if (result = /#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(color))
                return [parseInt(result[1]+result[1],16), parseInt(result[2]+result[2],16), parseInt(result[3]+result[3],16)];

        // Look for rgba(0, 0, 0, 0) == transparent in Safari 3
        if (result = /rgba\(0, 0, 0, 0\)/.exec(color))
                return colors['transparent'];

        // Otherwise, we're most likely dealing with a named color
        return colors[$.trim(color).toLowerCase()];
}

function getColor(elem, attr) {
        var color;

        do {
                color = $.curCSS(elem, attr);

                // Keep going until we find an element that has color, or we hit the body
                if ( color != '' && color != 'transparent' || $.nodeName(elem, "body") )
                        break;

                attr = "backgroundColor";
        } while ( elem = elem.parentNode );

        return getRGB(color);
};

It's only 1.43kb after compressing with YUI:

$.each(["backgroundColor","borderBottomColor","borderLeftColor","borderRightColor","borderTopColor","borderColor","color","outlineColor"],function(b,a){$.fx.step[a]=function(c){if(!c.colorInit){c.start=getColor(c.elem,a);c.end=getRGB(c.end);c.colorInit=true}c.elem.style[a]="rgb("+Math.max(Math.min(parseInt((c.pos*(c.end[0]-c.start[0]))+c.start[0],10),255),0)+","+Math.max(Math.min(parseInt((c.pos*(c.end[1]-c.start[1]))+c.start[1],10),255),0)+","+Math.max(Math.min(parseInt((c.pos*(c.end[2]-c.start[2]))+c.start[2],10),255),0)+")"}});function getRGB(b){var a;if(b&&b.constructor==Array&&b.length==3){return b}if(a=/rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(b)){return[parseInt(a[1],10),parseInt(a[2],10),parseInt(a[3],10)]}if(a=/rgb\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*\)/.exec(b)){return[parseFloat(a[1])*2.55,parseFloat(a[2])*2.55,parseFloat(a[3])*2.55]}if(a=/#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(b)){return[parseInt(a[1],16),parseInt(a[2],16),parseInt(a[3],16)]}if(a=/#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(b)){return[parseInt(a[1]+a[1],16),parseInt(a[2]+a[2],16),parseInt(a[3]+a[3],16)]}if(a=/rgba\(0, 0, 0, 0\)/.exec(b)){return colors.transparent}return colors[$.trim(b).toLowerCase()]}function getColor(c,a){var b;do{b=$.curCSS(c,a);if(b!=""&&b!="transparent"||$.nodeName(c,"body")){break}a="backgroundColor"}while(c=c.parentNode);return getRGB(b)};

You can also animate colors using CSS3 transitions but it's only supported by modern browsers.

a.test {
  color: red;
  -moz-transition-property: color;  /* FF4+ */
  -moz-transition-duration: 1s;
  -webkit-transition-property: color;  /* Saf3.2+, Chrome */
  -webkit-transition-duration: 1s;
  -o-transition-property: color;  /* Opera 10.5+ */
  -o-transition-duration: 1s;
  -ms-transition-property: color;  /* IE10? */
  -ms-transition-duration: 1s;
  transition-property: color;  /* Standard */
  transition-duration: 1s;
  }

  a.test:hover {
  color: blue;
  }

Using shorthand property:

/* shorthand notation for transition properties */
/* transition: [transition-property] [transition-duration] [transition-timing-function] [transition-delay]; */

a.test {
  color: red;
  -moz-transition: color 1s;
  -webkit-transition: color 1s;
  -o-transition: color 1s;
  -ms-transition: color 1s;
  transition: color 1s;
  }

a.test {
  color: blue;
 }

Unlike regular javascript transitions, CSS3 transitions are hardware accelerated and therefore smoother. You can use Modernizr, to find out if the browser supports CSS3 transitions, if it didn't then you can use jQuery as a fallback:

if ( !cssTransitions() ) {
    $(document).ready(function(){
        $(".test").hover(function () {
                $(this).stop().animate({ backgroundColor: "red" },500)
             }, function() {
                 $(this).stop().animate({ backgroundColor: "blue" },500)}    
             );
    }); 
}

Remember to use stop() to stop the current animation before starting a new one otherwise when you pass over the element too fast, the effect keeps blinking for a while.

Answer 2

I stumbled across this page with the same issue, but the following problems:

1. I can't include an extra jQuery plugin file with my current set-up.
2. I'm not comfortable pasting large blocks of code that I don't have time to read over and validate.
3. I don't have access to the css.
4. I hardly had any time for implementation (it was only a visual improvement to an admin page)

With the above that pretty much ruled out every answer. Considering my fade of colour was very simple, I used the following quick hack instead:

element
  .css('color','#FF0000')
;
$('<div />')
  .css('width',0)
  .animate(
    {'width':100},
    {
      duration: 3000,
      step:function(now){
        var v = (255 - 255/100 * now).toString(16);
        v = (v.length < 2 ? '0' : '') + v.substr(0,2);
        element.css('color','#'+v+'0000');
      }
    }
  )
;

The above creates a temporary div that is never placed in the document flow. I then use jQuery's built-in animation to animate a numeric property of that element - in this case width - which can represent a percentage (0 to 100). Then, using the step function, I transfer this numeric animation to the text colour with a simple hex cacluation.

The same could have been achieved with setInterval, but by using this method you can benefit from jQuery's animation methods - like .stop() - and you can use easing and duration.

Obivously it's only of use for simple colour fades, for more complicated colour conversions you'll need to use one of the above answers - or code your own colour fade math :)

Answer 3

I had the same problem and fixed it by including jQuery UI. Here is the complete script :

<!-- include Google's AJAX API loader -->
<script src="http://www.google.com/jsapi"></script>
<!-- load JQuery and UI from Google (need to use UI to animate colors) -->
<script type="text/javascript">
google.load("jqueryui", "1.5.2");
</script>


<script type="text/javascript">
$(document).ready(function() {
$('#menu ul li.item').hover(
    function() {
        $(this).stop().animate({backgroundColor:'#4E1402'}, 300);
        }, function () {
        $(this).stop().animate({backgroundColor:'#943D20'}, 100);
    });
});
</script>

Answer 4

Try this one:

jQuery(".usercontent").hover(function() {
    jQuery(this).animate({backgroundColor:"pink"}, "slow");
},function(){
    jQuery(this).animate({backgroundColor:"white"}, "slow");
});

Revised way with effects:

jQuery(".usercontent").hover(function() {

    jQuery(this).fadeout("slow",function(){
        jQuery(this).animate({"color","yellow"}, "slow");
    });
});

Answer 5

Try to use it

-moz-transition: background .2s linear;
-webkit-transition: background .2s linear;
-o-transition: background .2s linear;
transition: background .2s linear;

Answer 6

Do it with CSS3-Transitions. Support is great (all modern browsers, even IE). With Compass and SASS this is quickly done:

#foo {background:red; @include transition(background 1s)}
#foo:hover {background:yellow}

Pure CSS:

#foo {
background:red;
-webkit-transition:background 1s;
-moz-transition:background 1s;
-o-transition:background 1s;
transition:background 1s
}
#foo:hover {background:yellow}

I've wrote an german article about this topic: http://www.solife.cc/blog/animation-farben-css3-transition.html