Transition between CSS background images

Question

In my site I have a switch between a down arrow & and an up arrow. See here: http://jsfiddle.net/4uLghzg7/

Is there a way I can add a slight animation transition when clicked? So it fades in/out between the two icons?

function close_accordion_section(source) {
    $(source).parent().find('.accordion-section-title').removeClass('active');
    $(source).parent().find('.accordion-section-content').slideUp(300).removeClass('open');
}

$('.accordion-section-title').click(function (e) {
    if ($(e.target).is('.active')) {
        close_accordion_section(e.target);
    } else {
        $(this).addClass('active');
        $(e.target).parent().find('.accordion-section-content').slideDown(300).addClass('open')
    }

    e.preventDefault();
});

.accordion {
    overflow: hidden;
    margin-bottom: 40px;
}
.accordion-section {
    padding: 15px;
    border: 1px solid #d8d8d8;
    background: #fbfbfb;
}
.accordion-section-title {
    width: 100%;
    display: inline-block;
    background-image: url("https://cdn3.iconfinder.com/data/icons/google-material-design-icons/48/ic_keyboard_arrow_up_48px-512.png");
    background-size: 5% 100%;
    background-repeat: no-repeat;
    background-position: top right;
}
.accordion-section-title.active {

  background: url("https://cdn3.iconfinder.com/data/icons/google-material-design-icons/48/ic_keyboard_arrow_down_48px-128.png") top right no-repeat;
     background-size: 5% 100%;
    background-repeat: no-repeat;
}
.accordion-section-title.active, .accordion-section-title:hover {
    text-decoration: none;
    transition: color 0.1s linear;
}
.accordion-section-content {
    padding: 15px 0;
    display: none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<div class="accordion">
    <div class="accordion-section"> <a class="accordion-section-title" href="#accordion-1">More information</a>

        <div id="accordion-1" class="accordion-section-content">
            <p>Text.</p>
            <p>
        </div>
    </div>
</div>

Answer 1

You could change the arrows to be actual elements (pseudo elements in the following example) and put them on top of each other. Then have the down arrow fade in/out on top of the up arrow to create the effect you're looking for.

 // up arrow positioned absolutely
.accordion-section-title:before {
    content: '';
    position: absolute;
}

 // down arrow positioned absolutely
.accordion-section-title:after {
    content: '';
    opacity: 0;
    transition: opacity 0.2s ease;
    position: absolute;
}

 // animate in down arrow
.accordion-section-title:after {
    content: '';
    opacity: 1;
    position: absolute;
}

jsfiddle working example: http://jsfiddle.net/4uLghzg7/6/

Hopefully this answers what you were asking about.

Answer 2

You need a special trick to fade between background-images, you will need two elements, and fade the inner elements opacity:

<div id="arrowUp">
    <div id="arrowDown">
    </div>
</div>

Demo of your code (modified):

function close_accordion_section(source) {
  $(source).parent().find('.arrowDown').removeClass('active');
  $(source).parent().find('.accordion-section-content').slideUp(300).removeClass('open');
}

$('.accordion-section-title').click(function(e) {
  if ($('.arrowDown').is('.active')) {
    close_accordion_section(e.target);
  } else {
    $('.arrowDown').addClass('active');
    $(e.target).parent().find('.accordion-section-content').slideDown(300).addClass('open')
  }

  e.preventDefault();
});

.accordion {
  overflow: hidden;
  margin-bottom: 40px;
}
.accordion-section {
  padding: 15px;
  border: 1px solid #d8d8d8;
  background: #fbfbfb;
}
.arrowUp {
  width: 20px;
  height: 20px;
  background-image: url("https://cdn3.iconfinder.com/data/icons/google-material-design-icons/48/ic_keyboard_arrow_up_48px-512.png");
  background-size: 100%;
  background-repeat: no-repeat;
  background-position: center center;
}
.arrowDown {
  opacity: 0;
  width: 20px;
  height: 20px;
  background-color: white;
  background-image: url("https://cdn3.iconfinder.com/data/icons/google-material-design-icons/48/ic_keyboard_arrow_down_48px-128.png");
  background-size: 100%;
  background-repeat: no-repeat;
  -webkit-transition: opacity 0.3s linear;
  transition: opacity 0.3s linear;
}
.arrowDown.active {
  opacity: 1;
  background-position: center center;
  -webkit-transition: opacity 0.3s linear;
  transition: opacity 0.3s linear;
}
.accordion-section-title.active,
.accordion-section-title:hover {
  text-decoration: none;
  transition: color 0.1s linear;
}
.accordion-section-content {
  padding: 15px 0;
  display: none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<div class="accordion">
  <div class="accordion-section">
    <a class="accordion-section-title" href="#accordion-1">More information</a>

    <div class="arrowUp" style="float: right">
      <div class="arrowDown">
      </div>
    </div>

    <div id="accordion-1" class="accordion-section-content">
      <p>Text.</p>
      <p>
    </div>
  </div>
</div>

Answer 3

you can't actually do much animation on raster background images but if css 3 transition is acceptable you can try something like

.fade-background{
    transition: background 1s cubic-bezier(0.55, 0.06, 0.68, 0.19) !important;
}

I added a class "fade-background" on your anchor tag, fiddle here

http://jsfiddle.net/dango_x_daikazoku/4uLghzg7/5/

Answer 4

just write .click function in

$(function() {
});

Try this..

$(function() {
    $('.accordion-section-title').click(function (e) {
         e.preventDefault();
        if ($(e.target).is('.active')) {
            close_accordion_section(e.target);
        } else {
            $(this).addClass('active');
            $(e.target).parent().find('.accordion-section-content').slideDown(300).addClass('open')
        }
    });
});