title: Angular ng-class slow to load background image?
body: <p>I'm using ng-click to change the background image of a span tag. On changing the image the first time, it takes a second or two to load. But then alternating back and forth between the images is perfect. Both images are approx. 500 bytes so I don't think size is an issue.</p>
  
  <p>I'm working on an angular app for mobile. In my mobile emulator in chrome, the images load perfectly. It is only on a mobile device that the problem appears.</p>
  
  <pre><code>    &lt;div class="data_table" ng-click="collapsed = !collapsed"&gt;
          &lt;table&gt;
          &lt;tr class="top_row"&gt;
                &lt;td&gt;
                  &lt;div&gt;
                      Data
                  &lt;/div&gt;
                &lt;/td&gt;
                &lt;td&gt;
                  &lt;span ng-class="!collapsed ? 'collapse_icon' : 'expand_icon'"&gt;&lt;/span&gt;
                &lt;/td&gt;
         &lt;/tr&gt;
     &lt;/div&gt;
  
  
  
  .collapse_icon {
      font-size: 22px;
      line-height: 18px;
      font-weight: bold;
      float:left;
      width: 5%;
      color: #000;
      height: 22px;
      width: 22px;
      background-image: url(../images/collapse2.png);
      background-repeat: no-repeat;
      background-size: 22px 22px;
      padding-right: 2px;
  }
  
  .expand_icon {
      font-size: 22px;
      line-height: 18px;
      font-weight: bold;
      float:left;
      width: 5%;
      color: #000;
      height: 22px;
      width: 22px;
      background-image: url(../images/expand2.png);
      background-repeat: no-repeat;
      background-size: 22px 22px;
      padding-right: 2px;
  }
  </code></pre>
  
  <p>So is this just a mobile issue or am I using the wrong directive?</p>