title: up/down arrow key issue with typeahead control (angular bootstrap UI)
body: <p>Check this <a href="http://plnkr.co/edit/grrAxz158PTShzpxz2f0" rel="noreferrer">PLNKR</a> , i have implemented <strong>typeahead</strong> control, 
  By default in type ahead control they are not setting any max-height or height to list, but as per requirement i have to fix height of list to 110px. So, when we have longer list at a time only 4 data will be shown and rest can be seen by scrolling down.
  Scrolling is working while user click on scroll up/down arrows, but it's not working with keyboard up/down keys.</p>
  
  <p>The problem is explained in steps:-</p>
  
  <ol>
  <li>Type something i.e "a" to get data in typeahead (list will be populated) </li>
  <li>Press down-arrow key (focus will be on list item)</li>
  <li>Press down-arrow key 4-5 time to go further down (When we traverse
  down to list, scroll is not getting moved.)</li>
  <li>It always show top 4 items in list. Ideal behavior is it should shift.</li>
  </ol>
  
  <p>User is able to scroll by clicking on scroll manually but with arrow key it's not scrolling.</p>
  
  <p><img src="https://i.stack.imgur.com/Cuy85.png" alt="Type &quot;a&quot; and traverse down to list with down-arrow key scrolling is not working."></p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;!doctype html&gt;
  &lt;html ng-app="ui.bootstrap.demo"&gt;
  &lt;head&gt;
   &lt;script src="//ajax.googleapis.com/ajax/libs/angularjs/1.2.16/angular.js"&gt;&lt;/script&gt;
   &lt;script src="//angular-ui.github.io/bootstrap/ui-bootstrap-tpls-0.12.0.js"&gt;&lt;/script&gt;
   &lt;script src="example.js"&gt;&lt;/script&gt;
   &lt;link href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css" rel="stylesheet"&gt;
   &lt;link href="style.css" rel="stylesheet"&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div class='container-fluid' ng-controller="TypeaheadCtrl"&gt;
    &lt;h4&gt;Static arrays&lt;/h4&gt;
    &lt;pre&gt;Model: {{selected | json}}&lt;/pre&gt;
    &lt;input type="text" ng-model="selected" typeahead="state for state in states | filter:$viewValue | limitTo:8" class="form-control"&gt;
   &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p><strong>CSS</strong></p>
  
  <pre><code>.dropdown-menu{
   height:110px;
   overflow:auto;
  }
  </code></pre>
  
  <p><strong>javascript datalist</strong></p>
  
  <pre><code>$scope.states = ['Alabama', 'Alaska', 'Arizona', 'Arkansas', 'California', 'Colorado', 'Connecticut', 'Delaware', 'Florida', 'Georgia', 'Hawaii', 'Idaho', 'Illinois', 'Indiana', 'Iowa', 'Kansas', 'Kentucky', 'Louisiana', 'Maine', 'Maryland', 'Massachusetts', 'Michigan', 'Minnesota', 'Mississippi', 'Missouri', 'Montana', 'Nebraska', 'Nevada', 'New Hampshire', 'New Jersey', 'New Mexico', 'New York', 'North Dakota', 'North Carolina', 'Ohio', 'Oklahoma', 'Oregon', 'Pennsylvania', 'Rhode Island', 'South Carolina', 'South Dakota', 'Tennessee', 'Texas', 'Utah', 'Vermont', 'Virginia', 'Washington', 'West Virginia', 'Wisconsin', 'Wyoming'];
  </code></pre>