title: JAVAFX - unable to add items to listview
body: <p>I have a <code>Tab</code> called chat. Inside this Tab I have a list of users as <code>ListView&lt;string&gt;</code>.
  The content of this <code>ListView</code> was loaded from FXML file using: </p>
  
  <pre><code>FXMLLoader.load(getClass().getResource("chat.fxml"))
  </code></pre>
  
  <p>I am trying to add items to my <code>listview</code> using java, but when I open the GUI, chat tab, the items I add does not get displayed in the users <code>listview</code>.</p>
  
  <p>One of the ways I tried was:</p>
  
  <pre><code>List&lt;String&gt; values = Arrays.asList("one", "two", "three");
  listOfUsers.setItems(FXCollections.observableList(values));
  </code></pre>
  
  <p>I have tried other ways as well, but nothing seems to work. I'd appreciate your help.</p>