title: How to filter list when use FutureBuilder?
body: <p>I use FutureBuilder in IndexedListView to show a phonebook list,</p>
  <pre><code>Widget _buildBody(context) {
    String url = api_url_phonebook;
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 10.0),
      child: Column(
        children: [
          TextField(
            onTap: () =&gt; onTextChanged(_controller.text),
            ...
          ),
          Expanded(
            child: IndexedListView(
              100.0,
              _getData(context, url),
              ...
            ),
          ),
        ],
      ),
    );
  }
  
  Future&lt;Either&lt;ResponseError, List&lt;dynamic&gt;&gt;&gt; _getData(context, url) {
    final result = RequestApi(url).fetchList();
    return result;
  }
  
  onSearchTextChanged(String text) {
    ...
  }
  </code></pre>
  <p>Now I want filter this phonebook when I input text in TextField, what can I do?</p>