title: Is there any way to listen device location on or off?
body: <p>I used <code>Geolocator</code> plugin. It's working. but not display a message immediately. the message is displayed like after 2,3 minutes. It does not display real-time.
  <code>Geolocator().isLocationServiceEnabled()</code> is future, can't listen right?</p>
  
  <pre><code>FutureBuilder&lt;bool&gt;(
                    future: Geolocator().isLocationServiceEnabled(),
                      builder: (context,snapshot){
                      if(snapshot.hasData){
                        if(!snapshot.data)
                        return CustomText(
                                text: 'GPS Interrupted',
                            );
                        else
                          return Container();
                      } else{
                        return Container();
                      }
                      }
                  )
  </code></pre>
  
  <p>I used this widget like this,</p>
  
  <pre><code> bottom: PreferredSize(child: FutureBuilder&lt;bool&gt;(
  </code></pre>