title: Call React-native from custom component
body: <p>I am fairly new to react-native and I cannot figure out how I can call an event from a custom component.
  The component I am using is react-native-android-snackbar and I am trying to check if the snackbar is active.</p>
  <p>By inspecting the <a href="https://github.com/luggit/react-native-android-snackbar/blob/master/android/src/main/java/com/lugg/ReactSnackbar/ReactSnackbarModule.java" rel="nofollow noreferrer">code</a> I have found that there is an event called EVENT_SHOWN. This is exactly what I need but unfortunally I don't know how I can check for this event.</p>
  <p>I tried the following:</p>
  <pre><code>export default class LoginScreen extends Component {
      constructor(props, context) {
          super(props, context);
          this.state = {username: '', password: '',spinnerVisible:false};
          this._event = this._event.bind(this);
          DeviceEventEmitter.addListener('EVENT_SHOW',this._event);
      }
      _event(event: Event){
          Alert.alert(&quot;Event handler&quot;,&quot;Event handler&quot;);
      }
  </code></pre>
  <p>But unfortunally it doesn't work the function doesn't get called when I activate the snackbar.</p>
  <p>Hope somebody can help me in the right direction.</p>