title: Get current location, latitude and longitude in ReactNative using react-native-maps
body: <p>I am developing a map location. When I click in some particular place I get the latitude and longitude, but not the current location, latitude and longitude.</p>
  
  <p>I don't know how to find out.</p>
  
  <p>How can I get them and how can I put the marker at that position?</p>
  
  <p>Here is my code:</p>
  
  <pre><code>class Maps extends React.Component {
    constructor(props) {
      super(props);
      this.state = {
        region: {
          latitude:       LATITUDE,
          longitude:      LONGITUDE,
          latitudeDelta:  LATITUDE_DELTA,
          longitudeDelta: LONGITUDE_DELTA,
        },
        marker: {
          latlng:{
            latitude:       null,
            longitude:      null,
            latitudeDelta:  LATITUDE_DELTA,
            longitudeDelta: LONGITUDE_DELTA
          }
        }
      }
    }
  
    componentDidMount() {
      navigator.geolocation.getCurrentPosition (
        (position) =&gt; { alert("value:" + position) },
        (error)    =&gt; { console.log(error) },
        {
          enableHighAccuracy: true,
          timeout:            20000,
          maximumAge:         10000
        }
      )
    }
  
    onMapPress(e) {
      alert("coordinates:" + JSON.stringify(e.nativeEvent.coordinate))
        this.setState({
          marker: [{ coordinate: e.nativeEvent.coordinate }]
        })
      }
  
    render() {
      return (
        &lt;View style={styles.container}&gt;
          &lt;View style={{flexGrow:1}}&gt;
            &lt;MapView
              ref="map"
              provider={this.props.provider}
              style={styles.map}
              onPress={this.onMapPress.bind(this)}
              provider = {PROVIDER_DEFAULT}
              mapType="standard"
              zoomEnabled={true}
              pitchEnabled={true}
              showsUserLocation={true}
              followsUserLocation={true}
              showsCompass={true}
              showsBuildings={true}
              showsTraffic={true}
              showsIndoors={true}&gt;
            &lt;/MapView&gt;
          &lt;/View&gt;
        &lt;/View&gt;
      )
    }
  }
  </code></pre>