ErEduGilMor/screens/main/Map.js

import * as React from 'react';
import MapView, { Marker } from 'react-native-maps';
import { StyleSheet, Text, View, Dimensions } from 'react-native';

export default function Map() {
  const [pin, setPin] = React.useState({
    latitude: 18.4655,
    longitude: -66.1057,
  })
  
  return (
    <View style={styles.container}>
      <MapView style={styles.map}
        initialRegion={{
          latitude: 18.4655,
          longitude: -66.1057,
          latitudeDelta: 0.0922,
          longitudeDelta: 0.0421,
        }}
        onLongPress={(e) => {
          setPin({
            latitude: e.nativeEvent.coordinate.latitude,
            longitude: e.nativeEvent.coordinate.longitude
          })}}
        provider="google"
      >
        <Marker coordinate={pin} />
      </MapView>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
  map: {
    width: Dimensions.get('window').width,
    height: Dimensions.get('window').height,
  },
});