import React, { Component } from 'react';import {Text,View,StyleSheet,Alert,TouchableOpacity,Image} from 'react-native';import Camera from 'react-native-camera';export default class BarcodeScan extends Component {constructor(props) {super(props);this.handleTourch = this.handleTourch.bind(this);this.state = {torchOn: false}}onBarCodeRead = (e) => {Alert.alert("Barcode value is" + e.data, "Barcode type is" + e.type);}render() {return (<View style={styles.container}><Camerastyle={styles.preview}torchMode={this.state.torchOn ? Camera.constants.TorchMode.on : Camera.constants.TorchMode.off}onBarCodeRead={this.onBarCodeRead}ref={cam => this.camera = cam}aspect={Camera.constants.Aspect.fill}><Text style={{backgroundColor: 'white'}}>BARCODE SCANNER</Text></Camera><View style={styles.bottomOverlay}><TouchableOpacity onPress={() => this.handleTourch(this.state.torchOn)}><Image style={styles.cameraIcon}source={this.state.torchOn === true ? require('../../images/flasher_on.png') : require('../../images/flasher_off.png')} /></TouchableOpacity></View></View>)}handleTourch(value) {if (value === true) {this.setState({ torchOn: false });} else {this.setState({ torchOn: true });}}}const styles = StyleSheet.create({container: {flex: 1,flexDirection: 'row',},preview: {flex: 1,justifyContent: 'flex-end',alignItems: 'center'},cameraIcon: {margin: 5,height: 40,width: 40},bottomOverlay: {position: "absolute",width: "100%",flex: 20,flexDirection: "row",justifyContent: "space-between"},});