// 没有权限需要自己申请，推荐react-native-permissions 这个库
//从相册选取二维码 没有则返回""
BarcodeUtil.decodePictureFromPhotos().then(code=>console.log(code))
//切换闪光灯
BarcodeUtil.switchFlashLightState(true or false)

import React, {
    Component,
} from 'react'
import {
    View,
    StyleSheet,
    Alert,
} from 'react-native'

import Barcode from 'react-native-smart-barcode'
import TimerEnhance from 'react-native-smart-timer-enhance'

class BarcodeTest extends Component {

    // 构造
    constructor(props) {
        super(props);
        // 初始状态
        this.state = {
            viewAppear: false,
        };
    }

    render() {

        return (
            <View style={{flex: 1, backgroundColor: 'black',}}>
                {this.state.viewAppear ? <Barcode style={{flex: 1, }}
                                                  ref={ component => this._barCode = component }
                                                  onBarCodeRead={this._onBarCodeRead}/> : null}
            </View>
        )
    }

    componentDidMount() {
        let viewAppearCallBack = (event) => {
            this.setTimeout( () => {
                this.setState({
                    viewAppear: true,
                })
            }, 255)

        }
        this._listeners = [
            this.props.navigator.navigationContext.addListener('didfocus', viewAppearCallBack)
        ]

    }

    componentWillUnmount () {
        this._listeners && this._listeners.forEach(listener => listener.remove());
    }

    _onBarCodeRead = (e) => {
        console.log(`e.nativeEvent.data.type = ${e.nativeEvent.data.type}, e.nativeEvent.data.code = ${e.nativeEvent.data.code}`)
        this._stopScan()
        Alert.alert(e.nativeEvent.data.type, e.nativeEvent.data.code, [
            {text: 'OK', onPress: () => this._startScan()},
        ])
    }

    _startScan = (e) => {
        this._barCode.startScan()
    }

    _stopScan = (e) => {
        this._barCode.stopScan()
    }

}

export default TimerEnhance(BarcodeTest)