Flutter版仿火币k线与深度线

flutter_k_chart基本实现了火币里面各项指标线以及深度线，Flutter目前没有比较好的开源组件，就自己写了一个，声明式ui自定义起来有点怪怪的，但大致与android差不多，先上效果图

k_chart.2019-09-01 10_19_56.gif
depth.2019-09-01 10_21_31.gif
screenshots.png

使用方式

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<KLineEntity> datas;
  bool showLoading = true;
  MainState _mainState = MainState.MA;
  SecondaryState _secondaryState = SecondaryState.MACD;
  bool isLine = true;
  List<DepthEntity> _bids, _asks;

  @override
  void initState() {
    super.initState();
    getData('1day');
    rootBundle.loadString('assets/depth.json').then((result) {
      final parseJson = json.decode(result);
      Map tick = parseJson['tick'];
      var bids = tick['bids'].map((item) => DepthEntity(item[0], item[1])).toList().cast<DepthEntity>();
      var asks = tick['asks'].map((item) => DepthEntity(item[0], item[1])).toList().cast<DepthEntity>();
      initDepth(bids, asks);
    });
  }

  void initDepth(List<DepthEntity> bids, List<DepthEntity> asks) {
    if (bids == null || asks == null || bids.isEmpty || asks.isEmpty) return;
    _bids = List();
    _asks = List();
    double amount = 0.0;
    bids?.sort((left, right) => left.price.compareTo(right.price));
    //倒序循环 //累加买入委托量
    bids.reversed.forEach((item) {
      amount += item.amount;
      item.amount = amount;
      _bids.insert(0, item);
    });

    amount = 0.0;
    asks?.sort((left, right) => left.price.compareTo(right.price));
    //倒序循环 //累加买入委托量
    asks?.forEach((item) {
      amount += item.amount;
      item.amount = amount;
      _asks.add(item);
    });
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Color(0xff17212F),
//      appBar: AppBar(title: Text(widget.title)),
      body: ListView(
        children: <Widget>[
          Stack(children: <Widget>[
            Container(
              height: 450,
              width: double.infinity,
              child: KChartWidget(
                datas,
                isLine: isLine,
                mainState: _mainState,
                secondaryState: _secondaryState,
              ),
            ),
            if (showLoading)
              Container(
                  width: double.infinity,
                  height: 450,
                  alignment: Alignment.center,
                  child: CircularProgressIndicator()),
          ]),
          buildButtons(),
          Container(
            height: 230,
            width: double.infinity,
            child: DepthChart(_bids, _asks),
          )
        ],
      ),
    );
  }

  Widget buildButtons() {
    return Wrap(
      alignment: WrapAlignment.spaceEvenly,
      children: <Widget>[
        button("分时", onPressed: () => isLine = true),
        button("k线", onPressed: () => isLine = false),
        button("MA", onPressed: () => _mainState = MainState.MA),
        button("BOLL", onPressed: () => _mainState = MainState.BOLL),
        button("隐藏", onPressed: () => _mainState = MainState.NONE),
        button("MACD", onPressed: () => _secondaryState = SecondaryState.MACD),
        button("KDJ", onPressed: () => _secondaryState = SecondaryState.KDJ),
        button("RSI", onPressed: () => _secondaryState = SecondaryState.RSI),
        button("WR", onPressed: () => _secondaryState = SecondaryState.WR),
        button("隐藏副视图", onPressed: () => _secondaryState = SecondaryState.NONE),
      ],
    );
  }

  Widget button(String text, {VoidCallback onPressed}) {
    return FlatButton(
        onPressed: () {
          if (onPressed != null) {
            onPressed();
            setState(() {});
          }
        },
        child: Text("$text"),
        color: Colors.blue);
  }

  void getData(String period) {
    Future<String> future = getIPAddress('$period');
    future.then((result) {
      Map parseJson = json.decode(result);
      List list = parseJson['data'];
      datas = list.map((item) => KLineEntity.fromJson(item)).toList().reversed.toList().cast<KLineEntity>();
      DataUtil.calculate(datas);
      showLoading = false;
      setState(() {});
    }).catchError((_) {
      showLoading = false;
      setState(() {});
      print('获取数据失败');
    });
  }

  Future<String> getIPAddress(String period) async {
    var url =
        'https://api.huobi.br.com/market/history/kline?period=${period ?? '1day'}&size=300&symbol=btcusdt';
    String result;
    var response = await http.get(url);
    if (response.statusCode == 200) {
      result = response.body;
    } else {
      print('Failed getting IP address');
    }
    return result;
  }
}

GitHub地址：https://github.com/gwhcn/flutter_k_chart
后期会持续完善，欢迎指出问题以及star