flutter-todos/lib/widgets/net_loading_widget.dart

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:todo_list/i10n/localization_intl.dart';

import 'loading_widget.dart';

class NetLoadingWidget extends StatefulWidget {
  final LoadingController loadingController;
  final Widget successWidget;
  final String loadingText;
  final String errorText;
  final String successText;
  final String emptyText;
  final String idleText;
  final VoidCallback onRequest;
  final VoidCallback onSuccess;
  final CancelToken cancelToken;

  const NetLoadingWidget({
    Key key,
    this.loadingController,
    this.successWidget, this.loadingText, this.errorText, this.successText, this.emptyText, this.idleText, this.onRequest, this.cancelToken, this.onSuccess,
  }) : super(key: key);

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

class _NetLoadingWidgetState extends State<NetLoadingWidget> {
  LoadingFlag loadingFlag = LoadingFlag.loading;

  @override
  Widget build(BuildContext context) {
    final size = MediaQuery.of(context).size;

    return GestureDetector(
      onTap: (){
        Navigator.pop(context);
      },
      child: Scaffold(
        backgroundColor: Colors.black.withOpacity(0.3),
        body: Container(
          width: size.width,
          height: size.height,
          alignment: Alignment.center,
          child: Container(
            width: size.width / 3 * 2,
            height: size.height / 3,
            child: Card(
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(30.0),
              ),
              child: LoadingWidget(
                flag: loadingFlag,
                loadingText: getLoadingText(),
                successWidget: Container(
                  margin: EdgeInsets.all(10),
                  child: widget.successWidget ?? Column(
                    mainAxisAlignment: MainAxisAlignment.spaceAround,
                    children: <Widget>[
                      Column(
                        children: <Widget>[
                          Text(
                            widget.successText ?? "",
                            textAlign: TextAlign.center,
                            style: TextStyle(fontSize: 30),
                          ),
                        ],
                      ),
                      FlatButton(
                        color: Theme.of(context).primaryColor,
                        highlightColor: Theme.of(context).primaryColorLight,
                        colorBrightness: Brightness.dark,
                        splashColor: Theme.of(context).primaryColorDark,
                        shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(20.0)),
                        onPressed: widget.onSuccess ?? (){},
                        child: Text(IntlLocalizations.of(context).ok),
                      )
                    ],
                  ),
                ),
                errorCallBack: widget.onRequest ?? (){},
                errorText: getLoadingText(),
              ),
            ),
          ),
        ),
      ),
    );
  }



  @override
  void initState() {
    super.initState();
    widget?.loadingController?._setState(this);
    if(widget.onRequest != null){
      widget.onRequest();
    }
  }

  void refresh(){
    if(mounted) setState(() {});
  }


  @override
  void dispose() {
    widget?.cancelToken?.cancel();
    super.dispose();
  }

  String getLoadingText() {
    switch (loadingFlag) {
      case LoadingFlag.loading:
        return widget.loadingText ?? IntlLocalizations.of(context).waitAMoment;
        break;
      case LoadingFlag.error:
        return widget.errorText ?? IntlLocalizations.of(context).submitAgain;
        break;
      case LoadingFlag.success:
        return widget.successText ?? IntlLocalizations.of(context).submitSuccess;
        break;
      case LoadingFlag.empty:
        return widget.emptyText ??  "";
        break;
      case LoadingFlag.idle:
        return widget.idleText ?? "";
        break;
    }
  return "";
  }
}

//这里面的state没有去执行dispose，不知道会不会内存泄漏
class LoadingController {
  _NetLoadingWidgetState _state;
  LoadingFlag _flag = LoadingFlag.loading;

  void setFlag(LoadingFlag loadingFlag) {
    _state?.loadingFlag = loadingFlag;
    _flag = loadingFlag;
    _state?.refresh();
    print("设置:${_state?.loadingFlag}");
  }

  void _setState(_NetLoadingWidgetState state) {
    if (this?._state == null) {
      this?._state = state;
    } else {
      this._state = null;
      this._state = state;
    }
    print("设置了:${this._state}");
  }

  LoadingFlag get flag => _flag;


}