cloudsolutions-atoms/lib/views/widgets/loaders/loading_manager.dart

import 'package:flutter/material.dart';
import 'package:test_sa/controllers/http_status_manger/http_status_manger.dart';
import 'package:test_sa/controllers/localization/localization.dart';
import 'package:test_sa/models/subtitle.dart';

import 'app_loading.dart';
import 'failed_loading.dart';
class LoadingManager extends StatefulWidget {
  final bool isLoading;
  final bool isFailedLoading;
  final bool isNotPage;
  final int progress;
  final bool askOnBack;
  final int stateCode;
  final Future<void> Function() onRefresh;
  final Widget child;

  LoadingManager({
    Key key,
    @required this.isLoading,
    @required this.isFailedLoading,
    @required this.stateCode,
    @required this.onRefresh,
    @required this.child,
    this.progress,
    this.isNotPage = false,
    this.askOnBack = false,
  }) : super(key: key);

  @override
  State<LoadingManager> createState() => _LoadingManagerState();
}

class _LoadingManagerState extends State<LoadingManager> {

  @override
  void initState() {
    if(widget.onRefresh != null && widget.stateCode == null){
      WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
        widget.onRefresh();
      });
    }
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    Subtitle subtitle = AppLocalization.of(context).subtitle;
    Widget placeHolder;
    // to load data if load not start
    if(widget.isLoading == false && widget.stateCode == null){
      WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
        widget.onRefresh();
      });
    }

    // if loading of still not start in loading (true or null)
    // return loading widget
    if(widget.isLoading != false || widget.stateCode == null){
      placeHolder = ALoading();
    }else if(widget.isFailedLoading && !widget.isNotPage){
      // if failed return failed widget
      placeHolder = FailedLoading(
        message: HttpStatusManger.getStatusMessage(
            status: widget.stateCode, subtitle: subtitle),
        onReload: widget.onRefresh,
      );
    }

    // if load end successfully return loaded widget
    return RefreshIndicator(
      onRefresh: () async{
        await widget.onRefresh();
      },
      child: AnimatedSwitcher(
        duration: const Duration(milliseconds: 400),
        child: placeHolder ?? widget.child,
      ),
    );
  }
}