Unit-App/lib/Util/Util.dart

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
import 'package:flushbar/flushbar.dart';
import '../main.dart';
import 'package:location/location.dart';
import 'package:permission_handler/permission_handler.dart' as pHandler;
import 'package:app_settings/app_settings.dart';

class Util{
  JsonDataPostRaw(Map jsonData, String url,{timeout:false}) async{
    const JsonDecoder decoder = const JsonDecoder();
    try {
      var response;
      if (timeout)
        response = await http.post(
            '$url', headers: {'Content-type': 'application/json'},
            body: json.encode(jsonData)).timeout(
            const Duration(seconds: 10));
      else
        response = await http.post(
            '$url', headers: {'Content-type': 'application/json'},
            body: json.encode(jsonData));
      final Map data = decoder.convert(response.body);
      return data;
    } on TimeoutException catch(e){
      return {"STATUS":0,"DATA":"Request Timeout"};
    }
    on Exception catch(exception){
      print(url);
//      Toast("Not Connected to Server", Colors.red);
      return {"STATUS":0,"DATA":"Not Connected to Server. $exception"};
    }
  }

  showLoading(context,{dissmissable=false,onwillpop}){
    showDialog(
        context: context,
        builder: (BuildContext context) {
      return WillPopScope(
        onWillPop: onwillpop??()async{return true;},
        child: new Center(
          child: new CircularProgressIndicator(),
        ),
      );
    },
    barrierDismissible: dissmissable,
    );
  }

  showFlushbar(context,text,{color:Colors.grey}){
    Flushbar(
        message:  "$text",
        backgroundColor: color,
        duration:  Duration(seconds: 5),
      )..show(context);
  }
  streamLocation(context)async{
    print('checking location');
    bool gpsEnabled = false;
    pHandler.PermissionStatus permissionEnabled = await pHandler.Permission.locationWhenInUse.status;
    if(await location.serviceEnabled()){
      gpsEnabled = await location.serviceEnabled();
    }
    else{
      print('requesting gps');
      gpsEnabled = await location.requestService();
      await streamLocation(context);
    }
//    print([gpsEnabled,permissionEnabled]);
    if(gpsEnabled){
      if(permissionEnabled == pHandler.PermissionStatus.granted){
        if(locationStream==null){
          locationStream = location.onLocationChanged.listen((LocationData event) {
            currentPosisiton = event;
          });
        }
      }
      else if(permissionEnabled==pHandler.PermissionStatus.denied || permissionEnabled==pHandler.PermissionStatus.undetermined){
        print('requesting permission');
        showFlushbar(context,'Location permission is needed to locate your REAL location. Please grant the permission!');
        await Future.delayed(Duration(seconds: 1));
        await pHandler.Permission.locationWhenInUse.request();
        await streamLocation(context);
      }
      else if (permissionEnabled==pHandler.PermissionStatus.permanentlyDenied){
        showFlushbar(context,'It seems, your system security explicitly denied the permission to access your location. Please MANUALLY enable it in setings!');
        await Future.delayed(Duration(seconds: 3));
        AppSettings.openAppSettings();
        exit(0);
      }
    }
  }
}