deliveryboy/lib/order_tracking_page.dart

import 'dart:async';
import 'dart:developer';

import 'package:flutter/material.dart';
import 'package:flutter_polyline_points/flutter_polyline_points.dart';
import 'package:get/get.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';

import 'location_controller.dart';


class OrderTrackingPage extends StatefulWidget {

  var lat;
  var lng;
  OrderTrackingPage({
    this.lat,this.lng
  });

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

class OrderTrackingPageState extends State<OrderTrackingPage> {
  final Completer<GoogleMapController> mapController = Completer();
  PolylinePoints polylinePoints = PolylinePoints();
  double latitude=0;
  double longitude=0;

  String googleAPiKey = "AIzaSyBOigf-qg4v_aD0Jrx2wFOMNzObxXrfDEM";

  Set<Marker> markers = {};
  Map<PolylineId, Polyline> polylines = {};

  LatLng startLocation = const LatLng(0,0);


  LocationController locationController = Get.put(LocationController());

  @override
  void initState() {
    super.initState();
    latitude=widget.lat;
    longitude=widget.lng;
    LatLng endLocation =  LatLng(widget.lat,widget.lng);

    ever<LatLng?>(locationController.locationPosition, (value) {
      if (value != null) {
        log("${value.latitude} ${value.longitude}");
        var latitude = value.latitude;
        var longitude = value.longitude;
        startLocation = LatLng(latitude, longitude);
        getDirections(endLocation);
      }
    });

    getDirections(endLocation); //fetch direction polylines from Google API
  }

  getDirections(endLocation) async {
    markers.clear();

    markers.add(Marker(
      markerId: MarkerId(startLocation.toString()),
      position: startLocation,
      infoWindow: const InfoWindow(
        title: 'Starting Point ',
        snippet: 'Start Marker',
      ),
      icon: locationController.pickupMarker ?? BitmapDescriptor.defaultMarker,
    ));

    markers.add(Marker(
      markerId: MarkerId(endLocation.toString()),
      position: endLocation, //position of marker
      infoWindow: const InfoWindow(
        title: 'Destination Point ',
        snippet: 'Destination Marker',
      ),
      icon: locationController.dropMarker ?? BitmapDescriptor.defaultMarker,
    ));

    List<LatLng> polylineCoordinates = [];

    PolylineResult result = await polylinePoints.getRouteBetweenCoordinates(
      googleAPiKey,
      PointLatLng(startLocation.latitude, startLocation.longitude),
      PointLatLng(endLocation.latitude, endLocation.longitude),
      travelMode: TravelMode.driving,
    );

    if (result.points.isNotEmpty) {
      for (var point in result.points) {
        polylineCoordinates.add(LatLng(point.latitude, point.longitude));
      }
    } else {
      log(result.errorMessage ?? "Something went wrong");
    }
    addPolyLine(polylineCoordinates);
  }

  addPolyLine(List<LatLng> polylineCoordinates) async {
    PolylineId id = const PolylineId("poly");
    Polyline polyline = Polyline(
      polylineId: id,
      color: Colors.blueAccent,
      points: polylineCoordinates,
      width: 8,
    );
    polylines[id] = polyline;

    var position = CameraPosition(
        target: LatLng(startLocation.latitude, startLocation.longitude),
        zoom: 21);

    final GoogleMapController controller = await mapController.future;
    controller.animateCamera(CameraUpdate.newCameraPosition(position));

    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: GoogleMap(
        //Map widget from google_maps_flutter package
        zoomGesturesEnabled: true,
        //enable Zoom in, out on map
        initialCameraPosition: CameraPosition(
          //innital position in map
          target: startLocation, //initial position
          zoom: 5.0, //initial zoom level
        ),
        markers: markers,
        //markers to show on map
        polylines: Set<Polyline>.of(polylines.values),
        //polylines
        mapType: MapType.normal,
        //map type
        onMapCreated: (controller) {
          //method called when map is created
          if (!mapController.isCompleted) {
            mapController.complete(controller);
          }
        },
      ),
    );
  }
}