Converting Latitude and Longitude to Address with Google Map API in Flutter
Introduction
Flutter is an open-source mobile app development framework created by Google. It enables developers to build natively compiled applications for mobile, web, and desktop from a single codebase. When building a Flutter application that involves maps, it’s essential to understand how to convert latitude and longitude coordinates to a human-readable address. In this article, we’ll explore how to use the Google Map API to convert latitude and longitude to an address in Flutter.
Prerequisites
Before we dive into the implementation, make sure you have the following:
1. Google Cloud Platform Account: Create a Google Cloud Platform account and enable the Google Maps JavaScript API, if not already enabled.
2. Google Maps API Key: Create a new API key and enable the `Geocoding API` and `Maps SDK for Android` and `Maps SDK for iOS` services.
3. Flutter SDK: Install the Flutter SDK and set up your environment.
4. pubspec.yaml File: Update your `pubspec.yaml` file to include the necessary packages.
Section 1: Adding Required Packages
To use the Google Maps API in Flutter, you need to add the following packages to your `pubspec.yaml` file.
“`yml
dependencies:
googlemapsflutter: ^2.2.2
googlemapsdirections: ^2.1.0
“`
Run `flutter pub get` to install the packages.
Section 2: Setting up Google Maps API Key
Create a new file called `googleMapsApiKey.dart` and add the following code.
“`dart
const String apiKey = ‘YOURAPIKEYHERE’;
“`
Replace `YOURAPIKEY_HERE` with the actual API key you created in the Google Cloud Console.
Section 3: Converting Latitude and Longitude to Address
To convert latitude and longitude coordinates to an address, use the `Geocoding API` provided by Google Maps.
“`dart
import ‘package:flutter/material.dart’;
import ‘package:googlemapsflutter/googlemapsflutter.dart’;
import ‘package:googlemapsdirections/googlemapsdirections.dart’;
class GeocodingExample extends StatefulWidget {
@override
GeocodingExampleState createState() => GeocodingExampleState();
}
class _GeocodingExampleState extends State
final TextEditingController _latitudeController = TextEditingController();
final TextEditingController _longitudeController = TextEditingController();
GeocoderResponse _geocoderResponse;
Future
final latitude = double.parse(_latitudeController.text);
final longitude = double.parse(_longitudeController.text);
final geocoderResponse = await GeocodingAPI()
.reverseGeocode(LatLng(latitude, longitude), apiKey: _apiKey);
setState(() {
_geocoderResponse = geocoderResponse;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(‘Geocoding Example’),
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
children:
TextField(
controller: _latitudeController,
keyboardType: TextInputType.numberWithOptions(decimal: true),
decoration: InputDecoration(
labelText: ‘Latitude’,
border: OutlineInputBorder(),
),
),
TextField(
controller: _longitudeController,
keyboardType: TextInputType.numberWithOptions(decimal: true),
decoration: InputDecoration(
labelText: ‘Longitude’,
border: OutlineInputBorder(),
),
),
SizedBox(height: 16),
ElevatedButton(
onPressed: _getAddress,
child: Text(‘Get Address’),
),
SizedBox(height: 16),
if (_geocoderResponse != null)
Text(
“${geocoderResponse.streetNumber} ${geocoderResponse.streetName}, ${geocoderResponse.city} ${geocoderResponse.state} ${_geocoderResponse.countryCode}”,
style: TextStyle(fontSize: 16),
),
],
),
),
);
}
}
“`
This code prompts the user to enter a latitude and longitude, and then uses the `GeocodingAPI` to convert those coordinates to a human-readable address.
Conclusion
In this article, we covered how to convert latitude and longitude coordinates to a human-readable address using the Google Maps API in Flutter. We also demonstrated how to set up the necessary packages, obtain a Google Maps API key, and create a simple Flutter app to test the geocoding functionality.
Frequently Asked Questions (FAQs)
Q1: Do I need a Google Cloud Platform account to use the Google Maps API?
A1: Yes, you need a Google Cloud Platform account to use the Google Maps API.
Q2: What services do I need to enable on my Google Cloud Platform account?
A2: You need to enable the `Geocoding API`, `Maps SDK for Android`, and `Maps SDK for iOS` services on your Google Cloud Platform account.
Q3: How do I obtain a Google Maps API key?
A3: Follow these steps to obtain a Google Maps API key: (1) create a Google Cloud Platform account, (2) enable the required services, (3) navigate to the Google Cloud Console API Library, and (4) click on “Enable” next to “Geocoding API” and “Maps SDK for Android” and “Maps SDK for iOS” services.
Q4: What are the restrictions on using the Google Maps API?
A4: Google Maps API usage is subject to various restrictions, including but not limited to (1) usage limits, (2) attribution requirements, (3) monetization limitations, and (4) compliance with applicable laws and regulations.
Q5: What are the costs associated with using the Google Maps API?
A5: Google Maps API usage incurs costs, including but not limited to (1) base usage fees, (2) per-request fees, (3) usage-based fees, and (4) enterprise licensing fees. Review the Google Maps API pricing page for the most up-to-date pricing information.
