Map perspective¶
Setup¶
Prerequisites¶
Build and run¶
Go to the map_perspective
directory within the Flutter examples directory, which is the name of this example project.
Note - the gem_kit
directory containing the Maps SDK for Flutter
should be in the plugins
directory of the example, e.g.
example_pathname/plugins/gem_kit
- see the environment setup guide above.
Replace example_pathname
with the actual example path name,
such as address_search
Download project dependencies:
flutter upgrade
run the following terminal commands in the project directory,
where the pubspec.yaml
file is located:
flutter clean
flutter pub get
Run the example:
First, verify that the ANDROID_SDK_ROOT
environment variable
is set to the root path of your android SDK.
In android/build.gradle
add the maven {}
block as shown,
within the allprojects {} block
, for both debug and release builds,
without the line numbers, those are for reference:
1allprojects {
2 repositories {
3 google()
4 mavenCentral()
5 maven {
6 url "${rootDir}/../plugins/gem_kit/android/build"
7 }
8 }
9}
in android/app/build.gradle
within the android {}
block, in the defaultConfig {}
block,
the android SDK version minSdk
must be set as shown below.
Additionally, for release builds, in android/app/build.gradle
,
within the android {}
block, add the buildTypes {}
block as shown:
Replace example_pathname
with the actual example pathname, such as center_coordinates
1android {
2 defaultConfig {
3 applicationId "com.magiclane.gem_kit.examples.example_pathname"
4 minSdk 21
5 targetSdk flutter.targetSdk
6 versionCode flutterVersionCode.toInteger()
7 versionName flutterVersionName
8 }
9 buildTypes {
10 release {
11 minifyEnabled false
12 shrinkResources false
13
14 // TODO: Add your own signing config for the release build.
15 // Signing with the debug keys for now, so `flutter run --release` works.
16 signingConfig signingConfigs.debug
17 }
18 }
19}
Then run the project:
flutter run --debug
flutter run --release
In the ios/Podfile
configuration text file, at the top, set the minimum ios
platform to 13 like this:
platform :ios, '13.0'
Then run the project:
flutter run --debug
flutter run --release
How it works¶
1import 'package:gem_kit/core.dart';
2import 'package:gem_kit/map.dart';
3import 'package:flutter/cupertino.dart';
4import 'package:flutter/material.dart';
5
6Future<void> main() async {
7 const projectApiToken = String.fromEnvironment('GEM_TOKEN');
8
9 await GemKit.initialize(appAuthorization: projectApiToken);
10
11 runApp(const MyApp());
12}
13
14class MyApp extends StatelessWidget {
15 const MyApp({super.key});
16
17 @override
18 Widget build(BuildContext context) {
19 return const MaterialApp(
20 debugShowCheckedModeBanner: false,
21 title: 'Map Perspective',
22 home: MyHomePage(),
23 );
24 }
25}
26
27class MyHomePage extends StatefulWidget {
28 const MyHomePage({super.key});
29
30 @override
31 State<MyHomePage> createState() => _MyHomePageState();
32}
33
34class _MyHomePageState extends State<MyHomePage> {
35 // Map preferences are used to change map perspective
36 late MapViewPreferences _mapPreferences;
37
38 late bool _isInPerspectiveView = false;
39
40 // Tilt angle for perspective view
41 final double _3dViewAngle = 30;
42
43 // Tilt angle for orthogonal/vertical view
44 final double _2dViewAngle = 90;
45
46 @override
47 void dispose() {
48 GemKit.release();
49 super.dispose();
50 }
51
52 // The callback for when map is ready to use
53 void _onMapCreated(GemMapController controller) async {
54 _mapPreferences = controller.preferences;
55 }
56
57 void _onChangePerspectiveButtonPressed() async {
58 setState(() => _isInPerspectiveView = !_isInPerspectiveView);
59
60 // Based on view type, set the view angle
61 if (_isInPerspectiveView) {
62 _mapPreferences.tiltAngle = _3dViewAngle;
63 } else {
64 _mapPreferences.tiltAngle = _2dViewAngle;
65 }
66 }
67}
The dart
material package is imported, along with the required gem_kit
packages.
The map view angle is set using _mapPreferences.tiltAngle
, where the map preferences are obtained from the GemMapController controller
that is passed into the _onMapCreated()
callback, which is called when the interactive map is initialized and ready to use.
The map view angle is set to 90 degrees (looking vertically downward at the map) for 2D mode.
The map view angle is set to 30 degrees (looking 30 degrees downward from the horizon) for 3D mode.