Add platform_services sample (#8058)

* Add platform_services sample

* update build.gradle to use latest scripts

* use FlutterActivity

* Updated ExampleInstrumentedTest.java and deleted FlutterPlugin.groovy

* Remove getRandom code from main.dart

* remove unused import

examples/platform_services/.gitignore

+.DS_Store
+.atom/
+.idea
+.packages
+.pub/
+build/
+packages/
+pubspec.lock

examples/platform_services/README.md

+# Example of calling platform services from Flutter
+
+This project demonstrates how to connect a Flutter app to platform specific services. 
+
+You can read more about
+[accessing platform and third-party services in Flutter](https://flutter.io/platform-services/).
+
+## iOS
+
+### Configure
+
+Create an `ios/Flutter/Generated.xcconfig` file with this entry:
+
+ * `FLUTTER_ROOT=[absolute path to the Flutter SDK]`
+
+There are a number of other parameters you can control with this file:
+
+ * `FLUTTER_APPLICATION_PATH`: The path to the directory that contains your
+   `pubspec.yaml` file relative to your `xcodeproj` file.
+ * `FLUTTER_BUILD_MODE`: Whether to build for `debug`, `profile`, or `release`.
+   Defaults to `release`.
+ * `FLUTTER_TARGET`: The path to your `main.dart` relative to your
+   `pubspec.yaml`. Defaults to `lib/main.dart`.
+ * `FLUTTER_FRAMEWORK_DIR`: The absolute path to the directory that contains
+   `Flutter.framework`. Defaults to the `ios-release` version of
+   `Flutter.framework` in the `bin/cache` directory of the Flutter SDK.
+
+### Build
+
+Once you've configured your project, you can open `ios/Runner.xcodeproj`
+in Xcode and build the project as usual.
+
+## Android
+
+### Configure
+
+Create an `android/local.properties` file with these entries:
+
+ * `sdk.dir=[path to the Android SDK]`
+ * `flutter.sdk=[path to the Flutter SDK]`
+
+There are a number of other parameters you can control with this file:
+
+ * `flutter.buildMode`: Whether to build for `debug`, `profile`, or `release`.
+   Defaults to `release`.
+ * `flutter.jar`: The path to `flutter.jar`. Defaults to the
+   `android-arm-release` version of `flutter.jar` in the `bin/cache` directory
+   of the Flutter SDK.
+
+See `android/app/build.gradle` for project specific settings, including:
+
+ * `source`: The path to the directory that contains your `pubspec.yaml` file
+   relative to your `build.gradle` file.
+ * `target`: The path to your `main.dart` relative to your `pubspec.yaml`.
+   Defaults to `lib/main.dart`.
+
+### Build
+
+To build directly with `gradle`, use the following commands:
+
+ * `cd android`
+ * `gradle wrapper`
+ * `./gradlew build`
+
+To build with Android Studio, open the `android` folder in Android Studio and
+build the project as usual.

examples/platform_services/android/.gitignore

+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build
+/captures
+
+/gradle
+/gradlew
+/gradlew.bat

examples/platform_services/android/app/.gitignore

+/build

examples/platform_services/android/app/build.gradle

+def localProperties = new Properties()
+def localPropertiesFile = rootProject.file('local.properties')
+if (localPropertiesFile.exists()) {
+    localPropertiesFile.withInputStream { stream ->
+        localProperties.load(stream)
+    }
+}
+
+def flutterRoot = localProperties.getProperty('flutter.sdk')
+if (flutterRoot == null) {
+    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
+}
+
+apply plugin: 'com.android.application'
+apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
+
+android {
+    compileSdkVersion 25
+    buildToolsVersion '25.0.2'
+
+    lintOptions {
+        disable 'InvalidPackage'
+    }
+
+    defaultConfig {
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            // TODO: Add your own signing config for the release build.
+            // Signing with the debug keys for now, so `flutter run --release` works.
+            signingConfig signingConfigs.debug
+        }
+    }
+}
+
+flutter {
+    source '../..'
+}
+
+dependencies {
+    androidTestCompile 'com.android.support:support-annotations:25.0.0'
+    androidTestCompile 'com.android.support.test:runner:0.5'
+    androidTestCompile 'com.android.support.test:rules:0.5'
+}

examples/platform_services/android/app/src/androidTest/java/com/example/flutter/ExampleInstrumentedTest.java

+package com.example.flutter;
+
+import android.graphics.Bitmap;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.rule.ActivityTestRule;
+import android.support.test.runner.AndroidJUnit4;
+
+import io.flutter.view.FlutterView;
+
+import android.app.Instrumentation;
+import android.support.test.InstrumentationRegistry;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Rule
+    public ActivityTestRule<ExampleActivity> activityRule =
+        new ActivityTestRule<>(ExampleActivity.class);
+
+
+    @Test
+    public void testBitmap() {
+        final Instrumentation instr = InstrumentationRegistry.getInstrumentation();
+        final BitmapPoller poller = new BitmapPoller(5);
+        instr.runOnMainSync(new Runnable() {
+            public void run() {
+                final FlutterView flutterView = (FlutterView) activityRule.getActivity()
+                    .getFlutterView();
+
+                // Call onPostResume to start the engine's renderer even if the activity
+                // is paused in the test environment.
+                flutterView.onPostResume();
+
+                poller.start(flutterView);
+            }
+        });
+
+        Bitmap bitmap = null;
+        try {
+            bitmap = poller.waitForBitmap();
+        } catch (InterruptedException e) {
+            fail(e.getMessage());
+        }
+
+        assertNotNull(bitmap);
+        assertTrue(bitmap.getWidth() > 0);
+        assertTrue(bitmap.getHeight() > 0);
+
+        // Check that a pixel matches the default Material background color.
+        assertTrue(bitmap.getPixel(bitmap.getWidth() - 1, bitmap.getHeight() - 1) == 0xFFFAFAFA);
+    }
+
+    // Waits on a FlutterView until it is able to produce a bitmap.
+    private class BitmapPoller {
+        private int triesPending;
+        private int waitMsec;
+        private FlutterView flutterView;
+        private Bitmap bitmap;
+        private CountDownLatch latch = new CountDownLatch(1);
+
+        private final int delayMsec = 1000;
+
+        BitmapPoller(int tries) {
+            triesPending = tries;
+            waitMsec = delayMsec * tries + 100;
+        }
+
+        void start(FlutterView flutterView) {
+            this.flutterView = flutterView;
+            flutterView.postDelayed(checkBitmap, delayMsec);
+        }
+
+        Bitmap waitForBitmap() throws InterruptedException {
+            latch.await(waitMsec, TimeUnit.MILLISECONDS);
+            return bitmap;
+        }
+
+        private Runnable checkBitmap = new Runnable() {
+            public void run() {
+                bitmap = flutterView.getBitmap();
+                triesPending--;
+                if (bitmap != null || triesPending == 0) {
+                    latch.countDown();
+                } else {
+                    flutterView.postDelayed(checkBitmap, delayMsec);
+                }
+            }
+        };
+    }
+}

examples/platform_services/android/app/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.flutter"
+    android:versionCode="1"
+    android:versionName="1.0.0" >
+
+    <uses-sdk android:minSdkVersion="16" android:targetSdkVersion="22" />
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
+
+    <application android:name="io.flutter.app.FlutterApplication" android:label="@string/app_name" >
+        <activity
+            android:name=".ExampleActivity"
+            android:launchMode="singleTop"
+            android:theme="@android:style/Theme.Black.NoTitleBar"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection"
+            android:hardwareAccelerated="true"
+            android:windowSoftInputMode="adjustResize">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

examples/platform_services/android/app/src/main/java/com/example/flutter/ExampleActivity.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package com.example.flutter;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.location.Location;
+import android.location.LocationManager;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+import android.widget.Button;
+import android.widget.TextView;
+
+import io.flutter.app.FlutterActivity;
+import io.flutter.view.FlutterMain;
+import io.flutter.view.FlutterView;
+
+import java.io.File;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+public class ExampleActivity extends FlutterActivity {
+    private static final String TAG = "ExampleActivity";
+    private FlutterView flutterView;
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        flutterView = getFlutterView();
+        flutterView.addOnMessageListener("getLocation",
+            new FlutterView.OnMessageListener() {
+                @Override
+                public String onMessage(FlutterView view, String message) {
+                    return onGetLocation(message);
+                }
+            });
+    }
+
+    private String onGetLocation(String json) {
+        String provider;
+        try {
+            JSONObject message = new JSONObject(json);
+            provider = message.getString("provider");
+        } catch (JSONException e) {
+            Log.e(TAG, "JSON exception", e);
+            return null;
+        }
+
+        String locationProvider;
+        if (provider.equals("network")) {
+            locationProvider = LocationManager.NETWORK_PROVIDER;
+        } else if (provider.equals("gps")) {
+            locationProvider = LocationManager.GPS_PROVIDER;
+        } else {
+            return null;
+        }
+
+        String permission = "android.permission.ACCESS_FINE_LOCATION";
+        Location location = null;
+        if (checkCallingOrSelfPermission(permission) == PackageManager.PERMISSION_GRANTED) {
+            LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
+            location = locationManager.getLastKnownLocation(locationProvider);
+        }
+
+        JSONObject reply = new JSONObject();
+        try {
+            if (location != null) {
+              reply.put("latitude", location.getLatitude());
+              reply.put("longitude", location.getLongitude());
+            } else {
+              reply.put("latitude", 0);
+              reply.put("longitude", 0);
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, "JSON exception", e);
+            return null;
+        }
+
+        return reply.toString();
+    }
+}
\ No newline at end of file

examples/platform_services/android/app/src/main/res/values/strings.xml

+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Platform Services</string>
+    <string name="title">Flutter Application</string>
+</resources>

examples/platform_services/android/build.gradle

+buildscript {
+    repositories {
+        jcenter()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:2.2.3'
+    }
+}
+
+allprojects {
+    repositories {
+        jcenter()
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
+
+task wrapper(type: Wrapper) {
+    gradleVersion = '2.14.1'
+}

examples/platform_services/android/buildSrc/build.gradle

+repositories {
+  jcenter()
+}
+
+dependencies {
+  compile "com.android.tools.build:gradle:2.2.3"
+}

examples/platform_services/android/buildSrc/src/main/resources/META-INF/gradle-plugins/flutter.properties

+implementation-class=io.flutter.gradle.FlutterPlugin

examples/platform_services/android/gradle.properties

+org.gradle.jvmargs=-Xmx1536M

examples/platform_services/android/settings.gradle

+include ':app'

examples/platform_services/ios/.gitignore

+.idea/
+.vagrant/
+.sconsign.dblite
+.svn/
+
+.DS_Store
+*.swp
+*.lock
+profile
+
+DerivedData/
+build/
+
+*.pbxuser
+*.mode1v3
+*.mode2v3
+*.perspectivev3
+
+!default.pbxuser
+!default.mode1v3
+!default.mode2v3
+!default.perspectivev3
+
+xcuserdata
+
+*.moved-aside
+
+*.pyc
+*sync/
+Icon?
+.tags*
+
+/Flutter/app.flx
+/Flutter/app.dylib
+/Flutter/app.zip
+/Flutter/Flutter.framework
+/Flutter/Generated.xcconfig
+/ServiceDefinitions.json

examples/platform_services/ios/Flutter/Flutter.xcconfig

+#include "Generated.xcconfig"

examples/platform_services/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata

+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:PlatformServices.xcodeproj">
+   </FileRef>
+</Workspace>

examples/platform_services/ios/Runner/AppDelegate.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <UIKit/UIKit.h>
+#import <Flutter/Flutter.h>
+
+@interface AppDelegate : FlutterAppDelegate
+
+@end

examples/platform_services/ios/Runner/AppDelegate.m

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "AppDelegate.h"
+
+#import <Flutter/Flutter.h>
+#import "LocationProvider.h"
+
+@implementation AppDelegate {
+    LocationProvider* _locationProvider;
+}
+
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+    FlutterDartProject* project = [[FlutterDartProject alloc] initFromDefaultSourceForConfiguration];
+    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
+    FlutterViewController* flutterController = [[FlutterViewController alloc] initWithProject:project
+                                                                                      nibName:nil
+                                                                                       bundle:nil];
+    _locationProvider = [[LocationProvider alloc] init];
+    [flutterController addMessageListener:_locationProvider];
+
+    self.window.rootViewController = flutterController;
+    [self.window makeKeyAndVisible];
+    return YES;
+}
+
+@end

examples/platform_services/ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json

+{
+  "images" : [
+    {
+      "idiom" : "iphone",
+      "size" : "29x29",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "29x29",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "40x40",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "40x40",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "60x60",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "60x60",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "29x29",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "29x29",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "40x40",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "40x40",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "76x76",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "76x76",
+      "scale" : "2x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file

examples/platform_services/ios/Runner/Base.lproj/LaunchScreen.storyboard

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="Llm-lL-Icb"/>
+                        <viewControllerLayoutGuide type="bottom" id="xb3-aO-Qok"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+</document>

examples/platform_services/ios/Runner/Base.lproj/Main.storyboard

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="6211" systemVersion="14A298i" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="BYZ-38-t0r">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="6204"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="tne-QT-ifu">
+            <objects>
+                <viewController id="BYZ-38-t0r" customClass="ViewController" customModuleProvider="" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
+                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
+            </objects>
+        </scene>
+    </scenes>
+</document>

examples/platform_services/ios/Runner/Info.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>PlatformServices</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIMainStoryboardFile</key>
+	<string>Main</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

examples/platform_services/ios/Runner/LocationProvider.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Flutter/Flutter.h>
+
+@interface LocationProvider : NSObject <FlutterMessageListener>
+
+@end

examples/platform_services/ios/Runner/LocationProvider.m

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "LocationProvider.h"
+
+#import <CoreLocation/CoreLocation.h>
+
+@implementation LocationProvider {
+    CLLocationManager* _locationManager;
+}
+
+@synthesize messageName = _messageName;
+
+- (instancetype) init {
+    self = [super init];
+    if (self)
+        self->_messageName = @"getLocation";
+    return self;
+}
+
+- (NSString*)didReceiveString:(NSString*)message {
+    if (_locationManager == nil) {
+        _locationManager = [[CLLocationManager alloc] init];
+        [_locationManager startMonitoringSignificantLocationChanges];
+    }
+
+    CLLocation* location = _locationManager.location;
+
+    NSDictionary* response = @{
+        @"latitude": @(location.coordinate.latitude),
+        @"longitude": @(location.coordinate.longitude),
+    };
+
+    NSData* data = [NSJSONSerialization dataWithJSONObject:response options:0 error:nil];
+    return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
+}
+
+@end

examples/platform_services/ios/Runner/main.m

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <UIKit/UIKit.h>
+#import <Flutter/Flutter.h>
+#import "AppDelegate.h"
+
+int main(int argc, char * argv[]) {
+    @autoreleasepool {
+        return UIApplicationMain(argc, argv, nil,
+                                 NSStringFromClass([AppDelegate class]));
+    }
+}

examples/platform_services/lib/main.dart

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+class PlatformServices extends StatefulWidget {
+  @override
+  _PlatformServicesState createState() => new _PlatformServicesState();
+}
+
+class _PlatformServicesState extends State<PlatformServices> {
+  double _latitude;
+  double _longitude;
+
+  @override
+  Widget build(BuildContext context) {
+    return new Material(
+      child: new Center(
+        child: new Column(
+          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+          children: <Widget>[
+            new Text('Hello from Flutter!'),
+            new RaisedButton(
+              child: new Text('Get Location'),
+              onPressed: _getLocation
+            ),
+            new Text('Latitude: $_latitude, Longitude: $_longitude'),
+          ]
+        )
+      )
+    );
+  }
+
+  Future<Null> _getLocation() async {
+    final Map<String, String> message = <String, String>{'provider': 'network'};
+    final Map<String, dynamic> reply = await PlatformMessages.sendJSON('getLocation', message);
+    // If the widget was removed from the tree while the message was in flight,
+    // we want to discard the reply rather than calling setState to update our
+    // non-existent appearance.
+    if (!mounted)
+      return;
+    setState(() {
+      _latitude = reply['latitude'].toDouble();
+      _longitude = reply['longitude'].toDouble();
+    });
+  }
+}
+
+void main() {
+  runApp(new PlatformServices());
+}

examples/platform_services/pubspec.yaml

+name: platform_services
+
+dependencies:
+  flutter:
+    sdk: flutter
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter