Teach hello_services to provide a platform service (#4277)

Currently this service just returns mock data, but it exercises the plumbing.

examples/hello_services/ios/HelloServices.xcodeproj/project.pbxproj

@@ -13,6 +13,8 @@
 		9740EEB41CF90195004384FC /* Flutter.xcconfig in Resources */ = {isa = PBXBuildFile; fileRef = 9740EEB21CF90195004384FC /* Flutter.xcconfig */; };
 		9740EEB51CF90195004384FC /* Generated.xcconfig in Resources */ = {isa = PBXBuildFile; fileRef = 9740EEB31CF90195004384FC /* Generated.xcconfig */; };
 		9740EEBB1CF902C7004384FC /* app.flx in Resources */ = {isa = PBXBuildFile; fileRef = 9740EEB71CF902C7004384FC /* app.flx */; };
+		977505191CFDF23500BC28DA /* LocationProvider.m in Sources */ = {isa = PBXBuildFile; fileRef = 977505181CFDF23500BC28DA /* LocationProvider.m */; };
+		97A38A351CFDEC880099F1B4 /* AppDelegate.m in Sources */ = {isa = PBXBuildFile; fileRef = 97A38A341CFDEC880099F1B4 /* AppDelegate.m */; };
 		97C146F31CF9000F007C117D /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = 97C146F21CF9000F007C117D /* main.m */; };
 		97C146FC1CF9000F007C117D /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FA1CF9000F007C117D /* Main.storyboard */; };
 		97C146FE1CF9000F007C117D /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FD1CF9000F007C117D /* Assets.xcassets */; };
@@ -40,6 +42,10 @@
 		9740EEB71CF902C7004384FC /* app.flx */ = {isa = PBXFileReference; lastKnownFileType = file; name = app.flx; path = Flutter/app.flx; sourceTree = "<group>"; };
 		9740EEB81CF902C7004384FC /* app.so */ = {isa = PBXFileReference; lastKnownFileType = "compiled.mach-o.dylib"; name = app.so; path = Flutter/app.so; sourceTree = "<group>"; };
 		9740EEBA1CF902C7004384FC /* Flutter.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Flutter.framework; path = Flutter/Flutter.framework; sourceTree = "<group>"; };
+		977505171CFDF21E00BC28DA /* LocationProvider.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = LocationProvider.h; sourceTree = "<group>"; };
+		977505181CFDF23500BC28DA /* LocationProvider.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = LocationProvider.m; sourceTree = "<group>"; };
+		97A38A331CFDEC680099F1B4 /* AppDelegate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = AppDelegate.h; sourceTree = "<group>"; };
+		97A38A341CFDEC880099F1B4 /* AppDelegate.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = AppDelegate.m; sourceTree = "<group>"; };
 		97C146EE1CF9000F007C117D /* HelloServices.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = HelloServices.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		97C146F21CF9000F007C117D /* main.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = main.m; sourceTree = "<group>"; };
 		97C146FB1CF9000F007C117D /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/Main.storyboard; sourceTree = "<group>"; };
@@ -97,6 +103,10 @@
 				97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */,
 				97C147021CF9000F007C117D /* Info.plist */,
 				97C146F11CF9000F007C117D /* Supporting Files */,
+				97A38A331CFDEC680099F1B4 /* AppDelegate.h */,
+				97A38A341CFDEC880099F1B4 /* AppDelegate.m */,
+				977505171CFDF21E00BC28DA /* LocationProvider.h */,
+				977505181CFDF23500BC28DA /* LocationProvider.m */,
 			);
 			path = HelloServices;
 			sourceTree = "<group>";
@@ -200,7 +210,9 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				97A38A351CFDEC880099F1B4 /* AppDelegate.m in Sources */,
 				97C146F31CF9000F007C117D /* main.m in Sources */,
+				977505191CFDF23500BC28DA /* LocationProvider.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

examples/hello_services/ios/HelloServices/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>
+
+@interface AppDelegate : UIResponder <UIApplicationDelegate>
+
+@property (strong, nonatomic) UIWindow *window;
+
+@end
+

examples/hello_services/ios/HelloServices/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* controller = [[FlutterViewController alloc] initWithProject:project
+                                                                               nibName:nil
+                                                                                bundle:nil];
+    _locationProvider = [[LocationProvider alloc] init];
+    [controller addMessageListener: _locationProvider];
+
+    self.window.rootViewController = controller;
+    [self.window makeKeyAndVisible];
+    return YES;
+}
+
+@end

examples/hello_services/ios/HelloServices/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="8150" systemVersion="15A204g" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+<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>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="8122"/>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
     </dependencies>
     <scenes>
         <!--View Controller-->
@@ -15,7 +16,6 @@
                     <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"/>
-                        <animations/>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
                     </view>
                 </viewController>

examples/hello_services/ios/HelloServices/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/hello_services/ios/HelloServices/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"
+
+@implementation LocationProvider
+
+@synthesize messageName = _messageName;
+
+- (instancetype) init {
+    self = [super init];
+    if (self)
+        self->_messageName = @"getLocation";
+    return self;
+}
+
+- (NSString*)didReceiveString:(NSString*)message {
+    NSDictionary* response = @{
+        @"latitude": @3.29334,
+        @"longitude": @8.2492492
+    };
+
+    NSData* data = [NSJSONSerialization dataWithJSONObject:response options:0 error:nil];
+    return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
+}
+
+@end

examples/hello_services/ios/HelloServices/main.m

@@ -4,11 +4,12 @@
 
 #import <UIKit/UIKit.h>
 #import <Flutter/Flutter.h>
+#import "AppDelegate.h"
 
 int main(int argc, char * argv[]) {
     FlutterInit(argc, (const char**)argv);
     @autoreleasepool {
         return UIApplicationMain(argc, argv, nil,
-                                 NSStringFromClass([FlutterAppDelegate class]));
+                                 NSStringFromClass([AppDelegate class]));
     }
 }

examples/hello_services/lib/main.dart

-// Copyright 2015 The Chromium Authors. All rights reserved.
+// 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 'package:flutter/widgets.dart';
+import 'dart:async';
+import 'dart:convert';
+import 'dart:math';
 
-void main() => runApp(new Center(child: new Text('Hello, world!')));
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+final Random random = new Random();
+
+Future<String> handleGetRandom(String json) async {
+  Map<String, dynamic> message = JSON.decode(json);
+  double min = message['min'].toDouble();
+  double max = message['max'].toDouble();
+
+  double value = (random.nextDouble() * (max - min)) + min;
+
+  Map<String, double> reply = <String, double>{'value': value};
+  return JSON.encode(reply);
+}
+
+class HelloServices extends StatefulWidget {
+  @override
+  _HelloServicesState createState() => new _HelloServicesState();
+}
+
+class _HelloServicesState extends State<HelloServices> {
+  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'),
+          ]
+        )
+      )
+    );
+  }
+
+  void _getLocation() {
+    Map<String, String> message = <String, String>{'provider': 'network'};
+    HostMessages.sendToHost('getLocation', JSON.encode(message))
+        .then(_onReceivedLocation);
+  }
+
+  void _onReceivedLocation(String json) {
+    Map<String, double> reply = JSON.decode(json);
+    setState(() {
+      _latitude = reply['latitude'];
+      _longitude = reply['longitude'];
+    });
+  }
+}
+
+void main() {
+  runApp(new HelloServices());
+
+  HostMessages.addMessageHandler('getRandom', handleGetRandom);
+}