Tue Feb 22 09:54:27 PM HKT 2022

README.md

@@ -45,6 +45,21 @@ ros2 run tutorial publisher
 cd example/subscriber
 flutter run -d linux
 ```
+### Subscribe using roslibdart
+```
+ros = Ros(url: 'ws://127.0.0.1:9090');
+chatter = Topic(ros: ros, name: '/topic', type: "std_msgs/String", reconnectOnClose: true, queueLength: 10, queueSize: 10);
+ros.connect();
+await chatter.subscribe(subscribeHandler);
+
+Future<void> subscribeHandler(Map<String, dynamic> msg) async {
+  msgReceived = json.encode(msg);
+  setState(() {});
+}
+```
+
+
+
 ## Testing subscriber
 ### Run topic subscriber
 ```
@@ -54,8 +69,16 @@ ros2 run tutorial subscriber
 ```
 cd example/publisher
 flutter run -d linux
-
 ```
+### Publish using roslibdart
+```
+ros = Ros(url: 'ws://127.0.0.1:9090');
+chatter = Topic(ros: ros, name: '/topic', type: "std_msgs/String", reconnectOnClose: true, queueLength: 10, queueSize: 10);
+ros.connect();
+Map<String, dynamic> json = {"data": msgToPublished.toString()};
+await chatter.publish(json);
+```
+
 ## Testing call 
 ### Run tutorial addtwoint service
 ```
@@ -65,18 +88,46 @@ ros2 run tutorial service
 cd example/client
 flutter run -d linux
 ```
-
-
+### Call a service using roslibdart
+```
+ros = Ros(url: 'ws://127.0.0.1:9090');
+service = Service(name: 'add_two_ints', ros: ros, type: "tutorial_interfaces/AddTwoInts");
+ros.connect();
+Map<String, dynamic> json = {"a": 1, "b": 2};
+Map<String, dynamic> result = await service.call(json);
+msgToPublished = result['sum'];
+```
 ## Testing providing service
 ### Fire up flutter service
-
-
+```
+cd example/service
+flutter run -d linux
+```
+### Run tutorial call
+```
+ros2 run tutorial client
+```
 
 ### Run the client from shell
 ```
 ros2 run tutorial client 2 3
 ```
+### Provide service using roslibdart
+```
+ros = Ros(url: 'ws://127.0.0.1:9090');
+service = Service(name: 'add_two_ints', ros: ros, type: "tutorial_interfaces/AddTwoInts");
+ros.connect();
+await service.advertise(serviceHandler);
+
+Future<Map<String, dynamic>>? serviceHandler(Map<String, dynamic> args) async {
+  Map<String, dynamic> response = {};
+  response['sum'] = args['a'] + args['b'];
+  return response;
+}
+```
+
 ## Links
 - [ROSBridge Protocol v2.0](https://github.com/biobotus/rosbridge_suite/blob/master/ROSBRIDGE_PROTOCOL.md).
 - [Original roslib library from Conrad Heidebrecht](https://github.com/Eternali/roslib)
 - [RosBridge server implementation](https://github.com/RobotWebTools/rosbridge_suite)
+- [roslibjs example](https://github.com/RobotWebTools/roslibjs/blob/develop/examples/simple.html)

example/caller/README.md

@@ -1,4 +1,4 @@
-# client
+# caller
 
 A new Flutter project.
 

example/caller/android/app/build.gradle

@@ -43,7 +43,7 @@ android {
 
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId "com.example.client"
+        applicationId "com.example.caller"
         minSdkVersion flutter.minSdkVersion
         targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()

example/caller/android/app/src/debug/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.client">
+    package="com.example.caller">
     <!-- Flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->

example/caller/android/app/src/main/AndroidManifest.xml

@@ -1,7 +1,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.client">
+    package="com.example.caller">
    <application
-        android:label="client"
+        android:label="caller"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
         <activity

example/caller/android/app/src/main/kotlin/com/example/caller/MainActivity.kt

@@ -1,4 +1,4 @@
-package com.example.client
+package com.example.caller
 
 import io.flutter.embedding.android.FlutterActivity
 

example/caller/android/app/src/profile/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.client">
+    package="com.example.caller">
     <!-- Flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->

example/caller/ios/Runner.xcodeproj/project.pbxproj

@@ -294,7 +294,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = com.example.client;
+				PRODUCT_BUNDLE_IDENTIFIER = com.example.caller;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "Runner/Runner-Bridging-Header.h";
 				SWIFT_VERSION = 5.0;
@@ -422,7 +422,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = com.example.client;
+				PRODUCT_BUNDLE_IDENTIFIER = com.example.caller;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "Runner/Runner-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -444,7 +444,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = com.example.client;
+				PRODUCT_BUNDLE_IDENTIFIER = com.example.caller;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "Runner/Runner-Bridging-Header.h";
 				SWIFT_VERSION = 5.0;

example/caller/ios/Runner/Info.plist

@@ -5,7 +5,7 @@
 	<key>CFBundleDevelopmentRegion</key>
 	<string>$(DEVELOPMENT_LANGUAGE)</string>
 	<key>CFBundleDisplayName</key>
-	<string>Client</string>
+	<string>Caller</string>
 	<key>CFBundleExecutable</key>
 	<string>$(EXECUTABLE_NAME)</string>
 	<key>CFBundleIdentifier</key>
@@ -13,7 +13,7 @@
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleName</key>
-	<string>client</string>
+	<string>caller</string>
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>

example/caller/lib/main.dart

@@ -14,11 +14,11 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Roslibdart Client Example',
+      title: 'Roslibdart Caller Example',
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: const MyHomePage(title: 'Roslibdart Client Example'),
+      home: const MyHomePage(title: 'Roslibdart Caller Example'),
     );
   }
 }
@@ -54,10 +54,6 @@ class _MyHomePageState extends State<MyHomePage> {
     });
   }
 
-  void initConnection() async {
-    setState(() {});
-  }
-
   void destroyConnection() async {
     await ros.close();
     setState(() {});

example/caller/linux/CMakeLists.txt

@@ -1,8 +1,8 @@
 cmake_minimum_required(VERSION 3.10)
 project(runner LANGUAGES CXX)
 
-set(BINARY_NAME "client")
-set(APPLICATION_ID "com.example.client")
+set(BINARY_NAME "caller")
+set(APPLICATION_ID "com.example.caller")
 
 cmake_policy(SET CMP0063 NEW)
 

example/caller/linux/my_application.cc

@@ -40,11 +40,11 @@ static void my_application_activate(GApplication* application) {
   if (use_header_bar) {
     GtkHeaderBar* header_bar = GTK_HEADER_BAR(gtk_header_bar_new());
     gtk_widget_show(GTK_WIDGET(header_bar));
-    gtk_header_bar_set_title(header_bar, "client");
+    gtk_header_bar_set_title(header_bar, "caller");
     gtk_header_bar_set_show_close_button(header_bar, TRUE);
     gtk_window_set_titlebar(window, GTK_WIDGET(header_bar));
   } else {
-    gtk_window_set_title(window, "client");
+    gtk_window_set_title(window, "caller");
   }
 
   gtk_window_set_default_size(window, 1280, 720);

example/caller/test/widget_test.dart

@@ -8,7 +8,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import 'package:client/main.dart';
+import 'package:caller/main.dart';
 
 void main() {
   testWidgets('Counter increments smoke test', (WidgetTester tester) async {

example/caller/web/index.html

@@ -23,13 +23,13 @@
   <!-- iOS meta tags & icons -->
   <meta name="apple-mobile-web-app-capable" content="yes">
   <meta name="apple-mobile-web-app-status-bar-style" content="black">
-  <meta name="apple-mobile-web-app-title" content="client">
+  <meta name="apple-mobile-web-app-title" content="caller">
   <link rel="apple-touch-icon" href="icons/Icon-192.png">
 
   <!-- Favicon -->
   <link rel="icon" type="image/png" href="favicon.png"/>
 
-  <title>client</title>
+  <title>caller</title>
   <link rel="manifest" href="manifest.json">
 </head>
 <body>

example/caller/web/manifest.json

@@ -1,6 +1,6 @@
 {
-    "name": "client",
-    "short_name": "client",
+    "name": "caller",
+    "short_name": "caller",
     "start_url": ".",
     "display": "standalone",
     "background_color": "#0175C2",

example/service/lib/main.dart

@@ -49,10 +49,6 @@ class _MyHomePageState extends State<MyHomePage> {
     });
   }
 
-  void initConnection() async {
-    setState(() {});
-  }
-
   void destroyConnection() async {
     await ros.close();
     setState(() {});
@@ -81,7 +77,7 @@ class _MyHomePageState extends State<MyHomePage> {
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
-            Text('return answer ' + msgToPublished.toString()),
+            Text('Service returns answer ' + msgToPublished.toString()),
           ],
         ),
       ),

example/subscriber/lib/main.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:roslibdart/roslibdart.dart';
+import 'dart:async';
+import 'dart:convert';
 
 void main() {
   runApp(const ExampleApp());
@@ -37,12 +39,11 @@ class _HomePageState extends State<HomePage> {
         queueLength: 10,
         queueSize: 10);
     super.initState();
-  }
-
-  void initConnection() async {
     ros.connect();
-    await chatter.subscribe();
-    setState(() {});
+    Timer(const Duration(seconds: 3), () async {
+      await chatter.subscribe(subscribeHandler);
+      // await chatter.subscribe();
+    });
   }
 
   void destroyConnection() async {
@@ -51,51 +52,28 @@ class _HomePageState extends State<HomePage> {
     setState(() {});
   }
 
+  String msgReceived = '';
+  Future<void> subscribeHandler(Map<String, dynamic> msg) async {
+    msgReceived = json.encode(msg);
+    setState(() {});
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
         title: const Text('Roslibdart Subscriber Example'),
       ),
-      body: StreamBuilder<Object>(
-          stream: ros.statusStream,
-          builder: (context, snapshot) {
-            return Center(
-              child: Column(
-                crossAxisAlignment: CrossAxisAlignment.center,
-                mainAxisAlignment: MainAxisAlignment.center,
-                children: <Widget>[
-                  StreamBuilder<Map<String, dynamic>>(
-                    stream: chatter.subscription,
-                    builder: (BuildContext context2,
-                        AsyncSnapshot<Map<String, dynamic>> snapshot2) {
-                      if (snapshot2.hasData && snapshot2.data != null) {
-                        return Text('${snapshot2.data!['msg']}');
-                      } else {
-                        return const CircularProgressIndicator();
-                      }
-                    },
-                  ),
-                  ActionChip(
-                    label: Text(snapshot.data == Status.connected
-                        ? 'DISCONNECT'
-                        : 'CONNECT'),
-                    backgroundColor: snapshot.data == Status.connected
-                        ? Colors.green[300]
-                        : Colors.grey[300],
-                    onPressed: () {
-                      // print(snapshot.data);
-                      if (snapshot.data != Status.connected) {
-                        initConnection();
-                      } else {
-                        destroyConnection();
-                      }
-                    },
-                  ),
-                ],
-              ),
-            );
-          }),
+      body: Center(
+        // Center is a layout widget. It takes a single child and positions it
+        // in the middle of the parent.
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            Text(msgReceived + ' received'),
+          ],
+        ),
+      ),
     );
   }
 }

lib/core/topic.dart

@@ -4,6 +4,9 @@ import 'dart:async';
 import 'ros.dart';
 import 'request.dart';
 
+// Receiver function to handle requests when the service is advertising.
+typedef SubscribeHandler = Future<void> Function(Map<String, dynamic> args);
+
 /// Wrapper to interact with ROS topics.
 class Topic {
   Topic({
@@ -72,7 +75,7 @@ class Topic {
   ///
   /// Defaults to true.
   bool reconnectOnClose;
-
+  /*
   /// Subscribe to the topic if not already subscribed.
   Future<void> subscribe() async {
     if (subscribeId == null) {
@@ -91,6 +94,30 @@ class Topic {
       ));
     }
   }
+  */
+
+  Future<void> subscribe(SubscribeHandler subscribeHandler) async {
+    if (subscribeId == null) {
+      // Create the listenable broadcast subscription stream.
+      subscription = ros.stream;
+      subscribeId = ros.requestSubscriber(name);
+      await safeSend(Request(
+        op: 'subscribe',
+        id: subscribeId,
+        type: type,
+        topic: name,
+        compression: compression,
+        throttleRate: throttleRate,
+        queueLength: queueLength,
+      ));
+      subscription!.listen((Map<String, dynamic> message) async {
+        if (message['topic'] != name) {
+          return;
+        }
+        await subscribeHandler(message['msg']);
+      });
+    }
+  }
 
   /// Unsubscribe from the topic.
   Future<void> unsubscribe() async {