Support sending proto definitions from the websocket server

Changelog.md

@@ -2,6 +2,9 @@
 
 ### Ignition Launch 1.X.X
 
+1. Added ability to get protobuf definitions from the websocket server
+    * [Pull Request 21](https://github.com/ignitionrobotics/ign-launch/pull/21)
+
 1. Added ability to set the publication rate of the websocket server.
     * [Pull Request 17](https://github.com/ignitionrobotics/ign-launch/pull/17)
 

plugins/websocket_server/CMakeLists.txt

@@ -3,6 +3,17 @@ if (websockets_FOUND)
   set (sources WebsocketServer.cc)
 
   add_library(${plugin} SHARED ${sources})
+
+  file (READ combined.proto MESSAGE_DEFINITIONS)
+  configure_file("MessageDefinitions.hh.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/MessageDefinitions.hh" @ONLY)
+  # Add a dependency on binary source dir so that you can change the
+  # combinded.proto file and `make` will rebuild the plugin.
+  set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS combined.proto)
+  target_include_directories(${plugin} PRIVATE
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/>
+  )
+
   target_link_libraries(${plugin}
     PRIVATE
       ${websockets_LIBRARIES}

plugins/websocket_server/MessageDefinitions.hh.in

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2019 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#ifndef IGNITION_LAUNCH_WEBSOCKETSERVER_MESSAGE_DEFINITIONS_HH_
+#define IGNITION_LAUNCH_WEBSOCKETSERVER_MESSAGE_DEFINITIONS_HH_
+
+namespace ignition
+{
+  namespace launch
+  {
+    /// \brief All of the protobuf messages provided by the websocket
+    /// server.
+    /// \todo Get this information from a running simulation. The problem
+    /// right now is that Ignition Transport does not show subscribers.
+    static const std::string kMessageDefinitions =
+      R"protos(@MESSAGE_DEFINITIONS@)protos";
+  }
+}
+#endif

plugins/websocket_server/WebsocketServer.cc

@@ -19,6 +19,7 @@
 #include <ignition/common/Util.hh>
 #include <ignition/msgs.hh>
 
+#include "MessageDefinitions.hh"
 #include "WebsocketServer.hh"
 
 using namespace ignition::launch;
@@ -268,10 +269,19 @@ void WebsocketServer::OnDisconnect(int _socketId)
 //////////////////////////////////////////////////
 void WebsocketServer::OnMessage(int _socketId, const std::string &_msg)
 {
+  // Handle the case where the client requests the message definitions.
+  if (_msg == "message_definitions")
+  {
+    igndbg << "Message definitions request recieved\n";
+    this->QueueMessage(this->connections[_socketId].get(),
+        kMessageDefinitions.c_str(), kMessageDefinitions.length());
+    return;
+  }
+
   ignition::msgs::WebRequest requestMsg;
   requestMsg.ParseFromString(_msg);
 
-  if (requestMsg.operation() == "list")
+  if (requestMsg.operation() == "topic_list")
   {
     igndbg << "Topic list request recieved\n";
     ignition::msgs::Packet msg;
@@ -285,6 +295,8 @@ void WebsocketServer::OnMessage(int _socketId, const std::string &_msg)
     for (const std::string &topic : topics)
       msg.mutable_string_msg_v()->add_data(topic);
 
+    msg.set_topic("/topic_list");
+    msg.set_type("ignition.msgs.StringMsg_V");
     std::string data = msg.SerializeAsString();
 
     // Queue the message for delivery.

plugins/websocket_server/WebsocketServer.hh

@@ -35,15 +35,31 @@ namespace ignition
     /// \brief Reads from a USB joystick device and outputs
     ///  ignition::msgs::WebsocketServer messages.
     ///
+    /// # Websocket Server Interface
+    ///
+    /// \todo: Describe the websocket API.
+    ///
     /// # Example usage
     ///
+    /// ## Websocket Server
+    ///
+    /// 1. Define a launch file by copying the following contents to a file
+    ///    called `websocket.ign`.
+    ///
     /// <!-- Inform ignition::Launch about the JoyToTwist plugin -->
     ///  <plugin name="ignition::launch::WebsocketServer"
     ///      filename="libignition-launch-joystick0.so">
     ///
     ///    <!-- Publication Hz -->
     ///    <publication_hz>30</publication_hz>
     /// </plugin>
+    ///
+    /// 2. Run the launch file
+    ///
+    /// `ign launch -v 4 websocket.ign`
+    ///
+    /// 3. Open the [index.html](https://github.com/ignitionrobotics/ign-launch/blob/master/plugins/websocket_server/index.html) webpage.
+    ///
     class WebsocketServer : public ignition::launch::Plugin
     {
       /// \brief Constructor

plugins/websocket_server/combined.proto

@@ -0,0 +1,125 @@
+syntax = "proto3";
+
+package ignition.msgs;
+
+message Time {
+  int64 sec = 1;
+  int32 nsec = 2;
+}
+
+message Clock
+{
+  Header header = 1;
+  Time system = 2;
+  Time real   = 3;
+  Time sim    = 4;
+}
+message Header {
+  message Map {
+    string key = 1;
+    repeated string value = 2;
+  }
+  Time stamp         = 1;
+  repeated Map data  = 2;
+}
+message WebRequest
+{
+  Header header         = 1;
+  string operation      = 2;
+  string topic          = 3;
+  string msg_type       = 4;
+  string compression    = 5;
+  double hz             = 6;
+}
+message StringMsg_V
+{
+  repeated string data = 2;
+}
+message CmdVel2D
+{
+  Header header    = 1;
+  double velocity  = 2;
+  double theta     = 3;
+}
+enum PixelFormatType
+{
+  UNKNOWN_PIXEL_FORMAT = 0;
+  L_INT8 = 1;
+  L_INT16 = 2;
+  RGB_INT8 = 3;
+  RGBA_INT8 = 4;
+  BGRA_INT8 = 5;
+  RGB_INT16 = 6;
+  RGB_INT32 = 7;
+  BGR_INT8 = 8;
+  BGR_INT16 = 9;
+  BGR_INT32 = 10;
+  R_FLOAT16 = 11;
+  RGB_FLOAT16 = 12;
+  R_FLOAT32 = 13;
+  RGB_FLOAT32 = 14;
+  BAYER_RGGB8 = 15;
+  BAYER_RGGR8 = 16;
+  BAYER_GBRG8 = 17;
+  BAYER_GRBG8 = 18;
+}
+
+message Image
+{
+  Header header        = 1;
+  uint32 width         = 2;
+  uint32 height        = 3;
+  uint32 pixel_format  = 4;
+  uint32 step          = 5;
+  bytes data          = 6;
+}
+message Vector3d
+{
+  Header header = 1;
+  double x = 2;
+  double y = 3;
+  double z = 4;
+}
+message Pose
+{
+  Header header          = 1;
+  string name            = 2;
+  uint32 id              = 3;
+  Vector3d position      = 4;
+  Quaternion orientation = 5;
+}
+message Quaternion
+{
+  Header header = 1;
+  double x = 2;
+  double y = 3;
+  double z = 4;
+  double w = 5;
+}
+message Double_V
+{
+  repeated double data = 1;
+}
+message Pose_V
+{
+  Header header = 1;
+  repeated Pose pose = 2;
+}
+message Packet
+{
+  string topic = 1;
+  string type  = 2;
+
+  oneof content
+  {
+    CmdVel2D cmd_vel2d = 3;
+    Image image = 4;
+    StringMsg_V string_msg_v = 5;
+    WebRequest web_request = 6;
+    Pose pose = 7;
+    Double_V doublev = 8;
+    Pose_V pose_v = 9;
+    Time time = 10;
+    Clock clock = 11;
+  }
+}