Added graph queries getTopicNamesAndTypes, getServiceNamesAndTypes an…

…d getActionNamesAndTypes to Ros2 singleton.

docs/pages/Ros2-Singleton.rst

@@ -27,18 +27,31 @@ As described in the API documentation for :cpp:func:`Ros2.init <qml_ros2_plugin:
 node name or additionally use provided command line args instead of the command
 line args provided to your executable.
 
-Query Topics
+Query Graph
 ------------
 
-You can also use the Ros2 singleton to query the available topics.
-Currently, three methods are provided:
+You can also use the Ros2 singleton to query the available topics, services and actions.
+These are available as:
+
+* | ``QVariantMap getTopicNamesAndTypes()``
+  | Retrieves a map of topic names and their types as a list of strings.
+* | ``QVariantMap getServiceNamesAndTypes()``
+  | Retrieves a map of service names and their types as a list of strings.
+* | ``QVariantMap getActionNamesAndTypes()``
+  | Retrieves a map of action names and their types as a list of strings.
+
+Note that the return value is a ``QVariantMap``, which is a wrapped ``QMap<QString, QStringList>``
+to make it compatible with QML.
+Also check out the ``graph_queries.qml`` example in the repo's examples folder.
+
+Additionally, for topics three convenience methods are also provided:
 
 * | ``QStringList queryTopics( const QString &datatype = QString())``
   | Queries a list of topics with the given datatype or all topics if no type provided.
 * | ``QList<TopicInfo> queryTopicInfo()``
-  | Retrieves a list of all advertised topics including their datatype. See :cpp:class:`TopicInfo`
-* | ``QString queryTopicType( const QString &name )``
-  | Retrieves the datatype for a given topic.
+  | Retrieves a list of all advertised topics including their datatypes. See :cpp:class:`TopicInfo`
+* | ``QString queryTopicTypes( const QString &name )``
+  | Retrieves the datatypes for a given topic.
 
 Example:
 
@@ -50,15 +63,15 @@ Example:
   var cameraTopics = []
   var topics = Ros2.queryTopicInfo()
   for (var i = 0; i < topics.length; ++i) {
-    if (topics[i].datatype == "sensor_msgs/msg/Image") cameraTopics.push(topics[i].name)
+    if (topics[i].datatypes.includes("sensor_msgs/msg/Image")) cameraTopics.push(topics[i].name)
   }
-  // The type of a specific topic can be retrieved as follows
-  var datatype = Ros2.queryTopicType("/topic/that/i/care/about")
+  // The types of a specific topic can be retrieved as follows
+  var datatypes = Ros2.queryTopicTypes("/topic/that/i/care/about")
   // Using this we can make an even worse implementation of the same functionality
   var cameraTopics = []
   var topics = Ros2.queryTopics() // Gets all topics
   for (var i = 0; i < topics.length; ++i) {
-    if (Ros2.queryTopicType(topics[i]) == "sensor_msgs/msg/Image") cameraTopics.push(topics[i])
+    if (Ros2.queryTopicTypes(topics[i]).includes("sensor_msgs/msg/Image")) cameraTopics.push(topics[i])
   }
 
 Create Empty Message

examples/graph_queries.qml

@@ -0,0 +1,82 @@
+import QtQuick 2.6
+import QtQuick.Controls 2.2
+import QtQuick.Controls.Material 2.2
+import QtQuick.Layouts 1.0
+import Ros2 1.0
+
+ApplicationWindow {
+  id: page
+  width: 620
+  height: 400
+
+  // This connection makes sure the application exits if this ROS node is requested to shutdown
+  Connections {
+    target: Ros2
+    function onShutdown() {
+      Qt.quit()
+    }
+  }
+  property var topics: ({})
+  property var services: ({})
+  property var actions: ({})
+
+  function update() {
+    Ros2.info("Updating.")
+    topics = Ros2.getTopicNamesAndTypes()
+    services = Ros2.getServiceNamesAndTypes()
+    actions = Ros2.getActionNamesAndTypes()
+  }
+  function printNamesAndTypes(map) {
+    let result = ""
+    for (let key in map) {
+      result += key + ": " + map[key] + "\n"
+    }
+    return result
+  }
+
+  ScrollView {
+    anchors.fill: parent
+
+    ColumnLayout {
+      anchors.margins: 12
+
+
+      Button {
+        Layout.columnSpan: 3
+        text: "Update"
+        onClicked: page.update()
+      }
+
+      Text {
+        text: "Topics:"
+      }
+      Text {
+        leftPadding: 12
+        text: printNamesAndTypes(topics)
+      }
+      Text {
+        text: "Services:"
+      }
+      Text {
+        leftPadding: 12
+        text: printNamesAndTypes(services)
+      }
+      Text {
+        text: "Actions:"
+      }
+      Text {
+        leftPadding: 12
+        text: printNamesAndTypes(actions)
+      }
+    }
+  }
+
+  Component.onCompleted: {
+    // Initialize ROS with the given name. The command line args are passed by the plugin
+    // Optionally, you can call init with a string list ["arg1", "arg2"] after the name to use those
+    // args instead of the ones supplied by the command line.
+    Ros2.init("qml_graph_queries_demo")
+    update()
+  }
+
+}

include/qml_ros2_plugin/ros2.hpp

@@ -80,6 +80,26 @@ class Ros2Qml : public QObject
    */
   QStringList queryTopicTypes( const QString &name ) const;
 
+  /*!
+   * Queries the internal node for its known topics and their types.
+   * See rclcpp::Node::get_topic_names_and_types() for more information.
+   * @return A map with the topic names as keys and the types as values.
+   */
+  QMap<QString, QStringList> getTopicNamesAndTypes() const;
+
+  /*!
+   * Queries the internal node for its known services and their types.
+   * See rclcpp::Node::get_service_names_and_types() for more information.
+   * @return A map with the service names as keys and the types as values.
+   */
+  QMap<QString, QStringList> getServiceNamesAndTypes() const;
+
+  /*!
+   * Queries the internal node for its known actions and their types.
+   * @return A map with the action names as keys and the types as values.
+   */
+  QMap<QString, QStringList> getActionNamesAndTypes() const;
+
   /*!
    * Creates an empty message for the given message type, e.g., "geometry_msgs/Point".
    * If the message type is known, an empty message with all members set to their default is returned.
@@ -115,9 +135,7 @@ class Ros2Qml : public QObject
   //! Emitted when this ROS node was shut down and it is time to exit.
   void shutdown();
 
-
 private:
-
   std::thread executor_thread_;
   std::shared_ptr<rclcpp::Context> context_;
   std::shared_ptr<rclcpp::Node> node_;
@@ -169,6 +187,15 @@ class Ros2QmlSingletonWrapper : public QObject
   //! @copydoc Ros2Qml::queryTopicTypes
   Q_INVOKABLE QStringList queryTopicTypes( const QString &name ) const;
 
+  //! @copydoc Ros2Qml::getTopicNamesAndTypes
+  Q_INVOKABLE QVariantMap getTopicNamesAndTypes() const;
+
+  //! @copydoc Ros2Qml::getServiceNamesAndTypes
+  Q_INVOKABLE QVariantMap getServiceNamesAndTypes() const;
+
+  //! @copydoc Ros2Qml::getActionNamesAndTypes
+  Q_INVOKABLE QVariantMap getActionNamesAndTypes() const;
+
   //! @copydoc Ros2Qml::createEmptyMessage
   Q_INVOKABLE QVariant createEmptyMessage( const QString &datatype ) const;
 

src/ros2.cpp

@@ -12,6 +12,7 @@
 
 #include <QCoreApplication>
 #include <QJSEngine>
+#include <rcl_action/graph.h>
 #include <thread>
 
 namespace qml_ros2_plugin
@@ -89,8 +90,7 @@ QStringList Ros2Qml::queryTopics( const QString &datatype ) const
     QML_ROS2_PLUGIN_ERROR( "Tried to query topics before node was initialized!" );
     return {};
   }
-  std::map<std::string, std::vector<std::string>> topics_and_types =
-      node_->get_topic_names_and_types();
+  auto topics_and_types = node_->get_topic_names_and_types();
   QStringList result;
   std::string std_datatype = toFullyQualifiedDatatype( datatype );
   for ( const auto &[topic, types] : topics_and_types ) {
@@ -104,15 +104,14 @@ QStringList Ros2Qml::queryTopics( const QString &datatype ) const
 
 QList<TopicInfo> Ros2Qml::queryTopicInfo() const
 {
-  std::map<std::string, std::vector<std::string>> topics_and_types =
-      node_->get_topic_names_and_types();
+  auto topics_and_types = node_->get_topic_names_and_types();
   QList<TopicInfo> result;
-  for ( const auto &topic : topics_and_types ) {
-    QStringList types;
-    types.reserve( static_cast<int>( topic.second.size() ) );
-    std::transform( topic.second.begin(), topic.second.end(), std::back_inserter( types ),
+  for ( const auto &[topic, types] : topics_and_types ) {
+    QStringList result_types;
+    result_types.reserve( static_cast<int>( types.size() ) );
+    std::transform( types.begin(), types.end(), std::back_inserter( result_types ),
                     QString::fromStdString );
-    result.append( { QString::fromStdString( topic.first ), types } );
+    result.append( { QString::fromStdString( topic ), result_types } );
   }
   return result;
 }
@@ -121,21 +120,76 @@ QStringList Ros2Qml::queryTopicTypes( const QString &name ) const
 {
   if ( name.isEmpty() )
     return {};
-  std::map<std::string, std::vector<std::string>> topics_and_types =
-      node_->get_topic_names_and_types();
+  auto topics_and_types = node_->get_topic_names_and_types();
   std::string std_name = name.toStdString();
-  for ( const auto &topic : topics_and_types ) {
-    if ( std_name != topic.first )
+  for ( const auto &[topic, types] : topics_and_types ) {
+    if ( std_name != topic )
       continue;
-    QStringList types;
-    types.reserve( static_cast<int>( topic.second.size() ) );
-    std::transform( topic.second.begin(), topic.second.end(), std::back_inserter( types ),
-                    QString::fromStdString );
-    return types;
+    QStringList result;
+    result.reserve( static_cast<int>( types.size() ) );
+    std::transform( types.begin(), types.end(), std::back_inserter( result ), QString::fromStdString );
+    return result;
   }
   return {};
 }
 
+QMap<QString, QStringList> Ros2Qml::getTopicNamesAndTypes() const
+{
+  auto topics_and_types = node_->get_topic_names_and_types();
+  QMap<QString, QStringList> result;
+  for ( const auto &[topic, types] : topics_and_types ) {
+    QStringList result_types;
+    result_types.reserve( static_cast<int>( types.size() ) );
+    std::transform( types.begin(), types.end(), std::back_inserter( result_types ),
+                    QString::fromStdString );
+    result.insert( QString::fromStdString( topic ), result_types );
+  }
+  return result;
+}
+
+QMap<QString, QStringList> Ros2Qml::getServiceNamesAndTypes() const
+{
+  auto service_names_and_types = node_->get_service_names_and_types();
+  QMap<QString, QStringList> result;
+  for ( const auto &[service_name, types] : service_names_and_types ) {
+    QStringList result_types;
+    result_types.reserve( static_cast<int>( types.size() ) );
+    std::transform( types.begin(), types.end(), std::back_inserter( result_types ),
+                    QString::fromStdString );
+    result.insert( QString::fromStdString( service_name ), result_types );
+  }
+  return result;
+}
+
+QMap<QString, QStringList> Ros2Qml::getActionNamesAndTypes() const
+{
+  rcl_names_and_types_t names_and_types = rcl_get_zero_initialized_names_and_types();
+  const rcl_node_s *node_handle = node_->get_node_base_interface()->get_rcl_node_handle();
+  rcl_allocator_t allocator = rcutils_get_default_allocator();
+  if ( rcl_ret_t ret = rcl_action_get_names_and_types( node_handle, &allocator, &names_and_types );
+       ret != RCL_RET_OK ) {
+    QML_ROS2_PLUGIN_ERROR( "Failed to get action names and types: %s", rcl_get_error_string().str );
+    return {};
+  }
+  QMap<QString, QStringList> result;
+  for ( size_t i = 0; i < names_and_types.names.size; ++i ) {
+    const std::string name = names_and_types.names.data[i];
+    const auto &types = names_and_types.types[i];
+    QStringList result_types;
+    result_types.reserve( static_cast<int>( types.size ) );
+    for ( size_t j = 0; j < types.size; ++j ) {
+      result_types.append( QString::fromStdString( types.data[j] ) );
+    }
+    result.insert( QString::fromStdString( name ), result_types );
+  }
+  if ( rcl_names_and_types_fini( &names_and_types ) != RCL_RET_OK ) {
+    QML_ROS2_PLUGIN_ERROR(
+        "Failed to free action names and types: '%s'. Might have lost some memory.",
+        rcl_get_error_string().str );
+  }
+  return result;
+}
+
 QVariant Ros2Qml::createEmptyMessage( const QString &datatype ) const
 {
   try {
@@ -254,6 +308,36 @@ QStringList Ros2QmlSingletonWrapper::queryTopicTypes( const QString &name ) cons
   return Ros2Qml::getInstance().queryTopicTypes( name );
 }
 
+QVariantMap Ros2QmlSingletonWrapper::getTopicNamesAndTypes() const
+{
+  QVariantMap result;
+  QMap<QString, QStringList> topic_names_and_types = Ros2Qml::getInstance().getTopicNamesAndTypes();
+  for ( auto it = topic_names_and_types.begin(); it != topic_names_and_types.end(); ++it ) {
+    result.insert( it.key(), QVariant( it.value() ) );
+  }
+  return result;
+}
+
+QVariantMap Ros2QmlSingletonWrapper::getServiceNamesAndTypes() const
+{
+  QVariantMap result;
+  QMap<QString, QStringList> topic_names_and_types = Ros2Qml::getInstance().getServiceNamesAndTypes();
+  for ( auto it = topic_names_and_types.begin(); it != topic_names_and_types.end(); ++it ) {
+    result.insert( it.key(), QVariant( it.value() ) );
+  }
+  return result;
+}
+
+QVariantMap Ros2QmlSingletonWrapper::getActionNamesAndTypes() const
+{
+  QVariantMap result;
+  QMap<QString, QStringList> topic_names_and_types = Ros2Qml::getInstance().getActionNamesAndTypes();
+  for ( auto it = topic_names_and_types.begin(); it != topic_names_and_types.end(); ++it ) {
+    result.insert( it.key(), QVariant( it.value() ) );
+  }
+  return result;
+}
+
 QVariant Ros2QmlSingletonWrapper::createEmptyMessage( const QString &datatype ) const
 {
   return Ros2Qml::getInstance().createEmptyMessage( datatype );