Plugin Support & Development

Display plugins are responsible for subscribing to ROS messages and logging them in the recording stream.

ROS Message Support

awviz_plugin exports built-in display plugins. Even if there are ROS messages that are not supported by built-in plugins, we can define custom plugins.

ROS Built-in Messages

ROS Package	Message Type	Plugin Type
sensor_msgs	CameraInfo	CameraInfoDisplay
	CompressedImage	CompressedImageDisplay
	Image	ImageDisplay
	PointCloud2	PointCloud2Display

Autoware Messages

ROS Package	Message Type	Plugin Type
autoware_perception_msgs	DetectedObjects	DetectedObjectsDisplay
	TrackedObjects	TrackedObjectsDisplay

Custom Plugin Definition

awviz allows us to define custom display plugins powered by pluginlib.
pluginlib is a C++ library for loading and unloading plugins from within a ROS package. Plugins are dynamically loadable classes that are loaded from a runtime library.

Example

As an example, let's create a plugin to display a custom ROS message my_custom_msgs::msg::Foo as below:

builtin_interfaces/Time stamp
float32 data

1. Package Configuration

Then create your ROS packages named as my_custom_display.
The package structure is as follows:

my_custom_display
├── CMakeLists.txt
├── include
│   └── my_custom_display
│       └── foo.hpp
├── package.xml
├── plugin_description.xml
└── src
    └── foo.cpp

2. Plugin Implementation

Edit include/my_custom_display/foo.hpp and declare the inheritance of awviz_common::RosTopicDisplay:

#ifndef MY_CUSTOM_DISPLAY__FOO_HPP_
#define MY_CUSTOM_DISPLAY__FOO_HPP_
 
#include <awviz_common/display.hpp>
 
namespace my_custom_display
{
    class Foo : public awviz_common::RosTopicDisplay<my_custom_msgs::msg::Foo>
    {
    public:
        // Construct object.
        Foo();
 
    protected:
        // Callback to log subscribed message to the recording stream.
        void log_message(my_custom_msgs::msg::Foo::ConstSharedPtr msg) override;
    };
}  // namespace my_custom_display
 
#endif  // MY_CUSTOM_DISPLAY__FOO_HPP_

Edit src/foo.cpp and write implementations:

#include "my_custom_display/foo.hpp"
 
namespace my_custom_display
{
Foo::Foo() : awviz_common::RosTopicDisplay<my_custom_msgs::msg::Foo>()
{
}
 
void Foo::log_message(my_custom_msgs::msg::Foo::ConstSharedPtr msg)
{
    stream_->set_time_seconds(
        TIMELINE_NAME, rclcpp::Time(msg->stamp.sec, msg->stamp.nanosec).seconds());
 
    stream_->log(property_.entity(), rerun::Scalar(msg->data));
}
}  // namespace my_custom_display
 
#include <pluginlib/class_list_macros.hpp>
PLUGINLIB_EXPORT_CLASS(my_custom_display::Foo, awviz_common::Display);

3. Plugin Declaration XML

Edit plugin_description.xml with the following code:

<library path="my_custom_display">
    <class name="my_custom_display/Foo" type="my_custom_display::Foo"
        base_class_type="awviz_common::Display">
        <description>Some description of the plugin.</description>
        <message_type>my_custom_msgs/msg/Foo</message_type>
    </class>
</library>

XML tag and attribute represent followings:

• library: The Name of the library.
• class: A plugin declaration that we want to export.
  • name: There used to be a name attribute, but it is no longer required.
  • type: The fully qualified type of the plugin. Now, that is my_custom_display::Foo.
  • base_class_type: The fully qualified base class type for the plugin. Use awviz_common::Display.
  • description: A description of the plugin and what it does.
  • message_type: A ROS message type that the plugin displays. Now, that is my_custom_msgs/msg/Foo.

4. CMake Plugin Declaration

Edit CMakeLists.txt to export the plugin and its description:

cmake_minimum_required(VERSION 3.14)
project(my_custom_display)
 
# -------- find dependencies --------
find_package(ament_cmake_auto REQUIRED)
ament_auto_find_build_dependencies()
 
# -------- link targets --------
add_library(${PROJECT_NAME} SHARED ${CMAKE_CURRENT_SOURCE_DIR}/src/foo.cpp)
target_include_directories(${PROJECT_NAME} PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>
)
target_link_libraries(${PROJECT_NAME} awviz_common::awviz_common rerun_sdk)
ament_target_dependencies(${PROJECT_NAME} rclcpp my_custom_msgs)
 
# -------- export plugin description --------
pluginlib_export_plugin_description_file(awviz_common plugin_description.xml)
 
# -------- export targets --------
install(
  TARGETS ${PROJECT_NAME}
  EXPORT ${PROJECT_NAME}Export
  ARCHIVE DESTINATION lib
  LIBRARY DESTINATION lib
  RUNTIME DESTINATION bin
)
ament_export_libraries(${PROJECT_NAME})
ament_export_targets(${PROJECT_NAME}Export)
 
ament_auto_package()