system_interface.hpp

// Copyright 2020 - 2021 ros2_control Development Team
//
// 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 HARDWARE_INTERFACE__SYSTEM_INTERFACE_HPP_
#define HARDWARE_INTERFACE__SYSTEM_INTERFACE_HPP_
 
#include <memory>
#include <string>
#include <vector>
 
#include "hardware_interface/handle.hpp"
#include "hardware_interface/hardware_info.hpp"
#include "hardware_interface/types/hardware_interface_return_values.hpp"
#include "hardware_interface/types/lifecycle_state_names.hpp"
#include "lifecycle_msgs/msg/state.hpp"
#include "rclcpp_lifecycle/node_interfaces/lifecycle_node_interface.hpp"
#include "rclcpp_lifecycle/state.hpp"
 
using CallbackReturn = rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface::CallbackReturn;
 
namespace hardware_interface
{
 
class SystemInterface : public rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface
{
public:
  SystemInterface()
  : lifecycle_state_(rclcpp_lifecycle::State(
      lifecycle_msgs::msg::State::PRIMARY_STATE_UNKNOWN, lifecycle_state_names::UNKNOWN))
  {
  }
 
 
  SystemInterface(const SystemInterface & other) = delete;
 
  SystemInterface(SystemInterface && other) = default;
 
  virtual ~SystemInterface() = default;
 
 
  virtual CallbackReturn on_init(const HardwareInfo & hardware_info)
  {
    info_ = hardware_info;
    return CallbackReturn::SUCCESS;
  };
 
 
  virtual std::vector<StateInterface> export_state_interfaces() = 0;
 
 
  virtual std::vector<CommandInterface> export_command_interfaces() = 0;
 
 
  virtual return_type prepare_command_mode_switch(
    const std::vector<std::string> & /*start_interfaces*/,
    const std::vector<std::string> & /*stop_interfaces*/)
  {
    return return_type::OK;
  }
 
  // Perform switching to the new command interface.
  virtual return_type perform_command_mode_switch(
    const std::vector<std::string> & /*start_interfaces*/,
    const std::vector<std::string> & /*stop_interfaces*/)
  {
    return return_type::OK;
  }
 
 
  virtual return_type read() = 0;
 
 
  virtual return_type write() = 0;
 
 
  virtual std::string get_name() const { return info_.name; }
 
 
  const rclcpp_lifecycle::State & get_state() const { return lifecycle_state_; }
 
 
  void set_state(const rclcpp_lifecycle::State & new_state) { lifecycle_state_ = new_state; }
 
protected:
  HardwareInfo info_;
  rclcpp_lifecycle::State lifecycle_state_;
};
 
}  // namespace hardware_interface
#endif  // HARDWARE_INTERFACE__SYSTEM_INTERFACE_HPP_