Use PIMPL pattern in gzserver (#683)

Signed-off-by: Addisu Z. Taddese <[email protected]>

ros_gz_sim/include/ros_gz_sim/gzserver.hpp

@@ -15,7 +15,7 @@
 #ifndef ROS_GZ_SIM__GZSERVER_HPP_
 #define ROS_GZ_SIM__GZSERVER_HPP_
 
-#include <thread>
+#include <gz/utils/ImplPtr.hh>
 #include <rclcpp/node.hpp>
 
 // ROS node that executes a gz-sim Server given a world SDF file or string.
@@ -36,8 +36,9 @@ class GzServer : public rclcpp::Node
   void OnStart();
 
 private:
-  /// \brief We don't want to block the ROS thread.
-  std::thread thread_;
+  /// \internal
+  /// \brief Private data pointer.
+  GZ_UTILS_UNIQUE_IMPL_PTR(dataPtr)
 };
 }  // namespace ros_gz_sim
 

ros_gz_sim/src/gzserver.cpp

@@ -12,30 +12,40 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "ros_gz_sim/gzserver.hpp"
+
 #include <functional>
+#include <thread>
 #include <gz/common/Console.hh>
 #include <gz/sim/Server.hh>
 #include <gz/sim/SystemLoader.hh>
 #include <gz/sim/ServerConfig.hh>
 #include <rclcpp/rclcpp.hpp>
 #include <rclcpp_components/register_node_macro.hpp>
 
-#include <ros_gz_sim/gzserver.hpp>
 
 namespace ros_gz_sim
 {
 
+class GzServer::Implementation
+{
+  /// \brief We don't want to block the ROS thread.
+
+public:
+  std::thread thread;
+};
+
 GzServer::GzServer(const rclcpp::NodeOptions & options)
-: Node("gzserver", options)
+: Node("gzserver", options), dataPtr(gz::utils::MakeUniqueImpl<Implementation>())
 {
-  thread_ = std::thread(std::bind(&GzServer::OnStart, this));
+  this->dataPtr->thread = std::thread(std::bind(&GzServer::OnStart, this));
 }
 
 GzServer::~GzServer()
 {
   // Make sure to join the thread on shutdown.
-  if (thread_.joinable()) {
-    thread_.join();
+  if (this->dataPtr->thread.joinable()) {
+    this->dataPtr->thread.join();
   }
 }