expose explicit transition calls (#334)

rclcpp_lifecycle/include/rclcpp_lifecycle/lifecycle_node.hpp

@@ -371,21 +371,46 @@ public:
   const State &
   trigger_transition(uint8_t transition_id);
 
+  RCLCPP_LIFECYCLE_PUBLIC
+  const State &
+  configure();
+
+  RCLCPP_LIFECYCLE_PUBLIC
+  const State &
+  cleanup();
+
+  RCLCPP_LIFECYCLE_PUBLIC
+  const State &
+  activate();
+
+  RCLCPP_LIFECYCLE_PUBLIC
+  const State &
+  deactivate();
+
+  RCLCPP_LIFECYCLE_PUBLIC
+  const State &
+  shutdown();
+
   RCLCPP_LIFECYCLE_PUBLIC
   bool
   register_on_configure(std::function<rcl_lifecycle_ret_t(const State &)> fcn);
+
   RCLCPP_LIFECYCLE_PUBLIC
   bool
   register_on_cleanup(std::function<rcl_lifecycle_ret_t(const State &)> fcn);
+
   RCLCPP_LIFECYCLE_PUBLIC
   bool
   register_on_shutdown(std::function<rcl_lifecycle_ret_t(const State &)> fcn);
+
   RCLCPP_LIFECYCLE_PUBLIC
   bool
   register_on_activate(std::function<rcl_lifecycle_ret_t(const State &)> fcn);
+
   RCLCPP_LIFECYCLE_PUBLIC
   bool
   register_on_deactivate(std::function<rcl_lifecycle_ret_t(const State &)> fcn);
+
   RCLCPP_LIFECYCLE_PUBLIC
   bool
   register_on_error(std::function<rcl_lifecycle_ret_t(const State &)> fcn);

rclcpp_lifecycle/src/lifecycle_node.cpp

@@ -305,6 +305,41 @@ LifecycleNode::trigger_transition(uint8_t transition_id)
   return impl_->trigger_transition(transition_id);
 }
 
+const State &
+LifecycleNode::configure()
+{
+  return impl_->trigger_transition(
+    lifecycle_msgs::msg::Transition::TRANSITION_CONFIGURE);
+}
+
+const State &
+LifecycleNode::cleanup()
+{
+  return impl_->trigger_transition(
+    lifecycle_msgs::msg::Transition::TRANSITION_CLEANUP);
+}
+
+const State &
+LifecycleNode::activate()
+{
+  return impl_->trigger_transition(
+    lifecycle_msgs::msg::Transition::TRANSITION_ACTIVATE);
+}
+
+const State &
+LifecycleNode::deactivate()
+{
+  return impl_->trigger_transition(
+    lifecycle_msgs::msg::Transition::TRANSITION_DEACTIVATE);
+}
+
+const State &
+LifecycleNode::shutdown()
+{
+  return impl_->trigger_transition(
+    lifecycle_msgs::msg::Transition::TRANSITION_SHUTDOWN);
+}
+
 void
 LifecycleNode::add_publisher_handle(
   std::shared_ptr<rclcpp_lifecycle::LifecyclePublisherInterface> pub)