Add ActionImpl trait with internal messages and services

This is incomplete, since the service types aren't yet being generated.

Author: nwn

rosidl_generator_rs/resource/action.rs.em

@@ -1,4 +1,13 @@
 @{
+from rosidl_parser.definition import (
+    ACTION_FEEDBACK_MESSAGE_SUFFIX,
+    ACTION_FEEDBACK_SUFFIX,
+    ACTION_GOAL_SERVICE_SUFFIX,
+    ACTION_GOAL_SUFFIX,
+    ACTION_RESULT_SERVICE_SUFFIX,
+    ACTION_RESULT_SUFFIX,
+)
+
 action_msg_specs = []
 
 for subfolder, action in action_specs:
@@ -53,14 +62,23 @@ extern "C" {
 pub struct @(type_name);
 
 impl rosidl_runtime_rs::Action for @(type_name) {
-  type Goal = crate::@(subfolder)::rmw::@(type_name)_Goal;
-  type Result = crate::@(subfolder)::rmw::@(type_name)_Result;
-  type Feedback = crate::@(subfolder)::rmw::@(type_name)_Feedback;
+  type Goal = crate::@(subfolder)::rmw::@(type_name)@(ACTION_GOAL_SUFFIX);
+  type Result = crate::@(subfolder)::rmw::@(type_name)@(ACTION_RESULT_SUFFIX);
+  type Feedback = crate::@(subfolder)::rmw::@(type_name)@(ACTION_FEEDBACK_SUFFIX);
 
   fn get_type_support() -> *const std::os::raw::c_void {
     // SAFETY: No preconditions for this function.
     unsafe { rosidl_typesupport_c__get_action_type_support_handle__@(package_name)__@(subfolder)__@(type_name)() }
   }
 }
 
+impl rosidl_runtime_rs::ActionImpl for @(type_name) {
+  type GoalStatusMessage = action_msgs::msg::rmw::GoalStatusArray;
+  type FeedbackMessage = crate::@(subfolder)::rmw::@(type_name)@(ACTION_FEEDBACK_MESSAGE_SUFFIX);
+
+  type SendGoalService = crate::@(subfolder)::rmw::@(type_name)@(ACTION_GOAL_SERVICE_SUFFIX);
+  type CancelGoalService = action_msgs::srv::rmw::CancelGoal;
+  type GetResultService = crate::@(subfolder)::rmw::@(type_name)@(ACTION_RESULT_SERVICE_SUFFIX);
+}
+
 @[end for]

rosidl_runtime_rs/src/traits.rs

@@ -163,16 +163,36 @@ pub trait Service: 'static {
 /// Trait for actions.
 ///
 /// User code never needs to call this trait's method, much less implement this trait.
-pub trait Action: 'static {
-    /// The goal message associated with this service.
+pub trait Action: 'static + ActionImpl {
+    /// The goal message associated with this action.
     type Goal: Message;
 
-    /// The result message associated with this service.
+    /// The result message associated with this action.
     type Result: Message;
 
-    /// The feedback message associated with this service.
+    /// The feedback message associated with this action.
     type Feedback: Message;
 
     /// Get a pointer to the correct `rosidl_action_type_support_t` structure.
     fn get_type_support() -> *const std::os::raw::c_void;
 }
+
+/// Trait for action implementation details.
+///
+/// User code never needs to implement this trait, nor use its associated types.
+pub trait ActionImpl: 'static {
+    /// The goal_status message associated with this action.
+    type GoalStatusMessage: Message;
+
+    /// The feedback message associated with this action.
+    type FeedbackMessage: Message;
+
+    /// The send_goal service associated with this action.
+    type SendGoalService: Service;
+
+    /// The cancel_goal service associated with this action.
+    type CancelGoalService: Service;
+
+    /// The get_result service associated with this action.
+    type GetResultService: Service;
+}