add detail userdoc and configurable state interface

Signed-off-by: Paul Gesel <[email protected]>

antipodal_gripper_controller/doc/userdoc.rst

@@ -6,6 +6,11 @@ Antipodal Gripper Action Controller
 -----------------------------------
 
 Controller for executing a ``AntipodalGripperCommand`` action for simple antipodal grippers.
+This controller supports grippers that offer position only control as well as grippers that allow configuring the velocity and effort.
+By default, the controller will only claim the `{joint}/position` interface for control.
+The velocity and effort interfaces can be optionally claimed by setting the `max_velocity_interface` and `max_effort_interface` parameter, respectively.
+By default, the controller will try to claim position and velocity state interfaces.
+The claimed state interfaces can be configured by setting the `state_interfaces` parameter.
 
 Parameters
 ^^^^^^^^^^^

antipodal_gripper_controller/include/antipodal_gripper_controller/antipodal_gripper_action_controller_impl.hpp

@@ -108,8 +108,7 @@ void GripperActionController::accepted_callback(
   // This is the non-realtime command_struct
   // We use command_ for sharing
   command_struct_.position_cmd_ = goal_handle->get_goal()->command.position[0];
-  if (
-    !params_.max_velocity_interface.empty() && !goal_handle->get_goal()->command.velocity.empty())
+  if (!params_.max_velocity_interface.empty() && !goal_handle->get_goal()->command.velocity.empty())
   {
     command_struct_.max_velocity_ = goal_handle->get_goal()->command.velocity[0];
   }
@@ -380,10 +379,12 @@ GripperActionController::command_interface_configuration() const
 controller_interface::InterfaceConfiguration
 GripperActionController::state_interface_configuration() const
 {
-  return {
-    controller_interface::interface_configuration_type::INDIVIDUAL,
-    {params_.joint + "/" + hardware_interface::HW_IF_POSITION,
-     params_.joint + "/" + hardware_interface::HW_IF_VELOCITY}};
+  std::vector<std::string> interface_names;
+  for (const auto & interface : params_.state_interfaces)
+  {
+    interface_names.push_back(params_.joint + "/" + interface);
+  }
+  return {controller_interface::interface_configuration_type::INDIVIDUAL, interface_names};
 }
 
 GripperActionController::GripperActionController()

antipodal_gripper_controller/src/antipodal_gripper_action_controller_parameters.yaml

@@ -12,6 +12,10 @@ antipodal_gripper_action_controller:
     type: string,
     read_only: true,
   }
+  state_interfaces: {
+    type: string_array,
+    default_value: [position, velocity],
+  }
   goal_tolerance: {
     type: double,
     default_value: 0.01,