rename planning_interface::MoveGroup to planning_interface::MoveGroupInterface

[v4hn]

An often observed source of confusion in MoveIt is the class "MoveGroup".

While everyone instantly believes to recognize this as the node that encapsulates most of MoveIt's functionality in ROS, this class actually lives in "planning_interface" and only provides a client interface to interact with the node via ROS-interfaces. It is often believed that most of the class methods call library functions and do not wrap ROS interfaces.

As such it should be renamed "MoveGroupInterface" in kinetic. This includes a number of steps (in order)

• move move_group.h to move_group_interface.h and rename the class
• provide a new move_group.h that provides a typedef named MoveGroup to be downward compatible
• rename the class throughout MoveIt's own code base
• adjust the tutorials to the new name
• add a deprecation notice to move_group.h

[davetcoleman]

I want to clarify what you are saying because it was hard to follow. The problem is that there are two files with the name move_group.cpp and one is confusing.

The executable moveit_ros/move_group/src/move_group.cpp is the ROS node that encapsulates most of MoveIt's functionality in ROS. When it is launched it creates a bunch of ROS-msg/service/action interfaces that allow you to do planning, etc. It is the central "brain" in MoveIt!.

The class planning_interface/move_group_interface/src/move_group.cpp is the interface library for interacting with MoveIt! via ROS comm (as opposed to directly as a library). It would be better if it was renamed to match the folder it lives in - move_group_interface.cpp

+1 to @v4hn's idea

[v4hn]

I want to clarify what you are saying because it was hard to follow.

Thanks, I'm a bit under the weather today. I see that my explanation was hard to follow...

You got it right.

[OBSOLETE DUE TO EDIT ABOVE]

Two minor corrections:

• There is only one class MoveGroup. It's just that the loose term "move group" is generally associated with the node and therefore the class should actually be called MoveGroupInterface.
  (moveit_ros/move_group/move_group.cpp actually uses the name MoveGroupExe internally)
• move_group (the node) is not a library. It's a ROS node. It's as simple as that. :-)

[davetcoleman]

Good points. I've updated my previous comment to be a bit more semantically correct.

[rhaschke]

+1

[v4hn]

#251 implements the proposal. Discussion should be continued there.

[davetcoleman]

I like your checklist, above. It seems this issue should not actually be closed yet

[v4hn]

you're right, I missed the tutorial updates.
Everything else is addressed in the pull-request

[davetcoleman]

tutorials updated: ros-planning/moveit_tutorials#38