Add holonomic motion disable option (ROS 2 turtlesim)

[Tiryoh]

This PR adds an option to turtlesim to disable holonomic motion.

Related issue: https://github.com/ros/ros_tutorials/issues/127

Usage

ros2 run turtlesim turtlesim_node --ros-args -p holonomic:=false

Note that the right terminal shows the teleop_twist_keyboard, which is not contained in this PR.

[Tiryoh]

@sloretz Sorry to bother you but is there any chance of merging this PR and ROS 1's PR (#130)?

[sloretz]

@sloretz Sorry to bother you but is there any chance of merging this PR and ROS 1's PR (#130)?

I don't have a moment to look at this right now, but at first glance it seems like an API change / ABI break. Those can be merged into ROS Rolling (ROS 2), but not ROS 1 as there's no future ROS 1 distro to target.

[jacobperron]

@Tiryoh I've rebased your branch and pushed an additional commit that simplifies the logic (maintaining ABI compatibility). It also changes the default behavior such that the holonomic feature is off by default, maintaining the current behavior.

I'm tagging current maintainers to review since I've made significant changes.

[Tiryoh]

@jacobperron Thank you for the update.

[audrow]

Here's CI:

• Linux
• Linux-aarch64
• Windows

[audrow]

Thanks for the PR @Tiryoh, and thanks for the changes and for merging @jacobperron!