ros2
ros2 topic delay for tf
Feature request
Feature description
It would be nice to be able to run ros2 topic delay for the /tf topic. It has the message type tf2_msgs/msg/TFMessage which is a list of TransformStamped, each containing a header.
Implementation considerations
Either messages of type tf2_msgs/msg/TFMessage could always be treated in this way or a command line option could be added that makes it possible to give a subfield that should be checked for headers.
I think ros2 topic delay is meant to measure and display the delay of messages via topic, not contents in the message. but i would like to hear from others.
If I understand it correctly, ros2 topic delay reads the contents of the message's header and determines the difference to the current clock. So it does already use contents of the message. My proposal would just be to use different fields for the /tf topic.
I don't think we should special-case TFMessage here, but I would be for a new command-line option to allow the field to be chosen.
That said, I don't think we'll get to this anytime soon, so please consider making a pull request to implement this functionality.
