Add WorldControlState msg type

[adlarkin]

Signed-off-by: Ashton Larkin [email protected]

🎉 New feature

Part of gazebosim/gz-sim#1106

Summary

As discussed in gazebosim/design#8 (comment), if the GUI's ECM is updated while simulation is paused, the GUI should share any ECM updates that occurred with the server when simulation is resumed. This PR creates a WorldControlState message to accomplish this. This message type contains both WorldControl and a SerializedState (the SerializedState can be used to contain ECM information, and WorldControl is used for the same purpose - play/pause/step).

Test it

This message can be tested with gazebosim/gz-sim#1109.

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge

[codecov]

Codecov Report

Merging #190 (4c8057b) into ign-msgs8 (5415083) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           ign-msgs8     #190   +/-   ##
==========================================
  Coverage      84.56%   84.56%           
==========================================
  Files              7        7           
  Lines            855      855           
==========================================
  Hits             723      723           
  Misses           132      132           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5415083...4c8057b. Read the comment docs.

[chapulina]

This looks ok to me as is, but I'd like the full implementation to be complete and iterated on before merging. This is targeting a release branch, so once it's merged / released, we can't change it.

Leaving a "request changes" to signify this.

[nkoenig]

Minor documentation comments.

[nkoenig]

Targeting fortress is fine for the subt work.

[adlarkin]

All review feedback has been addressed. As mentioned previously, if this goes into Fortress, the message types can't be changed once they're merged. So, I will hold off on merging this until gazebosim/gz-gui#306 and gazebosim/gz-sim#1109 are finalized.

[adlarkin]

Following the discussion I had with @nkoenig in gazebosim/gz-sim#1109 (comment), I've updated this PR to only create a WorldControlState msg type. We do not need the SerializedState_V msg type for achieving gazebosim/gz-sim#1106.

[nkoenig]

I've tested this with gazebosim/gz-gui#306 and it seems to work well. I'll merge and get a release out the door so that we can move forward with downstream PRs.

Tested with downstream PRs.