The python client and Qt6

The python client is based on Qt and we have been using version 5 so far. Qt5 has been replaced by Qt6 quite some time ago and as Qt5 is not really maintained any more, we have been looking at switching to Qt6 for a long time. Finally we have taken the step, this blog post will outline what has changed.

The switch to PyQt6 is not that complicated for the majority of the client code base, apart from some minor changes in various classes, the biggest update is that enumerations are handled differently. If you check out the changes in the pull request you will see that imports have changed for obvious reasons

# PyQt5
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QMessageBox
# ...
# PyQt6
from PyQt6.QtCore import Qt
from PyQt6.QtWidgets import QMessageBox
# ...Code language: Python (python)

Enumerations are not available directly on the Qt type anymore, instead they must be named using their fully qualified names. For instance

# PyQt5
Qt.DisplayRole
# PyQt6
Qt.ItemDataRole.DisplayRoleCode language: Python (python)

And some other minor changes.

The Qualisys tab

The main blocker for doing this change has been that the Qualisys tab was using a library that used to be available in PyQt5 but that has not been added to PyQt6, we ended up removing the Qualisys tab to be able to move on. The Qualisys tab was originally contributed by Qualisys for demo purposes and it had two nice areas of functionality that we would like to re-implement:

1. Motion capture positioning. It was very easy to connect a Qualisys mocap system and feed the position information to the Crazyflie for automated flight.
2. Trajectory support. It was possible to fly some simple trajectories, for instance a circle which is nice for testing and demos.

The idea is to re-implement the mocap connectivity using the libmotioncapture library from Crazyswarm2, as an extra bonus this would support all major mocap systems. For the trajectory part, we would like to add this as a new tab that can be used by any positioning systems, mocap, Loco, Lighthouse or flow deck. If you are interested in helping out with this, let us know!

The state of the code

The changes for PyQt6 have been merged into the master branch. It seems to work but we have not tested all functionality yet, please let us know if you run into any problems or weird behavior.

When you have pulled in the code from github you will also have to re-install all dependencies by running

pip install -e .

Enjoy!