@KroMignon Hey! I forgot to answer to you! Did not meant to be rude and sorry for that :(
Conclusion: I gave some tries with your suggest and lots of other stuff on internet, but failed :D
So I have created a "Restart the system to apply all the language changes" screen and a "restart/cancel" choice on a language change state. I guess it will be okay even if it wont be "real-time" :P
Good Work!

@mrjj okay - thanks for help!

Hi @Charby

To my knowledge France has a big number of people using Qt. They probably are just spread around. And I guess people doing software development do read and speak english pretty well (including the french people I have met).

The main reason for missing french in the international section is to my knowledge the Developpez site that @SGaist referred to. (the origin is a bit too far in history for me to be sure). Some other languages that have big local communities are also missing as they have local sites.

The international section is there exactly to make sure people find what they are looking for. I don't follow them day to day, but I have the feeling that some members who are more fluent in english help out others there in finding the right places too.

I think we could open a french section if you want one. I don't see a problem with that. (assuming no one else sees a problem).

You have a meetup, would you like help or support with it? Or tweet about it if you need the visibility. Also I would be interested in hearing your experiences from the meetup.
Ping me on the chat and let me know if I can help.