Language user selectable in app

[McGiverGim]

This adds a select in the options menu to let the user select the prefered language for the app.

The language is hot changed, but with some problems in the actual code:

• It changes all the statics texts
• The texts generated in a .js file (like selects, for example), remains with the older language.
• The texts changed in a .js (like the connect and disconnect text button) return to the original value.
• When refreshing a tab or restarting the app, the texts are translated correctly.

All the problems are easily solvable. When adding an element to a select, or changing the content of a button, we need to add or change the i18n attribute too.

We can do two things:

• Don't hot change the language (a reboot of the app will be required).
• Let the code as is, with hot change, and I will push some PR to solve the above problems, or at least the major part of them.

I prefer the second solution, as I say is not as difficult, and the problems with the selects is a minor problem that with a tab change is solved.

[mikeller]

I am in favour of the first proposal, to require a restart:

• the restart can probably be triggered from within the application, with a dialog that pops up after the user changes the language;
• while changing everything on the fly is feasible, it will require special handling throughout all of the code. This will require all contributors to know about it, and increase the effort required for code reviews, and fixups of on the fly translations. In terms of maintainability I think this is not a desirable outcome.

[McGiverGim]

Is a pity. The 95% of the code is ready, and except the connect button, the only strings that are not translated are combos and if a developer forgets to add the code, nothing "bad" happens.
We wait for other opinions or I change it?

Hot change is useful if a user don't finds something in his language and changes momentary to English. Without hot change a reconnect will be necessary.

[mikeller]

There's the problem: The last 5% of the code will have to go all through the application, where they will require extra maintenance. I am not sure that much on-the-spot switching forth and back will be happening, most of the time the user will switch to their language of choice, and then stay there. This seems to be the assumption in a lot of other applications that require a restart to change the language at least.

[McGiverGim]

Ok, code changed. Now there's simply a text next to the language select saying that a restart is required.

Doing the restart can take more work, I'm not too sure how to maintain the state of the connection, check that is not in a dangerous moment (flashing firmware, etc.) or how to do it. Maybe in a future PR?

[mikeller]

Thanks for changing this, @McGiverGim. I think this is perfectly good for now. It solves the problem of users wanting to use a language that is different from their system language (which is normally a permanent choice). If users have to switch forth and back between languages in order to get the information they need, then I suspect this is more of a problem of the information not being clear, and should be fixed by clarification, and making it easy to switch languages is just a workaround.