pyside2 translation

main.py

#!/usr/bin/env python3

# This Python file uses the following encoding: utf-8

import sys
import os
from PySide2.QtCore import QLocale
from PySide2.QtGui import QGuiApplication
from PySide2.QtQml import QQmlApplicationEngine
from app_config import ConfigSerial
from app_config import ConfigGui
from app_config import ConfigMachine
from loguru import logger

from translationhelper import TranslationHelper

def main(argv):
    app = QGuiApplication(sys.argv)
    engine = QQmlApplicationEngine()
    
    translation_helper = TranslationHelper(engine, "movit_flr_")
    
    engine.rootContext().setContextProperty("FullscreenMode",ConfigGui.fullscreen_mode);
    engine.rootContext().setContextProperty("TranslationHelper", translation_helper)

    engine.load(os.path.join(os.path.dirname(__file__), "qml", "main.qml"))

    if not engine.rootObjects():
        sys.exit(-1)

    logger.info("========= Application exit =========")
    sys.exit(app.exec_())


if __name__ == "__main__":

    fmt = "{time:YYYY-MM-DD HH:mm:ss.SSS} | {level: <8} | {message}"
    logger.add('logs/log_movit_flr_debug.log', format = fmt, level='DEBUG',  rotation="10 MB")
    
    logger.info("========= Application start =========")
    with logger.catch():
        main(sys.argv)
   
  

main.qml

ApplicationWindow {
    id: mainWindow
    
    width: 1024
    height: 600
    visibility: FullscreenMode?"FullScreen":"Normal"
    visible: true
    title: qsTr("MovitFLR")
    
    
    ..... 
    // I need a better way to manage locale reference from QML.
    // For now I use integer value as described here:
    // https://doc.qt.io/qt-5/qlocale.html#Country-enum
    
   Button{
       text: "EN"
       x:100
       y:20
       z:100
       onClicked: {
           TranslationHelper.change_language(31)
       }
   }

   Button{
       text: "IT"
       y:20
       z:100
       onClicked: {
           TranslationHelper.change_language(58)
       }
   }
 }

translationhelper.py

from PySide2.QtCore import QLocale, QTranslator, Slot, QCoreApplication, QObject, Signal
import os

from loguru import logger
 
class TranslationHelper(QObject):
    
    def __init__(self, engine, basename) -> None:
        super().__init__()

        self.__translator = QTranslator()
        self.__engine = engine
        self.__language = QLocale.C
        
        trdir = os.path.join(os.path.dirname(__file__), 'translations')
        self.__basename = os.path.join(trdir, basename)
        
        self.change_language(self.__language);

    def __del__(self):
        pass

    # @Signal
    # def languageChanged(self) :
    #     pass

    @Slot()
    def get_language(self):
        return self.__language
        
    @Slot(int)
    def change_language(self, language):
        ret = False
        locale = QLocale(QLocale.Language(language))
        logger.info("Change language to {}", locale)
        
        if (language != self.__language):
            QCoreApplication.removeTranslator(self.__translator)
            
            if self.__translator.load(locale, self.__basename,  ):
                
                QCoreApplication.installTranslator(self.__translator)                
                                                
                # self.languageChanged
                self.__language = language
                logger.info("OK! Changed language to {}", language)
                ret = True
            else :
                logger.warning("Unable to load translation file for  {}", language)
                
            self.__engine.retranslate()

        else:
            logger.warning("Skip change language to {}", language)
            ret = True
        
        return ret