Multi-language support

App has multi-language support available with QtTranslator for Python.

Supported languages:

• English
• Russian

Switching languages

The required language is specified using an argument when starting the application (default: English language)

python3 main.py ru

• UI translation: Directory resources/lang/qm should contain the file of the corresponding translation. (Filename format: lang_<language_code>.qm, <language_code>: en, it, fr, ru)

  • If qm-file does not exist, app use default language (English).

• Element info translation: File doc/info.json must contain the required language in the lang-field for categories and info

  • If lang-field does not contains selected language, app use default language (English - it should always be, otherwise how did you add this element?).

UI translation

In app we use something similar to the code below:

_translate = QtCore.QCoreApplication.translate
translated_string = _translate("MainWindow", "Map characteristics")

QtCore.QCoreApplication.translate - QTranslator.translate

This allows to translate specific strings with the installed QtTranslator.

Such strings must be translated into the desired language in advance.

Adding new language for UI

For getting the strings, that must be translated, we use the pylupdate5 tool

# Example
pylupdate5 main.py -ts lang_en.ts

It creates *.ts-file, which contains strings in xml-format. For example, resources/lang/ts/lang_en.ts

• Place the translation in the appropriate tag, remove attr type

<translation type="unfinished"></translation>

• Create *.qm file from *.ts by lrelease tool

lrelease lang_it.ts

• Move created *.qm file to resources/lang/qm directory

Example resources/lang/ts/lang_ru.ts

File resources/lang/ts/lang_en.ts contains all the currently required strings, use it to translate into other languages.

Warning: application is not finished and will be improved, which means that new strings may be added

Element's info translation

For storing translations in doc/info.json, we use the following format for elements in categories and info:

"lang": {
    "ru": {
        "name": "Блоки дороги"
    },
    "en": {
        "name": "Road tiles"
    }
}
----------
"lang": {
    "ru": {
        "name": "Осторожно, уточки",
        "info": "Специальный знак. Обозначает место перехода уточками дорогу."
    },
    "en": {
        "name": "Duck crossing",
        "info": "Special sign. Indicates the place where ducks cross the road."
    }
}

Adding new language for element's info

Add translation to desired language in lang-field in file doc/info.json for categories and info.

If you don't want to translate something - it's okay. Application will use English by default if there is no translation.