how to change language of text edit or line edit using change of combobox item

[thomasjoy]

it means to say we cannot change user given text on run time into another than english language....is it???

[wysota]

It means Qt translation tools are not a general use dictionary and don't support such a thing (and I've never heard of a i18n mechanism that would support it). You'd have to practically implement a complete context-detecting dictionary engine for that. The translation in Qt (or in gettext) concers static strings with optional arguments (that have to be translated separately), not free written text.