PyQT - Multiple languages QT Designer auto.generated UI - pyqt

Question

I am using PyQt4 and I want to translate my UI created with QT Designer in different languages. I follow some tutorials, but I am not able to apply my translation files.
I created a TS file, edited with QT Linguist and release a QM file. I try to apply it to my app, but it is still in source language.
This is retranslate method:
def retranslateUi(self, CredentialsQT):
CredentialsQT.setWindowTitle(QtGui.QApplication.translate("CredentialsQT", "IngeMaster", None, QtGui.QApplication.UnicodeUTF8))
self.groupBox.setTitle(QtGui.QApplication.translate("CredentialsQT", "Credenciales de usuario", None, QtGui.QApplication.UnicodeUTF8))
self.label.setText(QtGui.QApplication.translate("CredentialsQT", "Usuario:", None, QtGui.QApplication.UnicodeUTF8))
self.label_2.setText(QtGui.QApplication.translate("CredentialsQT", "Contraseña:", None, QtGui.QApplication.UnicodeUTF8))
self.groupBox_2.setTitle(QtGui.QApplication.translate("CredentialsQT", "Lenguaje", None, QtGui.QApplication.UnicodeUTF8))
self.label_3.setText(QtGui.QApplication.translate("CredentialsQT", "Disponibles:", None, QtGui.QApplication.UnicodeUTF8))
self.comboBox.setItemText(0, QtGui.QApplication.translate("CredentialsQT", "Deustch", None, QtGui.QApplication.UnicodeUTF8))
self.comboBox.setItemText(1, QtGui.QApplication.translate("CredentialsQT", "English", None, QtGui.QApplication.UnicodeUTF8))
self.comboBox.setItemText(2, QtGui.QApplication.translate("CredentialsQT", "Español", None, QtGui.QApplication.UnicodeUTF8))
And this is main:
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
archivo = 'Credentials_en.qm'
import os.path
if os.path.exists(archivo):
print "El fichero existe"
else:
print "El fichero no existe"
CredentialsQT = QtGui.QDialog()
ui = Ui_CredentialsQT()
ui.setupUi(CredentialsQT)
#from QtGui import QTranslator
translator=QtCore.QTranslator(app)
if translator.load(archivo, os.getcwd()):
app.installTranslator(translator)
CredentialsQT.show()
sys.exit(app.exec_())
Do you know what I am doing wrong?

Answer 1

There is probably some kind of issue with your code. See how this example works and adapt it to your needs:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
#---------
# IMPORT
#---------
import sys, os, re
import sip
sip.setapi('QString', 2)
sip.setapi('QVariant', 2)
from PyQt4 import QtGui, QtCore
#---------
# DEFINE
#---------
class MyWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MyWindow, self).__init__(parent)
self.languageDirectory = "/usr/share/qt4/translations/"
self.languageLocale = "en"
self.languageTranslator = QtCore.QTranslator()
self.centralWidget = QtGui.QWidget(self)
self.labelLanguageSelect = QtGui.QLabel(self.centralWidget)
self.labelLanguageChange = QtGui.QLabel(self.centralWidget)
self.comboBoxLanguage = QtGui.QComboBox(self.centralWidget)
self.comboBoxLanguage.addItem("en" , "")
for filePath in os.listdir(self.languageDirectory):
fileName = os.path.basename(filePath)
fileMatch = re.match("qt_([a-z]{2,}).qm", fileName)
if fileMatch:
self.comboBoxLanguage.addItem(fileMatch.group(1), filePath)
self.sortFilterProxyModelLanguage = QtGui.QSortFilterProxyModel(self.comboBoxLanguage)
self.sortFilterProxyModelLanguage.setSourceModel(self.comboBoxLanguage.model())
self.comboBoxLanguage.model().setParent(self.sortFilterProxyModelLanguage)
self.comboBoxLanguage.setModel(self.sortFilterProxyModelLanguage)
self.comboBoxLanguage.currentIndexChanged.connect(self.on_comboBoxLanguage_currentIndexChanged)
self.comboBoxLanguage.model().sort(0)
self.buttonBox = QtGui.QDialogButtonBox(self.centralWidget)
self.buttonBox.setStandardButtons(QtGui.QDialogButtonBox.Yes|QtGui.QDialogButtonBox.Cancel)
self.buttonBox.clicked.connect(self.on_buttonBox_clicked)
self.layoutGrid = QtGui.QGridLayout(self.centralWidget)
self.layoutGrid.addWidget(self.labelLanguageSelect, 0, 0, 1, 1)
self.layoutGrid.addWidget(self.comboBoxLanguage, 0, 1, 1, 1)
self.layoutGrid.addWidget(self.labelLanguageChange, 1, 0, 1, 1)
self.layoutGrid.addWidget(self.buttonBox, 1, 1, 1, 1)
self.setCentralWidget(self.centralWidget)
self.retranslateUi()
self.resetLanguage()
self.updateButtons()
#QtCore.pyqtSlot()
def on_comboBoxLanguage_currentIndexChanged(self):
self.setLanguage()
self.updateButtons()
def changeEvent(self, event):
if event.type() == QtCore.QEvent.LanguageChange:
self.retranslateUi()
super(MyWindow, self).changeEvent(event)
#QtCore.pyqtSlot(QtGui.QAbstractButton)
def on_buttonBox_clicked(self, button):
buttonRole = self.buttonBox.buttonRole(button)
if buttonRole == QtGui.QDialogButtonBox.YesRole:
self.languageLocale = self.comboBoxLanguage.currentText()
self.updateButtons()
elif buttonRole == QtGui.QDialogButtonBox.RejectRole:
self.resetLanguage()
def resetLanguage(self):
index = self.comboBoxLanguage.findText(self.languageLocale)
self.comboBoxLanguage.setCurrentIndex(index)
def setLanguage(self):
app = QtGui.QApplication.instance()
app.removeTranslator(self.languageTranslator)
languageIndex = self.comboBoxLanguage.currentIndex()
languageFileName = self.comboBoxLanguage.itemData(languageIndex, QtCore.Qt.UserRole)
if languageFileName != "en":
languageFilePath = os.path.join(self.languageDirectory, languageFileName)
else:
languageFilePath = ""
self.languageTranslator = QtCore.QTranslator()
if self.languageTranslator.load(languageFilePath):
app.installTranslator(self.languageTranslator)
def updateButtons(self):
state = self.languageLocale != self.comboBoxLanguage.currentText()
self.buttonBox.button(QtGui.QDialogButtonBox.Cancel).setEnabled(state)
self.buttonBox.button(QtGui.QDialogButtonBox.Yes).setEnabled(state)
def retranslateUi(self):
# This text is not included in te .qm file.
# You'll have to create your own .qm file specifying the translation,
# otherwise it won't get translated.
self.labelLanguageSelect.setText(self.tr("Select Language:"))
self.labelLanguageChange.setText(self.tr("Change Language:"))
#---------
# MAIN
#---------
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
app.setApplicationName('MyWindow')
main = MyWindow()
main.resize(333, 111)
main.show()
sys.exit(app.exec_())

Answer 2

I have finally made it to fix it. The problem was the translated words context.
My class was named "Ui_Credentials" and my script "Credentials.py". The .bat that generated python code from QtDesigner automaticaly added "Ui_" prefix to my class.
The solution is to change my script name adding also "Ui_" prefix like "Ui_Credentials.py".
Thanks for the helps!