Hi, Over the past week, I have been getting alot of help from this list and have learnt alot from the knowledgeable people on the list.
Here is a summary of my attempt to create a test app (as a QMainWindow), loading a *.ui file directly and creating the UI on the fly and handling the language switching. My code works as far as I know but I do have two questions: (1) The way I am handling the language/translator switch/change, is that the correct way ? Any unforeseen resource leak ? (2) I see some examples where a translator is removed before installing a new one, I comment that away and it still works, is there some issue lurking in the background that will cause a crash later ? The full project is here https://github.com/nyue/QtQuestions/tree/main/Qt5/language_change/mainwindow HEADER ======= #pragma once #include <QMainWindow> #include <QCheckBox> #include <QLabel> #include <QComboBox> #include <QTranslator> #include <QCoreApplication> #include <QSharedPointer> #include <QVector> class MainWindow : public QMainWindow { // NOTICE THIS MACRO Q_OBJECT // typedef QSharedPointer<QTranslator> TranslatorShdPtr; struct abc { QString name; QString bcp47; TranslatorShdPtr translator; }; typedef QVector<abc> LanguageTranslatorVecContainer; public: MainWindow(QWidget *parent = 0); private: QCheckBox* ui_checkBox; QLabel* ui_label; QComboBox* ui_languageComboBox; QTranslator ui_translator; QLabel* ui_iconLabel; LanguageTranslatorVecContainer _ltc; private: void retranslateUi(); private slots: void handleLanguageChange(int index); }; SOURCE ======= #include "MainWindow.h" #include <QVBoxLayout> #include <QDebug> #include <QUiLoader> #include <QFile> #include <QDir> #include <QDirIterator> #include <QWidget> #include <QApplication> QString extract_bcp47(const QString language_file_path) { QStringList dotSplit = language_file_path.split("."); QString nameWithBCP47 = dotSplit[dotSplit.size()-2]; QStringList underscoreSplit = nameWithBCP47.split("_"); QString bcp47 = underscoreSplit[underscoreSplit.size()-1]; return bcp47; } MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) { QUiLoader loader; QFile file(":/designer/mainwindow.ui"); file.open(QFile::ReadOnly); QWidget *widget = loader.load(&file, parent); loader.setTranslationEnabled(true); file.close(); setCentralWidget(widget); // Build language drop down menu { ui_languageComboBox = findChild<QComboBox*>("comboBox"); Q_ASSERT(ui_languageComboBox); connect(ui_languageComboBox, SIGNAL(currentIndexChanged(int)), this, SLOT(handleLanguageChange(int))); // Find available languages // https://stackoverflow.com/questions/28463090/how-to-iterate-through-only-certain-type-of-files-using-qdiriterator#28463194 QDirIterator it(QString(":/language/.qm"), QStringList() << "*.qm", QDir::Files, QDirIterator::Subdirectories); while (it.hasNext()) { QString item = it.next(); QString language = extract_bcp47(item); QLocale locale(language); /* qDebug() << item; qDebug() << "bcp47 " << language; qDebug() << "countryToString " << QLocale::countryToString(locale.country()); qDebug() << "languageToString " << QLocale::languageToString(locale.language()); */ // Create a translator for each language found TranslatorShdPtr t(new QTranslator); if (t->load(item)) { struct abc stuff{QLocale::languageToString(locale.language()),language,t}; _ltc.push_back(stuff); } } // Iterate the languages found to build the drop down list QVectorIterator<struct abc> ii(_ltc); while (ii.hasNext()) { struct abc s = ii.next(); // qDebug() << s.name << ": " << s.translator; // qDebug() << "s.name " << s.name; ui_languageComboBox->addItem(s.name,s.name); } // Default to English int index = ui_languageComboBox->findData("English"); if ( index != -1 ) { // -1 for not found ui_languageComboBox->setCurrentIndex(index); } } ui_iconLabel = findChild<QLabel*>("iconLabel"); Q_ASSERT(ui_iconLabel); QIcon languageIcon; languageIcon.addFile(":/icons/Font_Awesome_5_solid_language.svg"); // languageIcon.addFile(":/icons/wl.png"); QPixmap iconPixmap = languageIcon.pixmap(32); ui_iconLabel->setPixmap(iconPixmap); ui_iconLabel->resize(iconPixmap.width(),iconPixmap.height()); } void MainWindow::handleLanguageChange(int index) { QString langFile = QString(":/language/.qm/mlc_%1.qm").arg(_ltc[index].bcp47); if (ui_translator.load(langFile)) { // qApp->removeTranslator(&ui_translator); bool installed = qApp->installTranslator(&ui_translator); if (installed) { this->retranslateUi(); } } } void MainWindow::retranslateUi() { ui_label = findChild<QLabel*>("label"); if (ui_label) ui_label->setText(QCoreApplication::translate("MainWindow", "Hello", nullptr)); } Cheers -- Nicholas Yue Graphics - Arnold, Alembic, RenderMan, OpenGL, HDF5 Custom Dev - C++ porting, OSX, Linux, Windows http://au.linkedin.com/in/nicholasyue https://vimeo.com/channels/naiadtools
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