Qt 5.11 | Qt Widgets | I18N Example | languagechooser.cpp Example File

Qt 5.11.3 Reference Documentation

# languagechooser.cpp Example File

tools/i18n/languagechooser.cpp

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      #include <QtWidgets>

      #include "languagechooser.h"
      #include "mainwindow.h"

      #if 0 // Used to be included in Qt4 for Q_WS_MAC
      extern void qt_mac_set_menubar_merge(bool merge);

      #endif

      LanguageChooser::LanguageChooser(const QString& defaultLang, QWidget *parent)
          : QDialog(parent, Qt::WindowStaysOnTopHint)
      {
          groupBox = new QGroupBox("Languages");

          QGridLayout *groupBoxLayout = new QGridLayout;

          QStringList qmFiles = findQmFiles();
          for (int i = 0; i < qmFiles.size(); ++i) {
              QCheckBox *checkBox = new QCheckBox(languageName(qmFiles[i]));
              qmFileForCheckBoxMap.insert(checkBox, qmFiles[i]);
              connect(checkBox,
                      QOverload<bool>::of(&QCheckBox::toggled),
                      this,
                      &LanguageChooser::checkBoxToggled);
              if (languageMatch(defaultLang, qmFiles[i]))
                      checkBox->setCheckState(Qt::Checked);
              groupBoxLayout->addWidget(checkBox, i / 2, i % 2);
          }
          groupBox->setLayout(groupBoxLayout);

          buttonBox = new QDialogButtonBox;

          showAllButton = buttonBox->addButton("Show All",
                                               QDialogButtonBox::ActionRole);
          hideAllButton = buttonBox->addButton("Hide All",
                                               QDialogButtonBox::ActionRole);

          connect(showAllButton, &QAbstractButton::clicked, this, &LanguageChooser::showAll);
          connect(hideAllButton, &QAbstractButton::clicked, this, &LanguageChooser::hideAll);

          QVBoxLayout *mainLayout = new QVBoxLayout;
          mainLayout->addWidget(groupBox);
          mainLayout->addWidget(buttonBox);
          setLayout(mainLayout);

      #if 0 // Used to be included in Qt4 for Q_WS_MAC
          qt_mac_set_menubar_merge(false);
      #endif

          setWindowTitle("I18N");
      }

      bool LanguageChooser::languageMatch(const QString& lang, const QString& qmFile)
      {
          //qmFile: i18n_xx.qm
          const QString prefix = "i18n_";
          const int langTokenLength = 2; /*FIXME: is checking two chars enough?*/
          return qmFile.midRef(qmFile.indexOf(prefix) + prefix.length(), langTokenLength) == lang.leftRef(langTokenLength);
      }

      bool LanguageChooser::eventFilter(QObject *object, QEvent *event)
      {
          if (event->type() == QEvent::Close) {
              MainWindow *window = qobject_cast<MainWindow *>(object);
              if (window) {
                  QCheckBox *checkBox = mainWindowForCheckBoxMap.key(window);
                  if (checkBox)
                      checkBox->setChecked(false);
              }
          }
          return QWidget::eventFilter(object, event);
      }

      void LanguageChooser::closeEvent(QCloseEvent * /* event */)
      {
          qApp->quit();
      }

      void LanguageChooser::checkBoxToggled()
      {
          QCheckBox *checkBox = qobject_cast<QCheckBox *>(sender());
          MainWindow *window = mainWindowForCheckBoxMap[checkBox];
          if (!window) {
              QTranslator translator;
              translator.load(qmFileForCheckBoxMap[checkBox]);
              qApp->installTranslator(&translator);

              window = new MainWindow;
              window->setPalette(colorForLanguage(checkBox->text()));

              window->installEventFilter(this);
              mainWindowForCheckBoxMap.insert(checkBox, window);
          }
          window->setVisible(checkBox->isChecked());
      }

      void LanguageChooser::showAll()
      {
          foreach (QCheckBox *checkBox, qmFileForCheckBoxMap.keys())
              checkBox->setChecked(true);
      }

      void LanguageChooser::hideAll()
      {
          foreach (QCheckBox *checkBox, qmFileForCheckBoxMap.keys())
              checkBox->setChecked(false);
      }

      QStringList LanguageChooser::findQmFiles()
      {
          QDir dir(":/translations");
          QStringList fileNames = dir.entryList(QStringList("*.qm"), QDir::Files,
                                                QDir::Name);
          QMutableStringListIterator i(fileNames);
          while (i.hasNext()) {
              i.next();
              i.setValue(dir.filePath(i.value()));
          }
          return fileNames;
      }

      QString LanguageChooser::languageName(const QString &qmFile)
      {
          QTranslator translator;
          translator.load(qmFile);

          return translator.translate("MainWindow", "English");
      }

      QColor LanguageChooser::colorForLanguage(const QString &language)
      {
          uint hashValue = qHash(language);
          int red = 156 + (hashValue & 0x3F);
          int green = 156 + ((hashValue >> 6) & 0x3F);
          int blue = 156 + ((hashValue >> 12) & 0x3F);
          return QColor(red, green, blue);
      }