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# languagechooser.cpp Example File

tools/i18n/languagechooser.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
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     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
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     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     #include <QtGui>

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

     #ifdef Q_WS_MAC
     extern void qt_mac_set_menubar_merge(bool merge);

     #endif

     LanguageChooser::LanguageChooser(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, SIGNAL(toggled(bool)), this, SLOT(checkBoxToggled()));
             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, SIGNAL(clicked()), this, SLOT(showAll()));
         connect(hideAllButton, SIGNAL(clicked()), this, SLOT(hideAll()));

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

     #ifdef Q_WS_MAC
         qt_mac_set_menubar_merge(false);
     #endif

         setWindowTitle("I18N");
     }

     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);
     }