view main/PreferencesDialog.cpp @ 961:f3c1546c8a5c

Address #1214, layer import produces wrong layer type. We needed a more principled approach to making sure the format gets updated properly and the dialog elements are consistent (basically separating making the dialog elements consistent from subsequently updating the format). This change should provide that, though there may be gotchas still.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "PreferencesDialog.h"

#include <QGridLayout>
#include <QComboBox>
#include <QCheckBox>
#include <QGroupBox>
#include <QDoubleSpinBox>
#include <QLabel>
#include <QPushButton>
#include <QHBoxLayout>
#include <QString>
#include <QDialogButtonBox>
#include <QMessageBox>
#include <QTabWidget>
#include <QLineEdit>
#include <QFileDialog>
#include <QMessageBox>
#include <QSpinBox>
#include <QListWidget>
#include <QSettings>

#include <set>

#include "widgets/WindowTypeSelector.h"
#include "widgets/IconLoader.h"
#include "base/Preferences.h"
#include "audioio/AudioTargetFactory.h"
#include "base/ResourceFinder.h"

#include "version.h"

PreferencesDialog::PreferencesDialog(QWidget *parent) :
    QDialog(parent),
    m_audioDevice(0),
    m_changesOnRestart(false)
{
    setWindowTitle(tr("Sonic Visualiser: Application Preferences"));

    Preferences *prefs = Preferences::getInstance();

    QGridLayout *grid = new QGridLayout;
    setLayout(grid);

    m_tabs = new QTabWidget;
    grid->addWidget(m_tabs, 0, 0);
    
    m_tabs->setTabPosition(QTabWidget::North);

    // Create this first, as slots that get called from the ctor will
    // refer to it
    m_applyButton = new QPushButton(tr("Apply"));

    // Create all the preference widgets first, then create the
    // individual tab widgets and place the preferences in their
    // appropriate places in one go afterwards

    int min, max, deflt, i;

    m_windowType = WindowType(prefs->getPropertyRangeAndValue
                              ("Window Type", &min, &max, &deflt));
    m_windowTypeSelector = new WindowTypeSelector(m_windowType);

    connect(m_windowTypeSelector, SIGNAL(windowTypeChanged(WindowType)),
            this, SLOT(windowTypeChanged(WindowType)));

    QComboBox *smoothing = new QComboBox;
    
    int sm = prefs->getPropertyRangeAndValue("Spectrogram Y Smoothing", &min, &max,
                                             &deflt);
    m_spectrogramSmoothing = sm;

    for (i = min; i <= max; ++i) {
        smoothing->addItem(prefs->getPropertyValueLabel("Spectrogram Y Smoothing", i));
    }

    smoothing->setCurrentIndex(sm);

    connect(smoothing, SIGNAL(currentIndexChanged(int)),
            this, SLOT(spectrogramSmoothingChanged(int)));

    QComboBox *xsmoothing = new QComboBox;
    
    int xsm = prefs->getPropertyRangeAndValue("Spectrogram X Smoothing", &min, &max,
                                             &deflt);
    m_spectrogramXSmoothing = xsm;

    for (i = min; i <= max; ++i) {
        xsmoothing->addItem(prefs->getPropertyValueLabel("Spectrogram X Smoothing", i));
    }

    xsmoothing->setCurrentIndex(xsm);

    connect(xsmoothing, SIGNAL(currentIndexChanged(int)),
            this, SLOT(spectrogramXSmoothingChanged(int)));

    QComboBox *propertyLayout = new QComboBox;
    int pl = prefs->getPropertyRangeAndValue("Property Box Layout", &min, &max,
                                         &deflt);
    m_propertyLayout = pl;

    for (i = min; i <= max; ++i) {
        propertyLayout->addItem(prefs->getPropertyValueLabel("Property Box Layout", i));
    }

    propertyLayout->setCurrentIndex(pl);

    connect(propertyLayout, SIGNAL(currentIndexChanged(int)),
            this, SLOT(propertyLayoutChanged(int)));


    m_tuningFrequency = prefs->getTuningFrequency();

    QDoubleSpinBox *frequency = new QDoubleSpinBox;
    frequency->setMinimum(100.0);
    frequency->setMaximum(5000.0);
    frequency->setSuffix(" Hz");
    frequency->setSingleStep(1);
    frequency->setValue(m_tuningFrequency);
    frequency->setDecimals(2);

    connect(frequency, SIGNAL(valueChanged(double)),
            this, SLOT(tuningFrequencyChanged(double)));

    QComboBox *octaveSystem = new QComboBox;
    int oct = prefs->getPropertyRangeAndValue
        ("Octave Numbering System", &min, &max, &deflt);
    m_octaveSystem = oct;
    for (i = min; i <= max; ++i) {
        octaveSystem->addItem(prefs->getPropertyValueLabel
                              ("Octave Numbering System", i));
    }
    octaveSystem->setCurrentIndex(oct);

    connect(octaveSystem, SIGNAL(currentIndexChanged(int)),
            this, SLOT(octaveSystemChanged(int)));

    QComboBox *audioDevice = new QComboBox;
    std::vector<QString> devices =
        AudioTargetFactory::getInstance()->getCallbackTargetNames();
    
    QSettings settings;
    settings.beginGroup("Preferences");
    QString targetName = settings.value("audio-target", "").toString();
    settings.endGroup();

    for (int i = 0; i < (int)devices.size(); ++i) {
        audioDevice->addItem(AudioTargetFactory::getInstance()
                             ->getCallbackTargetDescription(devices[i]));
        if (targetName == devices[i]) audioDevice->setCurrentIndex(i);
    }

    connect(audioDevice, SIGNAL(currentIndexChanged(int)),
            this, SLOT(audioDeviceChanged(int)));

    QComboBox *resampleQuality = new QComboBox;

    int rsq = prefs->getPropertyRangeAndValue("Resample Quality", &min, &max,
                                              &deflt);
    m_resampleQuality = rsq;

    for (i = min; i <= max; ++i) {
        resampleQuality->addItem(prefs->getPropertyValueLabel("Resample Quality", i));
    }

    resampleQuality->setCurrentIndex(rsq);

    connect(resampleQuality, SIGNAL(currentIndexChanged(int)),
            this, SLOT(resampleQualityChanged(int)));

    QCheckBox *resampleOnLoad = new QCheckBox;
    m_resampleOnLoad = prefs->getResampleOnLoad();
    resampleOnLoad->setCheckState(m_resampleOnLoad ? Qt::Checked :
                                  Qt::Unchecked);
    connect(resampleOnLoad, SIGNAL(stateChanged(int)),
            this, SLOT(resampleOnLoadChanged(int)));

    m_tempDirRootEdit = new QLineEdit;
    QString dir = prefs->getTemporaryDirectoryRoot();
    m_tempDirRoot = dir;
    dir.replace("$HOME", tr("<home directory>"));
    m_tempDirRootEdit->setText(dir);
    m_tempDirRootEdit->setReadOnly(true);
    QPushButton *tempDirButton = new QPushButton;
    tempDirButton->setIcon(IconLoader().load("fileopen"));
    connect(tempDirButton, SIGNAL(clicked()),
            this, SLOT(tempDirButtonClicked()));
    tempDirButton->setFixedSize(QSize(24, 24));

    QCheckBox *showSplash = new QCheckBox;
    m_showSplash = prefs->getShowSplash();
    showSplash->setCheckState(m_showSplash ? Qt::Checked : Qt::Unchecked);
    connect(showSplash, SIGNAL(stateChanged(int)),
            this, SLOT(showSplashChanged(int)));

#ifndef Q_OS_MAC
    QComboBox *bgMode = new QComboBox;
    int bg = prefs->getPropertyRangeAndValue("Background Mode", &min, &max,
                                             &deflt);
    m_backgroundMode = bg;
    for (i = min; i <= max; ++i) {
        bgMode->addItem(prefs->getPropertyValueLabel("Background Mode", i));
    }
    bgMode->setCurrentIndex(bg);

    connect(bgMode, SIGNAL(currentIndexChanged(int)),
            this, SLOT(backgroundModeChanged(int)));
#endif

    settings.beginGroup("Preferences");

    QString userLocale = settings.value("locale", "").toString();
    m_currentLocale = userLocale;
    
    QString permishTag = QString("network-permission-%1").arg(SV_VERSION);
    m_networkPermission = settings.value(permishTag, false).toBool();

    settings.endGroup();

    QComboBox *locale = new QComboBox;
    QStringList localeFiles = QDir(":i18n").entryList(QStringList() << "*.qm");
    locale->addItem(tr("Follow system locale"));
    m_locales.push_back("");
    if (userLocale == "") {
        locale->setCurrentIndex(0);
    }
    foreach (QString f, localeFiles) {
        QString f0 = f;
        f.replace("sonic-visualiser_", "").replace(".qm", "");
        if (f == f0) { // our expectations about filename format were not met
            cerr << "INFO: Unexpected filename " << f << " in i18n resource directory" << endl;
        } else {
            m_locales.push_back(f);
            QString displayText;
            // Add new translations here
            if (f == "ru") displayText = tr("Russian");
            else if (f == "en_GB") displayText = tr("British English");
            else if (f == "en_US") displayText = tr("American English");
            else if (f == "cs_CZ") displayText = tr("Czech");
            else displayText = f;
            locale->addItem(QString("%1 [%2]").arg(displayText).arg(f));
            if (userLocale == f) {
                locale->setCurrentIndex(locale->count() - 1);
            }
        }
    }
    connect(locale, SIGNAL(currentIndexChanged(int)),
            this, SLOT(localeChanged(int)));

    QCheckBox *networkPermish = new QCheckBox;
    networkPermish->setCheckState(m_networkPermission ? Qt::Checked : Qt::Unchecked);
    connect(networkPermish, SIGNAL(stateChanged(int)),
            this, SLOT(networkPermissionChanged(int)));

    QSpinBox *fontSize = new QSpinBox;
    int fs = prefs->getPropertyRangeAndValue("View Font Size", &min, &max,
                                             &deflt);
    m_viewFontSize = fs;
    fontSize->setMinimum(min);
    fontSize->setMaximum(max);
    fontSize->setSuffix(" pt");
    fontSize->setSingleStep(1);
    fontSize->setValue(fs);

    connect(fontSize, SIGNAL(valueChanged(int)),
            this, SLOT(viewFontSizeChanged(int)));

    QComboBox *ttMode = new QComboBox;
    int tt = prefs->getPropertyRangeAndValue("Time To Text Mode", &min, &max,
                                             &deflt);
    m_timeToTextMode = tt;
    for (i = min; i <= max; ++i) {
        ttMode->addItem(prefs->getPropertyValueLabel("Time To Text Mode", i));
    }
    ttMode->setCurrentIndex(tt);

    connect(ttMode, SIGNAL(currentIndexChanged(int)),
            this, SLOT(timeToTextModeChanged(int)));

    QCheckBox *hms = new QCheckBox;
    int showHMS = prefs->getPropertyRangeAndValue
        ("Show Hours And Minutes", &min, &max, &deflt);
    m_showHMS = (showHMS != 0);
    hms->setCheckState(m_showHMS ? Qt::Checked : Qt::Unchecked);
    connect(hms, SIGNAL(stateChanged(int)),
            this, SLOT(showHMSChanged(int)));
    
    // General tab

    QFrame *frame = new QFrame;
    
    QGridLayout *subgrid = new QGridLayout;
    frame->setLayout(subgrid);

    int row = 0;

    subgrid->addWidget(new QLabel(tr("%1:").arg(tr("User interface language"))),
                       row, 0);
    subgrid->addWidget(locale, row++, 1, 1, 1);

    subgrid->addWidget(new QLabel(tr("%1:").arg(tr("Allow network usage"))),
                       row, 0);
    subgrid->addWidget(networkPermish, row++, 1, 1, 1);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Temporary Directory Root"))),
                       row, 0);
    subgrid->addWidget(m_tempDirRootEdit, row, 1, 1, 1);
    subgrid->addWidget(tempDirButton, row, 2, 1, 1);
    row++;

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Resample On Load"))),
                       row, 0);
    subgrid->addWidget(resampleOnLoad, row++, 1, 1, 1);

    subgrid->addWidget(new QLabel(tr("Playback audio device:")), row, 0);
    subgrid->addWidget(audioDevice, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Resample Quality"))),
                       row, 0);
    subgrid->addWidget(resampleQuality, row++, 1, 1, 2);

    subgrid->setRowStretch(row, 10);
    
    m_tabOrdering[GeneralTab] = m_tabs->count();
    m_tabs->addTab(frame, tr("&General"));

    // Appearance tab

    frame = new QFrame;
    subgrid = new QGridLayout;
    frame->setLayout(subgrid);
    row = 0;

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Show Splash Screen"))),
                       row, 0);
    subgrid->addWidget(showSplash, row++, 1, 1, 1);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Property Box Layout"))),
                       row, 0);
    subgrid->addWidget(propertyLayout, row++, 1, 1, 2);

#ifndef Q_OS_MAC
    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Background Mode"))),
                       row, 0);
    subgrid->addWidget(bgMode, row++, 1, 1, 2);
#endif

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("View Font Size"))),
                       row, 0);
    subgrid->addWidget(fontSize, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Time To Text Mode"))),
                       row, 0);
    subgrid->addWidget(ttMode, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Show Hours And Minutes"))),
                       row, 0);
    subgrid->addWidget(hms, row++, 1, 1, 1);

    subgrid->setRowStretch(row, 10);
    
    m_tabOrdering[AppearanceTab] = m_tabs->count();
    m_tabs->addTab(frame, tr("&Appearance"));

    // Analysis tab

    frame = new QFrame;
    subgrid = new QGridLayout;
    frame->setLayout(subgrid);
    row = 0;

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Tuning Frequency"))),
                       row, 0);
    subgrid->addWidget(frequency, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Octave Numbering System"))),
                       row, 0);
    subgrid->addWidget(octaveSystem, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(prefs->getPropertyLabel
                                  ("Spectrogram Y Smoothing")),
                       row, 0);
    subgrid->addWidget(smoothing, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(prefs->getPropertyLabel
                                  ("Spectrogram X Smoothing")),
                       row, 0);
    subgrid->addWidget(xsmoothing, row++, 1, 1, 2);

    subgrid->addWidget(new QLabel(tr("%1:").arg(prefs->getPropertyLabel
                                                ("Window Type"))),
                       row, 0);
    subgrid->addWidget(m_windowTypeSelector, row++, 1, 2, 2);
    subgrid->setRowStretch(row, 10);
    row++;
    
    subgrid->setRowStretch(row, 10);
    
    m_tabOrdering[AnalysisTab] = m_tabs->count();
    m_tabs->addTab(frame, tr("Anal&ysis"));

    // Template tab

    frame = new QFrame;
    subgrid = new QGridLayout;
    frame->setLayout(subgrid);
    row = 0;
    
    subgrid->addWidget(new QLabel(tr("Default session template for audio files:")), row++, 0);

    QListWidget *lw = new QListWidget();
    subgrid->addWidget(lw, row, 0);
    subgrid->setRowStretch(row, 10);
    row++;

    settings.beginGroup("MainWindow");
    m_currentTemplate = settings.value("sessiontemplate", "").toString();
    settings.endGroup();

    lw->addItem(tr("Standard Waveform"));
    if (m_currentTemplate == "" || m_currentTemplate == "default") {
        lw->setCurrentRow(lw->count()-1);
    }
    m_templates.push_back("");

    QStringList templates = ResourceFinder().getResourceFiles("templates", "svt");

    std::set<QString> byName;
    foreach (QString t, templates) {
        byName.insert(QFileInfo(t).baseName());
    }

    foreach (QString t, byName) {
        if (t.toLower() == "default") continue;
        m_templates.push_back(t);
        lw->addItem(t);
        if (m_currentTemplate == t) {
            lw->setCurrentRow(lw->count()-1);
        }
    }

    connect(lw, SIGNAL(currentRowChanged(int)), this, SLOT(defaultTemplateChanged(int)));

    m_tabOrdering[TemplateTab] = m_tabs->count();
    m_tabs->addTab(frame, tr("Session &Template"));

    QDialogButtonBox *bb = new QDialogButtonBox(Qt::Horizontal);
    grid->addWidget(bb, 1, 0);
    
    QPushButton *ok = new QPushButton(tr("OK"));
    QPushButton *cancel = new QPushButton(tr("Cancel"));
    bb->addButton(ok, QDialogButtonBox::AcceptRole);
    bb->addButton(m_applyButton, QDialogButtonBox::ApplyRole);
    bb->addButton(cancel, QDialogButtonBox::RejectRole);
    connect(ok, SIGNAL(clicked()), this, SLOT(okClicked()));
    connect(m_applyButton, SIGNAL(clicked()), this, SLOT(applyClicked()));
    connect(cancel, SIGNAL(clicked()), this, SLOT(cancelClicked()));

    m_applyButton->setEnabled(false);
}

PreferencesDialog::~PreferencesDialog()
{
    SVDEBUG << "PreferencesDialog::~PreferencesDialog()" << endl;
}

void
PreferencesDialog::switchToTab(Tab t)
{
    if (m_tabOrdering.contains(t)) {
        m_tabs->setCurrentIndex(m_tabOrdering[t]);
    }
}

void
PreferencesDialog::windowTypeChanged(WindowType type)
{
    m_windowType = type;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::spectrogramSmoothingChanged(int smoothing)
{
    m_spectrogramSmoothing = smoothing;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::spectrogramXSmoothingChanged(int smoothing)
{
    m_spectrogramXSmoothing = smoothing;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::propertyLayoutChanged(int layout)
{
    m_propertyLayout = layout;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::tuningFrequencyChanged(double freq)
{
    m_tuningFrequency = freq;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::audioDeviceChanged(int s)
{
    m_audioDevice = s;
    m_applyButton->setEnabled(true);
    m_changesOnRestart = true;
}

void
PreferencesDialog::resampleQualityChanged(int q)
{
    m_resampleQuality = q;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::resampleOnLoadChanged(int state)
{
    m_resampleOnLoad = (state == Qt::Checked);
    m_applyButton->setEnabled(true);
    m_changesOnRestart = true;
}

void
PreferencesDialog::networkPermissionChanged(int state)
{
    m_networkPermission = (state == Qt::Checked);
    m_applyButton->setEnabled(true);
    m_changesOnRestart = true;
}

void
PreferencesDialog::showSplashChanged(int state)
{
    m_showSplash = (state == Qt::Checked);
    m_applyButton->setEnabled(true);
    m_changesOnRestart = true;
}

void
PreferencesDialog::defaultTemplateChanged(int i)
{
    m_currentTemplate = m_templates[i];
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::localeChanged(int i)
{
    m_currentLocale = m_locales[i];
    m_applyButton->setEnabled(true);
    m_changesOnRestart = true;
}

void
PreferencesDialog::tempDirRootChanged(QString r)
{
    m_tempDirRoot = r;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::tempDirButtonClicked()
{
    QString dir = QFileDialog::getExistingDirectory
        (this, tr("Select a directory to create cache subdirectory in"),
         m_tempDirRoot);
    if (dir == "") return;
    m_tempDirRootEdit->setText(dir);
    tempDirRootChanged(dir);
    m_changesOnRestart = true;
}

void
PreferencesDialog::backgroundModeChanged(int mode)
{
    m_backgroundMode = mode;
    m_applyButton->setEnabled(true);
    m_changesOnRestart = true;
}

void
PreferencesDialog::timeToTextModeChanged(int mode)
{
    m_timeToTextMode = mode;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::showHMSChanged(int state)
{
    m_showHMS = (state == Qt::Checked);
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::octaveSystemChanged(int system)
{
    m_octaveSystem = system;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::viewFontSizeChanged(int sz)
{
    m_viewFontSize = sz;
    m_applyButton->setEnabled(true);
}

void
PreferencesDialog::okClicked()
{
    applyClicked();
    accept();
}

void
PreferencesDialog::applyClicked()
{
    Preferences *prefs = Preferences::getInstance();
    prefs->setWindowType(WindowType(m_windowType));
    prefs->setSpectrogramSmoothing(Preferences::SpectrogramSmoothing
                                   (m_spectrogramSmoothing));
    prefs->setSpectrogramXSmoothing(Preferences::SpectrogramXSmoothing
                                   (m_spectrogramXSmoothing));
    prefs->setPropertyBoxLayout(Preferences::PropertyBoxLayout
                                (m_propertyLayout));
    prefs->setTuningFrequency(m_tuningFrequency);
    prefs->setResampleQuality(m_resampleQuality);
    prefs->setResampleOnLoad(m_resampleOnLoad);
    prefs->setShowSplash(m_showSplash);
    prefs->setTemporaryDirectoryRoot(m_tempDirRoot);
    prefs->setBackgroundMode(Preferences::BackgroundMode(m_backgroundMode));
    prefs->setTimeToTextMode(Preferences::TimeToTextMode(m_timeToTextMode));
    prefs->setShowHMS(m_showHMS);
    prefs->setViewFontSize(m_viewFontSize);
    
    prefs->setProperty("Octave Numbering System", m_octaveSystem);

    std::vector<QString> devices =
        AudioTargetFactory::getInstance()->getCallbackTargetNames();

    QSettings settings;
    settings.beginGroup("Preferences");
    QString permishTag = QString("network-permission-%1").arg(SV_VERSION);
    settings.setValue(permishTag, m_networkPermission);
    settings.setValue("audio-target", devices[m_audioDevice]);
    settings.setValue("locale", m_currentLocale);
    settings.endGroup();

    settings.beginGroup("MainWindow");
    settings.setValue("sessiontemplate", m_currentTemplate);
    settings.endGroup();

    m_applyButton->setEnabled(false);

    if (m_changesOnRestart) {
        QMessageBox::information(this, tr("Preferences"),
                                 tr("<b>Restart required</b><p>One or more of the application preferences you have changed may not take full effect until Sonic Visualiser is restarted.</p><p>Please exit and restart the application now if you want these changes to take effect immediately.</p>"));
        m_changesOnRestart = false;
    }
}    

void
PreferencesDialog::cancelClicked()
{
    reject();
}

void
PreferencesDialog::applicationClosing(bool quickly)
{
    if (quickly) {
        reject();
        return;
    }

    if (m_applyButton->isEnabled()) {
        int rv = QMessageBox::warning
            (this, tr("Preferences Changed"),
             tr("Some preferences have been changed but not applied.\n"
                "Apply them before closing?"),
             QMessageBox::Apply | QMessageBox::Discard,
             QMessageBox::Discard);
        if (rv == QMessageBox::Apply) {
            applyClicked();
            accept();
        } else {
            reject();
        }
    } else {
        accept();
    }
}