refactor: use QMetaEnum

app/mainwindow.cpp

@@ -167,12 +167,15 @@ void MainWindow::showUrls(const QList<QUrl> &urls)
 void MainWindow::initWindowSize()
 {
     switch (Settings::instance()->initWindowSizeBehavior()) {
-    case ActionAutoSize:
+    case Settings::WindowSizeBehavior::Auto:
         adjustWindowSizeBySceneRect();
         break;
-    case ActionMaximize:
+    case Settings::WindowSizeBehavior::Maximized:
         showMaximized();
         break;
+    default:
+        adjustWindowSizeBySceneRect();
+        break;
     }
 }
 
@@ -334,15 +337,15 @@ void MainWindow::mouseDoubleClickEvent(QMouseEvent *event)
     }
 
     switch (Settings::instance()->doubleClickBehavior()) {
-    case ActionCloseWindow:
+    case Settings::DoubleClickBehavior::Close:
         quitAppAction();
         event->accept();
         break;
-    case ActionMaximizeWindow:
+    case Settings::DoubleClickBehavior::Maximize:
         toggleMaximize();
         event->accept();
         break;
-    case ActionDoNothing:
+    case Settings::DoubleClickBehavior::Ignore:
         break;
     }
 
@@ -356,7 +359,7 @@ void MainWindow::wheelEvent(QWheelEvent *event)
     QPoint numDegrees = event->angleDelta() / 8;
     bool needWeelEvent = false, wheelUp = false;
     bool actionIsZoom = event->modifiers().testFlag(Qt::ControlModifier)
-            || Settings::instance()->mouseWheelBehavior() == ActionZoomImage;
+            || Settings::instance()->mouseWheelBehavior() == Settings::MouseWheelBehavior::Zoom;
 
     // NOTE: Only checking angleDelta since the QWheelEvent::pixelDelta() doc says
     //       pixelDelta() value is driver specific and unreliable on X11...

app/settings.cpp

@@ -4,6 +4,28 @@
 #include <QStandardPaths>
 #include <QDebug>
 #include <QDir>
+#include <QMetaEnum>
+
+namespace QEnumHelper
+{
+    template <typename E>
+    E fromString(const QString &text, const E defaultValue)
+    {
+        bool ok;
+        E result = static_cast<E>(QMetaEnum::fromType<E>().keyToValue(text.toUtf8(), &ok));
+        if (!ok) {
+            return defaultValue;
+        }
+        return result;
+    }
+
+    template <typename E>
+    QString toString(E value)
+    {
+        const int intValue = static_cast<int>(value);
+        return QString::fromUtf8(QMetaEnum::fromType<E>().valueToKey(intValue));
+    }
+}
 
 Settings *Settings::m_settings_instance = nullptr;
 
@@ -21,25 +43,25 @@ bool Settings::stayOnTop()
     return m_qsettings->value("stay_on_top", true).toBool();
 }
 
-DoubleClickBehavior Settings::doubleClickBehavior() const
+Settings::DoubleClickBehavior Settings::doubleClickBehavior() const
 {
-    QString result = m_qsettings->value("double_click_behavior", "close").toString().toLower();
+    QString result = m_qsettings->value("double_click_behavior", "Close").toString();
 
-    return stringToDoubleClickBehavior(result);
+    return QEnumHelper::fromString<DoubleClickBehavior>(result, DoubleClickBehavior::Close);
 }
 
-MouseWheelBehavior Settings::mouseWheelBehavior() const
+Settings::MouseWheelBehavior Settings::mouseWheelBehavior() const
 {
-    QString result = m_qsettings->value("mouse_wheel_behavior", "close").toString().toLower();
+    QString result = m_qsettings->value("mouse_wheel_behavior", "Zoom").toString();
 
-    return stringToMouseWheelBehavior(result);
+    return QEnumHelper::fromString<MouseWheelBehavior>(result, MouseWheelBehavior::Zoom);
 }
 
-WindowSizeBehavior Settings::initWindowSizeBehavior() const
+Settings::WindowSizeBehavior Settings::initWindowSizeBehavior() const
 {
-    QString result = m_qsettings->value("init_window_size_behavior", "auto").toString().toLower();
+    QString result = m_qsettings->value("init_window_size_behavior", "Auto").toString();
 
-    return stringToWindowSizeBehavior(result);
+    return QEnumHelper::fromString<WindowSizeBehavior>(result, WindowSizeBehavior::Auto);
 }
 
 void Settings::setStayOnTop(bool on)
@@ -50,84 +72,22 @@ void Settings::setStayOnTop(bool on)
 
 void Settings::setDoubleClickBehavior(DoubleClickBehavior dcb)
 {
-    m_qsettings->setValue("double_click_behavior", doubleClickBehaviorToString(dcb));
+    m_qsettings->setValue("double_click_behavior", QEnumHelper::toString(dcb));
     m_qsettings->sync();
 }
 
 void Settings::setMouseWheelBehavior(MouseWheelBehavior mwb)
 {
-    m_qsettings->setValue("mouse_wheel_behavior", mouseWheelBehaviorToString(mwb));
+    m_qsettings->setValue("mouse_wheel_behavior", QEnumHelper::toString(mwb));
     m_qsettings->sync();
 }
 
 void Settings::setInitWindowSizeBehavior(WindowSizeBehavior wsb)
 {
-    m_qsettings->setValue("init_window_size_behavior", windowSizeBehaviorToString(wsb));
+    m_qsettings->setValue("init_window_size_behavior", QEnumHelper::toString(wsb));
     m_qsettings->sync();
 }
 
-QString Settings::doubleClickBehaviorToString(DoubleClickBehavior dcb)
-{
-    static QMap<DoubleClickBehavior, QString> _map {
-        {ActionCloseWindow, "close"},
-        {ActionMaximizeWindow, "maximize"},
-        {ActionDoNothing, "ignore"}
-    };
-
-    return _map.value(dcb, "close");
-}
-
-QString Settings::mouseWheelBehaviorToString(MouseWheelBehavior mwb)
-{
-    static QMap<MouseWheelBehavior, QString> _map {
-        {ActionZoomImage, "zoom"},
-        {ActionPrevNextImage, "switch"}
-    };
-
-    return _map.value(mwb, "zoom");
-}
-
-QString Settings::windowSizeBehaviorToString(WindowSizeBehavior wsb)
-{
-    static QMap<WindowSizeBehavior, QString> _map {
-        {ActionAutoSize, "auto"},
-        {ActionMaximize, "maximized"}
-    };
-
-    return _map.value(wsb, "zoom");
-}
-
-DoubleClickBehavior Settings::stringToDoubleClickBehavior(QString str)
-{
-    static QMap<QString, DoubleClickBehavior> _map {
-        {"close", ActionCloseWindow},
-        {"maximize", ActionMaximizeWindow},
-        {"ignore", ActionDoNothing}
-    };
-
-    return _map.value(str, ActionCloseWindow);
-}
-
-MouseWheelBehavior Settings::stringToMouseWheelBehavior(QString str)
-{
-    static QMap<QString, MouseWheelBehavior> _map {
-        {"zoom", ActionZoomImage},
-        {"switch", ActionPrevNextImage}
-    };
-
-    return _map.value(str, ActionZoomImage);
-}
-
-WindowSizeBehavior Settings::stringToWindowSizeBehavior(QString str)
-{
-    static QMap<QString, WindowSizeBehavior> _map {
-        {"auto", ActionAutoSize},
-        {"maximized", ActionMaximize}
-    };
-
-    return _map.value(str, ActionAutoSize);
-}
-
 Settings::Settings()
     : QObject(qApp)
 {

app/settings.h

@@ -3,35 +3,29 @@
 #include <QObject>
 #include <QSettings>
 
-enum DoubleClickBehavior {
-    ActionDoNothing,
-    ActionCloseWindow,
-    ActionMaximizeWindow,
-
-    DCActionStart = ActionDoNothing,
-    DCActionEnd = ActionMaximizeWindow
-};
-
-enum MouseWheelBehavior {
-    ActionZoomImage,
-    ActionPrevNextImage,
-
-    MWActionStart = ActionZoomImage,
-    MWActionEnd = ActionPrevNextImage
-};
-
-enum WindowSizeBehavior {
-    ActionAutoSize,
-    ActionMaximize,
-
-    IWSActionStart = ActionAutoSize,
-    IWSActionEnd = ActionMaximize
-};
-
 class Settings : public QObject
 {
     Q_OBJECT
 public:
+    enum DoubleClickBehavior {
+        Ignore,
+        Close,
+        Maximize,
+    };
+    Q_ENUM(DoubleClickBehavior);
+
+    enum MouseWheelBehavior {
+        Zoom,
+        Switch,
+    };
+    Q_ENUM(MouseWheelBehavior);
+
+    enum WindowSizeBehavior {
+        Auto,
+        Maximized,
+    };
+    Q_ENUM(WindowSizeBehavior);
+
     static Settings *instance();
 
     bool stayOnTop();
@@ -44,13 +38,6 @@ public:
     void setMouseWheelBehavior(MouseWheelBehavior mwb);
     void setInitWindowSizeBehavior(WindowSizeBehavior wsb);
 
-    static QString doubleClickBehaviorToString(DoubleClickBehavior dcb);
-    static QString mouseWheelBehaviorToString(MouseWheelBehavior mwb);
-    static QString windowSizeBehaviorToString(WindowSizeBehavior wsb);
-    static DoubleClickBehavior stringToDoubleClickBehavior(QString str);
-    static MouseWheelBehavior stringToMouseWheelBehavior(QString str);
-    static WindowSizeBehavior stringToWindowSizeBehavior(QString str);
-
 private:
     Settings();
 

app/settingsdialog.cpp

@@ -18,35 +18,35 @@ SettingsDialog::SettingsDialog(QWidget *parent)
 
     QFormLayout * settingsForm = new QFormLayout(this);
 
-    static QMap<DoubleClickBehavior, QString> _dc_map {
+    static QList< QPair<Settings::DoubleClickBehavior, QString> > _dc_options {
-        { ActionDoNothing, tr("Do nothing") },
+        { Settings::DoubleClickBehavior::Ignore, tr("Do nothing") },
-        { ActionCloseWindow, tr("Close the window") },
+        { Settings::DoubleClickBehavior::Close, tr("Close the window") },
-        { ActionMaximizeWindow, tr("Toggle maximize") }
+        { Settings::DoubleClickBehavior::Maximize, tr("Toggle maximize") }
     };
 
-    static QMap<MouseWheelBehavior, QString> _mw_map {
+    static QList< QPair<Settings::MouseWheelBehavior, QString> > _mw_options {
-        { ActionZoomImage, tr("Zoom in and out") },
+        { Settings::MouseWheelBehavior::Zoom, tr("Zoom in and out") },
-        { ActionPrevNextImage, tr("View next or previous item") }
+        { Settings::MouseWheelBehavior::Switch, tr("View next or previous item") }
     };
 
-    static QMap<WindowSizeBehavior, QString> _iws_map {
+    static QList< QPair<Settings::WindowSizeBehavior, QString> > _iws_options {
-        { ActionAutoSize, "Auto size" },
+        { Settings::WindowSizeBehavior::Auto, "Auto size" },
-        { ActionMaximize, "Maximize" }
+        { Settings::WindowSizeBehavior::Maximized, "Maximize" }
     };
 
     QStringList dcbDropDown;
-    for (int dcb = DCActionStart; dcb <= DCActionEnd; dcb++) {
+    for (const QPair<Settings::DoubleClickBehavior, QString> & dcOption : _dc_options) {
-        dcbDropDown.append(_dc_map.value(static_cast<DoubleClickBehavior>(dcb)));
+        dcbDropDown.append(dcOption.second);
     }
 
     QStringList mwbDropDown;
-    for (int mwb = MWActionStart; mwb <= MWActionEnd; mwb++) {
+    for (const QPair<Settings::MouseWheelBehavior, QString> & mwOption : _mw_options) {
-        mwbDropDown.append(_mw_map.value(static_cast<MouseWheelBehavior>(mwb)));
+        mwbDropDown.append(mwOption.second);
     }
 
     QStringList iwsbDropDown;
-    for (int iwsb = IWSActionStart; iwsb <= IWSActionEnd; iwsb++) {
+    for (const QPair<Settings::WindowSizeBehavior, QString> & iwsOption : _iws_options) {
-        iwsbDropDown.append(_iws_map.value(static_cast<WindowSizeBehavior>(iwsb)));
+        iwsbDropDown.append(iwsOption.second);
     }
 
     settingsForm->addRow(tr("Stay on top when start-up"), m_stayOnTop);
@@ -56,13 +56,13 @@ SettingsDialog::SettingsDialog(QWidget *parent)
 
     m_stayOnTop->setChecked(Settings::instance()->stayOnTop());
     m_doubleClickBehavior->setModel(new QStringListModel(dcbDropDown));
-    DoubleClickBehavior dcb = Settings::instance()->doubleClickBehavior();
+    Settings::DoubleClickBehavior dcb = Settings::instance()->doubleClickBehavior();
     m_doubleClickBehavior->setCurrentIndex(static_cast<int>(dcb));
     m_mouseWheelBehavior->setModel(new QStringListModel(mwbDropDown));
-    MouseWheelBehavior mwb = Settings::instance()->mouseWheelBehavior();
+    Settings::MouseWheelBehavior mwb = Settings::instance()->mouseWheelBehavior();
     m_mouseWheelBehavior->setCurrentIndex(static_cast<int>(mwb));
     m_initWindowSizeBehavior->setModel(new QStringListModel(iwsbDropDown));
-    WindowSizeBehavior iwsb = Settings::instance()->initWindowSizeBehavior();
+    Settings::WindowSizeBehavior iwsb = Settings::instance()->initWindowSizeBehavior();
     m_initWindowSizeBehavior->setCurrentIndex(static_cast<int>(iwsb));
 
     connect(m_stayOnTop, &QCheckBox::stateChanged, this, [ = ](int state){
@@ -70,15 +70,15 @@ SettingsDialog::SettingsDialog(QWidget *parent)
     });
 
     connect(m_doubleClickBehavior, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [ = ](int index){
-        Settings::instance()->setDoubleClickBehavior(static_cast<DoubleClickBehavior>(index));
+        Settings::instance()->setDoubleClickBehavior(_dc_options.at(index).first);
     });
 
     connect(m_mouseWheelBehavior, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [ = ](int index){
-        Settings::instance()->setMouseWheelBehavior(static_cast<MouseWheelBehavior>(index));
+        Settings::instance()->setMouseWheelBehavior(_mw_options.at(index).first);
     });
 
     connect(m_initWindowSizeBehavior, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [ = ](int index){
-        Settings::instance()->setInitWindowSizeBehavior(static_cast<WindowSizeBehavior>(index));
+        Settings::instance()->setInitWindowSizeBehavior(_iws_options.at(index).first);
     });
 
     this->setMinimumSize(300, 90); // not sure why it complain "Unable to set geometry"