wow-app/src/qt/MoneroSettings.cpp

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
****************************************************************************/
// Copyright (c) 2014-2019, The Monero Project
//
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//    conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
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#include <QtCore>
#include <QMetaObject>
#include <QSettings>
#include <QPointer>
#include <QJSValue>
#include <QHash>
#include <QMetaProperty>

#include "qt/MoneroSettings.h"

/*!
    \qmlmodule moneroSettings 1.0
    \title Monero Settings QML Component
    \ingroup qmlmodules
    \brief Provides persistent platform-independent application settings.

    This component was introduced in order to have control over where the
    configuration file is written. This is needed for Tails OS and
    portable installations.

    For more information, see: https://doc.qt.io/qt-5/qml-qt-labs-settings-settings.html and
    https://github.com/qt/qtdeclarative/blob/v5.12.0/src/imports/settings/qqmlsettings.cpp

    To use this module, import the module with the following line:
    \code
    import moneroComponents.Settings 1.0
    \endcode

    Usage:
    \code
    MoneroSettings { id: persistentSettings, property bool foo: true }
    \endcode

    @TODO: Remove this QML component after migrating to Qt >= 5.12.0, as
    `Qt.labs.settings` provides the fileName via a Q_PROPERTY
*/


void MoneroSettings::load()
{
    const QMetaObject *mo = this->metaObject();
    const int offset = mo->propertyOffset();
    const int count = mo->propertyCount();

    for (int i = offset; i < count; ++i) {
        QMetaProperty property = mo->property(i);
        const QVariant previousValue = readProperty(property);
        const QVariant currentValue = this->m_settings->value(property.name(), previousValue);

        if (!currentValue.isNull() && (!previousValue.isValid()
                || (currentValue.canConvert(previousValue.type()) && previousValue != currentValue))) {
            property.write(this, currentValue);
#ifdef QT_DEBUG
            qDebug() << "QQmlSettings: load" << property.name() << "setting:" << currentValue << "default:" << previousValue;
#endif
        }

        // ensure that a non-existent setting gets written
        // even if the property wouldn't change later
        if (!this->m_settings->contains(property.name()))
            this->_q_propertyChanged();

        // setup change notifications on first load
        if (!this->m_initialized && property.hasNotifySignal()) {
            static const int propertyChangedIndex = mo->indexOfSlot("_q_propertyChanged()");
            int signalIndex = property.notifySignalIndex();
            QMetaObject::connect(this, signalIndex, this, propertyChangedIndex);
        }
    }
}

void MoneroSettings::_q_propertyChanged()
{
    // Called on QML property change
    const QMetaObject *mo = this->metaObject();
    const int offset = mo->propertyOffset();
    const int count = mo->propertyCount();
    for (int i = offset; i < count; ++i) {
        const QMetaProperty &property = mo->property(i);
        const QVariant value = readProperty(property);
        this->m_changedProperties.insert(property.name(), value);
#ifdef QT_DEBUG
        //qDebug() << "QQmlSettings: cache" << property.name() << ":" << value;
#endif
    }

    if (this->m_timerId != 0)
        this->killTimer(this->m_timerId);
    this->m_timerId = this->startTimer(settingsWriteDelay);
}

QVariant MoneroSettings::readProperty(const QMetaProperty &property) const
{
    QVariant var = property.read(this);
    if (var.userType() == qMetaTypeId<QJSValue>())
        var = var.value<QJSValue>().toVariant();
    return var;
}

void MoneroSettings::init()
{
    if (!this->m_initialized) {
        this->m_settings = this->m_fileName.isEmpty() ? new QSettings() : new QSettings(this->m_fileName, QSettings::IniFormat);
#ifdef QT_DEBUG
        qDebug() << "QQmlSettings: stored at" << this->m_settings->fileName();
#endif
        this->load();
        this->m_initialized = true;
    }
}

void MoneroSettings::reset()
{
    if (this->m_initialized && this->m_settings && !this->m_changedProperties.isEmpty())
        this->store();
    if (this->m_settings)
        delete this->m_settings;
}

void MoneroSettings::store()
{
    QHash<const char *, QVariant>::const_iterator it = this->m_changedProperties.constBegin();

    while (it != this->m_changedProperties.constEnd()) {
        this->m_settings->setValue(it.key(), it.value());

#ifdef QT_DEBUG
            //qDebug() << "QQmlSettings: store" << it.key() << ":" << it.value();
#endif

        ++it;
    }

    this->m_changedProperties.clear();
}

void MoneroSettings::setFileName(const QString &fileName)
{
    if (fileName != this->m_fileName) {
        this->reset();
        this->m_fileName = fileName;
        if (this->m_initialized)
            this->load();
    }
}

QString MoneroSettings::fileName() const
{
    return this->m_fileName;
}

void MoneroSettings::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == this->m_timerId) {
        killTimer(this->m_timerId);
        this->m_timerId = 0;
        this->store();
    }
    QObject::timerEvent(event);
}

void MoneroSettings::componentComplete()
{
    this->init();
}

void MoneroSettings::classBegin()
{
}

MoneroSettings::MoneroSettings(QObject *parent) :
    QObject(parent)
{
}