settingbase.h

// SPDX-FileCopyrightText: Lukas Sommer <sommerluk@gmail.com>
// SPDX-License-Identifier: BSD-2-Clause OR MIT
 
#ifndef SETTINGBASE_H
#define SETTINGBASE_H
 
#include <qglobal.h>
#include <qobject.h>
#include <qpointer.h>
#include <qstring.h>
 
#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
#include <qtmetamacros.h>
#else
#include <qobjectdefs.h>
#endif
 
class QSettings;
 
namespace PerceptualColor
{
 
class Settings;
 
/** @internal
 *
 * @brief Base class for @ref Setting.
 *
 * @internal
 *
 * @note <a href="https://stackoverflow.com/a/63021891">The <tt>Q_OBJECT</tt>
 * macro and templates cannot be combined.</a> Therefore,
 * @ref SettingBase serves as a base class to provide
 * signals for @ref Setting. */
class SettingBase : public QObject
{
    Q_OBJECT
 
public:
    virtual ~SettingBase() override;
 
Q_SIGNALS:
    /** @brief Notify signal for the value. */
    void valueChanged();
 
protected:
    SettingBase(const QString &key, Settings *settings, QObject *parent = nullptr);
 
    /** @brief <tt>QSettings</tt> key for the value. */
    const QString m_key;
 
    /** @brief Corresponding @ref Settings object. */
    QPointer<Settings> m_settings;
 
    QSettings *underlyingQSettings();
 
private:
    /** @internal @brief Only for unit tests. */
    friend class TestSettingBase;
};
 
} // namespace PerceptualColor
 
#endif // SETTINGBASE_H