Printable.h

/*
 * Copyright 2016-2025 Dmitry Ivanov
 *
 * This file is part of libquentier
 *
 * libquentier is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 * libquentier is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libquentier. If not, see <http://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <quentier/utility/Linkage.h>
 
#include <QDebug>
#include <QHash>
#include <QIODevice>
#include <QSet>
#include <QString>
#include <QTextStream>
 
namespace quentier::utility {

class QUENTIER_EXPORT Printable
{
public:
    virtual ~Printable() noexcept;
 
    virtual QTextStream & print(QTextStream & strm) const = 0;
 
    [[nodiscard]] QString toString() const;
 
    friend QUENTIER_EXPORT QTextStream & operator<<(
        QTextStream & strm, const Printable & printable);
 
    friend QUENTIER_EXPORT QDebug & operator<<(
        QDebug & debug, const Printable & printable);
};
 
} // namespace quentier::utility
 
// printing operators for existing classes not inheriting from Printable
 
template <class T>
[[nodiscard]] QString ToString(const T & object)
{
    QString str;
    QTextStream strm(&str, QIODevice::WriteOnly);
    strm << object;
    return str;
}
 
template <class TKey, class TValue>
[[nodiscard]] QString ToString(const QHash<TKey, TValue> & object)
{
    QString str;
    QTextStream strm(&str, QIODevice::WriteOnly);
    strm << QStringLiteral("QHash: \n");
 
    using CIter = typename QHash<TKey, TValue>::const_iterator;
    CIter hashEnd = object.end();
    for (CIter it = object.begin(); it != hashEnd; ++it) {
        strm << QStringLiteral("[") << it.key() << QStringLiteral("] = ")
             << it.value() << QStringLiteral(";\n");
    }
    return str;
}
 
template <class T>
[[nodiscard]] QString ToString(const QSet<T> & object)
{
    QString str;
    QTextStream strm(&str, QIODevice::WriteOnly);
    strm << QStringLiteral("QSet: \n");
 
    using CIter = typename QSet<T>::const_iterator;
    CIter setEnd = object.end();
    for (CIter it = object.begin(); it != setEnd; ++it) {
        strm << QStringLiteral("[") << *it << QStringLiteral("];\n");
    }
    return str;
}
 
#define QUENTIER_DECLARE_PRINTABLE(type, ...)                                  \
    QUENTIER_EXPORT QTextStream & operator<<(                                  \
        QTextStream & strm, const type & obj);                                 \
    inline QDebug & operator<<(QDebug & debug, const type & obj)               \
    {                                                                          \
        debug << ToString<type, ##__VA_ARGS__>(obj);                           \
        return debug;                                                          \
    }                                                                          \
    // QUENTIER_DECLARE_PRINTABLE