knumber.h

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/****************************************************************************
**
** This file is part of KDWinutils, KDAB's MFC to Qt migration tool.
**
** Copyright (C) 2023 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
** All rights reserved.
**
** This file is intended solely for use by the migration tools and services
** provided by Klarälvdalens Datakonsult AB.
**
**  Any other use or distribution of this software that is not otherwise agreed
**  upon in writing and signed by an authorized representative of Klarälvdalens
**  Datakonsult AB, KDAB (USA) LLC, KDAB (Deutschland) GmbH & Co. K.G.,
**  KDAB (France) SAS, KDAB (UK), Ltd., or any future subsidiary of Klarälvdalens
**  Datakonsult AB is hereby prohibited.
**
**  Contact info@kdab.com if any conditions stated above are unclear to you.
**
****************************************************************************/
 
#pragma once
 
#include "../kdwinutils_global.h"
 
#include <QComboBox>
#include <QLabel>
#include <QLineEdit>
#include <QString>
#include <QValidator>
 
#include <type_traits>
 
KDWINUTILS_BEGIN_NAMESPACE
 
template <typename T>
class KNumber
{
public:
    using Type = T;
    using value_type = T;
 
    explicit KNumber(T value)
        : m_value(std::move(value))
    {
    }
 
    QWidget *widget() const;
    void setWidget(QWidget *label);
 
    void setValidator(QValidator *validator);
 
    KNumber<T> &operator=(const T &value);
    operator T() const { return value(); };
 
private:
    [[nodiscard]] T convertToValue(const QString &text) const;
    [[nodiscard]] QString convertToString(const T &value) const;
 
    QString stringValue() const;
    T value() const;
    void setValue(const QString &text);
    void setValue(const T &value);
 
private:
    T m_value; // used only for the initialization, then move to the widget
    QWidget *m_widget = nullptr;
};
 
template <typename T>
inline QWidget *KNumber<T>::widget() const
{
    return m_widget;
}
 
template <typename T>
inline void KNumber<T>::setWidget(QWidget *label)
{
    Q_ASSERT(label);
    m_widget = label;
    setValue(m_value);
}
 
template <typename T>
inline void KNumber<T>::setValidator(QValidator *validator)
{
    Q_ASSERT(m_widget);
 
    if (auto lineEdit = qobject_cast<QLineEdit *>(m_widget))
        lineEdit->setValidator(validator);
    else if (auto comboBox = qobject_cast<QComboBox *>(m_widget))
        comboBox->setValidator(validator);
    else
        validator->deleteLater();
}
 
template <typename T>
inline KNumber<T> &KNumber<T>::operator=(const T &value)
{
    setValue(value);
    return *this;
}
 
template <typename T>
inline T KNumber<T>::convertToValue(const QString &text) const
{
    if constexpr (std::is_same_v<std::decay_t<T>, short>)
        return text.toShort();
    if constexpr (std::is_same_v<std::decay_t<T>, int>)
        return text.toInt();
    if constexpr (std::is_same_v<std::decay_t<T>, long>)
        return text.toLong();
    if constexpr (std::is_same_v<std::decay_t<T>, long long>)
        return text.toLongLong();
    if constexpr (std::is_same_v<std::decay_t<T>, unsigned int>)
        return text.toUInt();
    if constexpr (std::is_integral_v<T>)
        return text.toInt();
    if constexpr (std::is_same_v<std::decay_t<T>, float>)
        return text.toFloat();
    if constexpr (std::is_same_v<std::decay_t<T>, double>)
        return text.toDouble();
 
    // We shouldn't reach this, or a type is missing
    Q_UNREACHABLE();
}
 
template <typename T>
inline QString KNumber<T>::convertToString(const T &value) const
{
    if constexpr (std::is_integral_v<T> || std::is_floating_point_v<T>)
        return QString::number(value);
 
    // We shouldn't reach this, or a type is missing
    Q_UNREACHABLE();
}
 
template <typename T>
inline QString KNumber<T>::stringValue() const
{
    Q_ASSERT(m_widget);
    if (auto lineEdit = qobject_cast<QLineEdit *>(m_widget))
        return lineEdit->text();
    if (auto comboBox = qobject_cast<QComboBox *>(m_widget))
        return comboBox->currentText();
    if (auto label = qobject_cast<QLabel *>(m_widget))
        return label->text();
    // We shouldn't reach this, or a widget is missing
    Q_UNREACHABLE();
}
 
template <typename T>
inline T KNumber<T>::value() const
{
    Q_ASSERT(m_widget);
    return convertToValue(stringValue());
}
 
template <typename T>
inline void KNumber<T>::setValue(const QString &text)
{
    Q_ASSERT(m_widget);
    if (auto lineEdit = qobject_cast<QLineEdit *>(m_widget))
        lineEdit->setText(text);
    else if (auto comboBox = qobject_cast<QComboBox *>(m_widget))
        comboBox->setCurrentText(text);
    else if (auto label = qobject_cast<QLabel *>(m_widget))
        label->setText(text);
    // We shouldn't reach this, or a widget is missing
    else
        Q_UNREACHABLE();
}
 
template <typename T>
inline void KNumber<T>::setValue(const T &value)
{
    setValue(convertToString(value));
}
 
KDWINUTILS_END_NAMESPACE