qvalidator.cpp

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// Copyright (C) 2021 The Qt Company Ltd.
// Copyright (C) 2012 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:critical reason:data-parser
 
#include <qdebug.h>
 
#include "qvalidator.h"
#ifndef QT_NO_VALIDATOR
#include "private/qobject_p.h"
#include "private/qlocale_p.h"
#include "private/qnumeric_p.h"
#include "private/qstringiterator_p.h"
 
#include <limits.h>
#include <cmath>
 
QT_BEGIN_NAMESPACE
 
/*!
    \class QValidator
    \brief The QValidator class provides validation of input text.
    \inmodule QtGui
 
    The class itself is abstract. Two subclasses, \l QIntValidator and
    \l QDoubleValidator, provide basic numeric-range checking, and \l
    QRegularExpressionValidator provides general checking using a custom regular
    expression.
 
    If the built-in validators aren't sufficient, you can subclass
    QValidator. The class has two virtual functions: validate() and
    fixup().
 
    \l validate() must be implemented by every subclass. It returns
    \l Invalid, \l Intermediate or \l Acceptable depending on whether
    its argument is valid (for the subclass's definition of valid).
 
    These three states require some explanation. An \l Invalid string
    is \e clearly invalid. \l Intermediate is less obvious: the
    concept of validity is difficult to apply when the string is
    incomplete (still being edited). QValidator defines \l Intermediate
    as the property of a string that is neither clearly invalid nor
    acceptable as a final result. \l Acceptable means that the string
    is acceptable as a final result. One might say that any string
    that is a plausible intermediate state during entry of an \l
    Acceptable string is \l Intermediate.
 
    Here are some examples:
 
    \list
 
    \li For a line edit that accepts integers from 10 to 1000 inclusive,
    42 and 123 are \l Acceptable, the empty string, 5, or 1234 are \l
    Intermediate, and "asdf" and 10114 is \l Invalid.
 
    \li For an editable combobox that accepts URLs, any well-formed URL
    is \l Acceptable, "http://example.com/," is \l Intermediate
    (it might be a cut and paste action that accidentally took in a
    comma at the end), the empty string is \l Intermediate (the user
    might select and delete all of the text in preparation for entering
    a new URL) and "http:///./" is \l Invalid.
 
    \li For a spin box that accepts lengths, "11cm" and "1in" are \l
    Acceptable, "11" and the empty string are \l Intermediate, and
    "http://example.com" and "hour" are \l Invalid.
 
    \endlist
 
    \l fixup() is provided for validators that can repair some user
    errors. The default implementation does nothing. QLineEdit, for
    example, will call fixup() if the user presses Enter (or Return)
    and the content is not currently valid. This allows the fixup()
    function the opportunity of performing some magic to make an \l
    Invalid string \l Acceptable.
 
    A validator has a locale, set with setLocale(). It is typically used
    to parse localized data. For example, QIntValidator and QDoubleValidator
    use it to parse localized representations of integers and doubles.
 
    QValidator is typically used with QLineEdit, QSpinBox and
    QComboBox.
 
    \sa QIntValidator, QDoubleValidator, QRegularExpressionValidator, {Line Edits Example}
*/
 
 
/*!
    \enum QValidator::State
 
    This enum type defines the states in which a validated string can
    exist.
 
    \value Invalid       The string is \e clearly invalid.
    \value Intermediate  The string is a plausible intermediate value.
    \value Acceptable    The string is acceptable as a final result;
                         i.e. it is valid.
*/
 
/*!
    \fn void QValidator::changed()
 
    This signal is emitted when any property that may affect the validity of
    a string has changed.
*/
 
/*!
    \fn void QIntValidator::topChanged(int top)
 
    This signal is emitted after the top property changed.
 
    \sa QIntValidator::top(), QIntValidator::setTop(), QIntValidator::bottom(), QIntValidator::setBottom()
    \internal
*/
 
/*!
    \fn void QIntValidator::bottomChanged(int bottom)
 
    This signal is emitted after the bottom property changed.
 
    \sa QIntValidator::top(), QIntValidator::setTop(), QIntValidator::bottom(), QIntValidator::setBottom()
    \internal
*/
 
/*!
    \fn void QDoubleValidator::topChanged(double top)
 
    This signal is emitted after the top property changed.
 
    \sa QDoubleValidator::top(), QDoubleValidator::setTop(), QDoubleValidator::bottom(), QDoubleValidator::setBottom()
    \internal
*/
 
/*!
    \fn void QDoubleValidator::bottomChanged(double bottom)
 
    This signal is emitted after the bottom property changed.
 
    \sa QDoubleValidator::top(), QDoubleValidator::setTop(), QDoubleValidator::bottom(), QDoubleValidator::setBottom()
    \internal
*/
 
/*!
    \fn void QDoubleValidator::decimalsChanged(int decimals)
 
    This signal is emitted after the decimals property changed.
 
    \internal
*/
 
/*!
    \fn void QDoubleValidator::notationChanged(QDoubleValidator::Notation notation)
 
    This signal is emitted after the notation property changed.
 
    QDoubleValidator::Notation is not a registered metatype, so for queued connections,
    you will have to register it with Q_DECLARE_METATYPE() and qRegisterMetaType().
 
    \internal
*/
 
class QValidatorPrivate : public QObjectPrivate{
    Q_DECLARE_PUBLIC(QValidator)
public:
    QValidatorPrivate() : QObjectPrivate()
    {
    }
 
    QLocale locale;
};
 
 
/*!
    Sets up the validator. The \a parent parameter is
    passed on to the QObject constructor.
*/
 
QValidator::QValidator(QObject * parent)
    : QValidator(*new QValidatorPrivate, parent)
{
}
 
/*!
    Destroys the validator, freeing any storage and other resources
    used.
*/
 
QValidator::~QValidator()
{
}
 
/*!
    Returns the locale for the validator. The locale is by default initialized to the same as QLocale().
 
    \sa setLocale()
    \sa QLocale::QLocale()
*/
QLocale QValidator::locale() const
{
    Q_D(const QValidator);
    return d->locale;
}
 
/*!
    Sets the \a locale that will be used for the validator. Unless
    setLocale has been called, the validator will use the default
    locale set with QLocale::setDefault(). If a default locale has not
    been set, it is the operating system's locale.
 
    \sa locale(), QLocale::setDefault()
*/
void QValidator::setLocale(const QLocale &locale)
{
    Q_D(QValidator);
    if (d->locale != locale) {
        d->locale = locale;
        emit changed();
    }
}
 
/*!
    \fn QValidator::State QValidator::validate(QString &input, int &pos) const
 
    This virtual function returns \l Invalid if \a input is invalid
    according to this validator's rules, \l Intermediate if it
    is likely that a little more editing will make the input
    acceptable (e.g. the user types "4" into a widget which accepts
    integers between 10 and 99), and \l Acceptable if the input is
    valid.
 
    The function can change both \a input and \a pos (the cursor position)
    if required.
*/
 
 
/*!
    \fn void QValidator::fixup(QString & input) const
 
    This function attempts to change \a input to be valid according to
    this validator's rules. It need not result in a valid string:
    callers of this function must re-test afterwards; the default does
    nothing.
 
    Reimplementations of this function can change \a input even if
    they do not produce a valid string. For example, an ISBN validator
    might want to delete every character except digits and "-", even
    if the result is still not a valid ISBN; a surname validator might
    want to remove whitespace from the start and end of the string,
    even if the resulting string is not in the list of accepted
    surnames.
*/
 
void QValidator::fixup(QString &) const
{
}
 
 
/*!
    \class QIntValidator
    \brief The QIntValidator class provides a validator that ensures
    a string contains a valid integer within a specified range.
    \inmodule QtGui
 
    Example of use:
 
    \snippet code/src_gui_util_qvalidator.cpp 0
 
    Below we present some examples of validators. In practice they would
    normally be associated with a widget as in the example above.
 
    \snippet code/src_gui_util_qvalidator.cpp 1
 
    Notice that the value \c 999 returns Intermediate. Values
    consisting of a number of digits equal to or less than the max
    value are considered intermediate. This is intended because the
    digit that prevents a number from being in range is not necessarily the
    last digit typed. This also means that an intermediate number can
    have leading zeros.
 
    The minimum and maximum values are set in one call with setRange(),
    or individually with setBottom() and setTop().
 
    QIntValidator uses its locale() to interpret the number. For example,
    in Arabic locales, QIntValidator will accept Arabic digits.
 
    \note The QLocale::NumberOptions set on the locale() also affect the
    way the number is interpreted. For example, since QLocale::RejectGroupSeparator
    is not set by default, the validator will accept group separators. It is thus
    recommended to use QLocale::toInt() to obtain the numeric value.
 
    \sa QDoubleValidator, QRegularExpressionValidator, QLocale::toInt(), {Line Edits Example}
*/
 
/*!
    Constructs a validator with a \a parent object that
    accepts all integers.
*/
 
QIntValidator::QIntValidator(QObject * parent)
    : QIntValidator(INT_MIN, INT_MAX, parent)
{
}
 
 
/*!
    Constructs a validator with a \a parent, that accepts integers
    from \a minimum to \a maximum inclusive.
*/
 
QIntValidator::QIntValidator(int minimum, int maximum,
                              QObject * parent)
    : QValidator(parent)
{
    b = minimum;
    t = maximum;
}
 
 
/*!
    Destroys the validator.
*/
 
QIntValidator::~QIntValidator()
{
    // nothing
}
 
 
/*!
    \fn QValidator::State QIntValidator::validate(QString &input, int &pos) const
 
    Returns \l Acceptable if the \a input is an integer within the
    valid range. If \a input has at most as many digits as the top of the range,
    or is a prefix of an integer in the valid range, returns \l Intermediate.
    Otherwise, returns \l Invalid.
 
    If the valid range consists of just positive integers (e.g., 32 to 100) and
    \a input is a negative integer, then Invalid is returned. (On the other
    hand, if the range consists of negative integers (e.g., -100 to -32) and \a
    input is a positive integer without leading plus sign, then Intermediate is
    returned, because the user might be just about to type the minus (especially
    for right-to-left languages).
 
    Similarly, if the valid range is between 46 and 53, then 41 and 59 will be
    evaluated as \l Intermediate, as otherwise the user wouldn't be able to
    change a value from 49 to 51.
 
    \snippet code/src_gui_util_qvalidator.cpp 2
 
    By default, the \a pos parameter is not used by this validator.
*/
 
static int numDigits(qlonglong n)
{
    if (n == 0)
        return 1;
    return (int)std::log10(double(n)) + 1;
}
 
static qlonglong pow10(int exp)
{
    qlonglong result = 1;
    for (int i = 0; i < exp; ++i)
        result *= 10;
    return result;
}
 
template <typename T> static inline
std::optional<QValidator::State> initialResultCheck(T min, T max,
                                                    const QLocaleData::ParsingResult &result)
{
 
    using ParsingResult = QLocaleData::ParsingResult;
    if (result.state == ParsingResult::Invalid)
        return QValidator::Invalid;
 
    const QLocaleData::CharBuff &buff = result.buff;
    if (buff.isEmpty())
        return QValidator::Intermediate;
 
    char ch = buff[0];
    const bool signConflicts = (min >= 0 && ch == '-') || (max < 0 && ch == '+');
    if (signConflicts)
        return QValidator::Invalid;
 
    if (result.state == ParsingResult::Intermediate)
        return QValidator::Intermediate;
 
    return std::nullopt;
}
 
QValidator::State QIntValidator::validate(QString & input, int&) const
{
    QLocaleData::ParsingResult result =
        locale().d->m_data->validateChars(input, QLocaleData::IntegerMode, -1,
                                          locale().numberOptions());
 
    std::optional<State> opt = initialResultCheck(b, t, result);
    if (opt)
        return *opt;
 
    const QLocaleData::CharBuff &buff = result.buff;
    QSimpleParsedNumber r = QLocaleData::bytearrayToLongLong(buff, 10);
    if (!r.ok())
        return Invalid;
 
    qint64 entered = r.result;
    if (entered >= b && entered <= t) {
        bool ok = false;
        locale().toInt(input, &ok);
        return ok ? Acceptable : Intermediate;
    }
 
    if (entered >= 0) {
        // the -entered < b condition is necessary to allow people to type
        // the minus last (e.g. for right-to-left languages)
        // The buffLength > tLength condition validates values consisting
        // of a number of digits equal to or less than the max value as intermediate.
 
        int buffLength = buff.size();
        if (buff[0] == '+')
            buffLength--;
        const int tLength = t != 0 ? static_cast<int>(std::log10(qAbs(t))) + 1 : 1;
 
        return (entered > t && -entered < b && buffLength > tLength) ? Invalid : Intermediate;
    } else {
        return (entered < b) ? Invalid : Intermediate;
    }
}
 
/*! \reimp */
void QIntValidator::fixup(QString &input) const
{
    auto [parseState, buff] =
        locale().d->m_data->validateChars(input, QLocaleData::IntegerMode, -1,
                                          locale().numberOptions());
    if (parseState == QLocaleData::ParsingResult::Invalid)
        return;
 
    QSimpleParsedNumber r = QLocaleData::bytearrayToLongLong(buff, 10);
    if (r.ok())
        input = locale().toString(r.result);
}
 
/*!
    Sets the range of the validator to only accept integers between \a
    bottom and \a top inclusive.
*/
 
void QIntValidator::setRange(int bottom, int top)
{
    bool rangeChanged = false;
    if (b != bottom) {
        b = bottom;
        rangeChanged = true;
        emit bottomChanged(b);
    }
 
    if (t != top) {
        t = top;
        rangeChanged = true;
        emit topChanged(t);
    }
 
    if (rangeChanged)
        emit changed();
}
 
 
/*!
    \property QIntValidator::bottom
    \brief the validator's lowest acceptable value
 
    By default, this property's value is derived from the lowest signed
    integer available (-2147483648).
 
    \sa setRange()
*/
void QIntValidator::setBottom(int bottom)
{
    setRange(bottom, top());
}
 
/*!
    \property QIntValidator::top
    \brief the validator's highest acceptable value
 
    By default, this property's value is derived from the highest signed
    integer available (2147483647).
 
    \sa setRange()
*/
void QIntValidator::setTop(int top)
{
    setRange(bottom(), top);
}
 
/*!
    \internal
*/
QValidator::QValidator(QObjectPrivate &d, QObject *parent)
        : QObject(d, parent)
{
}
 
/*!
    \internal
*/
QValidator::QValidator(QValidatorPrivate &d, QObject *parent)
        : QObject(d, parent)
{
}
 
class QDoubleValidatorPrivate : public QValidatorPrivate
{
    Q_DECLARE_PUBLIC(QDoubleValidator)
public:
    QDoubleValidatorPrivate()
        : QValidatorPrivate()
        , notation(QDoubleValidator::ScientificNotation)
    {
    }
 
    QDoubleValidator::Notation notation;
 
    QValidator::State validateWithLocale(QString & input, QLocaleData::NumberMode numMode, const QLocale &locale) const;
    void fixupWithLocale(QString &input, QLocaleData::NumberMode numMode,
                         const QLocale &locale) const;
};
 
 
/*!
    \class QDoubleValidator
 
    \brief The QDoubleValidator class provides range checking of
    floating-point numbers.
    \inmodule QtGui
 
    QDoubleValidator provides an upper bound, a lower bound, and a
    limit on the number of digits after the decimal point.
 
    You can set the acceptable range in one call with setRange(), or
    with setBottom() and setTop(). Set the number of decimal places
    with setDecimals(). The validate() function returns the validation
    state.
 
    QDoubleValidator uses its locale() to interpret the number. For example,
    in the German locale, "1,234" will be accepted as the fractional number
    1.234. In Arabic locales, QDoubleValidator will accept Arabic digits.
 
    \note The QLocale::NumberOptions set on the locale() also affect the way the
    number is interpreted. For example, since QLocale::RejectGroupSeparator is
    not set by default (except on the \c "C" locale), the validator will accept
    group separators. If the string passes validation, pass it to
    locale().toDouble() to obtain its numeric value.
 
    \sa QIntValidator, QRegularExpressionValidator, QLocale::toDouble(), {Line Edits Example}
*/
 
 /*!
    \enum QDoubleValidator::Notation
    \since 4.3
    This enum defines the allowed notations for entering a double.
 
    \value StandardNotation The string is written in the standard format, a
                            whole number part optionally followed by a separator
                            and fractional part, for example \c{"0.015"}.
 
    \value ScientificNotation The string is written in scientific form, which
                              optionally appends an exponent part to the
                              standard format, for example \c{"1.5E-2"}.
 
    The whole number part may, as usual, include a sign. This, along with the
    separators for fractional part, exponent and any digit-grouping, depend on
    locale. QDoubleValidator doesn't check the placement (which would also
    depend on locale) of any digit-grouping separators it finds, but it will
    reject input that contains them if \l QLocale::RejectGroupSeparator is set
    in \c locale().numberOptions().
 
    \sa QLocale::numberOptions(), QLocale::decimalPoint(),
        QLocale::exponential(), QLocale::negativeSign()
*/
 
/*!
    Constructs a validator object with a \a parent object
    that accepts any double.
*/
 
QDoubleValidator::QDoubleValidator(QObject *parent)
    : QDoubleValidator(-HUGE_VAL, HUGE_VAL, -1, parent)
{
}
 
 
/*!
    Constructs a validator object with a \a parent object. This
    validator will accept doubles from \a bottom to \a top inclusive,
    with up to \a decimals digits after the decimal point.
*/
 
QDoubleValidator::QDoubleValidator(double bottom, double top, int decimals,
                                    QObject * parent)
    : QValidator(*new QDoubleValidatorPrivate , parent)
{
    b = bottom;
    t = top;
    dec = decimals;
}
 
 
/*!
    Destroys the validator.
*/
 
QDoubleValidator::~QDoubleValidator()
{
}
 
 
/*!
    \fn QValidator::State QDoubleValidator::validate(QString &input, int &pos) const
 
    Returns \l Acceptable if the string \a input is in the correct format and
    contains a double within the valid range.
 
    Returns \l Intermediate if \a input is in the wrong format or contains a
    double outside the range.
 
    Returns \l Invalid if the \a input doesn't represent a double or has too
    many digits after the decimal point.
 
    Note: If the valid range consists of just positive doubles (e.g. 0.0 to 100.0)
    and \a input is a negative double then \l Invalid is returned. If notation()
    is set to StandardNotation, and the input contains more digits before the
    decimal point than a double in the valid range may have, \l Invalid is returned.
    If notation() is ScientificNotation, and the input is not in the valid range,
    \l Intermediate is returned. The value may yet become valid by changing the exponent.
 
    By default, the \a pos parameter is not used by this validator.
*/
 
#ifndef LLONG_MAX
#   define LLONG_MAX Q_INT64_C(0x7fffffffffffffff)
#endif
 
QValidator::State QDoubleValidator::validate(QString & input, int &) const
{
    Q_D(const QDoubleValidator);
 
    QLocaleData::NumberMode numMode = QLocaleData::DoubleStandardMode;
    switch (d->notation) {
        case StandardNotation:
            numMode = QLocaleData::DoubleStandardMode;
            break;
        case ScientificNotation:
            numMode = QLocaleData::DoubleScientificMode;
            break;
    }
 
    return d->validateWithLocale(input, numMode, locale());
}
 
QValidator::State QDoubleValidatorPrivate::validateWithLocale(QString &input, QLocaleData::NumberMode numMode, const QLocale &locale) const
{
    Q_Q(const QDoubleValidator);
    QLocaleData::ParsingResult result =
            locale.d->m_data->validateChars(input, numMode, q->dec, locale.numberOptions());
 
    std::optional<QValidator::State> opt = initialResultCheck(q->b, q->t, result);
    if (opt)
        return *opt;
 
    bool ok = false;
    double i = locale.toDouble(input, &ok); // returns 0.0 if !ok
    Q_ASSERT(!qIsNaN(i)); // Would be caught by validateChars()
    if (!ok)
        return QValidator::Intermediate;
 
    if (i >= q->b && i <= q->t)
        return QValidator::Acceptable;
 
    if (notation == QDoubleValidator::StandardNotation) {
        double max = qMax(qAbs(q->b), qAbs(q->t));
        qlonglong v;
        // Need a whole number to pass to convertDoubleTo() or it fails. Use
        // floor, as max is positive so this has the same number of digits
        // before the decimal point, where qCeil() might take us up to a power
        // of ten, adding a digit.
        if (convertDoubleTo(qFloor(max), &v)) {
            qlonglong n = pow10(numDigits(v));
            // In order to get the highest possible number in the intermediate
            // range we need to get 10 to the power of the number of digits
            // after the decimal's and subtract that from the top number.
            //
            // For example, where q->dec == 2 and with a range of 0.0 - 9.0
            // then the minimum possible number is 0.00 and the maximum
            // possible is 9.99. Therefore 9.999 and 10.0 should be seen as
            // invalid.
            if (qAbs(i) > (n - std::pow(10, -q->dec)))
                return QValidator::Invalid;
        }
    }
 
    return QValidator::Intermediate;
}
 
/*!
    \since 6.3
    \overload
 
    Attempts to fix the \a input string to an \l Acceptable representation of a
    double.
 
    The format of the number is determined by \l notation(), \l decimals(),
    \l locale() and the latter's \l {QLocale::}{numberOptions()}.
 
    To comply with \l notation(), when \l ScientificNotation is used, the fixed
    value will be represented in its normalized form, which means that any
    non-zero value will have one non-zero digit before the decimal point.
 
    \snippet code/src_gui_util_qvalidator.cpp 7
 
    To comply with \l decimals(), when it is \c {-1} the number of digits used
    will be determined by \l QLocale::FloatingPointShortest. Otherwise, the
    fractional part of the number is truncated (with rounding, as appropriate)
    if its length exceeds \l decimals(). When \l notation() is
    \l ScientificNotation this is done after the number has been put into its
    normalized form.
 
    \snippet code/src_gui_util_qvalidator.cpp 8
 
    \note If \l decimals() is set to, and the string provides, more than
    \c {std::numeric_limits<double>::digits10}, digits beyond that many in the
    fractional part may be changed. The resulting string shall encode the same
    floating-point number, when parsed to a \c double.
*/
void QDoubleValidator::fixup(QString &input) const
{
    Q_D(const QDoubleValidator);
    const auto numberMode = d->notation == StandardNotation ? QLocaleData::DoubleStandardMode
                                                            : QLocaleData::DoubleScientificMode;
 
    d->fixupWithLocale(input, numberMode, locale());
}
 
void QDoubleValidatorPrivate::fixupWithLocale(QString &input, QLocaleData::NumberMode numMode,
                                              const QLocale &locale) const
{
    Q_Q(const QDoubleValidator);
    // Passing -1 as the number of decimals, because fixup() exists to improve
    // an Intermediate value, if it can.
    auto [parseState, buff] =
            locale.d->m_data->validateChars(input, numMode, -1, locale.numberOptions());
    if (parseState == QLocaleData::ParsingResult::Invalid)
        return;
 
    // buff contains data in C locale.
    bool ok = false;
    const double entered = QByteArrayView(buff).toDouble(&ok);
    if (ok) {
        // Here we need to adjust the output format accordingly
        char mode;
        if (numMode == QLocaleData::DoubleStandardMode) {
            mode = 'f';
        } else {
            // Scientific mode can be either 'e' or 'E'
            const QString exp = locale.exponential();
            bool preferUpper = false;
            QStringIterator scan(exp);
            while (!preferUpper && scan.hasNext()) {
                const char32_t ch = scan.next();
                if (QChar::isUpper(ch))
                    preferUpper = true;
            }
            if (preferUpper)
                mode = input.contains(exp.toLower()) ? 'e' : 'E';
            else // If case-free, we don't care which we use; otherwise, prefer lower.
                mode = input.contains(exp.toUpper()) ? 'E' : 'e';
        }
        int precision;
        if (q->dec < 0) {
            precision = QLocale::FloatingPointShortest;
        } else {
            if (mode == 'f') {
                const auto decimalPointIndex = buff.indexOf('.');
                precision = decimalPointIndex >= 0 ? buff.size() - decimalPointIndex - 1 : 0;
            } else {
                auto eIndex = buff.indexOf('e');
                // No need to check for 'E' because we can get only 'e' after a
                // call to validateChars()
                if (eIndex < 0)
                    eIndex = buff.size();
                precision = eIndex - (buff.contains('.') ? 1 : 0)
                        - (buff[0] == '-' || buff[0] == '+' ? 1 : 0);
            }
            // Use q->dec to limit the number of decimals, because we want the
            // fixup() result to pass validate().
            precision = qMin(precision, q->dec);
        }
        input = locale.toString(entered, mode, precision);
    }
}
 
/*!
    Sets the validator to accept doubles from \a minimum to \a maximum
    inclusive, with at most \a decimals digits after the decimal
    point.
 
    \note Setting the number of decimals to -1 effectively sets it to unlimited.
    This is also the value used by a default-constructed validator.
*/
 
void QDoubleValidator::setRange(double minimum, double maximum, int decimals)
{
    bool rangeChanged = false;
    if (b != minimum) {
        b = minimum;
        rangeChanged = true;
        emit bottomChanged(b);
    }
 
    if (t != maximum) {
        t = maximum;
        rangeChanged = true;
        emit topChanged(t);
    }
 
    if (dec != decimals) {
        dec = decimals;
        rangeChanged = true;
        emit decimalsChanged(dec);
    }
    if (rangeChanged)
        emit changed();
}
 
/*!
    \overload
 
    Sets the validator to accept doubles from \a minimum to \a maximum
    inclusive without changing the number of digits after the decimal point.
*/
void QDoubleValidator::setRange(double minimum, double maximum)
{
    setRange(minimum, maximum, decimals());
}
 
/*!
    \property QDoubleValidator::bottom
    \brief the validator's minimum acceptable value
 
    By default, this property contains a value of -infinity.
 
    \sa setRange()
*/
 
void QDoubleValidator::setBottom(double bottom)
{
    setRange(bottom, top(), decimals());
}
 
 
/*!
    \property QDoubleValidator::top
    \brief the validator's maximum acceptable value
 
    By default, this property contains a value of infinity.
 
    \sa setRange()
*/
 
void QDoubleValidator::setTop(double top)
{
    setRange(bottom(), top, decimals());
}
 
/*!
    \property QDoubleValidator::decimals
    \brief the validator's maximum number of digits after the decimal point
 
    By default, this property contains a value of -1, which means any number
    of digits is accepted.
 
    \sa setRange()
*/
 
void QDoubleValidator::setDecimals(int decimals)
{
    setRange(bottom(), top(), decimals);
}
 
/*!
    \property QDoubleValidator::notation
    \since 4.3
    \brief the notation of how a string can describe a number
 
    By default, this property is set to ScientificNotation.
 
    \sa Notation
*/
 
void QDoubleValidator::setNotation(Notation newNotation)
{
    Q_D(QDoubleValidator);
    if (d->notation != newNotation) {
        d->notation = newNotation;
        emit notationChanged(d->notation);
        emit changed();
    }
}
 
QDoubleValidator::Notation QDoubleValidator::notation() const
{
    Q_D(const QDoubleValidator);
    return d->notation;
}
 
#if QT_CONFIG(regularexpression)
 
/*!
    \class QRegularExpressionValidator
    \inmodule QtGui
    \brief The QRegularExpressionValidator class is used to check a string
    against a regular expression.
 
    \since 5.1
 
    QRegularExpressionValidator uses a regular expression (regexp) to
    determine whether an input string is \l Acceptable, \l
    Intermediate, or \l Invalid. The regexp can either be supplied
    when the QRegularExpressionValidator is constructed, or at a later time.
 
    If the regexp partially matches against the string, the result is
    considered \l Intermediate. For example, "" and "A" are \l Intermediate for
    the regexp \b{[A-Z][0-9]} (whereas "_" would be \l Invalid).
 
    QRegularExpressionValidator automatically wraps the regular expression in
    the \c{\\A} and \c{\\z} anchors; in other words, it always attempts to do
    an exact match.
 
    Example of use:
    \snippet code/src_gui_util_qvalidator.cpp 5
 
    Below we present some examples of validators. In practice they would
    normally be associated with a widget as in the example above.
 
    \snippet code/src_gui_util_qvalidator.cpp 6
 
    \sa QRegularExpression, QIntValidator, QDoubleValidator
*/
 
class QRegularExpressionValidatorPrivate : public QValidatorPrivate
{
    Q_DECLARE_PUBLIC(QRegularExpressionValidator)
 
public:
    QRegularExpression origRe; // the one set by the user
    QRegularExpression usedRe; // the one actually used
    void setRegularExpression(const QRegularExpression &re);
};
 
/*!
    Constructs a validator with a \a parent object that accepts
    any string (including an empty one) as valid.
*/
 
QRegularExpressionValidator::QRegularExpressionValidator(QObject *parent)
    : QValidator(*new QRegularExpressionValidatorPrivate, parent)
{
    // origRe in the private will be an empty QRegularExpression,
    // and therefore this validator will match any string.
}
 
/*!
    Constructs a validator with a \a parent object that
    accepts all strings that match the regular expression \a re.
*/
 
QRegularExpressionValidator::QRegularExpressionValidator(const QRegularExpression &re, QObject *parent)
    : QRegularExpressionValidator(parent)
{
    Q_D(QRegularExpressionValidator);
    d->setRegularExpression(re);
}
 
 
/*!
    Destroys the validator.
*/
 
QRegularExpressionValidator::~QRegularExpressionValidator()
{
}
 
/*!
    Returns \l Acceptable if \a input is matched by the regular expression for
    this validator, \l Intermediate if it has matched partially (i.e. could be
    a valid match if additional valid characters are added), and \l Invalid if
    \a input is not matched.
 
    In case the \a input is not matched, the \a pos parameter is set to
    the length of the \a input parameter; otherwise, it is not modified.
 
    For example, if the regular expression is \b{\\w\\d\\d} (word-character,
    digit, digit) then "A57" is \l Acceptable, "E5" is \l Intermediate, and
    "+9" is \l Invalid.
 
    \sa QRegularExpression::match()
*/
 
QValidator::State QRegularExpressionValidator::validate(QString &input, int &pos) const
{
    Q_D(const QRegularExpressionValidator);
 
    // We want a validator with an empty QRegularExpression to match anything;
    // since we're going to do an exact match (by using d->usedRe), first check if the rx is empty
    // (and, if so, accept the input).
    if (d->origRe.pattern().isEmpty())
        return Acceptable;
 
    const QRegularExpressionMatch m = d->usedRe.match(input, 0, QRegularExpression::PartialPreferCompleteMatch);
    if (m.hasMatch()) {
        return Acceptable;
    } else if (input.isEmpty() || m.hasPartialMatch()) {
        return Intermediate;
    } else {
        pos = input.size();
        return Invalid;
    }
}
 
/*!
    \property QRegularExpressionValidator::regularExpression
    \brief the regular expression used for validation
 
    By default, this property contains a regular expression with an empty
    pattern (which therefore matches any string).
*/
 
QRegularExpression QRegularExpressionValidator::regularExpression() const
{
    Q_D(const QRegularExpressionValidator);
    return d->origRe;
}
 
void QRegularExpressionValidator::setRegularExpression(const QRegularExpression &re)
{
    Q_D(QRegularExpressionValidator);
    d->setRegularExpression(re);
}
 
/*!
    \internal
 
    Sets \a re as the regular expression. It wraps the regexp that's actually used
    between \\A and \\z, therefore forcing an exact match.
*/
void QRegularExpressionValidatorPrivate::setRegularExpression(const QRegularExpression &re)
{
    Q_Q(QRegularExpressionValidator);
 
    if (origRe != re) {
        usedRe = origRe = re; // copies also the pattern options
        usedRe.setPattern(QRegularExpression::anchoredPattern(re.pattern()));
        emit q->regularExpressionChanged(re);
        emit q->changed();
    }
}
 
#endif // QT_CONFIG(regularexpression)
 
QT_END_NAMESPACE
 
#include "moc_qvalidator.cpp"
 
#endif // QT_NO_VALIDATOR