source: trunk/src/gui/widgets/qvalidator.cpp@ 461

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#include <qdebug.h>

#include "qvalidator.h"
#ifndef QT_NO_VALIDATOR
#include "private/qobject_p.h"
#include "private/qlocale_p.h"

#include <limits.h>
#include <math.h>

QT_BEGIN_NAMESPACE

/*!
    \class QValidator
    \brief The QValidator class provides validation of input text.

    \ingroup misc
    \mainclass

    The class itself is abstract. Two subclasses, \l QIntValidator and
    \l QDoubleValidator, provide basic numeric-range checking, and \l
    QRegExpValidator 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

    \i For a line edit that accepts integers from 10 to 1000 inclusive,
    42 and 123 are \l Acceptable, the empty string and 5 are \l
    Intermediate, and "asdf" and 1114 is \l Invalid.

    \i For an editable combobox that accepts URLs, any well-formed URL
    is \l Acceptable, "http://qtsoftware.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.

    \i For a spin box that accepts lengths, "11cm" and "1in" are \l
    Acceptable, "11" and the empty string are \l Intermediate, and
    "http://qtsoftware.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, QRegExpValidator, {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.

    \omitvalue Valid
*/

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)
    : QObject(*new QValidatorPrivate, parent)
{
}

#ifdef QT3_SUPPORT
/*!
  \obsolete
    Sets up the validator. The \a parent and \a name parameters are
    passed on to the QObject constructor.
*/

QValidator::QValidator(QObject * parent, const char *name)
    : QObject(*new QValidatorPrivate, parent)
{
    setObjectName(QString::fromAscii(name));
}
#endif

/*!
    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);
    d->locale = locale;
}

/*!
    \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.

    \ingroup misc

    Example of use:

    \snippet doc/src/snippets/code/src_gui_widgets_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 doc/src/snippets/code/src_gui_widgets_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 to be 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. In addition,
    QIntValidator is always guaranteed to accept a number formatted according
    to the "C" locale.

    \sa QDoubleValidator, QRegExpValidator, {Line Edits Example}
*/

/*!
    Constructs a validator with a \a parent object that
    accepts all integers.
*/

QIntValidator::QIntValidator(QObject * parent)
    : QValidator(parent)
{
    b = INT_MIN;
    t = INT_MAX;
}


/*!
    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;
}


#ifdef QT3_SUPPORT
/*!
  \obsolete

    Constructs a validator with a \a parent object and a \a name that
    accepts all integers.
*/

QIntValidator::QIntValidator(QObject * parent, const char *name)
    : QValidator(parent)
{
    setObjectName(QString::fromAscii(name));
    b = INT_MIN;
    t = INT_MAX;
}


/*!
  \obsolete

    Constructs a validator called \a name with a \a parent, that
    accepts integers from \a minimum to \a maximum inclusive.
*/

QIntValidator::QIntValidator(int minimum, int maximum,
                              QObject * parent, const char* name)
    : QValidator(parent)
{
    setObjectName(QString::fromAscii(name));
    b = minimum;
    t = maximum;
}
#endif

/*!
    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, \l Intermediate if the \a input is a prefix of an integer in the
    valid range, and \l Invalid otherwise.

    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, then Intermediate is returned, because
    the user might be just about to type the minus (especially for right-to-left
    languages).

    \snippet doc/src/snippets/code/src_gui_widgets_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)log10(double(n)) + 1;
};

static qlonglong pow10(int exp)
{
    qlonglong result = 1;
    for (int i = 0; i < exp; ++i)
        result *= 10;
    return result;
}