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Diffstat (limited to 'src/corelib/serialization/qjsonvalue.cpp')
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diff --git a/src/corelib/serialization/qjsonvalue.cpp b/src/corelib/serialization/qjsonvalue.cpp new file mode 100644 index 0000000000..33707b6ec3 --- /dev/null +++ b/src/corelib/serialization/qjsonvalue.cpp @@ -0,0 +1,863 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <qjsonobject.h> +#include <qjsonvalue.h> +#include <qjsonarray.h> +#include <qvariant.h> +#include <qstringlist.h> +#include <qdebug.h> + +#include "qjson_p.h" + +QT_BEGIN_NAMESPACE + +/*! + \class QJsonValue + \inmodule QtCore + \ingroup json + \ingroup shared + \reentrant + \since 5.0 + + \brief The QJsonValue class encapsulates a value in JSON. + + A value in JSON can be one of 6 basic types: + + JSON is a format to store structured data. It has 6 basic data types: + + \list + \li bool QJsonValue::Bool + \li double QJsonValue::Double + \li string QJsonValue::String + \li array QJsonValue::Array + \li object QJsonValue::Object + \li null QJsonValue::Null + \endlist + + A value can represent any of the above data types. In addition, QJsonValue has one special + flag to represent undefined values. This can be queried with isUndefined(). + + The type of the value can be queried with type() or accessors like isBool(), isString(), and so on. + Likewise, the value can be converted to the type stored in it using the toBool(), toString() and so on. + + Values are strictly typed internally and contrary to QVariant will not attempt to do any implicit type + conversions. This implies that converting to a type that is not stored in the value will return a default + constructed return value. + + \section1 QJsonValueRef + + QJsonValueRef is a helper class for QJsonArray and QJsonObject. + When you get an object of type QJsonValueRef, you can + use it as if it were a reference to a QJsonValue. If you assign to it, + the assignment will apply to the element in the QJsonArray or QJsonObject + from which you got the reference. + + The following methods return QJsonValueRef: + \list + \li \l {QJsonArray}::operator[](int i) + \li \l {QJsonObject}::operator[](const QString & key) const + \endlist + + \sa {JSON Support in Qt}, {JSON Save Game Example} +*/ + +/*! + Creates a QJsonValue of type \a type. + + The default is to create a Null value. + */ +QJsonValue::QJsonValue(Type type) + : ui(0), d(0), t(type) +{ +} + +/*! + \internal + */ +QJsonValue::QJsonValue(QJsonPrivate::Data *data, QJsonPrivate::Base *base, const QJsonPrivate::Value &v) + : d(0) +{ + t = (Type)(uint)v.type; + switch (t) { + case Undefined: + case Null: + dbl = 0; + break; + case Bool: + b = v.toBoolean(); + break; + case Double: + dbl = v.toDouble(base); + break; + case String: { + QString s = v.toString(base); + stringData = s.data_ptr(); + stringData->ref.ref(); + break; + } + case Array: + case Object: + d = data; + this->base = v.base(base); + break; + } + if (d) + d->ref.ref(); +} + +/*! + Creates a value of type Bool, with value \a b. + */ +QJsonValue::QJsonValue(bool b) + : d(0), t(Bool) +{ + this->b = b; +} + +/*! + Creates a value of type Double, with value \a n. + */ +QJsonValue::QJsonValue(double n) + : d(0), t(Double) +{ + this->dbl = n; +} + +/*! + \overload + Creates a value of type Double, with value \a n. + */ +QJsonValue::QJsonValue(int n) + : d(0), t(Double) +{ + this->dbl = n; +} + +/*! + \overload + Creates a value of type Double, with value \a n. + NOTE: the integer limits for IEEE 754 double precision data is 2^53 (-9007199254740992 to +9007199254740992). + If you pass in values outside this range expect a loss of precision to occur. + */ +QJsonValue::QJsonValue(qint64 n) + : d(0), t(Double) +{ + this->dbl = double(n); +} + +/*! + Creates a value of type String, with value \a s. + */ +QJsonValue::QJsonValue(const QString &s) + : d(0), t(String) +{ + stringDataFromQStringHelper(s); +} + +/*! + \fn QJsonValue::QJsonValue(const char *s) + + Creates a value of type String with value \a s, assuming + UTF-8 encoding of the input. + + You can disable this constructor by defining \c + QT_NO_CAST_FROM_ASCII when you compile your applications. + + \since 5.3 + */ + +void QJsonValue::stringDataFromQStringHelper(const QString &string) +{ + stringData = *(QStringData **)(&string); + stringData->ref.ref(); +} + +/*! + Creates a value of type String, with value \a s. + */ +QJsonValue::QJsonValue(QLatin1String s) + : d(0), t(String) +{ + // ### FIXME: Avoid creating the temp QString below + QString str(s); + stringDataFromQStringHelper(str); +} + +/*! + Creates a value of type Array, with value \a a. + */ +QJsonValue::QJsonValue(const QJsonArray &a) + : d(a.d), t(Array) +{ + base = a.a; + if (d) + d->ref.ref(); +} + +/*! + Creates a value of type Object, with value \a o. + */ +QJsonValue::QJsonValue(const QJsonObject &o) + : d(o.d), t(Object) +{ + base = o.o; + if (d) + d->ref.ref(); +} + + +/*! + Destroys the value. + */ +QJsonValue::~QJsonValue() +{ + if (t == String && stringData && !stringData->ref.deref()) + free(stringData); + + if (d && !d->ref.deref()) + delete d; +} + +/*! + Creates a copy of \a other. + */ +QJsonValue::QJsonValue(const QJsonValue &other) +{ + t = other.t; + d = other.d; + ui = other.ui; + if (d) + d->ref.ref(); + + if (t == String && stringData) + stringData->ref.ref(); +} + +/*! + Assigns the value stored in \a other to this object. + */ +QJsonValue &QJsonValue::operator =(const QJsonValue &other) +{ + QJsonValue copy(other); + swap(copy); + return *this; +} + +/*! + \fn QJsonValue::QJsonValue(QJsonValue &&other) + \since 5.10 + + Move-constructs a QJsonValue from \a other. +*/ + +/*! + \fn QJsonValue &QJsonValue::operator =(QJsonValue &&other) + \since 5.10 + + Move-assigns \a other to this value. +*/ + +/*! + \fn void QJsonValue::swap(QJsonValue &other) + \since 5.10 + + Swaps the value \a other with this. This operation is very fast and never fails. +*/ + +/*! + \fn bool QJsonValue::isNull() const + + Returns \c true if the value is null. +*/ + +/*! + \fn bool QJsonValue::isBool() const + + Returns \c true if the value contains a boolean. + + \sa toBool() + */ + +/*! + \fn bool QJsonValue::isDouble() const + + Returns \c true if the value contains a double. + + \sa toDouble() + */ + +/*! + \fn bool QJsonValue::isString() const + + Returns \c true if the value contains a string. + + \sa toString() + */ + +/*! + \fn bool QJsonValue::isArray() const + + Returns \c true if the value contains an array. + + \sa toArray() + */ + +/*! + \fn bool QJsonValue::isObject() const + + Returns \c true if the value contains an object. + + \sa toObject() + */ + +/*! + \fn bool QJsonValue::isUndefined() const + + Returns \c true if the value is undefined. This can happen in certain + error cases as e.g. accessing a non existing key in a QJsonObject. + */ + + +/*! + Converts \a variant to a QJsonValue and returns it. + + The conversion will convert QVariant types as follows: + + \table + \header + \li Source type + \li Destination type + \row + \li + \list + \li QMetaType::Nullptr + \endlist + \li QJsonValue::Null + \row + \li + \list + \li QMetaType::Bool + \endlist + \li QJsonValue::Bool + \row + \li + \list + \li QMetaType::Int + \li QMetaType::UInt + \li QMetaType::LongLong + \li QMetaType::ULongLong + \li QMetaType::Float + \li QMetaType::Double + \endlist + \li QJsonValue::Double + \row + \li + \list + \li QMetaType::QString + \endlist + \li QJsonValue::String + \row + \li + \list + \li QMetaType::QStringList + \li QMetaType::QVariantList + \endlist + \li QJsonValue::Array + \row + \li + \list + \li QMetaType::QVariantMap + \li QMetaType::QVariantHash + \endlist + \li QJsonValue::Object + \endtable + + For all other QVariant types a conversion to a QString will be attempted. If the returned string + is empty, a Null QJsonValue will be stored, otherwise a String value using the returned QString. + + \sa toVariant() + */ +QJsonValue QJsonValue::fromVariant(const QVariant &variant) +{ + switch (variant.userType()) { + case QMetaType::Nullptr: + return QJsonValue(Null); + case QVariant::Bool: + return QJsonValue(variant.toBool()); + case QVariant::Int: + case QMetaType::Float: + case QVariant::Double: + case QVariant::LongLong: + case QVariant::ULongLong: + case QVariant::UInt: + return QJsonValue(variant.toDouble()); + case QVariant::String: + return QJsonValue(variant.toString()); + case QVariant::StringList: + return QJsonValue(QJsonArray::fromStringList(variant.toStringList())); + case QVariant::List: + return QJsonValue(QJsonArray::fromVariantList(variant.toList())); + case QVariant::Map: + return QJsonValue(QJsonObject::fromVariantMap(variant.toMap())); + case QVariant::Hash: + return QJsonValue(QJsonObject::fromVariantHash(variant.toHash())); +#ifndef QT_BOOTSTRAPPED + case QMetaType::QJsonValue: + return variant.toJsonValue(); + case QMetaType::QJsonObject: + return variant.toJsonObject(); + case QMetaType::QJsonArray: + return variant.toJsonArray(); + case QMetaType::QJsonDocument: { + QJsonDocument doc = variant.toJsonDocument(); + return doc.isArray() ? QJsonValue(doc.array()) : QJsonValue(doc.object()); + } +#endif + default: + break; + } + QString string = variant.toString(); + if (string.isEmpty()) + return QJsonValue(); + return QJsonValue(string); +} + +/*! + Converts the value to a \l {QVariant::}{QVariant()}. + + The QJsonValue types will be converted as follows: + + \value Null QMetaType::Nullptr + \value Bool QMetaType::Bool + \value Double QMetaType::Double + \value String QString + \value Array QVariantList + \value Object QVariantMap + \value Undefined \l {QVariant::}{QVariant()} + + \sa fromVariant() + */ +QVariant QJsonValue::toVariant() const +{ + switch (t) { + case Bool: + return b; + case Double: + return dbl; + case String: + return toString(); + case Array: + return d ? + QJsonArray(d, static_cast<QJsonPrivate::Array *>(base)).toVariantList() : + QVariantList(); + case Object: + return d ? + QJsonObject(d, static_cast<QJsonPrivate::Object *>(base)).toVariantMap() : + QVariantMap(); + case Null: + return QVariant::fromValue(nullptr); + case Undefined: + break; + } + return QVariant(); +} + +/*! + \enum QJsonValue::Type + + This enum describes the type of the JSON value. + + \value Null A Null value + \value Bool A boolean value. Use toBool() to convert to a bool. + \value Double A double. Use toDouble() to convert to a double. + \value String A string. Use toString() to convert to a QString. + \value Array An array. Use toArray() to convert to a QJsonArray. + \value Object An object. Use toObject() to convert to a QJsonObject. + \value Undefined The value is undefined. This is usually returned as an + error condition, when trying to read an out of bounds value + in an array or a non existent key in an object. +*/ + +/*! + Returns the type of the value. + + \sa QJsonValue::Type + */ +QJsonValue::Type QJsonValue::type() const +{ + return t; +} + +/*! + Converts the value to a bool and returns it. + + If type() is not bool, the \a defaultValue will be returned. + */ +bool QJsonValue::toBool(bool defaultValue) const +{ + if (t != Bool) + return defaultValue; + return b; +} + +/*! + Converts the value to an int and returns it. + + If type() is not Double or the value is not a whole number, + the \a defaultValue will be returned. + */ +int QJsonValue::toInt(int defaultValue) const +{ + if (t == Double && int(dbl) == dbl) + return int(dbl); + return defaultValue; +} + +/*! + Converts the value to a double and returns it. + + If type() is not Double, the \a defaultValue will be returned. + */ +double QJsonValue::toDouble(double defaultValue) const +{ + if (t != Double) + return defaultValue; + return dbl; +} + +/*! + Converts the value to a QString and returns it. + + If type() is not String, the \a defaultValue will be returned. + */ +QString QJsonValue::toString(const QString &defaultValue) const +{ + if (t != String) + return defaultValue; + stringData->ref.ref(); // the constructor below doesn't add a ref. + QStringDataPtr holder = { stringData }; + return QString(holder); +} + +/*! + Converts the value to a QString and returns it. + + If type() is not String, a null QString will be returned. + + \sa QString::isNull() + */ +QString QJsonValue::toString() const +{ + if (t != String) + return QString(); + stringData->ref.ref(); // the constructor below doesn't add a ref. + QStringDataPtr holder = { stringData }; + return QString(holder); +} + +/*! + Converts the value to an array and returns it. + + If type() is not Array, the \a defaultValue will be returned. + */ +QJsonArray QJsonValue::toArray(const QJsonArray &defaultValue) const +{ + if (!d || t != Array) + return defaultValue; + + return QJsonArray(d, static_cast<QJsonPrivate::Array *>(base)); +} + +/*! + \overload + + Converts the value to an array and returns it. + + If type() is not Array, a \l{QJsonArray::}{QJsonArray()} will be returned. + */ +QJsonArray QJsonValue::toArray() const +{ + return toArray(QJsonArray()); +} + +/*! + Converts the value to an object and returns it. + + If type() is not Object, the \a defaultValue will be returned. + */ +QJsonObject QJsonValue::toObject(const QJsonObject &defaultValue) const +{ + if (!d || t != Object) + return defaultValue; + + return QJsonObject(d, static_cast<QJsonPrivate::Object *>(base)); +} + +/*! + \overload + + Converts the value to an object and returns it. + + If type() is not Object, the \l {QJsonObject::}{QJsonObject()} will be returned. +*/ +QJsonObject QJsonValue::toObject() const +{ + return toObject(QJsonObject()); +} + +/*! + Returns a QJsonValue representing the value for the key \a key. + + Equivalent to calling toObject().value(key). + + The returned QJsonValue is QJsonValue::Undefined if the key does not exist, + or if isObject() is false. + + \since 5.10 + + \sa QJsonValue, QJsonValue::isUndefined(), QJsonObject + */ +const QJsonValue QJsonValue::operator[](const QString &key) const +{ + if (!isObject()) + return QJsonValue(QJsonValue::Undefined); + + return toObject().value(key); +} + +/*! + \overload + \since 5.10 +*/ +const QJsonValue QJsonValue::operator[](QLatin1String key) const +{ + if (!isObject()) + return QJsonValue(QJsonValue::Undefined); + + return toObject().value(key); +} + +/*! + Returns a QJsonValue representing the value for index \a i. + + Equivalent to calling toArray().at(i). + + The returned QJsonValue is QJsonValue::Undefined, if \a i is out of bounds, + or if isArray() is false. + + \since 5.10 + + \sa QJsonValue, QJsonValue::isUndefined(), QJsonArray + */ +const QJsonValue QJsonValue::operator[](int i) const +{ + if (!isArray()) + return QJsonValue(QJsonValue::Undefined); + + return toArray().at(i); +} + +/*! + Returns \c true if the value is equal to \a other. + */ +bool QJsonValue::operator==(const QJsonValue &other) const +{ + if (t != other.t) + return false; + + switch (t) { + case Undefined: + case Null: + break; + case Bool: + return b == other.b; + case Double: + return dbl == other.dbl; + case String: + return toString() == other.toString(); + case Array: + if (base == other.base) + return true; + if (!base) + return !other.base->length; + if (!other.base) + return !base->length; + return QJsonArray(d, static_cast<QJsonPrivate::Array *>(base)) + == QJsonArray(other.d, static_cast<QJsonPrivate::Array *>(other.base)); + case Object: + if (base == other.base) + return true; + if (!base) + return !other.base->length; + if (!other.base) + return !base->length; + return QJsonObject(d, static_cast<QJsonPrivate::Object *>(base)) + == QJsonObject(other.d, static_cast<QJsonPrivate::Object *>(other.base)); + } + return true; +} + +/*! + Returns \c true if the value is not equal to \a other. + */ +bool QJsonValue::operator!=(const QJsonValue &other) const +{ + return !(*this == other); +} + +/*! + \internal + */ +void QJsonValue::detach() +{ + if (!d) + return; + + QJsonPrivate::Data *x = d->clone(base); + x->ref.ref(); + if (!d->ref.deref()) + delete d; + d = x; + base = static_cast<QJsonPrivate::Object *>(d->header->root()); +} + + +/*! + \class QJsonValueRef + \inmodule QtCore + \reentrant + \brief The QJsonValueRef class is a helper class for QJsonValue. + + \internal + + \ingroup json + + When you get an object of type QJsonValueRef, if you can assign to it, + the assignment will apply to the character in the string from + which you got the reference. That is its whole purpose in life. + + You can use it exactly in the same way as a reference to a QJsonValue. + + The QJsonValueRef becomes invalid once modifications are made to the + string: if you want to keep the character, copy it into a QJsonValue. + + Most of the QJsonValue member functions also exist in QJsonValueRef. + However, they are not explicitly documented here. +*/ + + +QJsonValueRef &QJsonValueRef::operator =(const QJsonValue &val) +{ + if (is_object) + o->setValueAt(index, val); + else + a->replace(index, val); + + return *this; +} + +QJsonValueRef &QJsonValueRef::operator =(const QJsonValueRef &ref) +{ + if (is_object) + o->setValueAt(index, ref); + else + a->replace(index, ref); + + return *this; +} + +QVariant QJsonValueRef::toVariant() const +{ + return toValue().toVariant(); +} + +QJsonArray QJsonValueRef::toArray() const +{ + return toValue().toArray(); +} + +QJsonObject QJsonValueRef::toObject() const +{ + return toValue().toObject(); +} + +QJsonValue QJsonValueRef::toValue() const +{ + if (!is_object) + return a->at(index); + return o->valueAt(index); +} + +#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY) +QDebug operator<<(QDebug dbg, const QJsonValue &o) +{ + QDebugStateSaver saver(dbg); + switch (o.t) { + case QJsonValue::Undefined: + dbg << "QJsonValue(undefined)"; + break; + case QJsonValue::Null: + dbg << "QJsonValue(null)"; + break; + case QJsonValue::Bool: + dbg.nospace() << "QJsonValue(bool, " << o.toBool() << ')'; + break; + case QJsonValue::Double: + dbg.nospace() << "QJsonValue(double, " << o.toDouble() << ')'; + break; + case QJsonValue::String: + dbg.nospace() << "QJsonValue(string, " << o.toString() << ')'; + break; + case QJsonValue::Array: + dbg.nospace() << "QJsonValue(array, "; + dbg << o.toArray(); + dbg << ')'; + break; + case QJsonValue::Object: + dbg.nospace() << "QJsonValue(object, "; + dbg << o.toObject(); + dbg << ')'; + break; + } + return dbg; +} +#endif + +QT_END_NAMESPACE |