qitem_p.h

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//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.

#ifndef Patternist_Item_H
#define Patternist_Item_H

#include <QtXmlPatterns/private/qcppcastinghelper_p.h>
#include <QtXmlPatterns/private/qitemtype_p.h>
#include <QtXmlPatterns/private/qsingletoniterator_p.h>
#include <QtXmlPatterns/QAbstractXmlNodeModel>

#include <QUrl>
#include <QVariant>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

template<typename T> class QList;
template<typename T> class QVector;
template<typename T> class QAbstractXmlForwardIterator;

class QSourceLocation;
class QAbstractXmlReceiver;

namespace QPatternist
{
    class DynamicContext;
    class Item;
    class ItemType;
    class QObjectNodeModel;
    template<typename T> class EmptyIterator;
    template<typename T, typename ListType> class ListIterator;

    class AtomicValue : public QSharedData
                      , public CppCastingHelper<AtomicValue>
    {
    public:
        virtual ~AtomicValue();

        typedef QExplicitlySharedDataPointer<AtomicValue> Ptr;

        typedef QList<AtomicValue::Ptr> List;

        virtual bool hasError() const;

        virtual bool evaluateEBV(const QExplicitlySharedDataPointer<DynamicContext> &context) const;

        virtual QString stringValue() const = 0;
        virtual ItemType::Ptr type() const = 0;

        static QVariant toQt(const AtomicValue *const value);

        static inline QVariant toQt(const AtomicValue::Ptr &value)
        {
            return toQt(value.data());
        }

        static Item toXDM(const QVariant &value);

        static ItemType::Ptr qtToXDMType(const QXmlItem &item);
    protected:
        inline AtomicValue()
        {
        }
    };

    class Item
    {
        friend class QT_PREPEND_NAMESPACE(QXmlItem);

    public:
        typedef QAbstractXmlForwardIterator<Item> Iterator;

        typedef QList<Item> List;

        typedef QVector<Item> Vector;

        typedef QPatternist::SingletonIterator<Item> SingletonIterator;
        typedef QPatternist::EmptyIterator<Item> EmptyIterator;

        inline Item()
        {
            node.reset();
        }

        inline Item(const QXmlNodeModelIndex &n) : node(n.m_storage)
        {
        }

        inline Item(const Item &other) : node(other.node)
        {
            Q_ASSERT_X(sizeof(QXmlNodeModelIndex) >= sizeof(AtomicValue), Q_FUNC_INFO,
                       "Since we're only copying the node member, it must be the largest.");
            if(isAtomicValue())
                atomicValue->ref.ref();
        }

        inline Item(const AtomicValue::Ptr &a)
        {
            node.reset();
            if(a)
            {
                atomicValue = a.data();
                atomicValue->ref.ref();

                /* Signal that we're housing an atomic value. */
                node.model = reinterpret_cast<const QAbstractXmlNodeModel *>(~0);
            }
        }

        inline Item(const AtomicValue *const a)
        {
            /* Note, the implementation is a copy of the constructor above. */
            node.reset();
            if(a)
            {
                atomicValue = a;
                atomicValue->ref.ref();

                /* Signal that we're housing an atomic value. */
                node.model = reinterpret_cast<const QAbstractXmlNodeModel *>(~0);
            }
        }

        inline ~Item()
        {
            if(isAtomicValue() && !atomicValue->ref.deref())
                delete atomicValue;
        }

        inline Item &operator=(const Item &other)
        {
            Q_ASSERT_X(sizeof(QXmlNodeModelIndex) >= sizeof(AtomicValue *), Q_FUNC_INFO,
                       "If this doesn't hold, we won't copy all data.");

            if(other.isAtomicValue())
                other.atomicValue->ref.ref();

            if(isAtomicValue())
            {
                if(!atomicValue->ref.deref())
                    delete atomicValue;
            }

            node = other.node;

            return *this;
        }

        template<typename TCastTarget>
        inline TCastTarget *as() const
        {
#if defined(Patternist_DEBUG) && !defined(Q_CC_XLC)
/* At least on aix-xlc-64, the compiler cries when it sees dynamic_cast. */
            Q_ASSERT_X(atomicValue == 0 || dynamic_cast<const TCastTarget *>(atomicValue),
                       Q_FUNC_INFO,
                       "The cast is invalid. This class does not inherit the cast target.");
#endif
            return const_cast<TCastTarget *>(static_cast<const TCastTarget *>(atomicValue));
        }

        inline QString stringValue() const
        {
            if(isAtomicValue())
                return atomicValue->stringValue();
            else
                return asNode().stringValue();
        }

        Item::Iterator::Ptr sequencedTypedValue() const;

        inline bool isAtomicValue() const
        {
            /* Setting node.model to ~0, signals that it's an atomic value. */
            return node.model == reinterpret_cast<QAbstractXmlNodeModel *>(~0);
        }

        inline bool isNode() const
        {
            //return !isAtomicValue();
            return node.model && node.model != reinterpret_cast<QAbstractXmlNodeModel *>(~0);
        }

        inline QExplicitlySharedDataPointer<ItemType> type() const
        {
            if(isAtomicValue())
                return atomicValue->type();
            else
                return asNode().type();
        }

        inline const AtomicValue *asAtomicValue() const
        {
            Q_ASSERT(isAtomicValue());
            return atomicValue;
        }

        inline const QXmlNodeModelIndex &asNode() const
        {
            Q_ASSERT_X(isNode() || isNull(), Q_FUNC_INFO,
                       "This item isn't a valid QXmlNodeModelIndex.");
            Q_ASSERT_X(sizeof(QXmlNodeModelIndex) == sizeof(QPatternist::NodeIndexStorage), Q_FUNC_INFO,
                       "If this doesn't hold, something is wrong.");

            return reinterpret_cast<const QXmlNodeModelIndex &>(node);
        }

        inline operator bool() const
        {
            return node.model;
        }

        inline bool isNull() const
        {
            return !node.model;
        }

        inline void reset()
        {
            /* Delete the atomicValue if necessary*/
            if(isAtomicValue() && !atomicValue->ref.deref())
                delete atomicValue;

            node.reset();
        }

        static inline Item fromPublic(const QXmlItem &i)
        {
            const Item it(i.m_node);
            if(it.isAtomicValue())
                it.asAtomicValue()->ref.ref();

            return it;
        }

        static inline QXmlItem toPublic(const Item &i)
        {
            return QXmlItem(i);
        }

    private:
        union
        {
            NodeIndexStorage node;
            const AtomicValue *atomicValue;
        };
    };

    template<typename T>
    inline Item toItem(const QExplicitlySharedDataPointer<T> atomicValue)
    {
        return Item(atomicValue.data());
    }

    static inline QString formatData(const QXmlNodeModelIndex node)
    {
        return node.stringValue(); // This can be improved a lot.
    }
}

    inline QXmlName QXmlNodeModelIndex::name() const
    {
        return m_storage.model->name(*this);
    }

    inline QXmlNodeModelIndex QXmlNodeModelIndex::root() const
    {
        return m_storage.model->root(*this);
    }

    inline QXmlNodeModelIndex::Iterator::Ptr QXmlNodeModelIndex::iterate(const QXmlNodeModelIndex::Axis axis) const
    {
        return m_storage.model->iterate(*this, axis);
    }

    inline QUrl QXmlNodeModelIndex::documentUri() const
    {
        return m_storage.model->documentUri(*this);
    }

    inline QUrl QXmlNodeModelIndex::baseUri() const
    {
        return m_storage.model->baseUri(*this);
    }

    inline QXmlNodeModelIndex::NodeKind QXmlNodeModelIndex::kind() const
    {
        return m_storage.model->kind(*this);
    }

    inline bool QXmlNodeModelIndex::isDeepEqual(const QXmlNodeModelIndex &other) const
    {
        return m_storage.model->isDeepEqual(*this, other);
    }

    inline QXmlNodeModelIndex::DocumentOrder QXmlNodeModelIndex::compareOrder(const QXmlNodeModelIndex &other) const
    {
        Q_ASSERT_X(model() == other.model(), Q_FUNC_INFO, "The API docs guarantees the two nodes are from the same model");
        return m_storage.model->compareOrder(*this, other);
    }

    inline bool QXmlNodeModelIndex::is(const QXmlNodeModelIndex &other) const
    {
        return m_storage.model == other.m_storage.model &&
               m_storage.data == other.m_storage.data &&
               m_storage.additionalData == other.m_storage.additionalData;
    }

    inline void QXmlNodeModelIndex::sendNamespaces(QAbstractXmlReceiver *const receiver) const
    {
        m_storage.model->sendNamespaces(*this, receiver);
    }

    inline QVector<QXmlName> QXmlNodeModelIndex::namespaceBindings() const
    {
        return m_storage.model->namespaceBindings(*this);
    }

    inline QXmlName::NamespaceCode QXmlNodeModelIndex::namespaceForPrefix(const QXmlName::PrefixCode prefix) const
    {
        return m_storage.model->namespaceForPrefix(*this, prefix);
    }

    inline QString QXmlNodeModelIndex::stringValue() const
    {
        return m_storage.model->stringValue(*this);
    }

    inline QPatternist::ItemType::Ptr QXmlNodeModelIndex::type() const
    {
        return m_storage.model->type(*this);
    }

    inline QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QPatternist::Item> > QXmlNodeModelIndex::sequencedTypedValue() const
    {
        return m_storage.model->sequencedTypedValue(*this);
    }

    inline QXmlItem::QXmlItem(const QPatternist::Item &i) : m_node(i.node)
    {
        if(isAtomicValue())
            m_atomicValue->ref.ref();
    }

Q_DECLARE_TYPEINFO(QPatternist::Item::Iterator::Ptr, Q_MOVABLE_TYPE);
Q_DECLARE_TYPEINFO(QPatternist::AtomicValue, Q_MOVABLE_TYPE);

QT_END_NAMESPACE

QT_END_HEADER

#endif