qabstractxmlnodemodel.cpp

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#include <QVector>

#include "qabstractxmlnodemodel_p.h"
#include "qabstractxmlreceiver.h"
#include "qcommonvalues_p.h"
#include "qemptyiterator_p.h"
#include "qitemmappingiterator_p.h"
#include "qitem_p.h"
#include "qnamespaceresolver_p.h"
#include "qsequencemappingiterator_p.h"
#include "qsingletoniterator_p.h"

#include "qabstractxmlnodemodel.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

typedef QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QXmlNodeModelIndex> > QXmlNodeModelIndexIteratorPointer;

bool QAbstractXmlNodeModel::isIgnorableInDeepEqual(const QXmlNodeModelIndex &n)
{
    Q_ASSERT(!n.isNull());
    const QXmlNodeModelIndex::NodeKind nk = n.kind();
    return nk == QXmlNodeModelIndex::ProcessingInstruction ||
           nk == QXmlNodeModelIndex::Comment;
}


using namespace QPatternist;

QAbstractXmlNodeModel::QAbstractXmlNodeModel() : d_ptr(0)
{
}

QAbstractXmlNodeModel::QAbstractXmlNodeModel(QAbstractXmlNodeModelPrivate *d) : d_ptr(d)
{
}

QAbstractXmlNodeModel::~QAbstractXmlNodeModel()
{
}

/*
### Qt 5:

Add the function:

    virtual QSourceLocation sourceLocation(const QXmlNodeModelIndex &nodeIndex) const = 0;

Such that the data model can communicate back source locations.
 */

namespace QPatternist
{
    class MergeIterator
    {
    public:
        inline MergeIterator()
        {
        }

        inline
        QXmlNodeModelIndexIteratorPointer
        mapToSequence(const QXmlNodeModelIndexIteratorPointer &it,
                      const DynamicContext::Ptr &) const
        {
            return it;
        }

    private:
        Q_DISABLE_COPY(MergeIterator)
    };

    static const MergeIterator mergeIterator;

    class IteratorVector : public ListIterator<QXmlNodeModelIndexIteratorPointer, QVector<QXmlNodeModelIndexIteratorPointer> >
    {
        typedef QVector<QXmlNodeModelIndexIteratorPointer> ItVector;
    public:
        typedef QAbstractXmlForwardIterator<QXmlNodeModelIndexIteratorPointer>::Ptr Ptr;

        IteratorVector(const ItVector &in) : ListIterator<QXmlNodeModelIndexIteratorPointer, QVector<QXmlNodeModelIndexIteratorPointer> >(in)
        {
        }

        virtual QAbstractXmlForwardIterator<QXmlNodeModelIndexIteratorPointer>::Ptr copy() const
        {
            ItVector result;

            for(int i = 0; i < m_list.count(); ++i)
                result.append(m_list.at(i)->copy());

            return Ptr(new IteratorVector(result));
        }
    };
}

static inline QXmlNodeModelIndexIteratorPointer mergeIterators(const QXmlNodeModelIndex &node,
                                                               const QXmlNodeModelIndexIteratorPointer &it2)
{
    QVector<QXmlNodeModelIndexIteratorPointer> iterators;
    iterators.append(makeSingletonIterator(node));
    iterators.append(it2);

    return makeSequenceMappingIterator<QXmlNodeModelIndex>(&mergeIterator,
                                                           IteratorVector::Ptr(new IteratorVector(iterators)),
                                                           DynamicContext::Ptr());
}

inline QAbstractXmlForwardIterator<QXmlNodeModelIndex>::Ptr
QAbstractXmlNodeModel::mapToSequence(const QXmlNodeModelIndex &ni,
                                     const DynamicContext::Ptr &) const
{
    Q_ASSERT(!ni.isNull());
    /* Since we pass in this here, mapToSequence is used recursively. */
    return mergeIterators(ni, makeSequenceMappingIterator<QXmlNodeModelIndex>(this,
                                                                              ni.iterate(QXmlNodeModelIndex::AxisChild),
                                                                              DynamicContext::Ptr()));
}

QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QXmlNodeModelIndex> >
QAbstractXmlNodeModel::iterate(const QXmlNodeModelIndex &ni,
                               QXmlNodeModelIndex::Axis axis) const
{
    /* Returns iterators that track state and calls nextFromSimpleAxis()
     * iteratively. Typically, when sub-classing QSimpleXmlNodeModel,
     * you don't reimplement this function, but instead implement
     * nextFromSimpleAxis(). */

    switch(axis)
    {
        case QXmlNodeModelIndex::AxisSelf:
            return makeSingletonIterator(ni);
        case QXmlNodeModelIndex::AxisParent:
        {
            if(kind(ni) == QXmlNodeModelIndex::Document)
                return makeEmptyIterator<QXmlNodeModelIndex>();
            else
                return makeSingletonIterator(nextFromSimpleAxis(Parent, ni));
        }
        case QXmlNodeModelIndex::AxisNamespace:
            return makeEmptyIterator<QXmlNodeModelIndex>();
        case QXmlNodeModelIndex::AxisAncestor:
        {
            QList<QXmlNodeModelIndex> ancestors;
            QXmlNodeModelIndex ancestor = nextFromSimpleAxis(Parent, ni);

            while(!ancestor.isNull())
            {
                ancestors.append(ancestor);
                ancestor = nextFromSimpleAxis(Parent, ancestor);
            }

            return makeListIterator(ancestors);
        }
        case QXmlNodeModelIndex::AxisAncestorOrSelf:
        {
            QList<QXmlNodeModelIndex> ancestors;
            ancestors.append(ni);
            QXmlNodeModelIndex ancestor = nextFromSimpleAxis(Parent, ni);

            while(!ancestor.isNull())
            {
                ancestors.append(ancestor);
                ancestor = nextFromSimpleAxis(Parent, ancestor);
            }

            return makeListIterator(ancestors);
        }
        case QXmlNodeModelIndex::AxisPrecedingSibling:
        {
            QList<QXmlNodeModelIndex> preceding;
            QXmlNodeModelIndex sibling = nextFromSimpleAxis(PreviousSibling, ni);

            while(!sibling.isNull())
            {
                preceding.append(sibling);
                sibling = nextFromSimpleAxis(PreviousSibling, sibling);
            }

            return makeListIterator(preceding);
        }
        case QXmlNodeModelIndex::AxisFollowingSibling:
        {
            QList<QXmlNodeModelIndex> preceding;
            QXmlNodeModelIndex sibling = nextFromSimpleAxis(NextSibling, ni);

            while(!sibling.isNull())
            {
                preceding.append(sibling);
                sibling = nextFromSimpleAxis(NextSibling, sibling);
            }

            return makeListIterator(preceding);
        }
        case QXmlNodeModelIndex::AxisChildOrTop:
        {
            if(nextFromSimpleAxis(Parent, ni).isNull())
            {
                switch(kind(ni))
                {
                    case QXmlNodeModelIndex::Comment:
                    /* Fallthrough. */
                    case QXmlNodeModelIndex::ProcessingInstruction:
                    /* Fallthrough. */
                    case QXmlNodeModelIndex::Element:
                    /* Fallthrough. */
                    case QXmlNodeModelIndex::Text:
                        return makeSingletonIterator(ni);
                    case QXmlNodeModelIndex::Attribute:
                    /* Fallthrough. */
                    case QXmlNodeModelIndex::Document:
                    /* Fallthrough. */
                    case QXmlNodeModelIndex::Namespace:
                        /* Do nothing. */;
                }
            }

            /* Else, fallthrough to AxisChild. */
        }
        case QXmlNodeModelIndex::AxisChild:
        {
            QList<QXmlNodeModelIndex> children;
            QXmlNodeModelIndex child = nextFromSimpleAxis(FirstChild, ni);

            while(!child.isNull())
            {
                children.append(child);
                child = nextFromSimpleAxis(NextSibling, child);
            }

            return makeListIterator(children);
        }
        case QXmlNodeModelIndex::AxisDescendant:
        {
            return makeSequenceMappingIterator<QXmlNodeModelIndex>(this,
                                                                   ni.iterate(QXmlNodeModelIndex::AxisChild),
                                                                   DynamicContext::Ptr());
        }
        case QXmlNodeModelIndex::AxisAttributeOrTop:
        {
            if(kind(ni) == QXmlNodeModelIndex::Attribute && nextFromSimpleAxis(Parent, ni).isNull())
                return makeSingletonIterator(ni);

            /* Else, fallthrough to AxisAttribute. */
        }
        case QXmlNodeModelIndex::AxisAttribute:
            return makeVectorIterator(attributes(ni));
        case QXmlNodeModelIndex::AxisDescendantOrSelf:
            return mergeIterators(ni, iterate(ni, QXmlNodeModelIndex::AxisDescendant));
        case QXmlNodeModelIndex::AxisFollowing:
        /* Fallthrough. */
        case QXmlNodeModelIndex::AxisPreceding:
        {
            /* We walk up along the ancestors, and for each parent, we grab its preceding/following
             * siblings, and evaluate the descendant axis. The descendant axes gets added
             * to a list and we then merge those iterators. */
            QVector<QXmlNodeModelIndexIteratorPointer> descendantIterators;

            QXmlNodeModelIndex current(ni);
            while(!current.isNull())
            {
                QXmlNodeModelIndex candidate(nextFromSimpleAxis(axis == QXmlNodeModelIndex::AxisPreceding ? PreviousSibling : NextSibling, current));
                if(candidate.isNull())
                {
                    /* current is an ancestor. We don't want it, so next iteration we
                     * will grab its preceding sibling. */
                    current = nextFromSimpleAxis(Parent, current);
                }
                else
                {
                    current = candidate;
                    descendantIterators.append(iterate(current, QXmlNodeModelIndex::AxisDescendantOrSelf)->toReversed());
                }
            }

            return makeSequenceMappingIterator<QXmlNodeModelIndex>(&mergeIterator,
                                                                   IteratorVector::Ptr(new IteratorVector(descendantIterators)),
                                                                   DynamicContext::Ptr());
        }
    }

    Q_ASSERT_X(false, Q_FUNC_INFO, "Unknown axis, internal error.");
    return makeEmptyIterator<QXmlNodeModelIndex>();
}

void QAbstractXmlNodeModel::sendNamespaces(const QXmlNodeModelIndex &n,
                                           QAbstractXmlReceiver *const receiver) const
{
    Q_ASSERT(receiver);
    const QVector<QXmlName> nss(namespaceBindings(n));

    /* This is by far the most common case. */
    if(nss.isEmpty())
        return;

    const int len = nss.size();
    for(int i = 0; i < len; ++i)
        receiver->namespaceBinding(nss.at(i));
}

QPatternist::ItemIteratorPtr QAbstractXmlNodeModel::sequencedTypedValue(const QXmlNodeModelIndex &ni) const
{
    const QVariant &candidate = typedValue(ni);
    if(candidate.isNull())
        return QPatternist::CommonValues::emptyIterator;
    else
        return makeSingletonIterator(AtomicValue::toXDM(candidate));
}

QPatternist::ItemTypePtr QAbstractXmlNodeModel::type(const QXmlNodeModelIndex &) const
{
    Q_ASSERT_X(false, Q_FUNC_INFO,
               "This function is internal and must not be called.");
    return QPatternist::ItemTypePtr();
}

QXmlName::NamespaceCode QAbstractXmlNodeModel::namespaceForPrefix(const QXmlNodeModelIndex &ni,
                                                                  const QXmlName::PrefixCode prefix) const
{
    Q_ASSERT(kind(ni) == QXmlNodeModelIndex::Element);

    const QVector<QXmlName> nbs(namespaceBindings(ni));
    const int len = nbs.size();

    for(int i = 0; i < len; ++i)
    {
        if(nbs.at(i).prefix() == prefix)
            return nbs.at(i).namespaceURI();
    }

    return NamespaceResolver::NoBinding;
}


bool QAbstractXmlNodeModel::isDeepEqual(const QXmlNodeModelIndex &n1,
                                        const QXmlNodeModelIndex &n2) const
{
    Q_ASSERT(!n1.isNull());
    Q_ASSERT(!n2.isNull());

    const QXmlNodeModelIndex::NodeKind nk = n1.kind();

    if(nk != n2.kind())
        return false;

    if(n1.name() != n2.name())
        return false;

    switch(nk)
    {
        case QXmlNodeModelIndex::Element:
        {
            QXmlNodeModelIndexIteratorPointer atts1(n1.iterate(QXmlNodeModelIndex::AxisAttribute));
            QXmlNodeModelIndex node(atts1->next());

            const QXmlNodeModelIndex::List atts2(n2.iterate(QXmlNodeModelIndex::AxisAttribute)->toList());
            const QXmlNodeModelIndex::List::const_iterator end(atts2.constEnd());

            while(!node.isNull())
            {
                bool equal = false;
                for(QXmlNodeModelIndex::List::const_iterator it = atts2.constBegin(); it != end; ++it)
                {
                    if(isDeepEqual(node, (*it)))
                        equal = true;
                }

                if(!equal)
                    return false;

                node = atts1->next();
            }

            /* Fallthrough, so we check the children. */
        }
        case QXmlNodeModelIndex::Document:
        {
            QXmlNodeModelIndexIteratorPointer itn1(n1.iterate(QXmlNodeModelIndex::AxisChild));
            QXmlNodeModelIndexIteratorPointer itn2(n2.iterate(QXmlNodeModelIndex::AxisChild));

            while(true)
            {
                QXmlNodeModelIndex no1(itn1->next());
                QXmlNodeModelIndex no2(itn2->next());

                while(!no1.isNull() && isIgnorableInDeepEqual(no1))
                    no1 = itn1->next();

                while(!no2.isNull() && isIgnorableInDeepEqual(no2))
                    no2 = itn2->next();

                if(!no1.isNull() && !no2.isNull())
                {
                   if(!isDeepEqual(no1, no2))
                       return false;
                }
                else
                    return no1.isNull() && no2.isNull();
            }

            return true;
        }
        case QXmlNodeModelIndex::Attribute:
        /* Fallthrough */
        case QXmlNodeModelIndex::ProcessingInstruction:
        /* Fallthrough. */
        case QXmlNodeModelIndex::Text:
        /* Fallthrough. */
        case QXmlNodeModelIndex::Comment:
            return n1.stringValue() == n2.stringValue();
        case QXmlNodeModelIndex::Namespace:
        {
            Q_ASSERT_X(false, Q_FUNC_INFO, "Not implemented");
            return false;
        }
    }

    return false;
}

QXmlItem::QXmlItem()
{
    m_node.reset();
}

bool QXmlItem::internalIsAtomicValue() const
{
    return m_node.model == reinterpret_cast<QAbstractXmlNodeModel *>(~0);
}

QXmlItem::QXmlItem(const QXmlItem &other) : m_node(other.m_node)
{
    if(internalIsAtomicValue())
        m_atomicValue->ref.ref();
}

QXmlItem::QXmlItem(const QVariant &atomicValue)
{
    m_node.reset();
    if(atomicValue.isNull())
    {
        /* Then we behave just like the default constructor. */
        return;
    }

    /*
      We can't assign directly to m_atomicValue, because the
      temporary will self-destruct before we've ref'd it.
    */
    const QPatternist::Item temp(QPatternist::AtomicValue::toXDM(atomicValue));

    if(temp)
    {
        temp.asAtomicValue()->ref.ref();
        m_node.model = reinterpret_cast<const QAbstractXmlNodeModel *>(~0);
        m_atomicValue = temp.asAtomicValue();
    }
    else
    {
        m_atomicValue = 0;
    }
}

QXmlItem::QXmlItem(const QXmlNodeModelIndex &node) : m_node(node.m_storage)
{
}


QXmlItem::~QXmlItem()
{
    if(internalIsAtomicValue() && !m_atomicValue->ref.deref())
        delete m_atomicValue;
}

bool QPatternist::NodeIndexStorage::operator!=(const NodeIndexStorage &other) const
{
    return data != other.data
           || additionalData != other.additionalData
           || model != other.model;
}

QXmlItem &QXmlItem::operator=(const QXmlItem &other)
{
    if(m_node != other.m_node)
    {
        if(internalIsAtomicValue() && !m_atomicValue->ref.deref())
            delete m_atomicValue;

        m_node = other.m_node;

        if(internalIsAtomicValue())
            m_atomicValue->ref.ref();
    }

    return *this;
}

bool QXmlItem::isNode() const
{
    return QPatternist::Item::fromPublic(*this).isNode();
}

bool QXmlItem::isAtomicValue() const
{
    return internalIsAtomicValue();
}

QVariant QXmlItem::toAtomicValue() const
{
    if(isAtomicValue())
        return QPatternist::AtomicValue::toQt(m_atomicValue);
    else
        return QVariant();
}

QXmlNodeModelIndex QXmlItem::toNodeModelIndex() const
{
    if(isNode())
        return reinterpret_cast<const QXmlNodeModelIndex &>(m_node);
    else
        return QXmlNodeModelIndex();
}

bool QXmlItem::isNull() const
{
    return !m_node.model;
}

uint qHash(const QXmlNodeModelIndex &index)
{
    return uint(index.data() + index.additionalData() + quintptr(index.model()));
}

bool QXmlNodeModelIndex::operator==(const QXmlNodeModelIndex &other) const
{
    return !(m_storage != other.m_storage);
}

bool QXmlNodeModelIndex::operator!=(const QXmlNodeModelIndex &other) const
{
    return !(operator==(other));
}

void QAbstractXmlNodeModel::copyNodeTo(const QXmlNodeModelIndex &node,
                                       QAbstractXmlReceiver *const receiver,
                                       const NodeCopySettings &copySettings) const
{
    Q_UNUSED(node);
    Q_UNUSED(receiver);
    Q_UNUSED(copySettings);
    Q_ASSERT_X(false, Q_FUNC_INFO,
               "This function is not expected to be called.");
}

QSourceLocation QAbstractXmlNodeModel::sourceLocation(const QXmlNodeModelIndex &index) const
{
    // TODO: make this method virtual in Qt5 to allow source location support in custom models
    if (d_ptr)
        return d_ptr->sourceLocation(index);
    else
        return QSourceLocation();
}

QT_END_NAMESPACE