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#include <QtCore/qdebug.h>
#include <QtCore/qstack.h>
#include <QXmlStreamReader>
#include "qmlcustomparser.h"
#include "qmlopenmetaobject.h"
#include <qmlcontext.h>
#include <qmlbindablevalue.h>
#include "qmllistmodel.h"

QT_BEGIN_NAMESPACE

#define DATA_ROLE_ID 1
#define DATA_ROLE_NAME "data"

Q_DECLARE_METATYPE(QListModelInterface *);
class QmlListModelPrivate
{
public:
    QmlListModelPrivate(QmlListModel *m)
        : q(m),
          type(QmlListModel::Invalid),
          listModelInterface(0),
          singleObject(0),
          roleCacheValid(false)
    {
    }

    void clear()
    {
        type = QmlListModel::Invalid;
        model = QVariant();
        if(listModelInterface) 
            listModelInterface->disconnect(q);
        listModelInterface = 0;
        singleObject = 0;
        roleCacheValid = false;
        roleCache.clear();
    }

    void updateRoleCache()
    {
        if(roleCacheValid)
            return;

        roleCacheValid = true;
        if(type == QmlListModel::SingleObject) 
            roleCache = QmlMetaProperty::properties(singleObject);
    }

    QmlListModel *q;
    
    QmlListModel::ModelType type;

    QVariant model;
    QListModelInterface *listModelInterface;
    QObject *singleObject;

    bool roleCacheValid;
    QStringList roleCache;
};

/*!
    \qmlclass ListModel QmlListModel
    \brief The ListModel element defines a free-form list data source.

    The ListModel is a simple XML heirarchy of items containing data roles.
    For example:

    \code
    <ListModel id="FruitModel">
        <Fruit>
            <name>Apple</name>
            <cost>2.45</cost>
        <Fruit>
        <Fruit>
            <name>Orange</name>
            <cost>3.25</cost>
        </Fruit>
        <Fruit>
            <name>Banana</name>
            <cost>1.95</cost>
        </Fruit>
    </ListModel>
    \endcode

    Elements beginning with a capital are items.  Elements beginning
    with lower-case are the data roles.  The above example defines a
    ListModel containing three items, with the roles "name" and "cost".

    The defined model can be used in views such as ListView:
    \code
    <Component id="FruitDelegate">
        <Item width="200" height="50">
            <Text text="{name}"/>
            <Text text="{'$'+cost}" anchors.right="{parent.right}"/>
        </Item>
    </Component>

    <ListView model="{FruitModel}" delegate="{FruitDelegate}" anchors.fill="{parent}"/>
    \endcode
*/
/*!
    \internal
    \class QmlListModel
*/
QmlListModel::QmlListModel(QObject *parent)
: QListModelInterface(parent), d(new QmlListModelPrivate(this))
{
}

QmlListModel::~QmlListModel()
{
    delete d; d = 0;
}

QmlListModel::ModelType QmlListModel::modelType() const
{
    return d->type;
}

bool QmlListModel::setModel(const QVariant &model)
{
    d->clear();

    QListModelInterface *iface = qvariant_cast<QListModelInterface *>(model);
    if(iface) {
        QObject::connect(iface, SIGNAL(itemsInserted(int,int)), 
                         this, SIGNAL(itemsInserted(int,int)));
        QObject::connect(iface, SIGNAL(itemsRemoved(int,int)), 
                         this, SIGNAL(itemsRemoved(int,int)));
        QObject::connect(iface, SIGNAL(itemsMoved(int,int,int)), 
                         this, SIGNAL(itemsMoved(int,int,int)));
        QObject::connect(iface, SIGNAL(itemsChanged(int,int,QList<int>)), 
                         this, SIGNAL(itemsChanged(int,int,QList<int>)));
        d->listModelInterface = iface;
        d->type = ListInterface;
        d->model = model;
        return true;
    } 

    QObject *object = qvariant_cast<QObject *>(model);
    if(object) {
        d->singleObject = object;
        d->type = SingleObject;
        d->model = model;
        return true;
    }

    if(QmlMetaType::isList(model)) {
        d->type = SimpleList;
        d->model = model;
        return true;
    }

    return false;
}

QVariant QmlListModel::model() const
{
    return d->model;
}

QList<int> QmlListModel::roles() const
{
    d->updateRoleCache();
    switch(modelType()) {
    case Invalid:
        return QList<int>();
    case SimpleList:
        return QList<int>() << DATA_ROLE_ID;
    case ListInterface:
        return d->listModelInterface->roles();
    case SingleObject:
        {
            QList<int> rv;
            for(int ii = 0; ii < d->roleCache.count(); ++ii)
                rv << ii;
            return rv;
        }
        break;
    };
    return QList<int>();
}

QString QmlListModel::toString(int role) const
{
    d->updateRoleCache();
    switch(modelType()) {
    case Invalid:
        return QString();
    case SimpleList:
        if(role == DATA_ROLE_ID)
            return QLatin1String(DATA_ROLE_NAME);
        else
            return QString();
    case ListInterface:
        return d->listModelInterface->toString(role);
    case SingleObject:
        if(role >= d->roleCache.count())
            return QString();
        else
            return d->roleCache.at(role);
    };
    return QString();
}

/*!
    \qmlproperty int ListModel::count
    This property holds the number of items in the list.
*/
int QmlListModel::count() const
{
    switch(modelType()) {
    case Invalid:
        return 0;
    case SimpleList:
        return QmlMetaType::listCount(model());
    case ListInterface:
        return d->listModelInterface->count();
    case SingleObject:
        return 1;
    }
    return 0;
}

QHash<int,QVariant> QmlListModel::data(int index, const QList<int> &roles) const
{
    d->updateRoleCache();
    QHash<int, QVariant> rv;
    switch(modelType()) {
    case Invalid:
        break;
    case SimpleList:
        if(roles.contains(DATA_ROLE_ID))
            rv.insert(DATA_ROLE_ID, QmlMetaType::listAt(d->model, index));
        break;
    case ListInterface:
        return d->listModelInterface->data(index, roles);
    case SingleObject: 
        {
            for(int ii = 0; ii < roles.count(); ++ii) {
                QmlMetaProperty prop(d->singleObject, toString(roles.at(ii)));
                rv.insert(roles.at(ii), prop.read());
            }
        }
        break;
    };

    return rv;
}



struct ModelNode;
class ListModel : public QListModelInterface
{
    Q_OBJECT
public:
    ListModel(QObject *parent=0);

    virtual QList<int> roles() const;
    virtual QString toString(int role) const;
    Q_PROPERTY(int count READ count);
    virtual int count() const;
    virtual QHash<int,QVariant> data(int index, const QList<int> &roles = (QList<int>())) const;

private:
    QVariant valueForNode(ModelNode *) const;
    mutable QStringList roleStrings;
    friend class ListModelParser;
    friend struct ModelNode;

    void checkRoles() const;
    void addRole(const QString &) const;
    mutable bool _rolesOk;
    ModelNode *_root;
};

class ModelObject : public QObject
{
    Q_OBJECT
public:
    ModelObject(ModelNode *);

    void setValue(const QByteArray &name, const QVariant &val)
    {
        _mo->setValue(name, val);
    }

private:
    ModelNode *_node;
    bool _haveProperties;
    QmlOpenMetaObject *_mo;
};

struct ModelNode
{
    ModelNode();
    ~ModelNode();
    QString className;

    QList<QVariant> values;
    QHash<QString, ModelNode *> properties;

    ListModel *model() {
        if(!modelCache) { 
            modelCache = new ListModel;
            modelCache->_root = this; 
        }
        return modelCache;
    }

    ModelObject *object() {
        if(!objectCache) {
            objectCache = new ModelObject(this);
            QHash<QString, ModelNode *>::iterator it;
            for (it = properties.begin(); it != properties.end(); ++it) {
                if (!(*it)->values.isEmpty())
                    objectCache->setValue(it.key().toLatin1(), (*it)->values.first());
            }
        }
        return objectCache;
    }

    ListModel *modelCache;
    ModelObject *objectCache;
};
Q_DECLARE_METATYPE(ModelNode *);

ModelObject::ModelObject(ModelNode *node)
: _node(node), _haveProperties(false), _mo(new QmlOpenMetaObject(this))
{
}

QML_DECLARE_TYPE(ListModel);
QML_DEFINE_TYPE(ListModel,ListModel);
ListModel::ListModel(QObject *parent)
: QListModelInterface(parent), _rolesOk(false), _root(0)
{
}

void ListModel::checkRoles() const
{
    if(_rolesOk)
        return;

    for(int ii = 0; ii < _root->values.count(); ++ii) {
        ModelNode *node = qvariant_cast<ModelNode *>(_root->values.at(ii));
        if(node) {
            foreach(QString role, node->properties.keys())
                addRole(role);
        } 
    }

    _rolesOk = true;
}

void ListModel::addRole(const QString &role) const
{
    if(!roleStrings.contains(role))
        roleStrings << role;
}

QList<int> ListModel::roles() const
{
    checkRoles();
    QList<int> rv;
    for(int ii = 0; ii < roleStrings.count(); ++ii)
        rv << ii;
    return rv;
}

QString ListModel::toString(int role) const
{
    checkRoles();
    if(role < roleStrings.count())
        return roleStrings.at(role);
    else
        return QString();
}

QVariant ListModel::valueForNode(ModelNode *node) const
{
    QObject *rv = 0;

    if(!node->properties.isEmpty()) {
        // Object
        rv = node->object();
    } else if(node->values.count() == 0) {
        // Invalid
        return QVariant();
    } else if(node->values.count() == 1) {
        // Value
        QVariant &var = node->values[0];
        ModelNode *valueNode = qvariant_cast<ModelNode *>(var);
        if(valueNode) {
            if(!valueNode->properties.isEmpty())
                rv = valueNode->object();
            else
                rv = valueNode->model();
        } else {
            return var;
        }
    } else if(node->values.count() > 1) {
        // List
        rv = node->model();
    }

    if(rv)
        return QVariant::fromValue(rv);
    else
        return QVariant();
}

QHash<int,QVariant> ListModel::data(int index, const QList<int> &roles) const
{
    checkRoles();
    QHash<int, QVariant> rv;
    if(index >= count())
        return rv;

    ModelNode *node = qvariant_cast<ModelNode *>(_root->values.at(index));
    if(!node) 
        return rv;

    for(int ii = 0; ii < roles.count(); ++ii) {
        const QString &roleString = roleStrings.at(roles.at(ii));

        QHash<QString, ModelNode *>::ConstIterator iter = 
            node->properties.find(roleString);
        if(iter != node->properties.end()) {
            ModelNode *row = *iter;
            rv.insert(roles.at(ii), valueForNode(row));
        }
    }

    return rv;
}

int ListModel::count() const
{
    if(!_root) return 0;
    return _root->values.count();
}

struct ListInstruction
{
    enum { Push, Pop, Value, Set } type;
    int dataIdx;
};

class ListModelParser : public QmlCustomParser
{
public:
    virtual QByteArray compile(QXmlStreamReader& reader, bool *);
    virtual QVariant create(const QByteArray &);
};
QML_DEFINE_CUSTOM_PARSER(ListModel, ListModelParser);

static void dump(ModelNode *node, int ind)
{
    QByteArray indentBa(ind * 4, ' ');
    const char *indent = indentBa.constData();

    for(int ii = 0; ii < node->values.count(); ++ii) {
        ModelNode *subNode = qvariant_cast<ModelNode *>(node->values.at(ii));
        if(subNode) {
            qWarning().nospace() << indent << "Sub-node " << ii << ": class " << subNode->className;
            dump(subNode, ind + 1);
        } else {
            qWarning().nospace() << indent << "Sub-node " << ii << ": " << node->values.at(ii).toString();
        }
    }

    for(QHash<QString, ModelNode *>::ConstIterator iter = node->properties.begin(); iter != node->properties.end(); ++iter) {
        qWarning().nospace() << indent << "Property " << iter.key() << ":";
        dump(iter.value(), ind + 1);
    }
}

ModelNode::ModelNode()
: modelCache(0), objectCache(0)
{
}

ModelNode::~ModelNode()
{
    qDeleteAll(properties);
    for(int ii = 0; ii < values.count(); ++ii) {
        ModelNode *node = qvariant_cast<ModelNode *>(values.at(ii));
        if(node) { delete node; node = 0; }
    }
    if(modelCache) { delete modelCache; modelCache = 0; }
}

struct ListModelData
{
    int dataOffset;
    int id;
    int instrCount;
    ListInstruction *instructions() const { return (ListInstruction *)((char *)this + sizeof(ListModelData)); }
};

QByteArray ListModelParser::compile(QXmlStreamReader& reader, bool *ok)
{
    *ok = true;

    QByteArray id;
    QByteArray data;
    QList<ListInstruction> instr;
    int depth=0;

    while(!reader.atEnd() && depth >= 0) {
        switch(reader.readNext()) {
            case QXmlStreamReader::StartElement:
                {
                    QStringRef name = reader.name();
                    bool isType = name.at(0).isUpper();

                    if (isType) {
                        ListInstruction li;
                        li.type = ListInstruction::Push;
                        li.dataIdx = -1;
                        instr << li;

                        for (int i = 0; i < reader.attributes().count(); ++i) {
                            const QXmlStreamAttribute &attr = reader.attributes().at(i);
                            QStringRef attrName = attr.name();
                            QStringRef attrValue = attr.value();

                            ListInstruction li;
                            int ref = data.count();
                            data.append(attrName.toString().toLatin1());
                            data.append('\0');
                            li.type = ListInstruction::Set;
                            li.dataIdx = ref;
                            instr << li;

                            ref = data.count();
                            data.append(attrValue.toString().toLatin1());
                            data.append('\0');
                            li.type = ListInstruction::Value;
                            li.dataIdx = ref;
                            instr << li;

                            li.type = ListInstruction::Pop;
                            li.dataIdx = -1;
                            instr << li;
                        }
                    } else {
                        ListInstruction li;
                        int ref = data.count();
                        data.append(name.toString().toLatin1());
                        data.append('\0');
                        li.type = ListInstruction::Set;
                        li.dataIdx = ref;
                        instr << li;
                    }
                }
                ++depth;
                break;
            case QXmlStreamReader::EndElement:
                {
                    ListInstruction li;
                    li.type = ListInstruction::Pop;
                    li.dataIdx = -1;
                    instr << li;
                    --depth;
                }
                break;
            case QXmlStreamReader::Characters:
                if (!reader.isWhitespace()) {
                    int ref = data.count();
                    QByteArray d = reader.text().toString().toLatin1();
                    d.append('\0');
                    data.append(d);

                    ListInstruction li;
                    li.type = ListInstruction::Value;
                    li.dataIdx = ref;
                    instr << li;
                }
                break;

            case QXmlStreamReader::Invalid:
            case QXmlStreamReader::NoToken:
            case QXmlStreamReader::StartDocument:
            case QXmlStreamReader::EndDocument:
            case QXmlStreamReader::Comment:
            case QXmlStreamReader::DTD:
            case QXmlStreamReader::EntityReference:
            case QXmlStreamReader::ProcessingInstruction:
                break;
        }
    }

    if (reader.hasError())
        *ok = true;

    if (!*ok)
        return QByteArray();

    int size = sizeof(ListModelData) + 
               instr.count() * sizeof(ListInstruction) + 
               data.count();

    QByteArray rv;
    rv.resize(size);

    ListModelData *lmd = (ListModelData *)rv.data();
    if(id.count())
        lmd->id = 0;
    else
        lmd->id = -1;
    lmd->dataOffset = sizeof(ListModelData) + 
                     instr.count() * sizeof(ListInstruction);
    lmd->instrCount = instr.count();
    for(int ii = 0; ii < instr.count(); ++ii)
        lmd->instructions()[ii] = instr.at(ii);
    ::memcpy(rv.data() + lmd->dataOffset, data.constData(), data.count());

    return rv;
}

QVariant ListModelParser::create(const QByteArray &d)
{
    ListModel *rv = new ListModel;
    ModelNode *root = new ModelNode;
    rv->_root = root;
    QStack<ModelNode *> nodes;
    nodes << root;

    const ListModelData *lmd = (const ListModelData *)d.constData();
    const char *data = ((const char *)lmd) + lmd->dataOffset;

    for(int ii = 0; ii < lmd->instrCount; ++ii) {
        const ListInstruction &instr = lmd->instructions()[ii];

        switch(instr.type) {
        case ListInstruction::Push:
            {
                ModelNode *n = nodes.top();
                ModelNode *n2 = new ModelNode;
                n->values << qVariantFromValue(n2);
                nodes.push(n2);
            }
            break;

        case ListInstruction::Pop:
            nodes.pop();
            break;

        case ListInstruction::Value:
            {
                ModelNode *n = nodes.top();
                n->values.append(QByteArray(data + instr.dataIdx));
            }
            break;

        case ListInstruction::Set:
            {
                ModelNode *n = nodes.top();
                ModelNode *n2 = new ModelNode;
                n->properties.insert(QLatin1String(data + instr.dataIdx), n2);
                nodes.push(n2);
            }
            break;
        }
    }

    if(lmd->id != -1) {
        QmlContext *ctxt = QmlContext::activeContext();
        ctxt->setContextProperty(QLatin1String(data + lmd->id), rv);
    }

    return QVariant::fromValue(rv);
}

QT_END_NAMESPACE
#include "qmllistmodel.moc"