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#include "qqmlobjectmodel_p.h"

#include <QtCore/qcoreapplication.h>
#include <QtQml/qqmlcontext.h>
#include <QtQml/qqmlengine.h>
#include <QtQml/qqmlinfo.h>

#include <private/qqmlchangeset_p.h>
#include <private/qqmlglobal_p.h>
#include <private/qobject_p.h>
#include <private/qpodvector_p.h>

#include <QtCore/qhash.h>
#include <QtCore/qlist.h>

QT_BEGIN_NAMESPACE

QHash<QObject*, QQmlObjectModelAttached*> QQmlObjectModelAttached::attachedProperties;


class QQmlObjectModelPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QQmlObjectModel)
public:
    class Item {
    public:
        Item(QObject *i) : item(i), ref(0) {}

        void addRef() { ++ref; }
        bool deref() { return --ref == 0; }

        QObject *item;
        int ref;
    };

    QQmlObjectModelPrivate() : QObjectPrivate() {}

    static void children_append(QQmlListProperty<QObject> *prop, QObject *item) {
        int index = static_cast<QQmlObjectModelPrivate *>(prop->data)->children.count();
        static_cast<QQmlObjectModelPrivate *>(prop->data)->insert(index, item);
    }

    static int children_count(QQmlListProperty<QObject> *prop) {
        return static_cast<QQmlObjectModelPrivate *>(prop->data)->children.count();
    }

    static QObject *children_at(QQmlListProperty<QObject> *prop, int index) {
        return static_cast<QQmlObjectModelPrivate *>(prop->data)->children.at(index).item;
    }

    static void children_clear(QQmlListProperty<QObject> *prop) {
        static_cast<QQmlObjectModelPrivate *>(prop->data)->clear();
    }

    void insert(int index, QObject *item) {
        Q_Q(QQmlObjectModel);
        children.insert(index, Item(item));
        for (int i = index; i < children.count(); ++i) {
            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(i).item);
            attached->setIndex(i);
        }
        QQmlChangeSet changeSet;
        changeSet.insert(index, 1);
        emit q->modelUpdated(changeSet, false);
        emit q->countChanged();
        emit q->childrenChanged();
    }

    void move(int from, int to, int n) {
        Q_Q(QQmlObjectModel);
        if (from > to) {
            // Only move forwards - flip if backwards moving
            int tfrom = from;
            int tto = to;
            from = tto;
            to = tto+n;
            n = tfrom-tto;
        }

        QPODVector<QQmlObjectModelPrivate::Item, 4> store;
        for (int i = 0; i < to - from; ++i)
            store.append(children[from + n + i]);
        for (int i = 0; i < n; ++i)
            store.append(children[from + i]);

        for (int i = 0; i < store.count(); ++i) {
            children[from + i] = store[i];
            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(from + i).item);
            attached->setIndex(from + i);
        }

        QQmlChangeSet changeSet;
        changeSet.move(from, to, n, 0);
        emit q->modelUpdated(changeSet, false);
        emit q->childrenChanged();
    }

    void remove(int index, int n) {
        Q_Q(QQmlObjectModel);
        for (int i = index; i < index + n; ++i) {
            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(i).item);
            attached->setIndex(-1);
        }
        children.erase(children.begin() + index, children.begin() + index + n);
        for (int i = index; i < children.count(); ++i) {
            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(i).item);
            attached->setIndex(i);
        }
        QQmlChangeSet changeSet;
        changeSet.remove(index, n);
        emit q->modelUpdated(changeSet, false);
        emit q->countChanged();
        emit q->childrenChanged();
    }

    void clear() {
        Q_Q(QQmlObjectModel);
        for (const Item &child : qAsConst(children))
            emit q->destroyingItem(child.item);
        remove(0, children.count());
    }

    int indexOf(QObject *item) const {
        for (int i = 0; i < children.count(); ++i)
            if (children.at(i).item == item)
                return i;
        return -1;
    }


    QList<Item> children;
};


/*!
    \qmltype ObjectModel
    \instantiates QQmlObjectModel
    \inqmlmodule QtQml.Models
    \ingroup qtquick-models
    \brief Defines a set of items to be used as a model

    An ObjectModel contains the visual items to be used in a view.
    When an ObjectModel is used in a view, the view does not require
    a delegate since the ObjectModel already contains the visual
    delegate (items).

    An item can determine its index within the
    model via the \l{ObjectModel::index}{index} attached property.

    The example below places three colored rectangles in a ListView.
    \code
    import QtQuick 2.0
    import QtQml.Models 2.1

    Rectangle {
        ObjectModel {
            id: itemModel
            Rectangle { height: 30; width: 80; color: "red" }
            Rectangle { height: 30; width: 80; color: "green" }
            Rectangle { height: 30; width: 80; color: "blue" }
        }

        ListView {
            anchors.fill: parent
            model: itemModel
        }
    }
    \endcode

    \image visualitemmodel.png

    \sa {Qt Quick Examples - Views}
*/
/*!
    \qmltype VisualItemModel
    \instantiates QQmlObjectModel
    \inqmlmodule QtQuick
    \brief Defines a set of objects to be used as a model

    The VisualItemModel type contains the objects to be used
    as a model.

    This element is now primarily available as ObjectModel in the QtQml.Models module.
    VisualItemModel continues to be provided, with the same implementation, in \c QtQuick for
    compatibility reasons.

    For full details about the type, see the \l ObjectModel documentation.

    \sa {QtQml.Models::ObjectModel}
*/

QQmlObjectModel::QQmlObjectModel(QObject *parent)
    : QQmlInstanceModel(*(new QQmlObjectModelPrivate), parent)
{
}

/*!
    \qmlattachedproperty int QtQml.Models::ObjectModel::index
    This attached property holds the index of this delegate's item within the model.

    It is attached to each instance of the delegate.
*/

QQmlListProperty<QObject> QQmlObjectModel::children()
{
    Q_D(QQmlObjectModel);
    return QQmlListProperty<QObject>(this,
                                        d,
                                        d->children_append,
                                        d->children_count,
                                        d->children_at,
                                        d->children_clear);
}

/*!
    \qmlproperty int QtQml.Models::ObjectModel::count

    The number of items in the model.  This property is readonly.
*/
int QQmlObjectModel::count() const
{
    Q_D(const QQmlObjectModel);
    return d->children.count();
}

bool QQmlObjectModel::isValid() const
{
    return true;
}

QObject *QQmlObjectModel::object(int index, bool)
{
    Q_D(QQmlObjectModel);
    QQmlObjectModelPrivate::Item &item = d->children[index];
    item.addRef();
    if (item.ref == 1) {
        emit initItem(index, item.item);
        emit createdItem(index, item.item);
    }
    return item.item;
}

QQmlInstanceModel::ReleaseFlags QQmlObjectModel::release(QObject *item)
{
    Q_D(QQmlObjectModel);
    int idx = d->indexOf(item);
    if (idx >= 0) {
        if (!d->children[idx].deref())
            return QQmlInstanceModel::Referenced;
    }
    return 0;
}

QString QQmlObjectModel::stringValue(int index, const QString &name)
{
    Q_D(QQmlObjectModel);
    if (index < 0 || index >= d->children.count())
        return QString();
    return QQmlEngine::contextForObject(d->children.at(index).item)->contextProperty(name).toString();
}

int QQmlObjectModel::indexOf(QObject *item, QObject *) const
{
    Q_D(const QQmlObjectModel);
    return d->indexOf(item);
}

QQmlObjectModelAttached *QQmlObjectModel::qmlAttachedProperties(QObject *obj)
{
    return QQmlObjectModelAttached::properties(obj);
}

/*!
    \qmlmethod object QtQml.Models::ObjectModel::get(int index)
    \since 5.6

    Returns the item at \a index in the model. This allows the item
    to be accessed or modified from JavaScript:

    \code
    Component.onCompleted: {
        objectModel.append(objectComponent.createObject())
        console.log(objectModel.get(0).objectName);
        objectModel.get(0).objectName = "first";
    }
    \endcode

    The \a index must be an element in the list.

    \sa append()
*/
QObject *QQmlObjectModel::get(int index) const
{
    Q_D(const QQmlObjectModel);
    if (index < 0 || index >= d->children.count())
        return 0;
    return d->children.at(index).item;
}

/*!
    \qmlmethod QtQml.Models::ObjectModel::append(object item)
    \since 5.6

    Appends a new item to the end of the model.

    \code
        objectModel.append(objectComponent.createObject())
    \endcode

    \sa insert(), remove()
*/
void QQmlObjectModel::append(QObject *object)
{
    Q_D(QQmlObjectModel);
    d->insert(count(), object);
}

/*!
    \qmlmethod QtQml.Models::ObjectModel::insert(int index, object item)
    \since 5.6

    Inserts a new item to the model at position \a index.

    \code
        objectModel.insert(2, objectComponent.createObject())
    \endcode

    The \a index must be to an existing item in the list, or one past
    the end of the list (equivalent to append).

    \sa append(), remove()
*/
void QQmlObjectModel::insert(int index, QObject *object)
{
    Q_D(QQmlObjectModel);
    if (index < 0 || index > count()) {
        qmlWarning(this) << tr("insert: index %1 out of range").arg(index);
        return;
    }
    d->insert(index, object);
}

/*!
    \qmlmethod QtQml.Models::ObjectModel::move(int from, int to, int n = 1)
    \since 5.6

    Moves \a n items \a from one position \a to another.

    The from and to ranges must exist; for example, to move the first 3 items
    to the end of the model:

    \code
        objectModel.move(0, objectModel.count - 3, 3)
    \endcode

    \sa append()
*/
void QQmlObjectModel::move(int from, int to, int n)
{
    Q_D(QQmlObjectModel);
    if (n <= 0 || from == to)
        return;
    if (from < 0 || to < 0 || from + n > count() || to + n > count()) {
        qmlWarning(this) << tr("move: out of range");
        return;
    }
    d->move(from, to, n);
}

/*!
    \qmlmethod QtQml.Models::ObjectModel::remove(int index, int n = 1)
    \since 5.6

    Removes the items at \a index from the model.

    \sa clear()
*/
void QQmlObjectModel::remove(int index, int n)
{
    Q_D(QQmlObjectModel);
    if (index < 0 || n <= 0 || index + n > count()) {
        qmlWarning(this) << tr("remove: indices [%1 - %2] out of range [0 - %3]").arg(index).arg(index+n).arg(count());
        return;
    }
    d->remove(index, n);
}

/*!
    \qmlmethod QtQml.Models::ObjectModel::clear()
    \since 5.6

    Clears all items from the model.

    \sa append(), remove()
*/
void QQmlObjectModel::clear()
{
    Q_D(QQmlObjectModel);
    d->clear();
}

QT_END_NAMESPACE

#include "moc_qqmlobjectmodel_p.cpp"
