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#include "qquickswipeview_p.h"

#include <QtLabsTemplates/private/qquickcontainer_p_p.h>

QT_BEGIN_NAMESPACE

/*!
    \qmltype SwipeView
    \inherits Container
    \instantiates QQuickSwipeView
    \inqmlmodule QtQuick.Controls
    \ingroup navigation
    \brief A swipe view control.

    TODO
*/

class QQuickSwipeViewPrivate : public QQuickContainerPrivate
{
    Q_DECLARE_PUBLIC(QQuickSwipeView)

public:
    QQuickSwipeViewPrivate() : updatingCurrent(false) { }

    void resizeItem(QQuickItem *item);
    void resizeItems();
    void _q_updateCurrent();

    void itemInserted(int index, QQuickItem *item) Q_DECL_OVERRIDE;
    void itemMoved(int from, int to) Q_DECL_OVERRIDE;

    static QQuickSwipeViewPrivate *get(QQuickSwipeView *view);

    bool updatingCurrent;
};

void QQuickSwipeViewPrivate::resizeItems()
{
    Q_Q(QQuickSwipeView);
    const int count = q->count();
    for (int i = 0; i < count; ++i) {
        QQuickItem *item = itemAt(i);
        if (item)
            item->setSize(QSizeF(contentItem->width(), contentItem->height()));
    }
}

void QQuickSwipeViewPrivate::_q_updateCurrent()
{
    Q_Q(QQuickSwipeView);
    if (!updatingCurrent)
        q->setCurrentIndex(contentItem ? contentItem->property("currentIndex").toInt() : -1);
}

void QQuickSwipeViewPrivate::itemInserted(int, QQuickItem *item)
{
    Q_Q(QQuickSwipeView);
    if (q->isComponentComplete())
        item->setSize(QSizeF(contentItem->width(), contentItem->height()));
}

void QQuickSwipeViewPrivate::itemMoved(int from, int to)
{
    Q_Q(QQuickSwipeView);
    updatingCurrent = true;
    if (from == currentIndex)
        q->setCurrentIndex(to);
    else if (from < currentIndex && to >= currentIndex)
        q->setCurrentIndex(currentIndex - 1);
    else if (from > currentIndex && to <= currentIndex)
        q->setCurrentIndex(currentIndex + 1);
    updatingCurrent = false;
}


QQuickSwipeViewPrivate *QQuickSwipeViewPrivate::get(QQuickSwipeView *view)
{
    return view->d_func();
}

QQuickSwipeView::QQuickSwipeView(QQuickItem *parent) :
    QQuickContainer(*(new QQuickSwipeViewPrivate), parent)
{
    setFlag(ItemIsFocusScope);
    setActiveFocusOnTab(true);
}

QQuickSwipeViewAttached *QQuickSwipeView::qmlAttachedProperties(QObject *object)
{
    QQuickItem *item = qobject_cast<QQuickItem *>(object);
    if (!item) {
        qWarning() << "SwipeView: attached properties must be accessed from within a child item";
        return Q_NULLPTR;
    }

    return new QQuickSwipeViewAttached(item);
}

void QQuickSwipeView::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
{
    Q_D(QQuickSwipeView);
    QQuickContainer::geometryChanged(newGeometry, oldGeometry);
    d->resizeItems();
}

void QQuickSwipeView::contentItemChange(QQuickItem *newItem, QQuickItem *oldItem)
{
    QQuickContainer::contentItemChange(newItem, oldItem);
    if (oldItem)
        disconnect(oldItem, SIGNAL(currentIndexChanged()), this, SLOT(_q_updateCurrent()));
    if (newItem)
        connect(newItem, SIGNAL(currentIndexChanged()), this, SLOT(_q_updateCurrent()));
}

/*!
    \qmlattachedproperty int QtQuick.Controls::SwipeView::index

    This attached property holds the index of each child item in the SwipeView.

    It is attached to each child item of the SwipeView.
*/

/*!
    \qmlattachedproperty bool QtQuick.Controls::SwipeView::isCurrentItem

    This attached property is \c true if this child is the current item.

    It is attached to each child item of the SwipeView.
*/

/*!
    \qmlattachedproperty SwipeView QtQuick.Controls::SwipeView::view

    This attached property holds the view that manages this child item.

    It is attached to each child item of the SwipeView.
*/

class QQuickSwipeViewAttachedPrivate : public QObjectPrivate, public QQuickItemChangeListener
{
    Q_DECLARE_PUBLIC(QQuickSwipeViewAttached)
public:
    QQuickSwipeViewAttachedPrivate(QQuickItem *item) :
        item(item),
        swipeView(Q_NULLPTR),
        index(-1),
        isCurrent(false)
    {
    }

    ~QQuickSwipeViewAttachedPrivate() {
    }

    void updateView(QQuickItem *parent);

    void itemChildAdded(QQuickItem *, QQuickItem *) Q_DECL_OVERRIDE;
    void itemChildRemoved(QQuickItem *, QQuickItem *) Q_DECL_OVERRIDE;
    void itemParentChanged(QQuickItem *, QQuickItem *) Q_DECL_OVERRIDE;

    void updateIndex();
    void updateIsCurrent();

    void setView(QQuickSwipeView *view);
    void setIndex(int i);
    void setIsCurrent(bool current);

    QQuickItem *item;
    QQuickSwipeView *swipeView;
    int index;
    // Better to store this so that we don't need to lump its calculation
    // together with index's calculation, as it would otherwise need to know
    // the old index to know if it should emit the change signal.
    bool isCurrent;
};

void QQuickSwipeViewAttachedPrivate::updateIndex()
{
    setIndex(swipeView ? QQuickSwipeViewPrivate::get(swipeView)->contentModel->indexOf(item, Q_NULLPTR) : -1);
}

void QQuickSwipeViewAttachedPrivate::updateIsCurrent()
{
    setIsCurrent(swipeView ? swipeView->currentIndex() == index : false);
}

void QQuickSwipeViewAttachedPrivate::setView(QQuickSwipeView *view)
{
    if (view == swipeView)
        return;

    if (swipeView) {
        QQuickItemPrivate *p = QQuickItemPrivate::get(swipeView);
        p->removeItemChangeListener(this, QQuickItemPrivate::Children);

        disconnect(swipeView, &QQuickSwipeView::currentIndexChanged,
            this, &QQuickSwipeViewAttachedPrivate::updateIsCurrent);
        disconnect(swipeView, &QQuickSwipeView::contentChildrenChanged,
            this, &QQuickSwipeViewAttachedPrivate::updateIndex);
    }

    swipeView = view;

    if (swipeView) {
        QQuickItemPrivate *p = QQuickItemPrivate::get(swipeView);
        p->addItemChangeListener(this, QQuickItemPrivate::Children);

        connect(swipeView, &QQuickSwipeView::currentIndexChanged,
            this, &QQuickSwipeViewAttachedPrivate::updateIsCurrent);
        connect(swipeView, &QQuickSwipeView::contentChildrenChanged,
            this, &QQuickSwipeViewAttachedPrivate::updateIndex);
    }

    Q_Q(QQuickSwipeViewAttached);
    emit q->viewChanged();

    updateIndex();
    updateIsCurrent();
}

void QQuickSwipeViewAttachedPrivate::setIsCurrent(bool current)
{
    if (current != isCurrent) {
        isCurrent = current;
        Q_Q(QQuickSwipeViewAttached);
        emit q->isCurrentItemChanged();
    }
}

void QQuickSwipeViewAttachedPrivate::setIndex(int i)
{
    if (i != index) {
        index = i;
        Q_Q(QQuickSwipeViewAttached);
        emit q->indexChanged();
    }
}

void QQuickSwipeViewAttachedPrivate::updateView(QQuickItem *parent)
{
    // parent can be, e.g.:
    // - The contentItem of a ListView (typically the case)
    // - A non-visual or weird type like TestCase, when child items are created from components
    //   wherein the attached properties are used
    // - null, when the item was removed with removeItem()
    QQuickSwipeView *view = Q_NULLPTR;
    if (parent) {
        view = qobject_cast<QQuickSwipeView*>(parent);
        if (!view) {
            if (parent->parentItem() && parent->parentItem()->property("contentItem").isValid()) {
                // The parent is the contentItem of some kind of view.
                view = qobject_cast<QQuickSwipeView*>(parent->parentItem()->parentItem());
            }
        }
    }

    setView(view);
}

void QQuickSwipeViewAttachedPrivate::itemChildAdded(QQuickItem *, QQuickItem *)
{
    updateIndex();
}

void QQuickSwipeViewAttachedPrivate::itemChildRemoved(QQuickItem *, QQuickItem *)
{
    updateIndex();
}

void QQuickSwipeViewAttachedPrivate::itemParentChanged(QQuickItem *, QQuickItem *parent)
{
    updateView(parent);
}

QQuickSwipeViewAttached::QQuickSwipeViewAttached(QQuickItem *item) :
    QObject(*(new QQuickSwipeViewAttachedPrivate(item)), item)
{
    Q_D(QQuickSwipeViewAttached);
    if (item->parentItem()) {
        d->updateView(item->parentItem());
    } else {
        QQuickItemPrivate *p = QQuickItemPrivate::get(item);
        p->addItemChangeListener(d, QQuickItemPrivate::Parent);
    }
}

QQuickSwipeViewAttached::~QQuickSwipeViewAttached()
{
}

QQuickSwipeView *QQuickSwipeViewAttached::view() const
{
    Q_D(const QQuickSwipeViewAttached);
    return d->swipeView;
}

int QQuickSwipeViewAttached::index() const
{
    Q_D(const QQuickSwipeViewAttached);
    return d->index;
}

bool QQuickSwipeViewAttached::isCurrentItem() const
{
    Q_D(const QQuickSwipeViewAttached);
    return d->swipeView ? d->swipeView->currentIndex() == d->index : false;
}

QT_END_NAMESPACE

#include "moc_qquickswipeview_p.cpp"