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#include "qquickoverlay_p.h"
#include "qquickpopup_p.h"
#include <QtQml/qqmlinfo.h>
#include <QtQuick/private/qquickitem_p.h>

QT_BEGIN_NAMESPACE

class QQuickOverlayPrivate : public QQuickItemPrivate
{
    Q_DECLARE_PUBLIC(QQuickOverlay)

public:
    QQuickOverlayPrivate();

    QHash<QQuickItem *, QQuickPopup *> popups;
    int modalPopups;
};

QQuickOverlayPrivate::QQuickOverlayPrivate() :
    modalPopups(0)
{
}

QQuickOverlay::QQuickOverlay(QQuickItem *parent)
    : QQuickItem(*(new QQuickOverlayPrivate), parent)
{
    setAcceptedMouseButtons(Qt::AllButtons);
    setFiltersChildMouseEvents(true);
    setVisible(false);
}

void QQuickOverlay::itemChange(ItemChange change, const ItemChangeData &data)
{
    Q_D(QQuickOverlay);
    QQuickItem::itemChange(change, data);

    QQuickItem *contentItem = const_cast<QQuickItem *>(data.item);
    QQuickPopup *popup = Q_NULLPTR;
    if (change == ItemChildAddedChange || change == ItemChildRemovedChange) {
        popup = qobject_cast<QQuickPopup *>(contentItem->parent());
        setVisible(!childItems().isEmpty());
    }
    if (!popup)
        return;

    if (change == ItemChildAddedChange) {
        if (QQuickPopup *prevPopup = d->popups.value(contentItem)) {
            qmlInfo(popup).nospace() << "Popup is sharing item " << contentItem << " with " << prevPopup
                                     << ". This is not supported and strange things are about to happen.";
            return;
        }

        d->popups.insert(contentItem, popup);
        if (popup->isModal())
            ++d->modalPopups;

        connect(this, &QQuickOverlay::pressed, popup, &QQuickPopup::pressedOutside);
        connect(this, &QQuickOverlay::released, popup, &QQuickPopup::releasedOutside);
    } else if (change == ItemChildRemovedChange) {
        Q_ASSERT(popup == d->popups.value(contentItem));

        disconnect(this, &QQuickOverlay::pressed, popup, &QQuickPopup::pressedOutside);
        disconnect(this, &QQuickOverlay::released, popup, &QQuickPopup::releasedOutside);

        if (popup->isModal())
            --d->modalPopups;
        d->popups.remove(contentItem);
    }
}

void QQuickOverlay::keyPressEvent(QKeyEvent *event)
{
    Q_D(QQuickOverlay);
    event->setAccepted(d->modalPopups > 0);
}

void QQuickOverlay::keyReleaseEvent(QKeyEvent *event)
{
    Q_D(QQuickOverlay);
    event->setAccepted(d->modalPopups > 0);
}

void QQuickOverlay::mousePressEvent(QMouseEvent *event)
{
    Q_D(QQuickOverlay);
    event->setAccepted(d->modalPopups > 0);
    emit pressed();
}

void QQuickOverlay::mouseMoveEvent(QMouseEvent *event)
{
    Q_D(QQuickOverlay);
    event->setAccepted(d->modalPopups > 0);
}

void QQuickOverlay::mouseReleaseEvent(QMouseEvent *event)
{
    Q_D(QQuickOverlay);
    event->setAccepted(d->modalPopups > 0);
    emit released();
}

bool QQuickOverlay::childMouseEventFilter(QQuickItem *item, QEvent *event)
{
    Q_D(QQuickOverlay);
    if (d->modalPopups == 0)
        return false;
    // TODO Filter touch events
    if (event->type() != QEvent::MouseButtonPress)
        return false;
    while (item->parentItem() != this)
        item = item->parentItem();

    bool modalBlocked = false;
    const QQuickItemPrivate *priv = QQuickItemPrivate::get(this);
    const QList<QQuickItem *> &sortedChildren = priv->paintOrderChildItems();
    for (int i = sortedChildren.count() - 1; i >= 0; --i) {
        QQuickItem *contentItem = sortedChildren[i];
        if (contentItem == item)
            break;

        QQuickPopup *popup = d->popups.value(contentItem);
        if (popup) {
            emit popup->pressedOutside();

            if (!modalBlocked && popup->isModal())
                modalBlocked = true;
        }
    }

    return modalBlocked;
}

QT_END_NAMESPACE