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** Copyright (C) 2016 The Qt Company Ltd.
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** This file is part of the Qt Quick Templates 2 module of the Qt Toolkit.
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****************************************************************************/

#include "qquickmenu_p.h"
#include "qquickmenu_p_p.h"
#include "qquickmenuitem_p.h"

#include <QtGui/qevent.h>
#include <QtQml/private/qqmlobjectmodel_p.h>
#include <QtQuick/private/qquickitem_p.h>
#include <QtQuick/private/qquickitemchangelistener_p.h>
#include <QtQuick/private/qquickitemview_p.h>
#include <QtQuick/private/qquickevents_p_p.h>
#include <QtQuick/private/qquickwindow_p.h>

QT_BEGIN_NAMESPACE

/*!
    \qmltype Menu
    \inherits Popup
    \instantiates QQuickMenu
    \inqmlmodule QtQuick.Controls
    \since 5.7
    \ingroup qtquickcontrols2-menus
    \ingroup qtquickcontrols2-popups
    \brief A menu control that can be used as a context menu or popup menu.

    \image qtquickcontrols2-menu.png

    Menu has two main use cases:
    \list
        \li Context menus; for example, a menu that is shown after right clicking
        \li Popup menus; for example, a menu that is shown after clicking a button
    \endlist

    \code
    Button {
        id: fileButton
        text: "File"
        onClicked: menu.open()

        Menu {
            id: menu
            y: fileButton.height

            MenuItem {
                text: "New..."
            }
            MenuItem {
                text: "Open..."
            }
            MenuItem {
                text: "Save"
            }
        }
    }
    \endcode

    \sa {Customizing Menu}, {Menu Controls}, {Popup Controls}
*/

QQuickMenuPrivate::QQuickMenuPrivate() :
    contentItem(nullptr),
    contentModel(nullptr)
{
    Q_Q(QQuickMenu);
    contentModel = new QQmlObjectModel(q);
}

QQuickItem *QQuickMenuPrivate::itemAt(int index) const
{
    return qobject_cast<QQuickItem *>(contentModel->get(index));
}

void QQuickMenuPrivate::insertItem(int index, QQuickItem *item)
{
    contentData.append(item);
    item->setParentItem(contentItem);
    if (qobject_cast<QQuickItemView *>(contentItem))
        QQuickItemPrivate::get(item)->setCulled(true); // QTBUG-53262
    if (complete)
        resizeItem(item);
    QQuickItemPrivate::get(item)->addItemChangeListener(this, QQuickItemPrivate::Destroyed | QQuickItemPrivate::Parent);
    contentModel->insert(index, item);

    QQuickMenuItem *menuItem = qobject_cast<QQuickMenuItem *>(item);
    if (menuItem) {
        Q_Q(QQuickMenu);
        QObjectPrivate::connect(menuItem, &QQuickMenuItem::pressed, this, &QQuickMenuPrivate::onItemPressed);
        QObject::connect(menuItem, &QQuickMenuItem::triggered, q, &QQuickPopup::close);
        QObjectPrivate::connect(menuItem, &QQuickItem::activeFocusChanged, this, &QQuickMenuPrivate::onItemActiveFocusChanged);
    }
}

void QQuickMenuPrivate::moveItem(int from, int to)
{
    contentModel->move(from, to);
}

void QQuickMenuPrivate::removeItem(int index, QQuickItem *item)
{
    contentData.removeOne(item);

    QQuickItemPrivate::get(item)->removeItemChangeListener(this, QQuickItemPrivate::Destroyed | QQuickItemPrivate::Parent);
    item->setParentItem(nullptr);
    contentModel->remove(index);

    QQuickMenuItem *menuItem = qobject_cast<QQuickMenuItem *>(item);
    if (menuItem) {
        Q_Q(QQuickMenu);
        QObjectPrivate::disconnect(menuItem, &QQuickMenuItem::pressed, this, &QQuickMenuPrivate::onItemPressed);
        QObject::disconnect(menuItem, &QQuickMenuItem::triggered, q, &QQuickPopup::close);
        QObjectPrivate::disconnect(menuItem, &QQuickItem::activeFocusChanged, this, &QQuickMenuPrivate::onItemActiveFocusChanged);
    }
}

void QQuickMenuPrivate::resizeItem(QQuickItem *item)
{
    if (!item || !contentItem)
        return;

    QQuickItemPrivate *p = QQuickItemPrivate::get(item);
    if (!p->widthValid) {
        item->setWidth(contentItem->width());
        p->widthValid = false;
    }
}

void QQuickMenuPrivate::resizeItems()
{
    if (!contentModel)
        return;

    for (int i = 0; i < contentModel->count(); ++i)
        resizeItem(itemAt(i));
}

void QQuickMenuPrivate::itemChildAdded(QQuickItem *, QQuickItem *child)
{
    // add dynamically reparented items (eg. by a Repeater)
    if (!QQuickItemPrivate::get(child)->isTransparentForPositioner() && !contentData.contains(child))
        insertItem(contentModel->count(), child);
}

void QQuickMenuPrivate::itemParentChanged(QQuickItem *item, QQuickItem *parent)
{
    // remove dynamically unparented items (eg. by a Repeater)
    if (!parent)
        removeItem(contentModel->indexOf(item, nullptr), item);
}

void QQuickMenuPrivate::itemSiblingOrderChanged(QQuickItem *)
{
    // reorder the restacked items (eg. by a Repeater)
    Q_Q(QQuickMenu);
    QList<QQuickItem *> siblings = contentItem->childItems();
    for (int i = 0; i < siblings.count(); ++i) {
        QQuickItem* sibling = siblings.at(i);
        int index = contentModel->indexOf(sibling, nullptr);
        q->moveItem(index, i);
    }
}

void QQuickMenuPrivate::itemDestroyed(QQuickItem *item)
{
    int index = contentModel->indexOf(item, nullptr);
    if (index != -1)
        removeItem(index, item);
}

void QQuickMenuPrivate::itemGeometryChanged(QQuickItem *, const QRectF &, const QRectF &)
{
    if (complete)
        resizeItems();
}

void QQuickMenuPrivate::onItemPressed()
{
    Q_Q(QQuickMenu);
    QQuickItem *item = qobject_cast<QQuickItem*>(q->sender());
    if (item)
        item->forceActiveFocus();
}

void QQuickMenuPrivate::onItemActiveFocusChanged()
{
    Q_Q(QQuickMenu);
    QQuickItem *item = qobject_cast<QQuickItem*>(q->sender());
    if (!item->hasActiveFocus())
        return;

    int indexOfItem = contentModel->indexOf(item, nullptr);
    setCurrentIndex(indexOfItem);
}

int QQuickMenuPrivate::currentIndex() const
{
    QVariant index = contentItem->property("currentIndex");
    if (!index.isValid())
        return -1;
    return index.toInt();
}

void QQuickMenuPrivate::setCurrentIndex(int index)
{
    contentItem->setProperty("currentIndex", index);
}

void QQuickMenuPrivate::contentData_append(QQmlListProperty<QObject> *prop, QObject *obj)
{
    QQuickMenuPrivate *p = static_cast<QQuickMenuPrivate *>(prop->data);
    QQuickMenu *q = static_cast<QQuickMenu *>(prop->object);
    QQuickItem *item = qobject_cast<QQuickItem *>(obj);
    if (item) {
        if (QQuickItemPrivate::get(item)->isTransparentForPositioner()) {
            QQuickItemPrivate::get(item)->addItemChangeListener(p, QQuickItemPrivate::SiblingOrder);
            item->setParentItem(p->contentItem);
        } else if (p->contentModel->indexOf(item, nullptr) == -1) {
            q->addItem(item);
        }
    } else {
        p->contentData.append(obj);
    }
}

int QQuickMenuPrivate::contentData_count(QQmlListProperty<QObject> *prop)
{
    QQuickMenuPrivate *p = static_cast<QQuickMenuPrivate *>(prop->data);
    return p->contentData.count();
}

QObject *QQuickMenuPrivate::contentData_at(QQmlListProperty<QObject> *prop, int index)
{
    QQuickMenuPrivate *p = static_cast<QQuickMenuPrivate *>(prop->data);
    return p->contentData.value(index);
}

void QQuickMenuPrivate::contentData_clear(QQmlListProperty<QObject> *prop)
{
    QQuickMenuPrivate *p = static_cast<QQuickMenuPrivate *>(prop->data);
    p->contentData.clear();
}

QQuickMenu::QQuickMenu(QObject *parent) :
    QQuickPopup(*(new QQuickMenuPrivate), parent)
{
    setFocus(true);
    setClosePolicy(CloseOnEscape | CloseOnPressOutside | CloseOnReleaseOutside);
}

/*!
    \qmlmethod Item QtQuick.Controls::Menu::itemAt(int index)

    Returns the item at \a index, or \c null if it does not exist.
*/
QQuickItem *QQuickMenu::itemAt(int index) const
{
    Q_D(const QQuickMenu);
    return d->itemAt(index);
}

/*!
    \qmlmethod void QtQuick.Controls::Menu::addItem(Item item)

    Adds \a item to the end of the list of items.
*/
void QQuickMenu::addItem(QQuickItem *item)
{
    Q_D(QQuickMenu);
    insertItem(d->contentModel->count(), item);
}

/*!
    \qmlmethod void QtQuick.Controls::Menu::insertItem(int index, Item item)

    Inserts \a item at \a index.
*/
void QQuickMenu::insertItem(int index, QQuickItem *item)
{
    Q_D(QQuickMenu);
    if (!item)
        return;
    const int count = d->contentModel->count();
    if (index < 0 || index > count)
        index = count;

    int oldIndex = d->contentModel->indexOf(item, nullptr);
    if (oldIndex != -1) {
        if (oldIndex < index)
            --index;
        if (oldIndex != index)
            d->moveItem(oldIndex, index);
    } else {
        d->insertItem(index, item);
    }
}

/*!
    \qmlmethod void QtQuick.Controls::Menu::moveItem(int from, int to)

    Moves an item \a from one index \a to another.
*/
void QQuickMenu::moveItem(int from, int to)
{
    Q_D(QQuickMenu);
    const int count = d->contentModel->count();
    if (from < 0 || from > count - 1)
        return;
    if (to < 0 || to > count - 1)
        to = count - 1;

    if (from != to)
        d->moveItem(from, to);
}

/*!
    \qmlmethod void QtQuick.Controls::Menu::removeItem(int index)

    Removes an item at \a index.

    \note The ownership of the item is transferred to the caller.
*/
void QQuickMenu::removeItem(int index)
{
    Q_D(QQuickMenu);
    const int count = d->contentModel->count();
    if (index < 0 || index >= count)
        return;

    QQuickItem *item = itemAt(index);
    if (item)
        d->removeItem(index, item);
}

/*!
    \qmlproperty model QtQuick.Controls::Menu::contentModel
    \readonly

    This property holds the model used to display menu items.

    By default, the model is an \l ObjectModel, in order to allow declaring
    menu items as children of the menu.
*/
QVariant QQuickMenu::contentModel() const
{
    Q_D(const QQuickMenu);
    return QVariant::fromValue(d->contentModel);
}

/*!
    \qmlproperty list<Object> QtQuick.Controls::Menu::contentData
    \default

    This property holds the list of content data.

    \sa Item::data
*/
QQmlListProperty<QObject> QQuickMenu::contentData()
{
    Q_D(QQuickMenu);
    return QQmlListProperty<QObject>(this, d,
        QQuickMenuPrivate::contentData_append,
        QQuickMenuPrivate::contentData_count,
        QQuickMenuPrivate::contentData_at,
        QQuickMenuPrivate::contentData_clear);
}

/*!
    \qmlproperty string QtQuick.Controls::Menu::title

    Title for the menu as a submenu or in a menubar.

    Its value defaults to an empty string.
*/
QString QQuickMenu::title() const
{
    Q_D(const QQuickMenu);
    return d->title;
}

void QQuickMenu::setTitle(QString &title)
{
    Q_D(QQuickMenu);
    if (title == d->title)
        return;
    d->title = title;
    emit titleChanged();
}

void QQuickMenu::componentComplete()
{
    Q_D(QQuickMenu);
    QQuickPopup::componentComplete();
    d->resizeItems();
}

void QQuickMenu::contentItemChange(QQuickItem *newItem, QQuickItem *oldItem)
{
    Q_D(QQuickMenu);
    Q_UNUSED(oldItem);
    QQuickPopup::contentItemChange(newItem, oldItem);
    d->contentItem = newItem;
}

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

    if (change == QQuickItem::ItemVisibleHasChanged) {
        if (!data.boolValue) {
            // Ensure that when the menu isn't visible, there's no current item
            // the next time it's opened.
            QQuickItem *focusItem = QQuickItemPrivate::get(d->contentItem)->subFocusItem;
            if (focusItem) {
                QQuickWindow *window = QQuickPopup::window();
                if (window)
                    QQuickWindowPrivate::get(window)->clearFocusInScope(d->contentItem, focusItem, Qt::OtherFocusReason);
            }
            d->setCurrentIndex(-1);
        }
    }
}

void QQuickMenu::keyReleaseEvent(QKeyEvent *event)
{
    Q_D(QQuickMenu);
    QQuickPopup::keyReleaseEvent(event);
    if (d->contentModel->count() == 0)
        return;

    // QTBUG-17051
    // Work around the fact that ListView has no way of distinguishing between
    // mouse and keyboard interaction, thanks to the "interactive" bool in Flickable.
    // What we actually want is to have a way to always allow keyboard interaction but
    // only allow flicking with the mouse when there are too many menu items to be
    // shown at once.
    switch (event->key()) {
    case Qt::Key_Up:
        if (d->contentItem->metaObject()->indexOfMethod("decrementCurrentIndex()") != -1)
            QMetaObject::invokeMethod(d->contentItem, "decrementCurrentIndex");
        break;

    case Qt::Key_Down:
        if (d->contentItem->metaObject()->indexOfMethod("incrementCurrentIndex()") != -1)
            QMetaObject::invokeMethod(d->contentItem, "incrementCurrentIndex");
        break;

    default:
        break;
    }

    int index = d->currentIndex();
    QQuickItem *item = itemAt(index);
    if (item)
        item->forceActiveFocus();
}

#ifndef QT_NO_ACCESSIBILITY
QAccessible::Role QQuickMenu::accessibleRole() const
{
    return QAccessible::PopupMenu;
}
#endif // QT_NO_ACCESSIBILITY

QT_END_NAMESPACE

#include "moc_qquickmenu_p.cpp"
