qquickrepeater.cpp

Go to the documentation of this file.

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qquickrepeater_p.h"
#include "qquickrepeater_p_p.h"
 
#include <private/qqmlglobal_p.h>
#include <private/qqmlchangeset_p.h>
#include <private/qqmldelegatemodel_p.h>
 
#include <QtQml/QQmlInfo>
 
QT_BEGIN_NAMESPACE
 
QQuickRepeaterPrivate::QQuickRepeaterPrivate()
    : model(nullptr)
    , ownModel(false)
    , dataSourceIsObject(false)
    , delegateValidated(false)
    , itemCount(0)
{
    setTransparentForPositioner(true);
}
 
QQuickRepeaterPrivate::~QQuickRepeaterPrivate()
{
    if (ownModel)
        delete model;
}
 
QQuickRepeater::QQuickRepeater(QQuickItem *parent)
  : QQuickItem(*(new QQuickRepeaterPrivate), parent)
{
}
 
QQuickRepeater::~QQuickRepeater()
{
}
 
QVariant QQuickRepeater::model() const
{
    Q_D(const QQuickRepeater);
 
    if (d->dataSourceIsObject) {
        QObject *o = d->dataSourceAsObject;
        return QVariant::fromValue(o);
    }
 
    return d->dataSource;
}
 
void QQuickRepeater::setModel(const QVariant &m)
{
    Q_D(QQuickRepeater);
    QVariant model = m;
    if (model.userType() == qMetaTypeId<QJSValue>())
        model = model.value<QJSValue>().toVariant();
 
    if (d->dataSource == model)
        return;
 
    clear();
    if (d->model) {
        qmlobject_disconnect(d->model, QQmlInstanceModel, SIGNAL(modelUpdated(QQmlChangeSet,bool)),
                this, QQuickRepeater, SLOT(modelUpdated(QQmlChangeSet,bool)));
        qmlobject_disconnect(d->model, QQmlInstanceModel, SIGNAL(createdItem(int,QObject*)),
                this, QQuickRepeater, SLOT(createdItem(int,QObject*)));
        qmlobject_disconnect(d->model, QQmlInstanceModel, SIGNAL(initItem(int,QObject*)),
                this, QQuickRepeater, SLOT(initItem(int,QObject*)));
    }
    d->dataSource = model;
    QObject *object = qvariant_cast<QObject*>(model);
    d->dataSourceAsObject = object;
    d->dataSourceIsObject = object != nullptr;
    QQmlInstanceModel *vim = nullptr;
    if (object && (vim = qobject_cast<QQmlInstanceModel *>(object))) {
        if (d->ownModel) {
            delete d->model;
            d->ownModel = false;
        }
        d->model = vim;
    } else {
        if (!d->ownModel) {
            d->model = new QQmlDelegateModel(qmlContext(this));
            d->ownModel = true;
            if (isComponentComplete())
                static_cast<QQmlDelegateModel *>(d->model.data())->componentComplete();
        }
        if (QQmlDelegateModel *dataModel = qobject_cast<QQmlDelegateModel*>(d->model))
            dataModel->setModel(model);
    }
    if (d->model) {
        qmlobject_connect(d->model, QQmlInstanceModel, SIGNAL(modelUpdated(QQmlChangeSet,bool)),
                this, QQuickRepeater, SLOT(modelUpdated(QQmlChangeSet,bool)));
        qmlobject_connect(d->model, QQmlInstanceModel, SIGNAL(createdItem(int,QObject*)),
                this, QQuickRepeater, SLOT(createdItem(int,QObject*)));
        qmlobject_connect(d->model, QQmlInstanceModel, SIGNAL(initItem(int,QObject*)),
                this, QQuickRepeater, SLOT(initItem(int,QObject*)));
        regenerate();
    }
    emit modelChanged();
    emit countChanged();
}
 
QQmlComponent *QQuickRepeater::delegate() const
{
    Q_D(const QQuickRepeater);
    if (d->model) {
        if (QQmlDelegateModel *dataModel = qobject_cast<QQmlDelegateModel*>(d->model))
            return dataModel->delegate();
    }
 
    return nullptr;
}
 
void QQuickRepeater::setDelegate(QQmlComponent *delegate)
{
    Q_D(QQuickRepeater);
    if (QQmlDelegateModel *dataModel = qobject_cast<QQmlDelegateModel*>(d->model))
       if (delegate == dataModel->delegate())
           return;
 
    if (!d->ownModel) {
        d->model = new QQmlDelegateModel(qmlContext(this));
        d->ownModel = true;
    }
 
    if (QQmlDelegateModel *dataModel = qobject_cast<QQmlDelegateModel*>(d->model)) {
        dataModel->setDelegate(delegate);
        regenerate();
        emit delegateChanged();
        d->delegateValidated = false;
    }
}
 
int QQuickRepeater::count() const
{
    Q_D(const QQuickRepeater);
    if (d->model)
        return d->model->count();
    return 0;
}
 
QQuickItem *QQuickRepeater::itemAt(int index) const
{
    Q_D(const QQuickRepeater);
    if (index >= 0 && index < d->deletables.size())
        return d->deletables[index];
    return nullptr;
}
 
void QQuickRepeater::componentComplete()
{
    Q_D(QQuickRepeater);
    if (d->model && d->ownModel)
        static_cast<QQmlDelegateModel *>(d->model.data())->componentComplete();
    QQuickItem::componentComplete();
    regenerate();
    if (d->model && d->model->count())
        emit countChanged();
}
 
void QQuickRepeater::itemChange(ItemChange change, const ItemChangeData &value)
{
    QQuickItem::itemChange(change, value);
    if (change == ItemParentHasChanged) {
        regenerate();
    }
}
 
void QQuickRepeater::clear()
{
    Q_D(QQuickRepeater);
    bool complete = isComponentComplete();
 
    if (d->model) {
        // We remove in reverse order deliberately; so that signals are emitted
        // with sensible indices.
        for (int i = d->deletables.size() - 1; i >= 0; --i) {
            if (QQuickItem *item = d->deletables.at(i)) {
                if (complete)
                    emit itemRemoved(i, item);
                d->model->release(item);
            }
        }
        for (QQuickItem *item : std::as_const(d->deletables)) {
            if (item)
                item->setParentItem(nullptr);
        }
    }
    d->deletables.clear();
    d->itemCount = 0;
}
 
void QQuickRepeater::regenerate()
{
    Q_D(QQuickRepeater);
    if (!isComponentComplete())
        return;
 
    clear();
 
    if (!d->model || !d->model->count() || !d->model->isValid() || !parentItem() || !isComponentComplete())
        return;
 
    d->itemCount = count();
    d->deletables.resize(d->itemCount);
    d->requestItems();
}
 
void QQuickRepeaterPrivate::requestItems()
{
    for (int i = 0; i < itemCount; i++) {
        QObject *object = model->object(i, QQmlIncubator::AsynchronousIfNested);
        if (object)
            model->release(object);
    }
}
 
void QQuickRepeater::createdItem(int index, QObject *)
{
    Q_D(QQuickRepeater);
    QObject *object = d->model->object(index, QQmlIncubator::AsynchronousIfNested);
    QQuickItem *item = qmlobject_cast<QQuickItem*>(object);
    emit itemAdded(index, item);
}
 
void QQuickRepeater::initItem(int index, QObject *object)
{
    Q_D(QQuickRepeater);
    if (index >= d->deletables.size()) {
        // this can happen when Package is used
        // calling regenerate does too much work, all we need is to call resize
        // so that d->deletables[index] = item below works
        d->deletables.resize(d->model->count() + 1);
    }
    QQuickItem *item = qmlobject_cast<QQuickItem*>(object);
 
    if (!d->deletables.at(index)) {
        if (!item) {
            if (object) {
                d->model->release(object);
                if (!d->delegateValidated) {
                    d->delegateValidated = true;
                    QObject* delegate = this->delegate();
                    qmlWarning(delegate ? delegate : this) << QQuickRepeater::tr("Delegate must be of Item type");
                }
            }
            return;
        }
        d->deletables[index] = item;
        item->setParentItem(parentItem());
 
        // If the item comes from an ObjectModel, it might be used as
        // ComboBox/Menu/TabBar's contentItem. These types unconditionally cull items
        // that are inserted, so account for that here.
        if (d->dataSourceIsObject)
            QQuickItemPrivate::get(item)->setCulled(false);
        if (index > 0 && d->deletables.at(index-1)) {
            item->stackAfter(d->deletables.at(index-1));
        } else {
            QQuickItem *after = this;
            for (int si = index+1; si < d->itemCount; ++si) {
                if (d->deletables.at(si)) {
                    after = d->deletables.at(si);
                    break;
                }
            }
            item->stackBefore(after);
        }
    }
}
 
void QQuickRepeater::modelUpdated(const QQmlChangeSet &changeSet, bool reset)
{
    Q_D(QQuickRepeater);
 
    if (!isComponentComplete())
        return;
 
    if (reset) {
        regenerate();
        if (changeSet.difference() != 0)
            emit countChanged();
        return;
    }
 
    int difference = 0;
    QHash<int, QVector<QPointer<QQuickItem> > > moved;
    for (const QQmlChangeSet::Change &remove : changeSet.removes()) {
        int index = qMin(remove.index, d->deletables.size());
        int count = qMin(remove.index + remove.count, d->deletables.size()) - index;
        if (remove.isMove()) {
            moved.insert(remove.moveId, d->deletables.mid(index, count));
            d->deletables.erase(
                    d->deletables.begin() + index,
                    d->deletables.begin() + index + count);
        } else while (count--) {
            QQuickItem *item = d->deletables.at(index);
            d->deletables.remove(index);
            emit itemRemoved(index, item);
            if (item) {
                d->model->release(item);
                item->setParentItem(nullptr);
            }
            --d->itemCount;
        }
 
        difference -= remove.count;
    }
 
    for (const QQmlChangeSet::Change &insert : changeSet.inserts()) {
        int index = qMin(insert.index, d->deletables.size());
        if (insert.isMove()) {
            QVector<QPointer<QQuickItem> > items = moved.value(insert.moveId);
            d->deletables = d->deletables.mid(0, index) + items + d->deletables.mid(index);
            QQuickItem *stackBefore = index + items.size() < d->deletables.size()
                    ? d->deletables.at(index + items.size())
                    : this;
            if (stackBefore) {
                for (int i = index; i < index + items.size(); ++i) {
                    if (i < d->deletables.size()) {
                        QPointer<QQuickItem> item = d->deletables.at(i);
                        if (item)
                            item->stackBefore(stackBefore);
                    }
                }
            }
        } else for (int i = 0; i < insert.count; ++i) {
            int modelIndex = index + i;
            ++d->itemCount;
            d->deletables.insert(modelIndex, nullptr);
            QObject *object = d->model->object(modelIndex, QQmlIncubator::AsynchronousIfNested);
            if (object)
                d->model->release(object);
        }
        difference += insert.count;
    }
 
    if (difference != 0)
        emit countChanged();
}
 
QT_END_NAMESPACE
 
#include "moc_qquickrepeater_p.cpp"