/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtDeclarative module of the Qt Toolkit.

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** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

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** $QT_END_LICENSE$

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****************************************************************************/

#include "private/qdeclarativeloader_p_p.h"

#include <qdeclarativeinfo.h>

#include <qdeclarativeengine_p.h>

#include <qdeclarativeglobal_p.h>

QT_BEGIN_NAMESPACE

QDeclarativeLoaderPrivate::QDeclarativeLoaderPrivate()

    : item(0), component(0), ownComponent(false)

{

}

QDeclarativeLoaderPrivate::~QDeclarativeLoaderPrivate()

{

}

void QDeclarativeLoaderPrivate::itemGeometryChanged(QDeclarativeItem *resizeItem, const QRectF &newGeometry, const QRectF &oldGeometry)

{

    if (resizeItem == item)

        _q_updateSize(false);

    QDeclarativeItemChangeListener::itemGeometryChanged(resizeItem, newGeometry, oldGeometry);

}

void QDeclarativeLoaderPrivate::clear()

{

    if (ownComponent) {

        component->deleteLater();

        component = 0;

        ownComponent = false;

    }

    source = QUrl();

    if (item) {

        if (QDeclarativeItem *qmlItem = qobject_cast<QDeclarativeItem*>(item)) {

            QDeclarativeItemPrivate *p =

                    static_cast<QDeclarativeItemPrivate *>(QGraphicsItemPrivate::get(qmlItem));

            p->removeItemChangeListener(this, QDeclarativeItemPrivate::Geometry);

        }

        // We can't delete immediately because our item may have triggered

        // the Loader to load a different item.

        if (item->scene()) {

            item->scene()->removeItem(item);

        } else {

            item->setParentItem(0);

            item->setVisible(false);

        }

        item->deleteLater();

        item = 0;

    }

}

void QDeclarativeLoaderPrivate::initResize()

{

    Q_Q(QDeclarativeLoader);

    if (QDeclarativeItem *qmlItem = qobject_cast<QDeclarativeItem*>(item)) {

        QDeclarativeItemPrivate *p =

                static_cast<QDeclarativeItemPrivate *>(QGraphicsItemPrivate::get(qmlItem));

        p->addItemChangeListener(this, QDeclarativeItemPrivate::Geometry);

    } else if (item && item->isWidget()) {

        QGraphicsWidget *widget = static_cast<QGraphicsWidget*>(item);

        widget->installEventFilter(q);

    }

    _q_updateSize();

}

/*!

    \qmlclass Loader QDeclarativeLoader

    \since 4.7

    \inherits Item

    \brief The Loader item allows dynamically loading an Item-based

    subtree from a URL or Component.

    \sa {dynamic-object-creation}{Dynamic Object Creation}

*/

QDeclarativeLoader::QDeclarativeLoader(QDeclarativeItem *parent)

  : QDeclarativeItem(*(new QDeclarativeLoaderPrivate), parent)

{

    Q_D(QDeclarativeLoader);

    d->flags |= QGraphicsItem::ItemIsFocusScope;

}

QDeclarativeLoader::~QDeclarativeLoader()

{

    Q_D(QDeclarativeLoader);

    if (d->item) {

        if (QDeclarativeItem *qmlItem = qobject_cast<QDeclarativeItem*>(d->item)) {

            QDeclarativeItemPrivate *p =

                    static_cast<QDeclarativeItemPrivate *>(QGraphicsItemPrivate::get(qmlItem));

            p->removeItemChangeListener(d, QDeclarativeItemPrivate::Geometry);

        }

    }

}

/*!

    \qmlproperty url Loader::source

    \sa sourceComponent, status, progress

*/

QUrl QDeclarativeLoader::source() const

{

    Q_D(const QDeclarativeLoader);

    return d->source;

}

void QDeclarativeLoader::setSource(const QUrl &url)

{

    Q_D(QDeclarativeLoader);

    if (d->source == url)

        return;

    d->clear();

    d->source = url;

    if (d->source.isEmpty()) {

        emit sourceChanged();

        emit statusChanged();

        emit progressChanged();

        emit itemChanged();

        return;

    }

    d->component = new QDeclarativeComponent(qmlEngine(this), d->source, this);

    d->ownComponent = true;

    if (!d->component->isLoading()) {

        d->_q_sourceLoaded();

    } else {

        connect(d->component, SIGNAL(statusChanged(QDeclarativeComponent::Status)),

                this, SLOT(_q_sourceLoaded()));

        connect(d->component, SIGNAL(progressChanged(qreal)),

                this, SIGNAL(progressChanged()));

        emit statusChanged();

        emit progressChanged();

        emit sourceChanged();

        emit itemChanged();

    }

}

/*!

    \qmlproperty Component Loader::sourceComponent

    This property holds the \l{Component} to instantiate.

    \qml

    Item {

        Component {

            id: redSquare

            Rectangle { color: "red"; width: 10; height: 10 }

        }

        Loader { sourceComponent: redSquare }

        Loader { sourceComponent: redSquare; x: 10 }

    }

    \endqml

    \sa source, progress

*/

QDeclarativeComponent *QDeclarativeLoader::sourceComponent() const

{

    Q_D(const QDeclarativeLoader);

    return d->component;

}

void QDeclarativeLoader::setSourceComponent(QDeclarativeComponent *comp)

{

    Q_D(QDeclarativeLoader);

    if (comp == d->component)

        return;

    d->clear();

    d->component = comp;

    d->ownComponent = false;

    if (!d->component) {

        emit sourceChanged();

        emit statusChanged();

        emit progressChanged();

        emit itemChanged();

        return;

    }

    if (!d->component->isLoading()) {

        d->_q_sourceLoaded();

    } else {

        connect(d->component, SIGNAL(statusChanged(QDeclarativeComponent::Status)),

                this, SLOT(_q_sourceLoaded()));

        connect(d->component, SIGNAL(progressChanged(qreal)),

                this, SIGNAL(progressChanged()));

        emit progressChanged();

        emit sourceChanged();

        emit statusChanged();

        emit itemChanged();

    }

}

void QDeclarativeLoader::resetSourceComponent()

{

    setSourceComponent(0);

}

void QDeclarativeLoaderPrivate::_q_sourceLoaded()

{

    Q_Q(QDeclarativeLoader);

    if (component) {

        if (!component->errors().isEmpty()) {

            QDeclarativeEnginePrivate::warning(qmlEngine(q), component->errors());

            emit q->sourceChanged();

            emit q->statusChanged();

            emit q->progressChanged();

            return;

        }

        QDeclarativeContext *ctxt = new QDeclarativeContext(qmlContext(q));

        ctxt->setContextObject(q);

        QDeclarativeComponent *c = component;

        QObject *obj = component->create(ctxt);

        if (component != c) {

            // component->create could trigger a change in source that causes

            // component to be set to something else. In that case we just

            // need to cleanup.

            delete obj;

            delete ctxt;

            return;

        }

        if (obj) {

            item = qobject_cast<QGraphicsObject *>(obj);

            if (item) {

                QDeclarative_setParent_noEvent(ctxt, obj);

                QDeclarative_setParent_noEvent(item, q);

                item->setParentItem(q);

//                item->setFocus(true);

                initResize();

            } else {

                qmlInfo(q) << QDeclarativeLoader::tr("Loader does not support loading non-visual elements.");

                delete obj;

                delete ctxt;

            }

        } else {

            if (!component->errors().isEmpty())

                QDeclarativeEnginePrivate::warning(qmlEngine(q), component->errors());

            delete obj;

            delete ctxt;

            source = QUrl();

        }

        emit q->sourceChanged();

        emit q->statusChanged();

        emit q->progressChanged();

        emit q->itemChanged();

        emit q->loaded();

    }

}

/*!

    \qmlproperty enumeration Loader::status

    This property holds the status of QML loading.  It can be one of:

    \list

    \o Loader.Null - no QML source has been set

    \o Loader.Ready - the QML source has been loaded

    \o Loader.Loading - the QML source is currently being loaded

    \o Loader.Error - an error occurred while loading the QML source

    \endlist

    Use this status to provide an update or respond to the status change in some way.

    For example, you could:

    \e {Trigger a state change:}

    \qml 

        State { name: 'loaded'; when: loader.status = Loader.Ready }

    \endqml

    \e {Implement an \c onStatusChanged signal handler:}

    \qml 

        Loader {

            id: loader

            onStatusChanged: if (loader.status == Loader.Ready) console.log('Loaded')

        }

    \endqml

    \e {Bind to the status value:}

    \qml

        Text { text: loader.status != Loader.Ready ? 'Not Loaded' : 'Loaded' }

    \endqml

    Note that if the source is a local file, the status will initially be Ready (or Error). While

    there will be no onStatusChanged signal in that case, the onLoaded will still be invoked.

    \sa progress

*/

QDeclarativeLoader::Status QDeclarativeLoader::status() const

{

    Q_D(const QDeclarativeLoader);

    if (d->component)

        return static_cast<QDeclarativeLoader::Status>(d->component->status());

    if (d->item)

        return Ready;

    return d->source.isEmpty() ? Null : Error;

}

void QDeclarativeLoader::componentComplete()

{

    QDeclarativeItem::componentComplete();

    if (status() == Ready)

        emit loaded();

}

/*!

    \qmlsignal Loader::onLoaded()

    This handler is called when the \l status becomes \c Loader.Ready, or on successful

    initial load.

*/

/*!

\qmlproperty real Loader::progress

This property holds the progress of loading QML data from the network, from

0.0 (nothing loaded) to 1.0 (finished).  Most QML files are quite small, so

this value will rapidly change from 0 to 1.

\sa status

*/

qreal QDeclarativeLoader::progress() const

{

    Q_D(const QDeclarativeLoader);

    if (d->item)

        return 1.0;

    if (d->component)

        return d->component->progress();

    return 0.0;

}

void QDeclarativeLoaderPrivate::_q_updateSize(bool loaderGeometryChanged)

{

    Q_Q(QDeclarativeLoader);

    if (!item)

        return;

    if (QDeclarativeItem *qmlItem = qobject_cast<QDeclarativeItem*>(item)) {

        q->setImplicitWidth(qmlItem->width());

        if (loaderGeometryChanged && q->widthValid())

            qmlItem->setWidth(q->width());

        q->setImplicitHeight(qmlItem->height());

        if (loaderGeometryChanged && q->heightValid())

            qmlItem->setHeight(q->height());

    } else if (item && item->isWidget()) {

        QGraphicsWidget *widget = static_cast<QGraphicsWidget*>(item);

        QSizeF widgetSize = widget->size();

        q->setImplicitWidth(widgetSize.width());

        if (loaderGeometryChanged && q->widthValid())

            widgetSize.setWidth(q->width());

        q->setImplicitHeight(widgetSize.height());

        if (loaderGeometryChanged && q->heightValid())

            widgetSize.setHeight(q->height());

        if (widget->size() != widgetSize)

            widget->resize(widgetSize);

    }

}

/*!

    \qmlproperty Item Loader::item

*/

QGraphicsObject *QDeclarativeLoader::item() const

{

    Q_D(const QDeclarativeLoader);

    return d->item;

}

void QDeclarativeLoader::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)

{

    Q_D(QDeclarativeLoader);

    if (newGeometry != oldGeometry) {

        d->_q_updateSize();

    }

    QDeclarativeItem::geometryChanged(newGeometry, oldGeometry);

}

QVariant QDeclarativeLoader::itemChange(GraphicsItemChange change, const QVariant &value)

{

    Q_D(QDeclarativeLoader);

    if (change == ItemSceneHasChanged) {