/****************************************************************************
**
** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt3D module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qlayerfilter.h"
#include "qlayerfilter_p.h"
#include "qlayer.h"
#include <Qt3DCore/qpropertyupdatedchange.h>
#include <Qt3DCore/qpropertynodeaddedchange.h>
#include <Qt3DCore/qpropertynoderemovedchange.h>
#include <Qt3DRender/qframegraphnodecreatedchange.h>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

QLayerFilterPrivate::QLayerFilterPrivate()
    : QFrameGraphNodePrivate()
{
}

/*!
    \class Qt3DRender::QLayerFilter
    \inmodule Qt3DRender
    \since 5.5
    \brief Controls layers Drawn in a frame graph branch.

    A Qt3DRender::QLayerFilter can be used to instruct the renderer as to which layer(s)
    to draw in that branch of the frame graph. The Qt3DRender::QLayerFilter selects which
    entities to draw based on the Qt3DRender::QLayer instances added to the QLayerFilter
    and as components to the \l Qt3DCore::QEntity.
*/

/*!
    \qmltype LayerFilter
    \instantiates Qt3DRender::QLayerFilter
    \inherits FrameGraphNode
    \inqmlmodule Qt3D.Render
    \since 5.5
    \brief Controls layers Drawn in a frame graph branch.

    A LayerFilter can be used to instruct the renderer as to which layer(s)
    to draw in that branch of the frame graph. The LayerFilter selects which
    entities to draw based on the \l Layer instances added to the LayerFilter
    and as components to the \l Entity.
*/

/*!
    \qmlproperty list<Layer> Qt3D.Render::LayerFilter::layers
    Holds a list of layers specifying the layers to select for drawing.
    \readonly
 */

/*!
    The constructor creates an instance with the specified \a parent.
 */
QLayerFilter::QLayerFilter(QNode *parent)
    : QFrameGraphNode(*new QLayerFilterPrivate, parent)
{
}

/*! \internal */
QLayerFilter::QLayerFilter(QLayerFilterPrivate &dd, QNode *parent)
    : QFrameGraphNode(dd, parent)
{
}

/*! \internal */
QLayerFilter::~QLayerFilter()
{
}

/*!
    Add \a layer to the current list of layers
 */
void QLayerFilter::addLayer(QLayer *layer)
{
    Q_ASSERT(layer);
    Q_D(QLayerFilter);
    if (!d->m_layers.contains(layer)) {
        d->m_layers.append(layer);

        // Ensures proper bookkeeping
        d->registerDestructionHelper(layer, &QLayerFilter::removeLayer, d->m_layers);

        // We need to add it as a child of the current node if it has been declared inline
        // Or not previously added as a child of the current node so that
        // 1) The backend gets notified about it's creation
        // 2) When the current node is destroyed, it gets destroyed as well
        if (!layer->parent())
            layer->setParent(this);

        if (d->m_changeArbiter != nullptr) {
            const auto change = Qt3DCore::QPropertyNodeAddedChangePtr::create(id(), layer);
            change->setPropertyName("layer");
            d->notifyObservers(change);
        }
    }
}

/*!
    Remove \a layer from the current list of layers
 */
void QLayerFilter::removeLayer(QLayer *layer)
{
    Q_ASSERT(layer);
    Q_D(QLayerFilter);
    if (d->m_changeArbiter != nullptr) {
        const auto change = Qt3DCore::QPropertyNodeRemovedChangePtr::create(id(), layer);
        change->setPropertyName("layer");
        d->notifyObservers(change);
    }
    d->m_layers.removeOne(layer);
    // Remove bookkeeping connection
    d->unregisterDestructionHelper(layer);
}

/*!
    \return the current list of layers
 */
QVector<QLayer *> QLayerFilter::layers() const
{
    Q_D(const QLayerFilter);
    return d->m_layers;
}

Qt3DCore::QNodeCreatedChangeBasePtr QLayerFilter::createNodeCreationChange() const
{
    auto creationChange = QFrameGraphNodeCreatedChangePtr<QLayerFilterData>::create(this);
    auto &data = creationChange->data;
    Q_D(const QLayerFilter);
    data.layerIds = qIdsForNodes(d->m_layers);
    return creationChange;
}

} // namespace Qt3DRender

QT_END_NAMESPACE
