/*

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

* All rights reserved.

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU Lesser General Public License as published by

* the Free Software Foundation, version 2.1 of the License.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU Lesser General Public License for more details.

*

* You should have received a copy of the GNU Lesser General Public License

* along with this program.  If not,

* see "http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html/".

*

* Description:

*

*/

#include "ScrollableViewBase.h"

#include "Kinetics/KineticScroller.h"

#include <QGraphicsScene>

#include <QGraphicsSceneMouseEvent>

#include <QPointF>

namespace GVA {

ScrollableViewBase::ScrollableViewBase(QGraphicsItem* parent, Qt::WindowFlags wFlags)

    : QGraphicsWidget(parent, wFlags)

    , m_scrollWidget(0)

{

    //To get only the mouse events within the ScrollableViewBase.

    setFlag(QGraphicsItem::ItemClipsToShape, true);

    //To disable childrens painting outside the ViewportItem's rect.

    setFlag(QGraphicsItem::ItemClipsChildrenToShape, true);

    //To speed up painting.

    setFlag(QGraphicsItem::ItemHasNoContents, true);

    setAttribute(Qt::WA_OpaquePaintEvent, true);

    m_kineticScroller = new KineticScroller(this);

    //Event filter on all children of the viewport, so that all mouse

    //events can be intercepted and used for kinetic scrolling.

    setFiltersChildEvents(true);

}

ScrollableViewBase::~ScrollableViewBase()

{}

void ScrollableViewBase::setWidget(QGraphicsWidget* view)

{

    if (view == m_scrollWidget)

        return;

    if (m_scrollWidget) {

        m_scrollWidget->setParentItem(0);

        delete m_scrollWidget;

    }

    m_scrollWidget = view;

    m_scrollWidget->setAttribute(Qt::WA_OpaquePaintEvent, true);

    m_scrollWidget->setParentItem(this);

}

QSize ScrollableViewBase::viewportSize() const

{

    return size().toSize();

}

QPoint ScrollableViewBase::maximumScrollPosition() const

{

    QSizeF contentsSize = m_scrollWidget->size();

    QSizeF viewportSize = size();

    QSize maxScrollSize = (contentsSize - viewportSize).toSize();

    return QPoint(qMax(0, maxScrollSize.width()), qMax(0, maxScrollSize.height()));

}

QPoint ScrollableViewBase::scrollPosition() const

{

    return (-scrollWidgetPos()).toPoint();

}

void ScrollableViewBase::setScrollPosition(const QPoint& pos, const QPoint& overShoot)

{

    m_overShoot = overShoot;

    setScrollWidgetPos(-pos);

}

void ScrollableViewBase::stateChanged(KineticScrollable::State oldState

                                      , KineticScrollable::State newState)

{

    Q_UNUSED(oldState);

    Q_UNUSED(newState);

}

void ScrollableViewBase::setScrollWidgetGeometry(const QRectF& geom)

{

    scrollWidget()->setGeometry(adjustScrollWidgetRect(geom));

}

QRectF ScrollableViewBase::adjustScrollWidgetRect(const QRectF& rect)

{

    //FIX ME : Stop animation of scroll widget before adjusting it here??

    QRectF newRect(rect);

    QSizeF widgetSize = rect.size();

    QSizeF viewportSize = size();

    qreal w = viewportSize.width() - widgetSize.width();

    qreal h = viewportSize.height() - widgetSize.height();

    if ( w > 0 ) {

        newRect.moveLeft(0);

        m_extraPos.setX(w/2);

      }

    else {

    	m_extraPos.setX(0);

        if (newRect.x() < w)

            newRect.moveLeft(w);

        if (newRect.x() > 0)

            newRect.moveLeft(0);

    }

    if ( h > 0 ) {

        m_extraPos.setY(h/2);

        newRect.moveTop(0);

      }

    else {

    	 m_extraPos.setY(0);

        if (newRect.y() < h)

            newRect.moveTop(h);

        if (newRect.y() > 0)

            newRect.moveTop(0);

    }

    //newRect.translate(m_extraPos);

    newRect.translate(m_overShoot);

    return newRect;

}

void ScrollableViewBase::setScrollWidgetPos(const QPointF& pos)

{

    setScrollWidgetGeometry(QRectF(pos, scrollWidget()->size()));

}

QPointF ScrollableViewBase::scrollWidgetPos() const

{

    return scrollWidget()->pos()  /*- m_extraPos*/ - m_overShoot;

}

} //namespace GVA