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

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser 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 will be met:

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

**

** 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 developer.feedback@nokia.com.

**

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

#include <QEvent>

#include <QGestureRecognizer>

#include <QGraphicsView>

#include <QMouseEvent>

#include "hbpangesture.h"

#include "hbpangesture_p.h"

#include "hbpangesturelogic_p.h"

const int KPanStopTime = 30;

const int KVelocitySampleTime = 30;

const int KPanThreshold = 20;

/*!

   @hbcore

   \internal

   \class HbPanGestureLogic

   \brief

*/

/*!

    \internal

    \brief

    \return

*/

HbPanGestureLogic::HbPanGestureLogic()

{

    mCurrentTime = QTime();

}

HbPanGestureLogic::~HbPanGestureLogic() {}

/*!

    \internal

    \brief

    \return

*/

bool HbPanGestureLogic::isMouseEvent(QEvent::Type eventType)

{

    return eventType == QEvent::MouseButtonPress ||

           eventType == QEvent::MouseMove ||

           eventType == QEvent::MouseButtonDblClick ||

           eventType == QEvent::MouseButtonRelease;

}

/*!

    \internal

    \brief

    \return

*/

void HbPanGestureLogic::resetGesture(HbPanGesture *gesture)

{

    gesture->d_ptr->mStartPos                     = QPointF(0,0);

    gesture->d_ptr->mDeltaSinceLastTimeStamp      = QPointF(0,0);

    gesture->d_ptr->mSceneStartPos                = QPointF(0,0);

    gesture->d_ptr->mSceneLastOffset              = QPointF(0,0);

    gesture->d_ptr->mSceneOffset                  = QPointF(0,0);

    gesture->d_ptr->mSceneDeltaSinceLastTimeStamp = QPointF(0,0);

    gesture->d_ptr->mAxisX.clear();

    gesture->d_ptr->mAxisY.clear();

    gesture->d_ptr->mSceneAxisX.clear();

    gesture->d_ptr->mSceneAxisY.clear();

    gesture->setLastOffset(QPointF());

    gesture->setOffset(QPointF(0,0));

    gesture->setAcceleration(0);

    gesture->setStartPos(QPointF());

}

/*!

    \internal

    \brief

    \return

*/

QGestureRecognizer::Result HbPanGestureLogic::handleMousePress(

        Qt::GestureState gestureState,

        HbPanGesture *gesture,

        QObject *watched,

        QMouseEvent *me )

{

    // Just ignore situations that are not interesting at all.

    if ( !( gestureState == Qt::NoGesture && me->button() == Qt::LeftButton ) )

    {

        return QGestureRecognizer::Ignore;

    }

    gesture->setHotSpot( me->globalPos() );

    gesture->setStartPos( me->globalPos() );

    gesture->setOffset( QPointF( 0,0 ) );

    gesture->setLastOffset( QPointF( 0,0 ) );

    QPointF scenePos = HbGestureUtils::mapToScene(watched, me->globalPos());

    gesture->d_ptr->mSceneStartPos       = scenePos;

    gesture->d_ptr->mSceneOffset         = HbGestureUtils::mapToScene(watched, QPointF(0,0));

    gesture->d_ptr->mSceneLastOffset     = HbGestureUtils::mapToScene(watched, QPointF(0,0));

    gesture->d_ptr->mLastTimeStamp = mCurrentTime;

    gesture->d_ptr->mAxisX.record( me->globalPos().x(), mCurrentTime );

    gesture->d_ptr->mAxisY.record( me->globalPos().y(), mCurrentTime );

    gesture->d_ptr->mSceneAxisX.record( scenePos.x(), mCurrentTime );

    gesture->d_ptr->mSceneAxisY.record( scenePos.y(), mCurrentTime );

    return QGestureRecognizer::MayBeGesture;

}

/*!

    \internal

    \brief

    \return

*/

QGestureRecognizer::Result HbPanGestureLogic::handleMouseMove(

        Qt::GestureState gestureState,

        HbPanGesture *gesture,

        QObject *watched,

        QMouseEvent *me )

{

    if ( !me->buttons().testFlag(Qt::LeftButton) )

    {

        return QGestureRecognizer::Ignore;

    }

    QPointF offset = me->globalPos() - gesture->startPos().toPoint();

    if (gestureState == Qt::NoGesture && offset.manhattanLength() <= KPanThreshold )

    {

        return QGestureRecognizer::MayBeGesture;

    }

    // Hotspot is updated on the press and on events after the gesture started.

    // Here we are checking the previously set gestureState.

    if (gestureState == Qt::GestureStarted || gestureState == Qt::GestureUpdated) {

        gesture->setHotSpot( me->globalPos() );

    }

    gesture->setLastOffset( gesture->offset().toPoint() );

    gesture->setOffset( offset );

    gesture->d_ptr->mSceneLastOffset = gesture->d_ptr->mSceneOffset;

    gesture->d_ptr->mSceneOffset =

            HbGestureUtils::mapToScene(watched, me->globalPos()) - gesture->d_ptr->mSceneStartPos;

    gesture->d_ptr->mLastTimeStamp = mCurrentTime;

    QPointF scenePos = HbGestureUtils::mapToScene(watched, me->globalPos());

    gesture->d_ptr->mAxisX.record( me->globalPos().x(), mCurrentTime );

    gesture->d_ptr->mAxisY.record( me->globalPos().y(), mCurrentTime );

    gesture->d_ptr->mSceneAxisX.record( scenePos.x(), mCurrentTime );

    gesture->d_ptr->mSceneAxisY.record( scenePos.y(), mCurrentTime );

    return QGestureRecognizer::TriggerGesture;

}

/*!

    \internal

    \brief

    \return

*/

QGestureRecognizer::Result HbPanGestureLogic::handleMouseRelease(

        Qt::GestureState gestureState,

        HbPanGesture *gesture,

        QObject *watched,

        QMouseEvent *me )

{   

    Q_UNUSED(me->globalPos());

    Q_UNUSED(gesture);

    Q_UNUSED(watched);

    gesture->d_ptr->mLastTimeStamp = mCurrentTime;

    if ( gestureState == Qt::GestureStarted || gestureState == Qt::GestureUpdated )

    {

        return QGestureRecognizer::FinishGesture;

    }

    else

    {

        return QGestureRecognizer::CancelGesture;

    }

}

/*!

    \internal

    \brief

    \return

*/

QGestureRecognizer::Result HbPanGestureLogic::recognize(

        Qt::GestureState gestureState,

        HbPanGesture *gesture,

        QObject *watched,

        QEvent *event )

{

    // Record the time right away.

    mCurrentTime = QTime::currentTime();

    if ( isMouseEvent(event->type()) )

    {

        QMouseEvent* me = static_cast<QMouseEvent*>(event);

        switch(event->type())

        {

        case QEvent::MouseButtonDblClick:

        case QEvent::MouseButtonPress:

            return handleMousePress(gestureState, gesture, watched, me);

        case QEvent::MouseMove:

            return handleMouseMove(gestureState, gesture, watched, me);

        case QEvent::MouseButtonRelease:

            return handleMouseRelease(gestureState, gesture, watched, me);

        default: break;

        }

    }

    return QGestureRecognizer::Ignore;

}