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

**

** 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.

**

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

/*!

//

//  W A R N I N G

//  -------------

//

// This implementation of Gesture filter is most probably removed in later releases.

// It exists purely as an implementation detail.

// This implementation may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

*/

#include "hbswipegesturerecognizer_p.h"

#include "hbswipegesture.h"

#include "hbswipegesture_p.h"

#include <QEvent>

#include <QTouchEvent>

#include <QGraphicsSceneMouseEvent>

#include <QPoint>

#include <QLine>

#include <QVariant>

#include <QDebug>

const int KMilliSecsToSecs = 1000;

/*!

	@proto

    @hbcore

	\class HbSwipeGestureRecognizer

    \brief HbSwipeGestureRecognizer Gesture recognizer for swipes (flicks).

*/

/*!

	Constructs new HbSwipeGestureRecognizer.

 */

HbSwipeGestureRecognizer::HbSwipeGestureRecognizer()

{

}

HbSwipeGestureRecognizer::~HbSwipeGestureRecognizer()

{

}

QGesture* HbSwipeGestureRecognizer::create(QObject *)

{

    return new HbSwipeGesture();

}

/*!

	The event filter function.

	\a obj Parameter not currently used.

	\internal

 */

QGestureRecognizer::Result HbSwipeGestureRecognizer::recognize(QGesture *state, QObject *, QEvent *event)

{

    HbSwipeGesture *q = qobject_cast<HbSwipeGesture *>(state);

    if (!q) {

        return QGestureRecognizer::Ignore;

    }

    if (QTouchEvent *touchEvent = dynamic_cast<QTouchEvent *>(event)) {

        return recognizeTouchEvent(q, touchEvent);

    }

    else if (QGraphicsSceneMouseEvent *mouseEvent = dynamic_cast<QGraphicsSceneMouseEvent *>(event)){

        return recognizeMouseEvent(q, mouseEvent);

    }

    return QGestureRecognizer::Ignore;

}

/*!

*/

QGestureRecognizer::Result HbSwipeGestureRecognizer::recognizeTouchEvent(HbSwipeGesture *q, QTouchEvent *touchEvent)

{

    QGestureRecognizer::Result result;

    switch (touchEvent->type()) {

    case QEvent::TouchBegin: {

        q->d_func()->mSpeed = 1;

        q->d_func()->mTouchPointCount = 1;

        q->d_func()->mTime = QTime::currentTime();

        result = QGestureRecognizer::MayBeGesture | QGestureRecognizer::ConsumeEventHint;

        break;

    }

    case QEvent::TouchEnd: {

        if (q->state() != Qt::NoGesture) {

            result = QGestureRecognizer::FinishGesture;

            q->setProperty("speed", (int)(q->d_func()->mSpeed*KMilliSecsToSecs));

        } else {

            result = QGestureRecognizer::CancelGesture;

        }

        break;

    }

    case QEvent::TouchUpdate: {

        if(q->d_func()->mInitialPoint == QPointF()) {

            q->d_func()->mInitialPoint = touchEvent->touchPoints().first().lastScreenPos();

        }

        q->setHotSpot(touchEvent->touchPoints().first().screenPos());

        int touchPointCount = touchEvent->touchPoints().size();

        qreal xDistance = 0;

        for (int i = 0; i < touchPointCount; i++) {

            qreal distance = touchEvent->touchPoints().at(i).screenPos().x() - touchEvent->touchPoints().at(i).lastScreenPos().x();

            if(qAbs(distance) > qAbs(xDistance)) {

                xDistance = distance;

            }

        }

        qreal yDistance = 0;

        for (int i = 0; i < touchPointCount; i++) {

            qreal distance = touchEvent->touchPoints().at(i).screenPos().y() - touchEvent->touchPoints().at(i).lastScreenPos().y();

            if(qAbs(distance) > qAbs(yDistance)) {

                yDistance = distance;

            }

        }

        xDistance = qAbs(xDistance);

        yDistance = qAbs(yDistance);

        const qreal distance = xDistance >= yDistance ? xDistance : yDistance;

        int elapsedTime = q->d_func()->mTime.msecsTo(QTime::currentTime());

        if (!elapsedTime)

            elapsedTime = 1;

        q->d_func()->mSpeed = 0.9 * q->d_func()->mSpeed + distance / elapsedTime;

        q->d_func()->mTime = QTime::currentTime();

        q->setSwipeAngle(QLineF(q->d_func()->mInitialPoint, touchEvent->touchPoints().first().screenPos()).angle());

        static const int MoveThreshold = 5;

        if (!touchMoveEvent(touchEvent)) {

            if (q->state() != Qt::NoGesture) {

                result = QGestureRecognizer::TriggerGesture/* | QGestureRecognizer::ConsumeEventHint*/;

            } else {

                result = QGestureRecognizer::MayBeGesture/* | QGestureRecognizer::ConsumeEventHint*/;

            }

        }

        else if (xDistance > MoveThreshold || yDistance > MoveThreshold) {

            // measure the distance to check if the direction changed

            QSwipeGesture::SwipeDirection horizontal = QSwipeGesture::NoDirection;

            if(xDistance >= MoveThreshold)

                horizontal = touchEvent->touchPoints().first().screenPos().x() - touchEvent->touchPoints().first().lastScreenPos().x() > 0 ? QSwipeGesture::Right : QSwipeGesture::Left;

            QSwipeGesture::SwipeDirection vertical = QSwipeGesture::NoDirection;

            if(yDistance >= MoveThreshold)

                vertical = touchEvent->touchPoints().first().screenPos().y() - touchEvent->touchPoints().first().lastScreenPos().y() > 0 ? QSwipeGesture::Down : QSwipeGesture::Up;

            if ((yDistance > MoveThreshold && q->d_func()->mVerticalDirection != QSwipeGesture::NoDirection &&  q->d_func()->mVerticalDirection != vertical) ||

                (xDistance > MoveThreshold && q->d_func()->mHorizontalDirection != QSwipeGesture::NoDirection && q->d_func()->mHorizontalDirection != horizontal)) {

                // the user has changed the direction!

                result = QGestureRecognizer::CancelGesture;

            }

            else {

                result = QGestureRecognizer::TriggerGesture/* | QGestureRecognizer::ConsumeEventHint*/;

            }

            q->d_func()->mVerticalDirection = vertical;

            q->d_func()->mHorizontalDirection = horizontal;

        } else {

            if (q->state() != Qt::NoGesture)

                result = QGestureRecognizer::CancelGesture;

            else

                result = QGestureRecognizer::MayBeGesture/* | QGestureRecognizer::ConsumeEventHint*/;

        }

        q->d_func()->mTouchPointCount = touchPointCount;

        break;

    }

    default:

        result = QGestureRecognizer::Ignore;

        break;    

    }

    return result;

}

/*!

*/

QGestureRecognizer::Result HbSwipeGestureRecognizer::recognizeMouseEvent(HbSwipeGesture *q, QGraphicsSceneMouseEvent *mouseEvent)

{

    QGestureRecognizer::Result result;

    switch (mouseEvent->type()) {

    case QEvent::GraphicsSceneMousePress: {

        q->d_func()->mSpeed = 1;

        q->d_func()->mTime = QTime::currentTime();

        result = QGestureRecognizer::MayBeGesture;

        break;

    }

    case QEvent::GraphicsSceneMouseRelease: {

        if (q->state() != Qt::NoGesture) {

            result = QGestureRecognizer::FinishGesture;

            q->setProperty("speed", (int)(q->d_func()->mSpeed*KMilliSecsToSecs));

        } else {

            result = QGestureRecognizer::CancelGesture;

        }

        break;

    }

    case QEvent::GraphicsSceneMouseMove: {

        if(q->d_func()->mInitialMousePoint == QPoint()) {

            q->d_func()->mInitialMousePoint = mouseEvent->lastScreenPos();

        }

        q->setHotSpot(mouseEvent->screenPos());

        int xDistance = qAbs(mouseEvent->lastScreenPos().x() - mouseEvent->screenPos().x());

        int yDistance = qAbs(mouseEvent->lastScreenPos().y() - mouseEvent->screenPos().y());

        const int distance = xDistance >= yDistance ? xDistance : yDistance;

        int elapsedTime = q->d_func()->mTime.msecsTo(QTime::currentTime());

        if (!elapsedTime)

            elapsedTime = 1;

        q->d_func()->mSpeed = 0.9 * q->d_func()->mSpeed + distance / elapsedTime;

        q->d_func()->mTime = QTime::currentTime();

        q->setSwipeAngle(QLineF(QLine(q->d_func()->mInitialMousePoint, mouseEvent->screenPos())).angle());

        static const int MoveThreshold = 5;

        if (xDistance > MoveThreshold || yDistance > MoveThreshold) {

            // measure the distance to check if the direction changed

            QSwipeGesture::SwipeDirection horizontal = QSwipeGesture::NoDirection;

            if(xDistance >= MoveThreshold)

                horizontal = mouseEvent->screenPos().x() - mouseEvent->lastScreenPos().x() > 0 ? QSwipeGesture::Right : QSwipeGesture::Left;

            QSwipeGesture::SwipeDirection vertical = QSwipeGesture::NoDirection;

            if(yDistance >= MoveThreshold)

                vertical = mouseEvent->screenPos().y() - mouseEvent->lastScreenPos().y() > 0 ? QSwipeGesture::Down : QSwipeGesture::Up;

            if ((yDistance > MoveThreshold && q->d_func()->mVerticalDirection != QSwipeGesture::NoDirection &&  q->d_func()->mVerticalDirection != vertical) ||

                (xDistance > MoveThreshold && q->d_func()->mHorizontalDirection != QSwipeGesture::NoDirection && q->d_func()->mHorizontalDirection != horizontal)) {

                // the user has changed the direction!

                result = QGestureRecognizer::CancelGesture;

            }

            else {

                result = QGestureRecognizer::TriggerGesture;

            }

            q->d_func()->mVerticalDirection = vertical;

            q->d_func()->mHorizontalDirection = horizontal;

        } else {

            if (q->state() != Qt::NoGesture)

                result = QGestureRecognizer::CancelGesture;

            else

                result = QGestureRecognizer::MayBeGesture;

        }

        break;

    }

    default:

        result = QGestureRecognizer::Ignore;

        break;    

    }

    return result;

}

/*!

*/

void HbSwipeGestureRecognizer::reset(QGesture* state)

{

    HbSwipeGesture *q = qobject_cast<HbSwipeGesture *>(state);

    if(q) {

        q->d_func()->mVerticalDirection = QSwipeGesture::NoDirection;

        q->d_func()->mHorizontalDirection = QSwipeGesture::NoDirection;

        q->setSwipeAngle(0);

        q->d_func()->mInitialPoint = QPointF();

        q->d_func()->mInitialMousePoint = QPoint();

        q->d_func()->mSpeed = 0;

        q->d_func()->mTime = QTime();

        q->setProperty("speed", QVariant());

        q->d_func()->mTouchPointCount= 0;

    }

    QGestureRecognizer::reset(state);

}

/*!

*/

bool HbSwipeGestureRecognizer::touchMoveEvent(QTouchEvent *touchEvent)

{

    QTouchEvent::TouchPoint touchPoint;

    foreach (touchPoint, touchEvent->touchPoints()) {

        if (QLineF(touchPoint.screenPos(), touchPoint.lastScreenPos()).length() > 2) {

            return true;

        }

    }

    return false;

}

/*!

*/

QPointF HbSwipeGestureRecognizer::touchPointsCenterPoint(QTouchEvent *touchEvent)

{

    qreal x = 0;

    for(int i = 0; i < touchEvent->touchPoints().size(); i++) {

        x += touchEvent->touchPoints().at(i).screenPos().x();

    }

    x /= touchEvent->touchPoints().size();

    qreal y = 0;

    for(int i = 0; i < touchEvent->touchPoints().size(); i++) {

        y += touchEvent->touchPoints().at(i).screenPos().y();

    }

    y /= touchEvent->touchPoints().size();

    return QPointF(x, y);

}

// End of File