/*

* 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:

*

*/

#ifndef QSTMPINCHGESTURERECOGNISER_H_

#define QSTMPINCHGESTURERECOGNISER_H_

#include <qstmgestureengine_if.h>

#include <qstmgesture_if.h>

#include <qstmgesturelistener_if.h>

namespace qstmGesture

{

/*!

 * Recognise pinching gesture. !!! very experimental !!!

 * It seems that in capacitive touch in Symbian 9.4 touching with two

 * fingers causes fast EDrag events which are far from each other.

 * This gesture recogniser tries to use that feature

 * to determine when the gestures looks like a pinch.

 * Would requires a lot of tuning to be really useful, if at all possible.

 * With current implementation it is easy to zoom in but

 * almost impossible to zoom out.

 */

class QStm_PinchGestureRecogniser : public QStm_GestureRecogniser

{

public:

    static const QStm_GestureUid KUid = EGestureUidPinch;

    virtual ~QStm_PinchGestureRecogniser();

    virtual QStm_GestureRecognitionState recognise(int numOfActiveStreams, QStm_GestureEngineIf* ge) ;

    virtual void release(QStm_GestureEngineIf* ge) ;

    virtual QStm_GestureUid gestureUid() const { return KUid; }

    /* define the pinch triggering as speed value */

    /* after EHold has been seen, then any move which is faster than this will enter pinch gesture */

    /* note that the value varies depending on techology, speed is measured as pixels / ms */

    void setPinchingSpeed(float aSpeed) /*__SOFTFP */;

    QStm_PinchGestureRecogniser(QStm_GestureListenerIf* listener) ;

    void calculateZoomingLine() ;

    float calculateDistance() ;

    int adjustPinchMove(float& aPreviousDistance, float aNewDistance) ;

private:

    bool     m_pinching ;

    float    m_pinchingspeed ;

    QPoint   m_pinchstart ;

    QPoint   m_pinchend ;

    float m_m ;

    float m_b ;

    float   m_ddistance ;

    bool    m_holdseen ;

    QPoint  m_holdseenAtPos ;

    QTime   m_holdseenAtTime ;

};

}

#endif /* QSTMPINCHGESTURERECOGNISER_H_ */