/*
* 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 ;
    bool    m_isReleased[2];
};

}

#endif /* QSTMPINCHGESTURERECOGNISER_H_ */