1 /*

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

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 

    18 

    19 #ifndef QSTMPINCHGESTURERECOGNISER_H_

    20 #define QSTMPINCHGESTURERECOGNISER_H_

    21 

    22 #include <qstmgestureengine_if.h>

    23 #include <qstmgesture_if.h>

    24 #include <qstmgesturelistener_if.h>

    25 

    26 

    27 namespace qstmGesture

    28 {

    29 /*!

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

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

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

    33  * This gesture recogniser tries to use that feature

    34  * to determine when the gestures looks like a pinch.

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

    36  * With current implementation it is easy to zoom in but

    37  * almost impossible to zoom out.

    38  */

    39 class QStm_PinchGestureRecogniser : public QStm_GestureRecogniser

    40 {

    41 public:

    42     static const QStm_GestureUid KUid = EGestureUidPinch;

    43 

    44     virtual ~QStm_PinchGestureRecogniser();

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

    46     virtual void release(QStm_GestureEngineIf* ge) ;

    47 

    48     virtual QStm_GestureUid gestureUid() const { return KUid; }

    49 

    50     /* define the pinch triggering as speed value */

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

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

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

    54 

    55     QStm_PinchGestureRecogniser(QStm_GestureListenerIf* listener) ;

    56 

    57     void calculateZoomingLine() ;

    58     float calculateDistance() ;

    59     int adjustPinchMove(float& aPreviousDistance, float aNewDistance) ;

    60 

    61 private:

    62     bool     m_pinching ;

    63     float    m_pinchingspeed ;

    64     QPoint   m_pinchstart ;

    65     QPoint   m_pinchend ;

    66 

    67     float m_m ;

    68     float m_b ;

    69 

    70     float   m_ddistance ;

    71     bool    m_holdseen ;

    72     QPoint  m_holdseenAtPos ;

    73     QTime   m_holdseenAtTime ;

    74 };

    75 

    76 }

    77 

    78 #endif /* QSTMPINCHGESTURERECOGNISER_H_ */