/*

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

* All rights reserved.

* This component and the accompanying materials are made available

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

* which accompanies this distribution, and is available

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

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Gesture helper implementation

*

*/

#include <e32math.h>

#include <rt_uievent.h>

#include "filelogger.h"

#include "zoomgesturerecogniser.h"

#include "GenericSimpleGesture.h"

using namespace stmGesture ;

_LIT8(KZoomInName, "ZoomIn") ;

_LIT8(KZoomOutName, "ZoomOut") ;

CZoomGestureRecogniser* CZoomGestureRecogniser::NewL(MGestureListener* aListener)

{

    CZoomGestureRecogniser* self = new (ELeave) CZoomGestureRecogniser(aListener) ;

    return self;

}

CZoomGestureRecogniser::CZoomGestureRecogniser(MGestureListener* aListener) :

    CGestureRecogniser(aListener), m_area(TRect::EUninitialized)

{

    m_rangesizeInPixels = 20 ;  // by default 20 pixels from the edges is the area

    m_zooming = false ;

}

CZoomGestureRecogniser::~CZoomGestureRecogniser()

{

}

TGestureRecognitionState CZoomGestureRecogniser::recognise(int numOfActiveStreams,

        MGestureEngineIf* pge)

{

    TGestureRecognitionState state = ENotMyGesture;

    // Check if we are enabled or not

    if (!m_gestureEnabled) return state ;

    // Look at the events to see if it looks like zoom with one pointer

    if (numOfActiveStreams == 1)

    {

        const stmUiEventEngine::MUiEvent* puie = pge->getUiEvents(0);

        int countOfEvents = puie->countOfEvents();

        stmUiEventEngine::TUiEventCode eventCode = puie->Code();

        if (m_loggingenabled)

        {

            LOGARG("CZoomGestureRecogniser: %d num %d code %d",

                    eventCode, countOfEvents, eventCode);

        }

        if (!m_zooming)

        {

            // We are not yet zoomin, check if we should start, i.e. whether we are

            // inside the zoom trigger areas near the corners when touch is done...

            if (eventCode == stmUiEventEngine::ETouch) // It must be ETouch inside the corner

            {

                if (m_loggingenabled)

                {

                    LOGARG("CZoomGestureRecogniser: 0x%x ETouch: num %d code %d, %d",

                            this, countOfEvents, puie->CurrentXY().iX, puie->CurrentXY().iY);

                    LOGARG("CZoomGestureRecogniser: area, %d,%d %d,%d, range: %d", m_area.iTl.iX, m_area.iTl.iY, m_area.iBr.iX, m_area.iBr.iY, m_rangesizeInPixels);

                }

                // the lower left rectangle is m_rangesizeIPixels from the corner

                TRect lowerleft(m_area.iTl.iX, m_area.iBr.iY-m_rangesizeInPixels,

                        m_area.iTl.iX+m_rangesizeInPixels, m_area.iBr.iY) ;

                TRect upperright(m_area.iBr.iX-m_rangesizeInPixels, m_area.iTl.iY,

                        m_area.iBr.iX, m_area.iTl.iY+m_rangesizeInPixels) ;

                m_previoustouch = m_startingtouch = puie->CurrentXY() ;

                m_delta = 0 ;

                if (lowerleft.Contains(m_startingtouch) || upperright.Contains(m_startingtouch))

                {

                    if (m_loggingenabled)

                    {

                        LOGARG("CZoomGestureRecogniser: ZOOM IN/OUT, (%d,%d) in %d,%d %d,%d, range: %d",

                            m_startingtouch.iX, m_startingtouch.iY,

                            m_area.iTl.iX, m_area.iTl.iY, m_area.iBr.iX, m_area.iBr.iY,

                            m_rangesizeInPixels);

                    }

                    m_zooming = true ;

                    if (lowerleft.Contains(m_startingtouch))

                    {

                        m_zoomtype = EZoomIn ;

                    }

                    else

                    {

                        m_zoomtype = EZoomOut ;

                    }

                    state = ELockToThisGesture ;    // keep zooming until release

                    TTwoPointGesture pgest(KUid, m_startingtouch, m_startingtouch);

                    pgest.setLogging(m_loggingenabled) ;

                    pgest.setDetails(m_delta) ;

                    pgest.setName(m_zoomtype == EZoomIn ? KZoomInName() : KZoomOutName()) ;

                    pgest.setType(m_zoomtype);

                    // Call the listener to inform that a gesture has happened

                    m_listener->gestureEnter(pgest) ;

                }

                else

                {

                    // It is not our gesture so do nothing...

                }

            }

            else

            {

                // It is not touch, so not our initiating UI event.. do nothing

            }

        }

        else

        {

            // We are already zooming, calculate the changes in zooming factor if it looks we are still zooming

            if (eventCode == stmUiEventEngine::ERelease) // ERelease stops zooming

            {

                // We were zooming, but if there are multiple touches we are not any more

                m_listener->gestureExit(KUid) ; // should we call this or not?

            }

            else    // all other UI events will keep on zooming

            {

                state = ELockToThisGesture ;    // Keep the gesture

                const TPoint& p = puie->CurrentXY() ;

                float newdist = calculateDistance(p) ;

                float olddist = calculateDistance(m_previoustouch) ;

                m_previoustouch = p ;

                m_delta = adjustZoom(olddist, newdist) ;

                state = EGestureActive ;

                // Inform listener only if there is something to say

                if (m_delta != 0)

                {

                    TTwoPointGesture pgest = TTwoPointGesture(KUid, p, m_startingtouch);

                    pgest.setLogging(m_loggingenabled) ;

                    pgest.setDetails(m_delta) ;

                    pgest.setName(m_zoomtype == EZoomIn ? KZoomInName() : KZoomOutName()) ;

                    pgest.setType(m_zoomtype);

                    // Call the listener to inform that a gesture has happened

                    m_listener->gestureEnter(pgest) ;

                }

            }

        }

    }

    else

    {

        if (m_zooming)

        {

            // We were zooming, but if there are multiple touches we are not any more

            m_listener->gestureExit(KUid) ; // should we call this or not?

        }

        m_zooming = false ;

    }

    return state;

}

void CZoomGestureRecogniser::release(MGestureEngineIf*)

{

    if (m_zooming)

    {

        m_zooming = false ;

        m_listener->gestureExit(KUid) ; // should we call this or not?

    }

    if (m_loggingenabled)

    {

        LOGARG("CZoomGestureRecogniser: 0x%x release", this);

    }

}

void CZoomGestureRecogniser::setRange(int rangeInPixels)

{

    m_rangesizeInPixels = rangeInPixels ;

}

void CZoomGestureRecogniser::setArea(const TRect& theArea)

{

    m_area = theArea ;

    if (m_loggingenabled)

    {

        LOGARG("CZoomGestureRecogniser: set area, %d,%d %d,%d",

                m_area.iTl.iX, m_area.iTl.iY, m_area.iBr.iX, m_area.iBr.iY);

    }

}

/*!

 * calculate the distance, return as as float

 */

float CZoomGestureRecogniser::calculateDistance(const TPoint& tp)

{

    double x = ((m_startingtouch.iX-tp.iX)*(m_startingtouch.iX-tp.iX)) +

                ((m_startingtouch.iY-tp.iY)*(m_startingtouch.iY-tp.iY)) ;

    double ddist ;

    Math::Sqrt(ddist, x) ;

    return ddist ;

}

int CZoomGestureRecogniser::adjustZoom(float& aPreviousDistance, float aNewDistance)

{

    float diff = aNewDistance - aPreviousDistance ;

    float logdiff = diff ;

    if (diff < 0) diff = -diff ;

    float changePercentage = (diff/aPreviousDistance)*100.f ;

    if (changePercentage > 10.f)

    {

        // change more than 10%, make at most 10%

        float newdiff = aPreviousDistance*0.1f;

        if (aPreviousDistance > aNewDistance) newdiff = -newdiff ;

        if (m_loggingenabled)

        {

            LOGARG("CZoomGestureRecogniser: adjust zoom from %f to %f : was, now %f %f",

                double(logdiff), double(newdiff), double(aPreviousDistance), double(aNewDistance));

        }

        aPreviousDistance = aPreviousDistance + newdiff ;

        diff = newdiff ;

    }

    else

    {

        if (m_loggingenabled)

        {

            LOGARG("CZoomGestureRecogniser: adjust zoom from %f to %f : was, now %f %f",

                double(logdiff), double(diff), double(aPreviousDistance), double(aNewDistance));

        }

        aPreviousDistance = aNewDistance ;  // accept the new value and update the new length

        diff = logdiff ;    // put the original back

    }

    return (int)diff ;

}