/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "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:

*

*/

#include "akntouchgesturefwdragtracer.h"

using namespace AknTouchGestureFw;

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

// Two-phased constructor.

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

//

CAknTouchGestureFwDragTracer* CAknTouchGestureFwDragTracer::NewL()

    {

    CAknTouchGestureFwDragTracer* self =

        CAknTouchGestureFwDragTracer::NewLC();

    CleanupStack::Pop( self );

    return self;

    }

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

// Two-phased constructor.

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

//

CAknTouchGestureFwDragTracer* CAknTouchGestureFwDragTracer::NewLC()

    {

    CAknTouchGestureFwDragTracer* self

        = new ( ELeave ) CAknTouchGestureFwDragTracer();

    CleanupStack::PushL( self );

    return self;

    }

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

// Destructor

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

//

CAknTouchGestureFwDragTracer::~CAknTouchGestureFwDragTracer()

    {

    }

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

// Initializes the drag tracer state.

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

//

void CAknTouchGestureFwDragTracer::Initialize( const TPoint& aStartPosition )

    {

    iHorizDirection = EDirectionNone;

    iVertDirection = EDirectionNone;

    iHorizCounter = 0;

    iVertCounter = 0;

    iPosition = aStartPosition;

    }

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

// Checks if the drag direction has been changed.

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

//

TBool CAknTouchGestureFwDragTracer::IsDirectionChanged(

    const TPoint& aPosition,

    TInt aSensitivity )

    {

    if ( aPosition == iPosition )

        {

        // Can't calculate direction.

        return EFalse;

        }

    TBool directionChanged( EFalse );

    // Horizontal direction

    if ( iHorizDirection == EDirectionNone )

        {

        // Calculate first horizontal direction based on current and

        // previous point.

        if ( aPosition.iX > iPosition.iX )

            {

            iHorizDirection = EDirectionForward;

            }

        else if ( aPosition.iX < iPosition.iX )

            {

            iHorizDirection = EDirectionBackward;

            }

        }

    else

        {

        // Horizontal direction changes only if certain amount of new points

        // is to reversed direction.

        // Note: direction counter is updated with the following calls.

        if ( IsDirectionChanged(

                aPosition.iX,

                iPosition.iX,

                iHorizDirection,

                iHorizCounter,

                aSensitivity ) )

            {

            directionChanged = ETrue;

            }

        }

    // Vertical direction

    if ( iVertDirection == EDirectionNone )

        {

        // Calculate first vertical direction based on current and

        // previous point.

        if ( aPosition.iY > iPosition.iY )

            {

            iVertDirection = EDirectionForward;

            }

        else if ( aPosition.iY < iPosition.iY )

            {

            iVertDirection = EDirectionBackward;

            }

        }

    else

        {

        // Vertical direction changes only if certain amount of new points

        // is to reversed direction.

        // Note: direction counter is updated with the following call.

        if ( IsDirectionChanged(

                aPosition.iY,

                iPosition.iY,

                iVertDirection,

                iVertCounter,

                aSensitivity ) )

            {

            directionChanged = ETrue;

            }

        }

    iPosition = aPosition;

    return directionChanged;

    }

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

// Checks if the drag direction has been changed.

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

//

TBool CAknTouchGestureFwDragTracer::IsDirectionChanged(

    TInt aCurrentCoordinate,

    TInt aPrevCoordinate,

    TDirection& aDirection,

    TInt& aCounter,

    TInt aSensitivity )

    {

    TBool directionChanged( EFalse );

    if ( aDirection == EDirectionForward )

        {

        if ( aCurrentCoordinate < aPrevCoordinate )

            {

            aCounter++;

            }

        else

            {

            aCounter = 0;

            }

        if ( aCounter == aSensitivity )

            {

            directionChanged = ETrue;

            aDirection = EDirectionBackward;

            aCounter = 0;

            }

        }

    else if ( aDirection == EDirectionBackward )

        {

        if ( aCurrentCoordinate > aPrevCoordinate )

            {

            aCounter++;

            }

        else

            {

            aCounter = 0;

            }

        if ( aCounter == aSensitivity )

            {

            directionChanged = ETrue;

            aDirection = EDirectionForward;

            aCounter = 0;

            }

        }

    return directionChanged;

    }

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

// Default C++ constructor.

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

//

CAknTouchGestureFwDragTracer::CAknTouchGestureFwDragTracer():

    iHorizDirection( EDirectionNone ),

    iVertDirection( EDirectionNone ),

    iHorizCounter( 0 ),

    iVertCounter( 0 ),

    iPosition( 0, 0 )

    {

    }

// End of File