1 /*

     2 * Copyright (c) 2009 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 #include "akntouchgesturefwdragtracer.h"

    19 

    20 using namespace AknTouchGestureFw;

    21 

    22 

    23 // ---------------------------------------------------------------------------

    24 // Two-phased constructor.

    25 // ---------------------------------------------------------------------------

    26 //

    27 CAknTouchGestureFwDragTracer* CAknTouchGestureFwDragTracer::NewL()

    28     {

    29     CAknTouchGestureFwDragTracer* self =

    30         CAknTouchGestureFwDragTracer::NewLC();

    31     CleanupStack::Pop( self );

    32     return self;

    33     }

    34 

    35 

    36 // ---------------------------------------------------------------------------

    37 // Two-phased constructor.

    38 // ---------------------------------------------------------------------------

    39 //

    40 CAknTouchGestureFwDragTracer* CAknTouchGestureFwDragTracer::NewLC()

    41     {

    42     CAknTouchGestureFwDragTracer* self

    43         = new ( ELeave ) CAknTouchGestureFwDragTracer();

    44     CleanupStack::PushL( self );

    45     return self;

    46     }

    47 

    48 

    49 // ---------------------------------------------------------------------------

    50 // Destructor

    51 // ---------------------------------------------------------------------------

    52 //

    53 CAknTouchGestureFwDragTracer::~CAknTouchGestureFwDragTracer()

    54     {

    55     }

    56 

    57 

    58 // ---------------------------------------------------------------------------

    59 // Initializes the drag tracer state.

    60 // ---------------------------------------------------------------------------

    61 //

    62 void CAknTouchGestureFwDragTracer::Initialize( const TPoint& aStartPosition )

    63     {

    64     iHorizDirection = EDirectionNone;

    65     iVertDirection = EDirectionNone;

    66 

    67     iHorizCounter = 0;

    68     iVertCounter = 0;

    69     iPosition = aStartPosition;

    70     }

    71 

    72 

    73 

    74 // ---------------------------------------------------------------------------

    75 // Checks if the drag direction has been changed.

    76 // ---------------------------------------------------------------------------

    77 //

    78 TBool CAknTouchGestureFwDragTracer::IsDirectionChanged(

    79     const TPoint& aPosition,

    80     TInt aSensitivity )

    81     {

    82     if ( aPosition == iPosition )

    83         {

    84         // Can't calculate direction.

    85         return EFalse;

    86         }

    87 

    88     TBool directionChanged( EFalse );

    89 

    90     // Horizontal direction

    91 

    92     if ( iHorizDirection == EDirectionNone )

    93         {

    94         // Calculate first horizontal direction based on current and

    95         // previous point.

    96         if ( aPosition.iX > iPosition.iX )

    97             {

    98             iHorizDirection = EDirectionForward;

    99             }

   100         else if ( aPosition.iX < iPosition.iX )

   101             {

   102             iHorizDirection = EDirectionBackward;

   103             }

   104         }

   105     else

   106         {

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

   108         // is to reversed direction.

   109 

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

   111         if ( IsDirectionChanged(

   112                 aPosition.iX,

   113                 iPosition.iX,

   114                 iHorizDirection,

   115                 iHorizCounter,

   116                 aSensitivity ) )

   117             {

   118             directionChanged = ETrue;

   119             }

   120         }

   121 

   122     // Vertical direction

   123 

   124     if ( iVertDirection == EDirectionNone )

   125         {

   126         // Calculate first vertical direction based on current and

   127         // previous point.

   128         if ( aPosition.iY > iPosition.iY )

   129             {

   130             iVertDirection = EDirectionForward;

   131             }

   132         else if ( aPosition.iY < iPosition.iY )

   133             {

   134             iVertDirection = EDirectionBackward;

   135             }

   136         }

   137     else

   138         {

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

   140         // is to reversed direction.

   141 

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

   143         if ( IsDirectionChanged(

   144                 aPosition.iY,

   145                 iPosition.iY,

   146                 iVertDirection,

   147                 iVertCounter,

   148                 aSensitivity ) )

   149             {

   150             directionChanged = ETrue;

   151             }

   152         }

   153 

   154     iPosition = aPosition;

   155     return directionChanged;

   156     }

   157 

   158 

   159 // ---------------------------------------------------------------------------

   160 // Checks if the drag direction has been changed.

   161 // ---------------------------------------------------------------------------

   162 //

   163 TBool CAknTouchGestureFwDragTracer::IsDirectionChanged(

   164     TInt aCurrentCoordinate,

   165     TInt aPrevCoordinate,

   166     TDirection& aDirection,

   167     TInt& aCounter,

   168     TInt aSensitivity )

   169     {

   170     TBool directionChanged( EFalse );

   171 

   172     if ( aDirection == EDirectionForward )

   173         {

   174         if ( aCurrentCoordinate < aPrevCoordinate )

   175             {

   176             aCounter++;

   177             }

   178         else

   179             {

   180             aCounter = 0;

   181             }

   182 

   183         if ( aCounter == aSensitivity )

   184             {

   185             directionChanged = ETrue;

   186             aDirection = EDirectionBackward;

   187             aCounter = 0;

   188             }

   189         }

   190     else if ( aDirection == EDirectionBackward )

   191         {

   192         if ( aCurrentCoordinate > aPrevCoordinate )

   193             {

   194             aCounter++;

   195             }

   196         else

   197             {

   198             aCounter = 0;

   199             }

   200 

   201         if ( aCounter == aSensitivity )

   202             {

   203             directionChanged = ETrue;

   204             aDirection = EDirectionForward;

   205             aCounter = 0;

   206             }

   207         }

   208     return directionChanged;

   209     }

   210 

   211 

   212 // ---------------------------------------------------------------------------

   213 // Default C++ constructor.

   214 // ---------------------------------------------------------------------------

   215 //

   216 CAknTouchGestureFwDragTracer::CAknTouchGestureFwDragTracer():

   217     iHorizDirection( EDirectionNone ),

   218     iVertDirection( EDirectionNone ),

   219     iHorizCounter( 0 ),

   220     iVertCounter( 0 ),

   221     iPosition( 0, 0 )

   222     {

   223     }

   224 

   225 // End of File