1 /*

     2 * Copyright (c) 2008 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 the License "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: Zoom Gesture Recognizer

    15 *

    16 */

    17 

    18 #ifndef ZOOMGESTURERECOGNISER_H_

    19 #define ZOOMGESTURERECOGNISER_H_

    20 

    21 #include "rt_gestureengineif.h"

    22 #include <rt_gestureif.h>

    23 #include <rt_gesturelistener.h>

    24 

    25 class CCoeControl ;

    26 

    27 namespace stmGesture

    28 {

    29 

    30 /*!

    31  * CZoomGestureRecogniser handles zoomin gesture: start from near lower left / upper right corner and drag

    32  * This is useful if one wants to implement single handed zooming so can be done using thumb

    33  * (no need to use pinch i.e. hold device in one hand and use two fingers of the other)

    34  * Current spec is:

    35  * - touch lower left corner and start dragging => initialize ZOOM IN

    36  * - touch upper right corner and start dragging => initialize ZOOM OUT

    37  * store the touch point and then calculate the distance until release

    38  * The distance is the zoom factor (probably needs some adjustment, not just the pixels...)

    39  */

    40 NONSHARABLE_CLASS( CZoomGestureRecogniser ): public CGestureRecogniser

    41 {

    42 public:

    43 	static const TGestureUid KUid = EGestureUidCornerZoom;

    44 

    45 	/** Two-phase constructor */

    46 	static CZoomGestureRecogniser* NewL(MGestureListener* aListener);

    47 	virtual ~CZoomGestureRecogniser();

    48 

    49 	/*!

    50 	 * MGestureRecogniserIf methods

    51 	 */

    52 	virtual TGestureRecognitionState recognise(int numOfActiveStreams, MGestureEngineIf* ge) ;

    53 	virtual void release(MGestureEngineIf* ge) ;

    54 	virtual TGestureUid gestureUid() const

    55 	{

    56 		return KUid;

    57 	}

    58 

    59 	/*!

    60 	 * Additional methods to set up zoom in gesture recogniser:

    61 	 * define the rectangle where the lower left corner is

    62 	 * \param theArea

    63 	 */

    64 	void setArea(const TRect& theArea) ;

    65 

    66 	/*!

    67 	 * Additional methods to set up zoom in gesture recogniser:

    68 	 * Define how close to the lower left corner the touch must happen

    69 	 * \param rangeInPixels

    70 	 */

    71 	void setRange(int rangeInPixels) ;

    72 

    73 private:

    74 	CZoomGestureRecogniser(MGestureListener* aListener) ;

    75 

    76 	float calculateDistance(const TPoint& aTp) ;

    77 	int adjustZoom(float& aPreviousDistance, float aNewDistance) ;

    78 

    79 private:

    80 	TRect m_area ;

    81 	int  m_rangesizeInPixels ;

    82 	TZoomType m_zoomtype ;

    83 	bool m_zooming ;

    84 	TPoint m_startingtouch ;

    85 	TPoint m_previoustouch ;

    86 	int m_delta ;

    87 

    88 };

    89 

    90 } // namespace

    91 

    92 #endif /* ZOOMGESTURERECOGNISER_H_ */