/*

* 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: Zoom Gesture Recognizer

*

*/

#ifndef ZOOMGESTURERECOGNISER_H_

#define ZOOMGESTURERECOGNISER_H_

#include "rt_gestureengineif.h"

#include <rt_gestureif.h>

#include <rt_gesturelistener.h>

class CCoeControl ;

namespace stmGesture

{

/*!

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

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

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

 * Current spec is:

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

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

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

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

 */

NONSHARABLE_CLASS( CZoomGestureRecogniser ): public CGestureRecogniser

{

public:

	static const TGestureUid KUid = EGestureUidCornerZoom;

	/** Two-phase constructor */

	static CZoomGestureRecogniser* NewL(MGestureListener* aListener);

	virtual ~CZoomGestureRecogniser();

	/*!

	 * MGestureRecogniserIf methods

	 */

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

	virtual void release(MGestureEngineIf* ge) ;

	virtual TGestureUid gestureUid() const

	{

		return KUid;

	}

	/*!

	 * Additional methods to set up zoom in gesture recogniser:

	 * define the rectangle where the lower left corner is

	 * \param theArea

	 */

	void setArea(const TRect& theArea) ;

	/*!

	 * Additional methods to set up zoom in gesture recogniser:

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

	 * \param rangeInPixels

	 */

	void setRange(int rangeInPixels) ;

private:

	CZoomGestureRecogniser(MGestureListener* aListener) ;

	float calculateDistance(const TPoint& aTp) ;

	int adjustZoom(float& aPreviousDistance, float aNewDistance) ;

private:

	TRect m_area ;

	int  m_rangesizeInPixels ;

	TZoomType m_zoomtype ;

	bool m_zooming ;

	TPoint m_startingtouch ;

	TPoint m_previoustouch ;

	int m_delta ;

};

} // namespace

#endif /* ZOOMGESTURERECOGNISER_H_ */