/*

* 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:  AknPhysics drag event observer

*

*/

#ifndef C_AKNPHYSICSDRAGOBSERVER_H

#define C_AKNPHYSICSDRAGOBSERVER_H

#include <e32base.h>

class TPointerEvent;

class CAknPhysicsParameterProvider;

class CAknPhysicsFlickTracker;

/**

 *  AknPhysics drag event observer

 *

 */

NONSHARABLE_CLASS( CAknPhysicsDragObserver ) : public CBase

    {

public:

    /**

     * Two-phased constructor.

     */

    static CAknPhysicsDragObserver* NewL( 

        CAknPhysicsParameterProvider* aProvider );

    /**

     * Two-phased constructor.

     */

    static CAknPhysicsDragObserver* NewLC(

        CAknPhysicsParameterProvider* aProvider );

    /**

     * Destructor.

     */

    virtual ~CAknPhysicsDragObserver();

    /**

     * Registers pointer event position.

     *

     * @param aEvent pointer event

     */

    void RegisterEventPosition( const TPointerEvent* aEvent );

    /**

     * Returns changed drag distance point.

     *

     * @return Changed drag distance.

     */

    TPoint ChangedDragDistance() const;

    /**

     * Returns changed vertical drag move time.

     *

     * @return Changed drag move time.

     */

    TInt ChangedVerticalDragMoveTime() const;

    /**

     * Returns changed horizontal drag move time.

     *

     * @return Changed drag move time.

     */

    TInt ChangedHorizontalDragMoveTime() const;

    /**

     * Returns ETrue if drag parameters has been changed during drag event.

     *

     * @return ETrue if drag parameters has been changed.

     */

    TBool DragChanged() const;

private:

    /**

     * C++ constructor.

     */

    CAknPhysicsDragObserver();

    /**

     * Symbian second-phase constructor.

     */

    void ConstructL( CAknPhysicsParameterProvider* aProvider );

    /**

     * Handles pointer down event.

     *

     * @param aPosition Down event position.

     */

    void HandlePointerDownEvent( const TPoint& aPosition );

    /**

     * Handles pointer drag event.

     *

     * @param aPosition Drag event position.

     */

    void HandlePointerDragEvent( const TPoint& aPosition );

    /**

     * Handles pointer up event.

     *

     * @param aPosition Up event position.

     */

    void HandlePointerUpEvent( const TPoint& aPosition );

    /**

     * Resets state.

     */

    void Reset();

private: // data

    /**

     * Dragging event down position.

     */

    TPoint iDownPosition;

    /**

     * Dragging event up position.

     */

    TPoint iUpPosition;

    /**

     * Vertical flick tracker.

     * Own.

     */

    CAknPhysicsFlickTracker* iVerticalTracker;

    /**

     * Horizontal flick tracker.

     * Own.

     */

    CAknPhysicsFlickTracker* iHorizontalTracker;

    /**

     * Boolean flag to indicate whether pointer is considered to be down.

     */

    TBool iPointerDown;

    };

#endif // C_AKNPHYSICSDRAGOBSERVER_H