/*

* 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:   Implements page scrolling functionality

*

*/

#ifndef WEBPAGESCROLLHANDLER_H

#define WEBPAGESCROLLHANDLER_H

//  INCLUDES

#include <e32base.h>

#include <coedef.h>

#include <w32std.h>

#include <stmgestureinterface.h>

#include "WebScrollingDecelerator.h"

// MACROS

// FORWARD DECLARATIONS

class WebView;

class WebFrame;

class WebFrameView;

class WebScrollbarDrawer;

class WebScrollingDeceleratorGH;

namespace WebCore

{

    class Element;        

};

enum ScrollDirectionState

{

    ScrollDirectionUnassigned,

    ScrollDirectionX,

    ScrollDirectionY,

    ScrollDirectionXY

};

class ScrollableView : public CBase

{

    public:

        ScrollableView() {}

        ~ScrollableView() {}

        TPoint contentPos();

        WebFrameView* activeFrameView();

    public:

        WebFrameView* m_frameView;

        WebCore::Element* m_scrollingElement;

};

// CLASS DECLARATION

class WebPageScrollHandler: public CBase

    {

    public:  // Constructor and destructor

        /**

        * Two-phased constructor.

        */

        static WebPageScrollHandler* NewL( WebView& webView );

        /**

        * Destructor.

        */

        virtual ~WebPageScrollHandler();

    private:  // Constructors

        /**

        * C++ default constructor.

        */

        WebPageScrollHandler( WebView& webView );

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void constructL();

    public: // New functions

        /**

        * @since 5.0

        * @param

        * @return

        */

        bool  touchScrolling() { return m_touchScrolling;}

        /**

        * @since 5.0

        * @param

        * @return

        */

        void handlePageOverviewScrollingL(const TPointerEvent& pointerEvent);

        /**

        * @since 5.0

        * param

        * return

        */

        void handlePageOverviewScrolling();

        /**

        * @since 5.0

        * param

        * return

        */

        void setupScrolling(const TPoint& aNewPosition);

        /**

        * @since 5.0

        * param

        * return

        */ 

        void clearScrollingElement();

        /**

        * @since 5.0

        * param

        * return

        */

        WebFrameView* currentScrollingFrameView() { return m_scrollableView.m_frameView;}

        /**

        * @since 5.0

        * param

        * return

        */

        WebCore::Element* currentScrollingElement() { return m_scrollableView.m_scrollingElement;}

        /**

        * @since 5.0

        * param

        * return

        */

        void updateScrolling(const TPointerEvent& pointerEvent);

        /**

        * @since 5.0

        * param

        * return

        */

        void scrollContent();

        /**

        * @since 5.0

        * param

        * return

        */

        void scrollContent(TPoint& scrollDelta);

        /**

        * @since 5.0

        * param

        * return

        */

        void handlePageOverviewScrollCallback();

        /**

        * @since 5.0

        * param

        * return

        */

        WebScrollbarDrawer*  scrollbarDrawer() {return m_scrollbarDrawer;}

        //callbacks

        static int pageOverviewScrollCallback( TAny* aPtr );

        //static int handleScrollTimerEventCallback( TAny* ptr);

        void scrollPageOverviewGH();

        void handleScrollingGH(const TStmGestureEvent& aGesture);

        void handleTouchDownGH(const TStmGestureEvent& aGesture);

        void handleTouchUpGH(const TStmGestureEvent& aGesture);

        void updateScrollbars(const TPoint& scrollPos, TPoint& newscrollDelta);

     private:

        void calculateScrollDirection(int absX, int absY);

        bool calculateScrollableFrameView(const TPoint& aNewPosition);

        bool calculateScrollableElement(const TPoint& aNewPosition);

        void scrollPageOverview(const TPointerEvent& pointerEvent);

        bool startDeceleration(const TStmGestureEvent& aGesture);

     private:  

        // Pointer to owning view

        WebView* m_webView; // not owned

        CPeriodic* m_pageOverviewScrollPeriodic;

        TPointerEvent m_lastPointerEvent;

        TPointerEvent m_currentPointerEvent;

        TPoint m_lastPosition;

        TPoint m_currentPosition;

        TPoint m_focalPoint;

        bool m_touchScrolling; // in page overview mode

        bool m_isXScrollable;

        bool m_isYScrollable;

        TTime m_lastMoveEventTime;

        TTime m_pageOverviewEventTime;

        WebScrollingDecelerator* m_decel;

        TPointerEvent m_lastDragEvent;

        CPeriodic* m_scrollTimer;

        ScrollableView m_scrollableView;

        TPoint m_currentNormalizedPosition; //normalized position

        enum ScrollDirectionState m_scrollDirectionState;        

        WebScrollbarDrawer* m_scrollbarDrawer;

    };

#endif      // WEBPAGESCROLLHANDLER_H

// End of File