/****************************************************************************

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

****************************************************************************/

#ifndef HBSCROLLAREA_P_H

#define HBSCROLLAREA_P_H

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

#include "hbscrollarea.h"

#include <hbwidget_p.h>

#include <QTimer>

#include <QTime>

class HbScrollBar;

class QEasingCurve;

class QPanGesture;

class HB_CORE_PRIVATE_EXPORT HbScrollAreaPrivate: public HbWidgetPrivate

{

    Q_DECLARE_PUBLIC( HbScrollArea )

public:

    HbScrollAreaPrivate();

    virtual ~HbScrollAreaPrivate();

    void init();

    void doLazyInit();

    bool mScrollFeedbackOngoing;

    bool mBoundaryReached;

    virtual void updateScrollBar(Qt::Orientation orientation);

    void displayScrollBar(Qt::Orientation orientation);

    void setScrollBarPolicy(Qt::Orientation orientation, HbScrollArea::ScrollBarPolicy policy);

    void replaceScrollBar(Qt::Orientation orientation, HbScrollBar *scrollBar);

    void changeLayoutDirection(Qt::LayoutDirection aNewDirection);

    // returns true if it was able to scroll in either direction

    bool scrollByAmount(const QPointF& delta);

    void startAnimating();

    void stopAnimating();

    virtual void stopScrolling();

    void animateScroll(QPointF speed); // speed in pixels per millisecond

    qreal calculateVelocity ( qreal timeDifference, qreal curVelocity, qreal pos, qreal min, qreal max );

    bool clampToBoundaries ( qreal& deltaRef, qreal pos, qreal min, qreal max );

    void addPositionToQueue(const QPointF& position, qreal time,

                            bool isRelative);

    virtual void setScrollBarMetrics(Qt::Orientation orientation);

    // private slot functions

    void _q_animateScrollTimeout();

    void _q_hideScrollBars();

    void _q_thumbPositionChanged(qreal value, Qt::Orientation orientation);

    void _q_groovePressed(qreal value, Qt::Orientation orientation);

    void _q_thumbPressed();

    void _q_thumbReleased();

    //void bounceBackValueChanged(qreal value);

    virtual void updateScrollMetrics();

    void prepareScrollBars();

    void setContentPosition( const QPointF &newPosition );

    bool sceneEvent(QEvent *event);

    bool positionOutOfBounds ();

    bool pan(QPanGesture *gesture);

    void adjustContent();

    virtual void ensureVisible(QPointF position, qreal xMargin, qreal yMargin);

    void startTargetAnimation (QPointF delta, const int time);

    void createPrimitives();

    void updatePrimitives();

    void updateIndicators(QPointF newPosition);

    void hideChildComponents();

    virtual void setContentPosition( qreal value, Qt::Orientation orientation, bool animate );

    virtual qreal topBoundary ()

    {

        return mContents->boundingRect().top();

    }

    virtual qreal bottomBoundary ()

    {

        Q_Q ( HbScrollArea );

        return mContents->boundingRect().bottom() - q->boundingRect().height();

    }

    virtual qreal leftBoundary ()

    {

        return mContents->boundingRect().left();

    }

    virtual qreal rightBoundary ()

    {

        Q_Q ( HbScrollArea );

        return mContents->boundingRect().right() - q->boundingRect().width();

    }

        // HbScrollAreaPrivate data

    QGraphicsWidget* mContents;

    // We need our own copy of this in order to pass it to the animation state machines

    // valid during animation

    QPointF mScrollPosition;

    Qt::Orientations mScrollDirections;    

    HbScrollBar* mHorizontalScrollBar;

    HbScrollBar* mVerticalScrollBar;

    HbScrollArea::ScrollBarPolicy mVerticalScrollBarPolicy;

    HbScrollArea::ScrollBarPolicy mHorizontalScrollBarPolicy;

    bool mAbleToScrollX;

    bool mAbleToScrollY;

    bool mIsScrolling;

    bool mIsAnimating;

    QPointF mScrollSpeed; // in pixels per ms

    QTimer mScrollTimer;

    QTime mScrollElapsedTime;

    qreal mLastElapsedTime;

    bool mTargetAnimationInProgress;

    qreal mElapsedTimeInAnimation;

    qreal mOverallTimeToTarget;

    QPointF mTargetDelta;

    QPointF mAnimationInitialPosition;

    QEasingCurve* mAnimationShape;

    QTimer mScrollBarHideTimer;

    bool mFrictionEnabled;

    bool mScrollbarVisible;

    bool mResetAlignment;

    HbScrollArea::ClampingStyle mClampingStyle;

    HbScrollArea::ScrollingStyle mScrollingStyle;    

    // TODO/Q: All circular array related members could go

    // to circular array class if so wanted.

    // circular array to keep track of last N event positions

    // this is used to compute the velocity at the end

    // of a panning action when the scrollingStyle is PanFollowOn

    QTime mDragElapsedTime;

    QPointF mEventPositionQueue[10];

    qreal mEventTimeQueue[10];

    uint mEventPositionQueueSize;

    uint mEventPositionQueueLastIndex;

    bool mEventPositionQueueIsFull;

    Qt::LayoutDirection mLayoutDirection;

    Qt::Alignment mAlignment;

    bool mContinuationIndicators;

    QGraphicsItem *continuationIndicatorTopItem;

    QGraphicsItem *continuationIndicatorBottomItem;

    QGraphicsItem *continuationIndicatorLeftItem;

    QGraphicsItem *continuationIndicatorRightItem;    

private:

    // Private access for the fute application to enable setting tweaking

    // should be removed at some point

    static HbScrollAreaPrivate *d_ptr(HbScrollArea *scrollArea) {

        Q_ASSERT(scrollArea);

        return scrollArea->d_func();

    }

    friend class ParameterTweakerWidget;

    // Tweakable settings

    qreal mSpeedFactor;

    qreal mInertiaSpeedFactor;

    qreal mMaxScrollSpeed;

    qreal mSpringStrength;

    qreal mSpringDampingFactor;

    qreal mFrictionPerMilliSecond;

    bool mMultiFlickEnabled;

};

#endif // HBSCROLLAREA_P_H