/*

* 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:   glxzoomwidget.h

*               definition of the class glxzoomwidget which controls the Zoom behavior of coverflow.

*

*/

#ifndef GLXZOOMWIDGET_H

#define GLXZOOMWIDGET_H

#include <QObject>

#include <QGraphicsWidget>

#include <QPixmap>

#include <hbscrollarea.h>

#include <glxzoomwidget_global.h>

class QGestureEvent;

class QPinchGesture;

class HbIconItem;

class GlxImageDecoderWrapper;

class QTimeLine;

class GLXZOOMWIDGETSHARED_EXPORT GlxZoomWidget : public HbScrollArea

{

    Q_OBJECT

    public:

    GlxZoomWidget (QGraphicsItem *parent = NULL);

    ~GlxZoomWidget ();

    void setModel (QAbstractItemModel *model) ;

    void indexChanged(int index);

    void setWindowSize(QSize windowSize);

    void cleanUp();

    void activate();

    void setMinMaxZValue(int minZvalue, int maxZvalue);

    void connectDecodeRequestToPinchEvent();

    /*

     * This is an overloaded function when an index is changes due to deletion 

     */

    void indexChanged();

    void forceZoomToBackground();

    signals:

    void pinchGestureReceived(int index);

    void zoomWidgetMovedBackground(int index);

    void stepZoom();

    public slots:

    //for Decoder support

    void decodedImageAvailable();

    void sendDecodeRequest(int index);

	//for animation effects

	void animateZoomIn(QPointF animRefPoint);

	void animateZoomOut(QPointF animRefPoint);

	void animationTimeLineFinished();

	//animate double tap

	void animateDoubleTap();

    protected:

    bool sceneEvent(QEvent *event);

    bool sceneEventFilter(QGraphicsItem *watched,QEvent *event);

    void timerEvent(QTimerEvent *event);

    protected slots:

    void dataChanged(QModelIndex startIndex, QModelIndex endIndex);

    void modelDestroyed();

    private:

    bool executeGestureEvent(QGraphicsItem *source,QGestureEvent *event);

    //Responsible for changing the transforms of the widget wrt the ZF and center

	//Also adjusts the ZF, center and final size so as to respect the boundaries

    void zoomImage(qreal zoomFactor, QPointF center);

    //This API will adjust the gesture center to maintain boundaries

	//called from GlxZoomWidget::zoomImage

    void adjustGestureCenter(QPointF & gestureCenter, qreal& zoomFactor);

    //this API will limit the max/min Zoom Size possible

	//called from GlxZoomWidget::zoomImage

    void limitRequiredSize(QSizeF &requiredSize);

	//gets the latest focussed image from the model

    void retreiveFocusedImage();

    //finalize the transform and update the sizehint of mZoomWidget

    void finalizeWidgetTransform();

    //get the focused image from the model

    QPixmap getFocusedImage();

    //set all the zoom parameters as per the circumstances

    void setZoomParams();

    bool isFocussedItemCorrupt();

    //data members

private:

    //to be in sync with the model

    QAbstractItemModel *mModel;

    //view Z values 

    //might push to layouts later

    int mMinZValue ;

    int mMaxZValue ;

    int mTimerId;

    //status flags

    //To check if the decode request has already been send or not

    bool mImageDecodeRequestSend; 

    //To check if the pinch gesture is in progress to block any events to HbScrollArea

    bool mPinchGestureOngoing; 

    //to check if decoded image is available

    bool mDecodedImageAvailable;

    //to check if the widget is actually in Foreground

    bool mZoomOngoing;

    //view widgets

    QGraphicsPixmapItem *mZoomItem;   //Item containing the pixmap

    QGraphicsWidget *mZoomWidget;     //container :all scaling and transforms would be done on this widget

    HbIconItem* mBlackBackgroundItem; //for setting black background

    int mFocusIndex;

    //size parameter

    QSizeF mItemSize;        // the actual pixmap size. Keep it updated with latest pixmap size

    QSizeF mStepCurrentSize; //to save the size before gesture started

    QSizeF mCurrentSize;     //save sizes scaled by gesture

    QSize mWindowSize;      //the window size

    QSizeF mMinScaleSize;   //minimum posible size

    QSizeF mMinDecScaleSize;   //the Minimum scale limit after which the image scaling down should be decelerated

    QSizeF mMaxScaleSize;   // the maximum scale limit

    QSizeF mMaxScaleDecSize;   // the Maximum scale limit after which the image scaling should be decelerated

	//for animation effect

	qreal m_FinalAnimatedScaleFactor;

	QPointF m_AnimRefPoint;

	QTimeLine *m_AnimTimeLine;

    //for Decoder support

    GlxImageDecoderWrapper* mImageDecoder;

    //stores the incremental scalingfactor(sf) while performing double tap animation

    qreal mIncSF;

    //stores the scalingfactor increment applicable for each step of double tap animation

    qreal msfInc;

    //stores the item size before performing zoomout or zoomin

    QSizeF minitSize;

    //counter to track the double tap animation steps

    int mdoubletapSteps;

};

#endif  //GLXZOOMWIDGET_H