/*

* 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:  Model Interface with utilities for scrollbar widget.

*

*/

#ifndef ALF_SCROLLBARMODEL_H

#define ALF_SCROLLBARMODEL_H

// Widget Model and Exported API includes

#include <alf/ialfscrollbarmodel.h>

// OsnCore includes

#include <osn/alfptrvector.h>

#include <osn/ustring.h>

// Namespace

using namespace osncore;

namespace Alf

    {

//Forward Declarations

class AlfModel;

class AlfScrollBarWidget;

/**

 *  ScrollBar model implementation.

 *

 *  Implements utility methods to create and update

 *  the data hierarchy of a scrollbar.

 */

class AlfScrollBarModel : public IAlfScrollBarModel

    {

public:

    /**

     * Constructor.

     */

    AlfScrollBarModel(IAlfVariantType* aDataSource = NULL);

    /**

     * Destructor.

     */

    ~AlfScrollBarModel();

    /** From base class IAlfModel

     *

     */

    /**

     *  Add a new observer to be notified of any changes in the model.

     *

     *  @param    aObserver   The model change observer to be added.

     *  @return void

     *  @since S60 ?S60_version

     */

    void addModelChangeObserver(IAlfModelChangeObserver& aObserver);

    /**

     *  Remove an observer which is added to get notified of any changes

     *  in the model.

     *

     *  @param aObserver The model change observer to be removed.

     *  @return void

     *  @since S60 ?S60_version

     */

    void removeModelChangeObserver(IAlfModelChangeObserver& aObserver);

    /**

     *  API to change the model completely at one short. 

     *  

     *  @see IAlfModel

     *  @param    aData    The new data.

     *  @return void

     *  @since S60 ?S60_version

     */

    void setData(IAlfVariantType* aData);

    /**

     * Change a given  of data fields in the model . All model change

     * observers are notified about the change.

     *

     * @param aNumContainerIndices The number of indices in aContainerIndices.

     * @param aContainerIndices    The container indices to find the correct 

     *                             location in the data hierarchy.The ownership 

     *                             is transferred. 

     * @param aData                The new data to be set.

     * @since S60 ?S60_version

     */

    void updateData(int  aNumContainerIndices,

        int* aContainerIndices,

        IAlfVariantType* aData);

    /**

     * Add a  number of data fields in the model data. All model change

     * observers are notified about the change.

     *

     * @param aNumContainerIndices The number of indices in aContainerIndices.

     * @param aContainerIndices    The container indices to find the correct 

     *                             location in the data hierarchy.The ownership

     *                             is transferred. 

     * @param aData                The new data.

     * @return void

     * @since S60 ?S60_version

     */

    void addData(int aNumContainerIndices,

        int* aContainerIndices,

        IAlfVariantType* aData);

    /**

     * Remove a  number of data fields in the model data. All model change

     * observers are notified about the change.

     *

     * @param aNumContainerIndices The number of indices in aContainerIndices.

     * @param aContainerIndices    The container indices to find the correct 

     *                             location in the data hierarchy.The ownership

     *                             is transferred.

     * @return void

     * @since S60 ?S60_version

     */

    void removeData(int aNumContainerIndices, int* aContainerIndices);

    /**

     *  API for executing batch operations

     *

     *  @param aOperationsArray    An RPOinterArray containing the list of 

     *                             operations to be executed in batch.

     *  @return void

     *  @since S60 ?S60_version

     */

    void executeOperations(AlfPtrVector<AlfModelOperation>&  aOperationsArray);

    /**

     *  API for executing one operation at a Time

     *

     *  @param aOperation          An Operation to be executed on the model.

     *  @since S60 ?S60_version

     */

    void executeOperation(AlfModelOperation* aOperation);

    /**

     *  Clears the Model.

     *

     *  @return void

     *  @since S60 ?S60_version

     */

    void clearModel();

    /**

    *  Get the root data object of this model.

    *

    *  @return The root data object.

    *  @since S60 ?S60_version

    */

    IAlfVariantType* data() const;

    //  From base class IAlfInterfaceBase

    IAlfInterfaceBase* makeInterface(const IfId& aType);

    //  From base class IAlfScrollBarModel     

	/**

	 * Create the default data structure for a ScrollBar widget.

	 * 

	 * @param       aTotalLengthInSteps

	 * @param       aViewLengthInSteps

	 * @param       aViewStartPosition

	 *

	 *

	 * @return      void

	 * @exception   std::bad_alloc

	 * @since       S60 ?S60_version

	 */  

    void initializeData(int aTotalLengthInSteps,

           int aViewLengthInSteps,

           int aViewStartPosition);

    /**

     * Sets the TotalLength for the Scrollbar. Does not notify observers about this.

     * 

     * @param aTotalLength  TotalLength value

     *

     * @return void.

     * @since S60 ?S60_version

     */

    void setTotalLength(int aTotalLength);

    /**

     * Sets the View Length for the Scrollbar. Does not notify observers 

     * about this.

     *

     * @param aViewSize 

     * 

     * @return void.

     * @since S60 ?S60_version

     */

    void setViewLength(int aViewSize);

    /**

     * Sets the View Start Position for the Scrollbar. Does not notify 

     * observers about this.

     *

     * @param aViewStartPosition

     * 

     * @return void.

     * @since S60 ?S60_version

     */

    void setViewStartPosition(int aViewStartPosition);

    /**

         * Sets the TotalLength for the Scrollbar. Does not notify observers about this.

         *

         * @param aTotalLength              TotalLength value

         * @param aViewLength       view length value

         * @param aViewStartPosition view start position  

         *

         * @return void.

         * @since S60 ?S60_version

         */

    void changeData(int aTotalLength,int aViewLength, int aViewStartPosition);   

    /**

     * Length of the document or viewable data.

     *

     * Arbitrary units are used, but the same units as the rest of the model.

     * This length is best current estimate of the length of the entire 

     * viewable data in this model's direction.(i.e, vertical, horizontal).

     * It represents physical extent (e.g. could be pixels), not logical

     * size of the data. It is understood to represent the physical laid out 

     * size of the data if it were possible to view it all at once.

     *

     * @return length in arbitrary units of the viewable data

     * @since S60 ?S60_version

     */

    int getTotalLength() const;

    /**

     * Length of the view.

     *

     * For horizontal models, this is the width of the view.

     * For veritcal, this is the height of the view.

     *

     * Note the units are arbitrary but uniform with the rest of the model.

     * Note that this measure is proportional to the physical width or height

     * of the view. This metric is sometimes called the Thumb size.

     *

     * @return position of the start of the view

     * @since S60 ?S60_version

     */

    int getViewLength() const;

    /**

     * Position in arbitrary units of the start of the currently viewed data.

     *

     * For horizontal models, this is the position of the left of the view 

     * relative to the far left end of the document.

     * For vertical, this is the position of the top of the view from the top

     * of the viewable data.

     *

     * Note the units are arbitrary but uniform with the rest of the model.

     * Position is in physical space as if the entire data were laid out.

     * This metric is sometimes called the Thumb position.

     *

     * @return position of the start of the view

     * @since S60 ?S60_version

     */

    int getViewStartPosition() const;

    /**

     * Updates the model according to the values passed.

     *

     * @param       aTotalLengthInSteps

     * @param       aViewLength

     * @param       aViewStartPosition

     *

     * @return void.

     * @since S60 ?S60_version

     *

     */

    void updateScrollBarModel(int aTotalLengthInSteps,

            int aViewLength,

            int aViewStartPosition);

     /**

     * Updates visualization of scrollbar according 

     * to the model values.

     */  

    void updateScrollBarVisualization(); 

    /**

     * Stores the scrollbar widget pointer in model

     */

    void storeWidget(AlfScrollBarWidget* aWidget);

private:

    /** 

     * This function validates view length passed and changes it if required

     * 

     * @param aViewLength - in/out param

     *

     * @return bool false, if the data was not valid and changes were made

     *              else returns true     

     */

    bool validateViewLength(int & aViewLength);

    /** 

     * This function validates view start position passed and changes it if

     *  required

     *

     * @param aViewStartPos - in/out param

     *

     * @return bool false, if the data was not valid and changes were made

     *              else returns true     

     */

    bool validateViewStartPos(int & aViewStartPos);

    /** 

     * This function validates total length passed and changes it if 

     * required. This validation can change aViewLength, aViewStartPos

     * too if reuired.

     * 

     * @param aTotalLength - in/out param

     * @param aViewLength - in/out param

     * @param aViewStartPos - in/out param

     *

     * @return bool false, if the data was not valid and changes were made

     *              else returns true

     */

    bool validateAllData(int & aTotalLength, 

        int & aViewLength, 

        int & aViewStartPos);

    /**

     * Private method to create the ScrollBar Widget.

     *

     * @param     aDataSource  Model for the ScrollBar

     * @return    void

     * @since S60 ?S60_version

     * 

     */

    void construct ( IAlfVariantType* aDataSource );

	/*

     * pointer to scrollbarmodelData.

     */ 

    struct ScrollbarModelDataImpl *mModelData;

    AlfModel* mModel;  //Owned

    AlfScrollBarWidget* mScrollWidget;

    }; // class AlfScrollBarModel

    } // End of namespace Alf

#endif // ALF_SCROLLBARMODEL_H

//End Of File