/*

* Copyright (c) 2007, 2008 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 implementation with utilities for scrollbar widget.

*

*/

//User Includes

#include "alfscrollbarmodel.h"

#include "alfscrollbarwidget.h"

//Widget includes

#include <alf/ialfscrollbardefaultbaseelement.h>

#include "ialfscrollbarbaseelementinternal.h"

#include "alfscrollbardefaultbaseelement.h"

#include <alf/ialfscrollbarwidget.h>

#include <alf/alfmodel.h>

#include <alf/alfexception.h>

namespace Alf

    {

/*

 * To store data required in the model class

 */

struct ScrollbarModelDataImpl

    {

    int mTotalLength;

    int mViewLength;

    int mViewStartPosition;

    };

// ======== MEMBER FUNCTIONS ========

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

//  C++ default constructor.

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

//

AlfScrollBarModel::AlfScrollBarModel(IAlfVariantType* aDataSource):

    mModel ( NULL )

    {

    construct ( aDataSource );

     // Create an instance of model specific data

    mModelData = new (EMM) ScrollbarModelDataImpl();

    // Initialise model data with default values

    mModelData->mTotalLength       = 0;

    mModelData->mViewLength        = 0;

    mModelData->mViewStartPosition = 0;

    mScrollWidget = NULL;

    }//End of AlfScrollBarModel function.

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

// Destructor.

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

//

AlfScrollBarModel::~AlfScrollBarModel()

    {

    if(mModelData)

        delete mModelData;

    delete mModel;

    }//End of ~AlfScrollBarModel function.

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

//  Second Phase Constructor.

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

//

void AlfScrollBarModel::construct ( IAlfVariantType* /*aDataSource */)

    {

    }//End of construct function.

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

// From class IAlfModel.

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

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

//

void AlfScrollBarModel::addModelChangeObserver(

    IAlfModelChangeObserver& /*aObserver*/)

    {

    }//End of addModelChangeObserver function.

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

// From class IAlfModel.

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

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

//

void AlfScrollBarModel::removeModelChangeObserver(

    IAlfModelChangeObserver& /*aObserver*/ )

    {

    }//End of function.

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

// From class IAlfModel.

// Api to change the model completely at one short.

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

//    

void AlfScrollBarModel::setData ( IAlfVariantType* /*aData*/ )

    {

    }//End of removeModelChangeObserver function.

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

// From class IAlfModel.

// Change a given  of data fields in the model.

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

//

void AlfScrollBarModel::updateData(

    TInt /*aNumContainerIndices*/,

    TInt* /*aContainerIndices*/,

    IAlfVariantType* /*aData*/)

    {

    ALF_THROW(AlfException,EInvalidArgument,"updateData")        

    }//End of updateData function.

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

// From class IAlfModel.

// Add a number of data fields in the model data.

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

//

void AlfScrollBarModel::addData(

    TInt /*aNumContainerIndices*/,

    TInt* /*aContainerIndices*/,

    IAlfVariantType* /*aData*/)

    {

    ALF_THROW(AlfException,EInvalidArgument,"addData")        

    }//End of addData function.

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

// From class IAlfModel.

// Remove a  number of data fields in the model data.

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

//  

void AlfScrollBarModel::removeData(

    TInt /*aNumContainerIndices*/,

    TInt* /*aContainerIndices*/ )

    {

    ALF_THROW(AlfException,EInvalidArgument,"removeData")        

    }//End of removeData function.

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

// From class IAlfModel.

// Api for executing batch operations.

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

//  

void AlfScrollBarModel::executeOperations(

    AlfPtrVector<AlfModelOperation>& /*aOperationsArray*/)

    {

    ALF_THROW(AlfException,EInvalidArgument,"executeOperations")    

    }//End of executeOperations function.

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

// From class IAlfModel.

// Api for executing one operation at a Time.

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

//  

void AlfScrollBarModel::executeOperation(AlfModelOperation* /*aOperation*/)

    {

    ALF_THROW(AlfException,EInvalidArgument,"executeOperation")    

    }//End of executeOperation function.

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

// From class IAlfModel.

// Clears the Model.

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

//  

void AlfScrollBarModel::clearModel()

    {

    }//End of clearModel function.

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

// From class IAlfModel.

// Get the root data object of this model.

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

//  

IAlfVariantType* AlfScrollBarModel::data() const

    {

    return NULL;

    }//End of data function.

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

// From class IAlfInterfaceBase.

// Getter for interfaces provided by the scrollbar model.

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

IAlfInterfaceBase* AlfScrollBarModel::makeInterface(const IfId& aType)

    {

    IAlfInterfaceBase* ret ( 0 );

    UString param ( aType.mImplementationId );

    if ( param == IAlfScrollBarModel::type().mImplementationId )

        {

        ret = static_cast<IAlfScrollBarModel*>(this);

        }

    else if ( param == IAlfModel::type().mImplementationId )

        {

        ret = static_cast<IAlfModel*>(this);

        }

    else

        {

        //do nothing

        }

    return ret;

    }//End of makeInterface function.

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

// From class IAlfScrollBarModel.

// Create the default data structure for a ScrollBar widget.

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

//

void AlfScrollBarModel::initializeData(

    int aTotalLength,

    int aViewLengthInSteps,

    int aViewStartPosition)

    {

    validateAllData(aTotalLength, 

        aViewLengthInSteps,

        aViewStartPosition);

    // Initialise model with the data provided

    mModelData->mTotalLength       = aTotalLength;

    mModelData->mViewLength        = aViewLengthInSteps;

    mModelData->mViewStartPosition = aViewStartPosition;

    changeData(

        mModelData->mTotalLength,

        mModelData->mViewLength,

        mModelData->mViewStartPosition);

    }//End of function.

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

// Set Total Length .

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

//

void AlfScrollBarModel::setTotalLength(int aTotalLength)

    {

    int viewLength = getViewLength();

    int viewStartPos = getViewStartPosition();

    if (validateAllData(aTotalLength, 

            viewLength, 

            viewStartPos))

        {

        updateScrollBarModel(aTotalLength, -1, -1 );

        }

    else

        {

        updateScrollBarModel(aTotalLength, viewLength, viewStartPos);

        }

    }//End of setTotalLength function.

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

// Set ViewLength.

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

//

void AlfScrollBarModel::setViewLength(int aViewLengthInSteps)

    {

    validateViewLength(aViewLengthInSteps);

    updateScrollBarModel ( -1, aViewLengthInSteps, -1);

    }//End of setViewLength function.

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

// Set Thumb Position.

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

//

void AlfScrollBarModel::setViewStartPosition ( int aViewStartPosition )

    {

    validateViewStartPos(aViewStartPosition);

    updateScrollBarModel (-1, -1, aViewStartPosition);

    }//End of setViewStartPosition function.

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

// Changes all the data of model with new values.

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

//

void AlfScrollBarModel::changeData(

    int aTotalLength,

    int aViewLength,

    int aViewStartPosition )

    {

    validateAllData(aTotalLength,

        aViewLength,

        aViewStartPosition);

     if(getViewStartPosition() == aViewStartPosition && 

        getTotalLength() == aTotalLength && 

        getViewLength() == aViewLength)

        { 

        // nothing is changed

        return ;

        }

    else

	    {

	    updateScrollBarModel(

	            aTotalLength,

	            aViewLength,

	            aViewStartPosition);

	    }

    }//End of changeData function.

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

// getTotalLength.

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

//

int AlfScrollBarModel::getTotalLength() const

    {

    return mModelData->mTotalLength;

    }//End of getTotalLength function.

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

// Returns ViewLength.

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

//

int AlfScrollBarModel::getViewLength() const

    {

    return mModelData->mViewLength;

    }//End of getViewLength function.

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

// Returns ViewStartPosition.

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

//

int AlfScrollBarModel::getViewStartPosition() const

    {

    return mModelData->mViewStartPosition;

    }//End of getViewStartPosition function.

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

// Updates the ScrollBar visualization

// according to the model data.

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

//

void AlfScrollBarModel::updateScrollBarVisualization()

    {

     //updateVisualization with new model

     IAlfElement* element = (mScrollWidget)->control()->findElement("BaseElement");

     IAlfScrollBarDefaultBaseElement* defaultLCTBaseElement = static_cast<IAlfScrollBarDefaultBaseElement*> (

    		 element->makeInterface (IAlfScrollBarDefaultBaseElement::type() ) );

     AlfScrollBarDefaultBaseElement* baseElement = (AlfScrollBarDefaultBaseElement*)defaultLCTBaseElement;

     baseElement->updateVisualization();

    }

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

// Updates the ScrollBar model according to the parameters.

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

//

void AlfScrollBarModel::updateScrollBarModel(

    int aTotalLength,

    int aViewLength,

    int aViewStartPosition)

    {

    //change only if the parameters are non negative . 

    if(aTotalLength!=-1)

        {

        mModelData->mTotalLength = aTotalLength;

        }

    else

        {

        // Do Nothing

        }

    if(aViewLength!=-1)

        {

        mModelData->mViewLength =  aViewLength; 

        }

    else

        {

        // Do Nothing 

        }

    if(aViewStartPosition!=-1)

        {

        mModelData->mViewStartPosition = aViewStartPosition;  

        }

    else

        {

        // Do Nothing  

        }

    //updateVisualization with new model    

    updateScrollBarVisualization();

    }//End of updateScrollBarModel function.

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

// validateViewLength

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

//

bool AlfScrollBarModel::validateViewLength(int & aViewLength)

    {

    bool ret = true;

    if (aViewLength <= 0)

        {

        // Minimum view length

        aViewLength = 1;

        ret = false;

        }

    else

        {

        int totalLength = getTotalLength();

        if (aViewLength > totalLength)

            {

            aViewLength = totalLength;

            ret = false;

            }

        else

            {

            // do nothing

            }

        }

    return ret;

    }

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

// validateViewStartPos

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

//

bool AlfScrollBarModel::validateViewStartPos(int & aViewStartPos)

    {

    bool ret = true;

    if (aViewStartPos < 0)

        {

        aViewStartPos = 0;

        ret = false;

        }

    else

        {

        int totalLength = getTotalLength();

        int viewLength = getViewLength();     

        if (aViewStartPos > (totalLength-viewLength))

            {

            // Maximum value

            aViewStartPos = totalLength-viewLength;            

            ret = false;

            }

        else

            {

            // do nothing

            }        

        }

    return ret;

    }

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

// validateAllData

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

//    

bool AlfScrollBarModel::validateAllData(int & aTotalLength, 

        int & aViewLength, 

        int & aViewStartPos)

    {

     bool ret = true;

     if (aTotalLength <= 0)

        {

        aTotalLength = 1;

        ret = false;

        }

     else

        {

        // do nothing

        }

     // validate view length   

     if (aViewLength <= 0)

        {

        aViewLength = 1;

        ret = false;

        }

     else if (aViewLength > aTotalLength)

        {

        // Setting maximum possible value of View Length

        aViewLength = aTotalLength;

        ret = false;

        }

     else

        {

        // do nothing

        }

     // validate view start pos

     if (aViewStartPos < 0)

        {

        aViewStartPos = 0;

        ret = false;