serviceproviders/sapi_mediamanagement/src/mginterface.cpp
author Dremov Kirill (Nokia-D-MSW/Tampere) <kirill.dremov@nokia.com>
Thu, 27 Aug 2009 07:43:07 +0300
changeset 22 fc9cf246af83
parent 19 989d2f495d90
permissions -rw-r--r--
Revision: 200931 Kit: 200935

/*
* Copyright (c) 2007-2007 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:  This Class provides the interface for
*				 calling the functionality to Media Management SAPI.
*  Interafce
*
*/



#include <liwcommon.h>
#include <utf.h>

#include "mginterface.h"
#include "mgservice.h"
#include "mgserviceobserver.h"
#include "serviceerrno.h"
#include"mgservicethumbnailobserver.h"

//using namespace LIW;

//Supported Operation
_LIT8(KGetList,"GetList");
_LIT8(KCmdCancel,"Cancel");

_LIT8(KGetThumbnail,"GetThumbnail"); 

//Input Keys/arguments

// for Url
_LIT8(KUrl,"Url");

// thumbnailsize
_LIT8(KThumbnailSize,"ThumbnailSize");

// Width
_LIT8(KWidth,"width");
//height
_LIT8(KHeight,"height");

// Data source name
_LIT8(KDsName,"Type");

// Filter Map
_LIT8(KFilter,"Filter");

// Sorting Map
_LIT8(KSort,"Sort");

//Required file type
_LIT8(KFileType,"FileType");

//Filter criteria
_LIT8(KKey,"Key");

//Start range of filter
_LIT8(KStartRange,"StartRange");

//End range of filter
_LIT8(KEndRange,"EndRange");


//Sorting order
_LIT8(KOrder,"Order");


//Possible DataSource or supported operation
_LIT(KFile,"FileInfo");
_LIT(KFileInfo,"FileInfo");


//Output Keys/arguments
_LIT8(KErrorCode,"ErrorCode");
_LIT8(KErrorMessage,"ErrorMessage");
_LIT8(KTransactionID,"TransactionID");
_LIT(KCmdInvalid, 	 "Command Not Supported");
_LIT(KMissing,		 " is missing");
_LIT(KMissingOrInvalid,		 " is missing/invalid");
_LIT(KInvalid,		 " is invalid");
_LIT(KNotSupported,	 " not supported");
_LIT(KInvalidAsyncParam,"Insufficient arguments for async request");
_LIT(KInvalidCancelParam,"Cancel bit not set in aCmdOptions");
_LIT(KServerBusy,	"Server busy");
//_LIT(KTypeMismatch, " Type mismatch");


// Constants for Error Message
_LIT(KErrorMsgSeparator, 	" : ");
_LIT(KDomainName, 			"MediaMgmt");

// Lenght for media file path 
const TInt KFilePath = 230;
const TInt KNegVal = -1;
// -----------------------------------------------------------------------------
// CMgInterface::NewLC
// Returns the instance of CMgInterface.
// -----------------------------------------------------------------------------
CMgInterface* CMgInterface::NewL()
	{

	CMgInterface* self = new ( ELeave )CMgInterface();
	CleanupStack::PushL( self );
	self->ConstructL();
	CleanupStack::Pop( self );
	return self;
	}


// -----------------------------------------------------------------------------
// CMgInterface::~CMgInterface
// Destructor of class
// -----------------------------------------------------------------------------
CMgInterface::~CMgInterface()
	{

    //Release the instance of service observer class
  //  delete iServiceObserver;
   // iServiceObserver = NULL;

	//Release the instance of core class
    delete iCoreClass;
	iCoreClass = NULL;

	}


// -----------------------------------------------------------------------------
// CMgService::ExecuteCmdL
// Request handler method of interface class
// -----------------------------------------------------------------------------

void CMgInterface::ExecuteCmdL(const TDesC8& aCmdName,
                           const CLiwGenericParamList& aInParamList,
                           CLiwGenericParamList& aOutParamList,
                           TUint aCmdOptions ,
                           MLiwNotifyCallback* aCallBack)
	{

    TInt32 transactionID = 0;
	TInt errCode = 0;
	TInt pos = 0;
	TPtrC dsName(KNullDesC);
    const TLiwGenericParam* param = NULL;
    TLiwGenericParam posbasedparam;
    TBool postionbasedsearching = EFalse;
    
    TPtrC url(KNullDesC);
    TPtrC thumbnailsize(KNullDesC);
    if( 0 == aCmdName.CompareF( KCmdCancel ) )
	    {
	    if( aCmdOptions & KLiwOptCancel ) // for cancel asynchronous request
			{

			param = aInParamList.FindFirst( pos, KTransactionID );
			if( ( !param ) && ( aInParamList.Count() > 0) )
			    {
			    pos = 0;
			    aInParamList.AtL( pos, posbasedparam );
			    if ( posbasedparam.Name().Compare(KNullDesC8) != 0 || posbasedparam.Value().IsEmpty() )
			        {
			        param = NULL;
			        }
			    else
			        {
			        param = &posbasedparam;
			        }
			    }
			if( param )
			    {
			    
			    if ((*param).Value().Get( transactionID ))
			    
			        {
				    errCode = iCoreClass->CancelL( transactionID );   
				   
					if ( KErrNone != errCode )
				        {
				        TInt sapiErr = SapiError(errCode);
				        AppendErrorMessageL( aCmdName, KTransactionID, KInvalid );
				        aOutParamList.AppendL( TLiwGenericParam ( KErrorMessage,TLiwVariant( iErrorMessage ) ) );
				        aOutParamList.AppendL(TLiwGenericParam(KErrorCode,TLiwVariant((TInt32)sapiErr)));
			        	}
					else
					    {

                        TInt sapiErr = SapiError(errCode);
                                        
                        aOutParamList.AppendL(TLiwGenericParam(KErrorCode,TLiwVariant((TInt32)sapiErr)));
                        
					    }
				    }
				else
				    {
				    AppendErrorMessageL( aCmdName, KTransactionID, KInvalid );
				    aOutParamList.AppendL( TLiwGenericParam ( KErrorMessage,TLiwVariant( iErrorMessage ) ) );
				    aOutParamList.AppendL( TLiwGenericParam ( KErrorCode,TLiwVariant( TInt32( SErrBadArgumentType ) ) ) );
				    }   

			    }
			else
			    {
			    AppendErrorMessageL( aCmdName, KTransactionID, KMissing );
			    aOutParamList.AppendL( TLiwGenericParam ( KErrorMessage,TLiwVariant( iErrorMessage ) ) );
			    aOutParamList.AppendL( TLiwGenericParam ( KErrorCode,TLiwVariant( TInt32( SErrMissingArgument ) ) ) );
			    }

			}
		else
			{
			AppendErrorMessageL( aCmdName, KNullDesC8, KInvalidCancelParam );			        
			aOutParamList.AppendL( TLiwGenericParam ( KErrorMessage,TLiwVariant( iErrorMessage ) ) );
			aOutParamList.AppendL( TLiwGenericParam ( KErrorCode,TLiwVariant( TInt32( SErrBadArgumentType ) ) ) );	
			}
	    return;	
	    }

	// Check the command name;Cmd name should be GetList
	else if( 0 == aCmdName.CompareF( KGetList ) )
		{
		pos = 0 ;
		param = aInParamList.FindFirst( pos, KDsName );
	    if( ( !param ) && ( aInParamList.Count() > 0 ) )
            {
            pos = 0;
            aInParamList.AtL( pos,posbasedparam );
            if ( (posbasedparam.Name().CompareF(KNullDesC8) != 0 ) || posbasedparam.Value().IsEmpty() ) 
                {
                param = NULL;
                }
            else
                {
                param = &posbasedparam;
                postionbasedsearching = ETrue;
                }
            }
		if(param)
			{
	    	if ((*param).Value().Get( dsName ))
	    	
	    	    {
	    	    //dsName.Set((*param).Value().AsDes());

			    if( ( 0 == dsName.CompareF( KFileInfo )  )
				    || ( 0 == dsName.CompareF( KFile ) )  )
				    {
				// check if core class ready to accept request
			    /*	if( EMgFree == iCoreClass->State() )
					    {*/
					    if( aCmdOptions & KLiwOptASyncronous ) //Asynchronous request
						    {
						    if( NULL != aCallBack ) // Asynchronous call
								{
								transactionID = aCallBack->GetTransactionID();
							   	 //Sending request to core class
							     TRAP (errCode,SendRequestL( aInParamList , transactionID ,postionbasedsearching,aCallBack ));

						        }
							else		//Callback  missing
								{
								AppendErrorMessageL( aCmdName, KNullDesC8, KInvalidAsyncParam );
								errCode = KErrNotFound;
								}

							}
						else //synchronous request
							{
						    //synch request currently not supported
						    AppendErrorMessageL( aCmdName, KNullDesC8, KInvalidAsyncParam );
						    errCode = KErrNotFound;
							}//synchronous request

						/*}//Sapi status
				    else
				        {
				        AppendErrorMessageL( aCmdName, KNullDesC8, KServerBusy );
				        errCode = KErrServerBusy;
				        }*/

					}//Data Source support
				else
				    {
				    //Incorrect Data source
				    AppendErrorMessageL( aCmdName, KDsName, KNotSupported );
				    errCode = KErrNotSupported;
				    }

	    	    
		    	}//DataType Mismatch
	    	else
	    	    {
	    	    AppendErrorMessageL( aCmdName, KDsName, KInvalid );
			    errCode = KErrArgument;   
	    	    }
		

		    }//datasource missing
		else
		    {
		    AppendErrorMessageL( aCmdName, KDsName, KMissing );
		    errCode = KErrNotFound;
		    }


		}//GetList
	else if(0 == aCmdName.CompareF( KGetThumbnail ))// Here we need to put implementation  for getThumbnail
	    {
	      //Call 
	        if( (aCmdOptions & KLiwOptASyncronous ) && ( NULL != aCallBack ) ) //Asynchronous request
	            {
	            //Asynch Call
	            transactionID = aCallBack->GetTransactionID();
	            TInt err =0;
	            
	            TRAP(err,GetThumbnailL( aInParamList, aOutParamList, aCallBack , transactionID ));
	            errCode = err;
	            }
		        else
	            {
	            AppendErrorMessageL( aCmdName, KNullDesC8, KInvalidAsyncParam );
                errCode = KErrNotFound;
	            }    
	    
	    
	    }// GetThumbnail
	else   
	    {
	    AppendErrorMessageL( aCmdName, KNullDesC8, KCmdInvalid );
	    errCode = KErrNotSupported; //command not supported
	    }

	// check error code if any error occurs then insert into output list
    posbasedparam.Reset();
    TInt sapiErr = SErrNone;
    if (errCode)
    	{
    	sapiErr = SapiError(errCode);
    	}
    		
    aOutParamList.AppendL(TLiwGenericParam(KErrorCode,TLiwVariant((TInt32)sapiErr)));
	if ( iErrorMessage )
		{
		aOutParamList.AppendL(TLiwGenericParam( KErrorMessage, 
									TLiwVariant(iErrorMessage->Des())));
		delete iErrorMessage;
		iErrorMessage = NULL;		
		}

	aOutParamList.AppendL( TLiwGenericParam( KTransactionID, TLiwVariant( (TInt32)transactionID ) ) );

	}


// -----------------------------------------------------------------------------
// CMgInterface::CMgInterface
// Constructor  of class
// -----------------------------------------------------------------------------

CMgInterface::CMgInterface()
             :iCoreClass( NULL )
			
	{
	
	}


// -----------------------------------------------------------------------------
// CMgInterface::ConstructL
// Two-phased constructor of class
// -----------------------------------------------------------------------------

void CMgInterface::ConstructL()
	{
	// Create the instance of core class
	iCoreClass = CMgService::NewL();

	//Create the instance of service observer class
	//iServiceObserver = CMgServiceObserver::NewL();

	}



// -----------------------------------------------------------------------------
// CMgInterface::SendRequestL
// This function will send the request to Core class
// -----------------------------------------------------------------------------

void CMgInterface::SendRequestL(const CLiwGenericParamList& aInParamList , TUint aTransactionID , TBool aPostionBasedSearching , MLiwNotifyCallback* aCallBack)

	{
	TInt   pos=0;
	const CLiwMap* filter = NULL;
    const CLiwMap* sorting = NULL;
 	TMgServiceRequest requestParam;
	const TLiwGenericParam* param;
	TLiwVariant fileType;
	TLiwVariant filterField;
	TLiwVariant startVal;
	TLiwVariant endVal;
	TLiwVariant sortingField;
	TLiwVariant order;
	TLiwGenericParam posbasedparam;

	//setting the TransactionID
    requestParam.iTransactionID = aTransactionID;
   
    //Get the Filter Map
    if ( aPostionBasedSearching && ( aInParamList.Count() > 1) )
        {
         pos = 1;
         aInParamList.AtL( pos,posbasedparam );
         if ( (posbasedparam.Name().CompareF(KNullDesC8) != 0 ) || posbasedparam.Value().IsEmpty() ) 
             {
             param = NULL;
             }
         else
             {
             param = &posbasedparam;
             }
        }
    else
        {
        pos=0;//Search from starting point
        //filter map
        param =  aInParamList.FindFirst( pos, KFilter );
        }
    
       
	HBufC8* heapBuffer3 = NULL;
	HBufC8* heapBuffer4 = NULL;
    
    
    if(param)
        {
        filter = (*param).Value().AsMap();
        if(!filter)
            {
            //Filter Map missing : 
            posbasedparam.Reset();
            AppendErrorMessageL( KGetList, KFilter, KInvalid );
  	        User ::Leave(KErrArgument);
            }
          
        }
        
    
    if( (param) &&  (filter) )
        {//filter map
     
	    TPtrC type16;
	    
	    CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &fileType) );	    
	    if( (filter->FindL( KFileType, fileType )) )
	        {
	        if ( (fileType.Get( type16 ))  && (type16.Length() > 0 ) )
		        {
		        heapBuffer3 = HBufC8::NewL( type16.Length() );
	            CleanupStack::PushL( heapBuffer3 );
	            TPtr8 type8( heapBuffer3->Des() );
	            type8.Copy( type16 );
	            requestParam.iFileType.Set(type8);
		        }
	    	else
		        {
		        //fileType.Reset();
		        posbasedparam.Reset();
		        AppendErrorMessageL( KGetList, KFileType, KMissingOrInvalid );
		        User ::Leave(KErrArgument);
	            }
	        }
	    else
	        {
	        //fileType.Reset();
		    posbasedparam.Reset();
		    AppendErrorMessageL( KGetList, KFileType, KMissing );
		    User ::Leave(KErrNotFound);  
	        } 
	        
	        
		CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &filterField) );	       
	    if( filter->FindL( KKey, filterField ) )
	        {
	        TPtrC filter16;
	    
	        if ( filterField.Get( filter16 ))
	            {
		        heapBuffer4 = HBufC8::NewL( filter16.Length() );
	            CleanupStack::PushL( heapBuffer4 );
	            TPtr8 filter8( heapBuffer4->Des() );
	            filter8.Copy( filter16 );
	            requestParam.iFilterField.Set(filter8);
		        }
		    else
		        {
		        //fileType.Reset();
		        //filterField.Reset();
		        posbasedparam.Reset();
		        AppendErrorMessageL( KGetList, KKey, KInvalid );
		        User ::Leave(KErrArgument);
		        }
	        }

 	    CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &startVal) );
 	    if(filter->FindL( KStartRange, startVal ))
 	        {
 	        if ( !startVal.Get( requestParam.iStartVal ))
 	            {
 	            //fileType.Reset();
		        //filterField.Reset();
		        //startVal.Reset();
		        posbasedparam.Reset();
		        AppendErrorMessageL( KGetList, KStartRange, KInvalid );
		        User ::Leave(KErrArgument);
 	            }
 	        }
	    
	    CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &endVal) );
	    if (filter->FindL( KEndRange, endVal  ))
	        {
	        if ( !endVal.Get( requestParam.iEndVal ))
 	            {
 	            //fileType.Reset();
		        //filterField.Reset();
		        //startVal.Reset();
		        //endVal.Reset();
		        posbasedparam.Reset();
		        AppendErrorMessageL( KGetList, KEndRange, KInvalid );
		        User ::Leave(KErrArgument);
		        }
	        }
	 
	    }//filter map

    else
        {
         //Filter Map missing : 
         posbasedparam.Reset();
         AppendErrorMessageL( KGetList, KFilter, KMissing );
  	     User ::Leave(KErrNotFound); 
        }

   if ( aPostionBasedSearching && ( aInParamList.Count() > 2) )
        {
         pos = 2;
         aInParamList.AtL( pos,posbasedparam );
         if ( (posbasedparam.Name().CompareF(KNullDesC8) != 0 ) || posbasedparam.Value().IsEmpty() ) 
             {
              param = NULL;
             }
         else
             {
             param = &posbasedparam;
             }
        }
    else
        {
        pos=0;//Search from starting point
	    //Sorting map
	    param =  aInParamList.FindFirst( pos, KSort );
        }
        
	HBufC8* heapBuffer1 = NULL;
	HBufC8* heapBuffer2 = NULL;
	    
    if(param)
        {
        sorting = (*param).Value().AsMap();
        if(!sorting)
            {
            //Filter Map missing : 
            posbasedparam.Reset();
            AppendErrorMessageL( KGetList, KSort, KInvalid );
  	        User ::Leave(KErrArgument);
            }
        }
        
	if( (param) &&  sorting )
	    {//sort map
	        CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &sortingField) );
	        if (sorting->FindL( KKey, sortingField ))
	            {
	            TPtrC sort16;
	            if ( sortingField.Get( sort16))
 	                {
 	                heapBuffer1 = HBufC8::NewL( sort16.Length() );
         	        CleanupStack::PushL( heapBuffer1 );
                    TPtr8 sort8( heapBuffer1->Des() );
                    sort8.Copy( sort16 );
                    requestParam.iSortField.Set(sort8);
		            }
		        else
		            {
		            //fileType.Reset();
		            //filterField.Reset();
		            //startVal.Reset();
		            //endVal.Reset();
		            //sortingField.Reset();
		            posbasedparam.Reset();
		            AppendErrorMessageL( KGetList, KKey, KInvalid );
		            User ::Leave(KErrArgument);
		            }
	            }

            CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &order) );
            if (sorting->FindL( KOrder, order ))
	            {
	            TPtrC sortOrder16;
	            if ( order.Get( sortOrder16))
 	                {
 	                heapBuffer2 = HBufC8::NewL( sortOrder16.Length() );
	                CleanupStack::PushL( heapBuffer2 );
	                TPtr8 sortOrder8( heapBuffer2->Des() );
	                sortOrder8.Copy( sortOrder16 );
		            order.Get( requestParam.iOrder );
		            requestParam.iOrder.Set(sortOrder8);
		            }
		        else
		            {
		            //fileType.Reset();
		            //filterField.Reset();
		            //startVal.Reset();
		            //endVal.Reset();
		            //sortingField.Reset();
		            //order.Reset();
		            posbasedparam.Reset();
		            AppendErrorMessageL( KGetList, KOrder, KInvalid );
		            User ::Leave(KErrArgument);
		            }
	            }

	    }//sort map


	// Need to give seperate observer for each call
	
	// Creating instance of serviceobserver for back to back callback support
	
	CMgServiceObserver* serviceObserver = CMgServiceObserver::NewL();
	CleanupStack::PushL(serviceObserver);
	// For supporting back to back callback 
	serviceObserver->SetMemberVar( EMgBlankCmdId,
     NULL,aCallBack );
	
	 iCoreClass->GetListL( requestParam,serviceObserver ) ;
	 CleanupStack::Pop(serviceObserver); 
	 
	 
	  //Sorting is an optional parameter, if it is present only then sorting fields and order present in stack
    if( (param) &&  sorting )
        {
       
        if( heapBuffer2 )
    		CleanupStack::PopAndDestroy( heapBuffer2 );
    
    	CleanupStack::Pop(&order);
	
		if( heapBuffer1 )
	    	CleanupStack::PopAndDestroy( heapBuffer1 );
	
    	CleanupStack::Pop(&sortingField); 
	
        }
     
	CleanupStack::Pop(&endVal); 
   	CleanupStack::Pop(&startVal);
   	 
   	if( heapBuffer4 )
	    CleanupStack::PopAndDestroy( heapBuffer4 );
   	 
   	CleanupStack::Pop(&filterField); 
   	 
    if( heapBuffer3 )
	    CleanupStack::PopAndDestroy( heapBuffer3 );
   	 
   	CleanupStack::Pop(&fileType); 
	
    fileType.Reset();
    filterField.Reset();
    startVal.Reset();
    endVal.Reset();
    sortingField.Reset();
    order.Reset();
    posbasedparam.Reset();

	}

// -----------------------------------------------------------------------------
// CMgInterface::SendRequestL
// This function is called by the user to get mapped SAPI generic error code
// from symbian error codes .
// -----------------------------------------------------------------------------

TInt CMgInterface::SapiError( TInt aSymbianErr )
    {
    TInt sapiErr(SErrGeneralError);

   	switch (aSymbianErr)
    	{
      	case KErrArgument:
   		    {
   		    sapiErr = SErrBadArgumentType;
   		    break;
   		    }
   	    case KErrNotFound:
   		    {
   		    sapiErr = SErrMissingArgument;
   		    break;
   		    }
   		    
   		case KErrNotSupported:
   		    {
   		    sapiErr = SErrServiceNotSupported;
   		    break;
   		    }
   		case KErrServerBusy:
   		    {
   		    sapiErr = SErrServerBusy;
   		    break;
   		    }
    	case KErrGeneral:
    		{
   		    sapiErr = SErrGeneralError;
   		    break;
   		    }
   		case KErrCancel:
	   		{
	   		sapiErr = SErrCancelSuccess;
			break;
	   		}
		case KErrNone:
			{
			sapiErr= SErrNone;
			break;
			}
	
		case KErrNoMemory:
			{
			sapiErr = SErrNoMemory;
			break;
			}
		case KErrInUse:
			{
			sapiErr = SErrServiceInUse;
			break;
			}
		case KErrNotReady:
        	{
        	sapiErr = SErrServiceNotReady;
        	break;
        	}
		case KErrBadName:
		    {
		    sapiErr = SErrUnknownFormat;
		    break;
		    }
        case KErrAlreadyExists:
            {
            sapiErr = SErrEntryExists;
            break;
            }
   		}
    return sapiErr;
    }

// ---------------------------------------------------------------------------
// Append Error Message
// ---------------------------------------------------------------------------
//
void CMgInterface::AppendErrorMessageL( const TDesC8& aCmdName, const TDesC8& aParameter, const TDesC& aMessage )
	{
	iErrorMessage = HBufC::NewL( KMaxErrorMessageLength );
	TPtr tmpMsgPtr = iErrorMessage->Des();
	tmpMsgPtr.Copy(KDomainName);
	
	HBufC* temp = HBufC::New( KMaxErrorMessageLength );

	if ( aCmdName.Length() )
		{
		tmpMsgPtr.Append( KErrorMsgSeparator );
		temp->Des().Copy( aCmdName ); 
		tmpMsgPtr.Append( temp->Des() );
		}

	tmpMsgPtr.Append(KErrorMsgSeparator);
	
	if ( aParameter.Length() )
		{
		temp->Des().Copy(aParameter); 
		tmpMsgPtr.Append(temp->Des());
		}
	
	if ( aMessage.Length() )
		{
		tmpMsgPtr.Append( aMessage );
		}

	delete temp;	
	}
// -----------------------------------------------------------------------------
// CMgInterface::GetThumbnailL
// This method will send request to core class fot getthumbnail
// -----------------------------------------------------------------------------

void CMgInterface::GetThumbnailL( const CLiwGenericParamList& aInParamList, 
                        CLiwGenericParamList& aOutParamList, 
                        MLiwNotifyCallback* aCallBack ,
                        TInt32 aTransactionID )
    {
    
    TLiwGenericParam posbasedparam;
    TBool postionbasedsearching = EFalse;
     const TLiwGenericParam* param = NULL;
    TInt pos = 0;
    const CLiwMap* thumbnailSizemap = NULL;
    TLiwVariant width;
    TLiwVariant height;
    TInt widthThumb  = KNegVal;
    TInt heightThumb = KNegVal;
    TBuf<KFilePath> mediaUrl; 
// Finding url by name
    param = aInParamList.FindFirst( pos, KUrl );

    if( !param )
       {
// finding url by position based
        if( aInParamList.Count() > 0 )
           {
           pos = 0;
           aInParamList.AtL( pos,posbasedparam );

           if ( (posbasedparam.Name().CompareF(KNullDesC8) != 0 ) || posbasedparam.Value().IsEmpty() ) 
               {
               param = NULL;
               }
           else
               {
               param = &posbasedparam;
               postionbasedsearching = ETrue;
               }
           }
       }
// checking the type of url it should be string
//    if ((param) && (param->Value().TypeId() != LIW::EVariantTypeNull)  && (param->Value().TypeId() != LIW::EVariantTypeDesC)  )
        if ((param) && (param->Value().TypeId() != LIW::EVariantTypeDesC )  )
        {
 
        posbasedparam.Reset();
        AppendErrorMessageL( KGetThumbnail, KUrl, KInvalid );        
        User::Leave(KErrArgument);
             
        }
    // present : Mandatory Argument

    if( ( (param)  && ( param->Value().AsDes().Length() < KFilePath ) && (param->Value().Get( mediaUrl )  )  ) )
        {
        // Got the url 
        
        // Now checking for optional argument Thumbnailsize
        param = NULL;
        
    
         if ( postionbasedsearching && ( aInParamList.Count() > 1) )
             {
             pos = 2;
             aInParamList.AtL( pos,posbasedparam );
             if ( (posbasedparam.Name().CompareF(KNullDesC8) != 0 ) || posbasedparam.Value().IsEmpty() ) 
                 {
                 param = NULL;
                 }
             else
                 {
                 param = &posbasedparam;
                 }
             }
         else
             {
             pos=0;//Search from starting point
             //ThumbnailSize map
             param =  aInParamList.FindFirst( pos, KThumbnailSize );
             }

// ThumbnailSize map is present
         if ( param )
              {
              if( (param->Value().TypeId() != LIW::EVariantTypeMap ) )
                   {
                    //ThumbnailSize Type MisMatch 
               
                  
                   posbasedparam.Reset();
                   AppendErrorMessageL( KGetThumbnail, KThumbnailSize, KInvalid );        
                    User::Leave(KErrArgument);
     
                  
              }
         
              thumbnailSizemap = param->Value().AsMap();
              
              if(thumbnailSizemap)
                    
                   {
                   CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &width) );
                   
                   if(thumbnailSizemap->FindL( KWidth, width ))
                       {
                       if ( width.TypeId() != LIW::EVariantTypeTInt32 )
                                {
                                  
                                CleanupStack::Pop(&width);
                                width.Reset() ;
                                posbasedparam.Reset();    
                                AppendErrorMessageL( KGetThumbnail, KWidth, KInvalid );        
                                 User::Leave(KErrArgument);
                       
                                }   
                       
                       
                       widthThumb = width.AsTInt32();
                       if(widthThumb <= 0 ) // If width is negative and zero then throw error
                           {
                            CleanupStack::Pop(&width);
                            width.Reset() ;
                            posbasedparam.Reset();    
                            AppendErrorMessageL( KGetThumbnail, KWidth, KInvalid );        
                            User::Leave(KErrArgument);                         
                           }
                       
                       
                       
                       CleanupStack::Pop(&width);
                       width.Reset();
                       
                       } // End if thumbnail width is there
                   else
                       {
                       CleanupStack::Pop(&width);
                              width.Reset();
                       
                       }
                   CleanupStack::PushL( TCleanupItem( TLiwVariant::VariantCleanup , &height) );
                   if(thumbnailSizemap->FindL( KHeight, height ))
                       {
                       if ( height.TypeId() != LIW::EVariantTypeTInt32 )
                                 {
                                   
                                 CleanupStack::Pop(&height);
                                 height.Reset() ;
                                  
                                 posbasedparam.Reset();    
                                  AppendErrorMessageL( KGetThumbnail, KHeight, KInvalid );        
                                 User::Leave(KErrArgument);
                  
                                 }   
                        
                        
                       heightThumb = height.AsTInt32();
                       if(heightThumb <= 0 ) // If height is negative or zero then throw error
                            {
                             CleanupStack::Pop(&height);
                             height.Reset() ;
                             posbasedparam.Reset();    
                             AppendErrorMessageL( KGetThumbnail, KHeight, KInvalid );        
                             User::Leave(KErrArgument);                         
                            }
        
                       
                       
                       CleanupStack::Pop(&height);
                         height.Reset();
                       
                       } // End If Height is there in thumbnail size map
                   else
                       {
                       CleanupStack::Pop(&height);
                               height.Reset();                       
                       }
                   }  // End of thumbnailsize map
        
        }// For optional argument thumbanil size
         
         // now calling GetThumbnailL method of core class
            
            
            if( aCallBack )
                  {
                   //Asynch Call
                  CServiceThumbnailObserver* observer = CServiceThumbnailObserver::NewL( aCallBack );
                   CleanupStack::PushL( observer );
               
                  iCoreClass->GetThumbnailL( observer, mediaUrl, aTransactionID,heightThumb , widthThumb);
                 
                  CleanupStack::Pop( observer );
                  }
         
            height.Reset();
             width.Reset();
             

           }// End of mandatory argument url
    else 
        {
        posbasedparam.Reset();    
         AppendErrorMessageL( KGetThumbnail, KUrl, KMissing );        
        User::Leave(KErrNotFound);
        }
    posbasedparam.Reset();
    
    }