/*

* Copyright (c) 2008-2009 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:   

*

*/

#ifndef _C_GLXDATASOURCETASKMDS_H_

#define _C_GLXDATASOURCETASKMDS_H_

/**

 * @author Simon Brooks, Alex Birkett

 */

// INCLUDES

#include <e32cmn.h>

#include <glxdatasource.h>

#include <glxdatasourcetask.h>

#include <glxfilterproperties.h>

#include <mdccommon.h>

#include <mdequery.h>

#include <mglxtnthumbnailcreatorclient.h>

#include <mpxfilter.h>

// FORWARD DECLARATIONS

class CGlxDataSourceMde;

class CGlxRequest;

class CGlxtnThumbnailCreator;

class CMdEObjectDef;

class CMdEObjectQuery;

class CMdESession;

/**

 * Query types supported by subclasses of CGlxDataSourceTaskMde

 */

enum TGlxQueryType

    {

    EContainerFirstItemQuery,    // CGlxDataSourceTaskMdeThumbnail+

    EIdListQuery,                // GlxDataSourceTaskMdeIdList

    EAttributeQuery,             // CGlxDataSourceTaskMdeAttribute

    ELocationAttributeQuery,     // CGlxDataSourceTaskMdeAttribute

    EImageVideoQuery,            // CGlxDataSourceTaskMdeAttribute (but should be general)

    ECommandRemoveFromContainer, // CGlxDataSourceTaskMdeCommand

    ECommandAddToContainer,      // CGlxDataSourceTaskMdeCommand

    ECommandRemoveLocation,      // CGlxDataSourceTaskMdeCommand

    ECommandAddContainer,        // CGlxDataSourceTaskMdeCommand adds a container

    ECommandDeleteContainers,    // CGlxDataSourceTaskMdeCommand deletes containers objects

    ECommandDeleteItems,          // CGlxDataSourceTaskMdeCommand deletes containers objects

    ECommandRenameContainer,

    ECommandRename

    };

/**

 *  CGlxDataSourceTaskMde class 

 *  Base class for mde tasks: provides task generic functionality.

 */

	{

public:

    /**

     * Constructor.

     * @param aRequest request to be executed.

     * @param aObserver observer to be informed when task has completed.

     * @param aDataSource data source to be used by this object.

     */

    /**

     * Destructor.

     */

    ~CGlxDataSourceTaskMde();

    /**

     * Second stage constructor

     */

    virtual void ConstructL();

protected: // to be implemented by deriving classes

    /**

     * See @ref CGlxDataSourceTask::ExecuteRequestL

     */ 

    virtual void ExecuteRequestL() = 0;

    /**

     * Must be implemented by deriving classes. To handle query completion

     * @param aQuery Query that has been completed.

     */

    virtual void DoHandleQueryCompletedL(CMdEQuery& aQuery) = 0;

    /**

     * Optionally implemented by deriving classes. Used if the deriving class has

     * to run more than one query. Should start the next query or call HandleRequestComplete() 

     * if no futher queries are required to be run. If the deriving class only has a single query,

     * HandleRequestComplete() can be called from DoHandleQueryCompletedL()

     */

    virtual void DoNextQueryL() {}

public: // From CGlxDataSourceTask

    /**

     * See @ref CGlxDataSourceTask::CancelRequest

     */ 

    void CancelRequest();

private: // from MMdEQueryObserver

    /**

     * See @ref MMdEQueryObserver::HandleQueryNewResults

     */ 

    void HandleQueryNewResults( CMdEQuery& aQuery,

                                TInt aFirstNewItemIndex,

                                TInt aNewItemCount );

    /**

     * See @ref MMdEQueryObserver::HandleQueryNewResults

     */

    void HandleQueryNewResults( CMdEQuery& aQuery,

                                TInt aNewObjectItemCount,

                                TInt aNewRelationItemCount,

                                TInt aNewEventItemCount);

    /**

     * See @ref MMdEQueryObserver::HandleQueryCompleted

     */

    void HandleQueryCompleted( CMdEQuery& aQuery, TInt aError);

protected:

    /**

     * Returns a pointer to the CGlxDataSourceMde object passed in on instantiation.

     * @return a pointer to the CGlxDataSourceMde object passed in on instantiation.

     */

    CGlxDataSourceMde* DataSource();

    void AddMonthFilterL(CMdEObject* aMonth, TGlxFilterProperties& aFilterProperties);

	/**

	 * Set query contditions by container id and filter properties.

     * @param aLogicCondition logic condition to add conditions to

     * @param aContainerId Id of the container

     * @param aContainerIsLeft. This should be set to to ETrue if the container is on the left side of the releation, or

     * EFalse if the container is on the right side of the relation

     * 

     */	

    /**

     * Returns the maximum number of items that a query should find.

     * @return Maximum number of results

     */

    TInt MaxQueryResultsCount(const TGlxFilterProperties& aFilterProperties) const;

    /**

     * Removes and destroys the oldest query in iQueries.

     */

    void RemoveQuery();

    /**

     * Adds queries for images and or videos to the query queue. The queries will return objects

     * of type image or video that have ids specified by aObjectIds. 

     * @param aObjectIds A list of the ids of the required objects.

     * @param aFilterProperties TGlxFilterProperties.iItemType is used to determine if only 

     * image or video queries are required if iItemType is not set to EGlxFilterImage or 

     * EGlxFitlerVideo a query for images will be queued first followed by a query for videos.

     */

    /**

     * Adds a query for tag objects that have ids specified by aObjectIds

     * to the query queue.

     * @param aObjectIds A list of the ids of the required objects.

     */

    void QueueTagObjectQueryL(const RArray<TGlxMediaId>& aObjectIds);

    /**

     * Adds a query for album objects that have ids specified by aObjectIds

     * to the query queue.

     * @param aObjectIds A list of the ids of the required objects.

     */

    void QueueAlbumObjectQueryL(const RArray<TGlxMediaId>& aObjectIds);

    /**

     * Adds a query for "month" objects that have ids specified by aObjectIds

     * to the query queue.

     * @param aObjectIds A list of the ids of the required objects.

     */

    void QueueMonthObjectQueryL(const RArray<TGlxMediaId>& aObjectIds);

    /**

     * Adds a query for objects of type specified by aObjectDef

     * that have ids specified by aObjectIds to the query queue.

     * @param aObjectDef type of objects required.

     * @param aObjectIds A list of the ids of the required objects.

     * @param aQueryType The query type.

     */

    void QueueObjectQueryL(CMdEObjectDef& aObjectDef, 

            const RArray<TGlxMediaId>& aObjectIds, const TGlxQueryType& aQueryType);

    /**

     * Appends a query to the query queue. (the ownership of the query is transferred)

     * @param aQuery query to append to the query queue ownership is transferred to 

     * the query queue. It is expected that aQuery is not on the cleanupstack before the

     * call to AppendQueryL is made

     * @param aQueryType the query type.

     */

    void AppendQueryL(CMdEQuery* aQuery, const TGlxQueryType& aQueryType);

    /**

     * Executes the query at ordinal 0 in the

     * query list implementation can be overidden by

     * deriving classes.

     */

    virtual void ExecuteQueryL();

private:

    /* 

    * Helper function TRAPed and called by HandleQueryCompleted()

    * @param aQuery the query that has been completed

    */

    void HandleQueryCompletedL(CMdEQuery& aQuery);

    /**

     * Removes the observer from any existing queries, cancels and destroys them

     */

    void DestroyQueries();

private:

    /**

     * Default namespace def (not owned)

     */

    CMdENamespaceDef* iDefaultNameSpaceDef;

protected:

    /**

     * Outstanding queries array (owned)

     */

    RPointerArray <CMdEQuery> iQueries;

    /**

     * Query types array (owned)

     */

    RArray <TGlxQueryType> iQueryTypes;

    /**

     * Filter properties

     */

    TGlxFilterProperties iFilterProperties;  

    };

#endif //_C_GLXDATASOURCETASKMDS_H_