/*

* Copyright (c) 2005-2006 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 "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members

* which accompanies this distribution, and is available

* at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  CPosLandmarkSearch class

*

*/

#ifndef CPOSLANDMARKSEARCH_H

#define CPOSLANDMARKSEARCH_H

#include <e32base.h>

#include <EPos_CPosLandmarkDatabase.h>

#include <EPos_CPosLmCategoryManager.h>

#include <EPos_CPosLmItemIterator.h>

#include <EPos_CPosLmOperation.h>

#include <EPos_TPosLmSortPref.h>

class CPosLmSearchCriteria;

class CPosLmDisplayData;

const TInt KPosLmMaxNumOfMatchesUnlimited = -1;

/**

*  This class is used to perform searches for landmarks or landmark categories

*  in a landmark database.

*

*  To search a landmark database, an instance of this class is created,

*  supplying the database to search. The client creates a criterion object to

*  specify what to search for. There are different criterion classes which all

*  inherit from @ref CPosLmSearchCriteria. For instance, the client can search

*  for landmarks which contain a certain text string by passing a

*  @ref CPosLmTextCriteria.

*

*  Some criterion classes are used for searching for landmarks (e.g.

*  @ref CPosLmCategoryCriteria is used for searching for landmarks which

*  contain a certain category) and some are used

*  to search for landmark categories (e.g. @ref CPosLmCatNameCriteria is used

*  to search for landmark categories by specifying a category name which may

*  contain wild-card characters).

*

*  Searches can be run in incremental mode.

*  @ref StartLandmarkSearchL and @ref StartCategorySearchL both return a

*  @p CPosLmOperation object which is used to execute the search. If it is

*  run incrementally the client can supervise the progress of the operation.

*  If it is sufficient to run the search synchronously, the client only has to

*  call @p CPosLmOperation::ExecuteL. The client can cancel

*  the search by deleting the @p CPosLmOperation object.

*

*  By default, these functions start a new search, but the client can specify

*  that only previous matches should be searched. This can be used to refine

*  the search when there are many matches.

*

*  During the search execution a read-lock is acquired for each database.

*

*  Only one search can be performed at a time by the single instance of

*  the class. If a search is already running, the search function leaves

*  with error code @p KErrInUse.

*

*  After search completion, the client can make a second search and specify

*  that only the matches from the previous search shall be considered.

*

*  The client can also set a limit on how many search matches should be

*  returned (see @ref SetMaxNumOfMatches).

*

*  The client retrieves the matches from the search by requesting an iterator

*  (see @ref MatchIteratorL) or by using display data (see @ref SetDisplayData).

*

*  @p NetworkServices capability is required for remote databases.

*

*  @lib eposlmsearchlib.lib

*  @since S60 3.0

*/

class CPosLandmarkSearch : public CBase

    {

    public:

        /**

        * Two-phased constructor.

        *

        * The client takes ownership of the returned search object.

        *

        * @param[in] aDatabase The landmark database to search.

        * @returns A new instance of this class.

        */

        IMPORT_C static CPosLandmarkSearch* NewL(

            CPosLandmarkDatabase&  aDatabase

        );

        /**

        * Destructor.

        */

        IMPORT_C virtual ~CPosLandmarkSearch();

    public:

        /**

        * Retrieves the maximum number of search matches limit.

        *

        * By default the maximum number of matches is unlimited.

        *

        * @return The maximum number of search matches or

        *   @p KPosLmMaxNumOfMatchesUnlimited if unlimited.

        */

        IMPORT_C TInt MaxNumOfMatches() const;

        /**

        * Sets the maximum number of search matches limit.

        *

        * If the limit is set, the search operation will stop when this limit

        * is reached.

        *

        * By default the maximum number of matches is unlimited.

        *

        * If a new value for maximum number of matches is set when a search is

        * ongoing, it will not affect the current search. The new maximum will

        * be utilized in the next search.

        *

        * @param[in] aMaxNumOfMatches the maximum number of search matches.

        *   KPosLmMaxNumOfMatchesUnlimited means that the number of matches is

        *   unlimited.

        */

        IMPORT_C void SetMaxNumOfMatches(

            TInt  aMaxNumOfMatches = KPosLmMaxNumOfMatchesUnlimited

        );

        /**

        * Starts a search for landmarks.

        *

        * The client takes ownership of the returned operation object.

        *

        * This function requires @p ReadUserData capability.

        *

        * @param[in] aCriteria The search criterion.

        * @param[in] aSearchOnlyPreviousMatches This flag may be used to perform a

        *   search within the results of previous search.

        * @returns A handle to the search operation.

        *

        * @leave KErrInUse Search is already running.

        * @leave KErrNotSupported search criterion is not supported.

        * @leave KErrArgument Search criterion is not valid for landmark searching.

        * @leave KErrArgument There are no previous matches and the client specifies that

        *   previous matches should be used.

        */

        virtual CPosLmOperation* StartLandmarkSearchL(

            const CPosLmSearchCriteria& aCriteria,

            TBool aSearchOnlyPreviousMatches = EFalse

        ) = 0;

        /**

        * Starts a search for landmarks.

        *

        * This overload of the @ref StartLandmarkSearchL function lets the

        * client define the sort order for the search matches. 

        * Only sorting by landmark name is supported.

        *

        * The client takes ownership of the returned operation object.

        *

        * This function requires @p ReadUserData capability.

        *

        * @param[in] aCriteria The search criterion.

        * @param[in] aSortPref A sort preference object.

        * @param[in] aSearchOnlyPreviousMatches This flag may be used to perform a

        *   search within the results of previous search.

        * @returns A handle to the search operation.

        *

        * @leave KErrInUse Search is already running.

        * @leave KErrArgument Search criterion is not valid for landmark searching.

        * @leave KErrArgument There are no previous matches and the client specifies that

        *   previous matches should be used.

        * @leave KErrNotSupported Search criterion is not supported.

        * @leave KErrNotSupported Client tries to sort by other attribute than name.

        */

        virtual CPosLmOperation* StartLandmarkSearchL(

            const CPosLmSearchCriteria& aCriteria,

            const TPosLmSortPref& aSortPref,

            TBool  aSearchOnlyPreviousMatches = EFalse

        ) = 0;

        /**

        * Starts a search for landmark categories.

        *

        * The criterion which defines whether a landmark category is a match or

        * not is passed as input to this function.

        *

        * The client takes ownership of the returned operation object.

        *

        * This function requires @p ReadUserData capability.

        *

        * @param[in] aCriteria The search criterion.

        * @param[in] aSortPref Sort preference for the search results.

        * @param[in] aSearchOnlyPreviousMatches This flag may be used to perform a

        *   search within the results of previous search.

        * @returns A handle to the search operation.

        *

        * @leave KErrInUse Search is already running.

        * @leave KErrArgument Search criterion is not valid for category searching.

        * @leave KErrNotSupported Search criterion is not supported.

        */

        virtual CPosLmOperation* StartCategorySearchL(

            const CPosLmSearchCriteria& aCriteria,

            CPosLmCategoryManager::TCategorySortPref aSortPref,

            TBool aSearchOnlyPreviousMatches = EFalse

        ) = 0;

        /**

        * Returns the number of matches so far in the search.

        *

        * This function can also be called during a search operation.

        *

        * @return The number of search matches.

        */

        virtual TUint NumOfMatches() const = 0;

        /**

        * Creates an iterator object to iterate the matching landmarks or

        * landmark categories.

        *

        * This function can also be called during a search in order to read the

        * matches encountered so far. Note that the iterator will not iterate

        * any new matches. If new matches are found, a new iterator must be

        * created.

        *

        * If a sort preference was specified when the search was started,

        * the landmarks/categories will be sorted when the search is complete

        * but the items are not necessarily sorted if this function is called

        * during a search.

        *

        * Note: If the client has set display data and resets the display data

        * during a search, the sort order in the iterator might be incorrect.

        *

        * The client takes ownership of the returned iterator object.

        *

        * Note that the iterator iterates matches in @ref CPosLandmarkSearch.

        * It cannot be used after the search object has been deleted. Make sure

        * to delete the iterator first.

        *

        * @return A search match iterator.

        */

        virtual CPosLmItemIterator* MatchIteratorL() = 0;

        /**

        * Display data can be used as an alternative way to get result

        * from a database search. Landmarks or categories are added to the

        * display data collection during a search depending on the search type.

        *

        * This function may replace the combination of using

        * @ref MatchIteratorL and reading landmark or category data.

        * Result data is read already during the search and no duplicate

        * access to database is needed.

        *

        * The display data object will be reset each time a new search is

        * started. No items during the search are removed from the

        * collection. New found matches can be added every time next

        * search step is completed, see @ref CPosLmDisplayData::NewItemIndex.

        *

        * Note: The database index of displayable data items in

        * @ref CPosLmDisplayData will be set to 0 as it has no meaning in a

        * single database search.

        *

        * The client owns the display data object. If the client deletes it

        * during a search, this may lead to unexpected errors. The client must

        * call @ref UnsetDisplayData before it deletes the display data object.

        *

        * Note: If the client resets the display data during a search, the sort

        * order in the iterator might become incorrect.

        *

        * @param[in,out] aData The displayable data.

        *

        * @panic "Landmarks Client"-EPosSearchOperationInUse 

        *   The client set display data during an ongoing search.

        */

        virtual void SetDisplayData( CPosLmDisplayData& aData ) = 0;

        /**

        * Unsets display data. No further data will be added to the display

        * data that was set with @ref SetDisplayData.

        *

        * @panic "Landmarks Client"-EPosSearchOperationInUse 

        *   The client unset display data during an ongoing search.

        */

        virtual void UnsetDisplayData() = 0;

    protected:

        // C++ constructor.

        IMPORT_C CPosLandmarkSearch();

    private:

        // Prohibit copy constructor

        CPosLandmarkSearch( const CPosLandmarkSearch& );

        // Prohibit assigment operator

        CPosLandmarkSearch& operator= ( const CPosLandmarkSearch& );

    private:

        TUid iDtorIdKey;

        TInt iMaxNumOfMatches;

    };

#endif      // CPOSLANDMARKSEARCH_H