1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: VideoThumbnailFetcher class definition

    15 *

    16 */

    17 

    18 #ifndef __VIDEOTHUMBNAILDATAFETCHER_H__

    19 #define __VIDEOTHUMBNAILDATAFETCHER_H__

    20 

    21 // INCLUDES

    22 #include <qobject.h>

    23 #include <qicon.h>

    24 #include <qlist.h>

    25 #include <qhash.h>

    26 

    27 #include <thumbnailmanager_qt.h>

    28 

    29 // FORWARD DECLARATIONS

    30 

    31 class VideoThumbnailFetcher : public QObject

    32 {

    33     /**

    34      * defined to be able to use signals and slots

    35      */

    36     Q_OBJECT

    37 

    38 public:

    39 

    40     /**

    41      * Default constructor

    42      */

    43     VideoThumbnailFetcher();

    44     

    45     /**

    46      * Desctructor

    47      */

    48     ~VideoThumbnailFetcher();

    49 

    50     /**

    51      * Adds thumbnail fetch to the fetch list. pauseFetching should be called 

    52      * before adding fetches for performance reasons. After all fetches have

    53      * been added, call continueFetching to start the fetch process which passes 

    54      * the internal data to thumbnail manager. Signal thumbnailReady is emitted 

    55      * when fetch is complete. 

    56      * 

    57      * @param fileName path to the media.

    58      * @param internal data identifying the media.

    59      * @param priority priority for the fetch.

    60      * 

    61      */

    62     void addFetch(const QString fileName, void *internal, int priority);    

    63     

    64     /**

    65      * Empties fetch list. This does not cancel the possible ongoing fetch on

    66      * thumbnail manager side.

    67      * 

    68      */

    69     void cancelFetches();

    70     

    71     /**

    72      * Returns count of the fetches.

    73      * 

    74      */

    75     int fetchCount();

    76     

    77     /**

    78      * Pauses thumbnail fetching process. This does not pause the possible 

    79      * ongoing fetch on thumbnail manager side. 

    80      * 

    81      */

    82     void pauseFetching();

    83     

    84     /**

    85      * Continues the fetching process. All fetches added with addFetch are 

    86      * started without create thumbnail flag. If there's not any of those, 

    87      * starts creating thumbnails for fetches that have no thumbnail yet. 

    88      * Signal allThumbnailsFetched is emitted if there's nothing to do.

    89      * 

    90      */

    91     void continueFetching();

    92     

    93     /**

    94      * Enables or disables the thumbnail creation for videos that do  

    95      * not have thumbnail already in the database.

    96      * 

    97      * @param enable true enables thumbnail creation, false disables. 

    98      * 

    99      */

   100     void enableThumbnailCreation(bool enable);

   101 

   102 private:

   103 

   104     class ThumbnailFetchData

   105     {

   106         public:         

   107         ThumbnailFetchData() { mInternal = 0; };

   108             QString mFileName;

   109             int mPriority;

   110             void *mInternal;

   111     };

   112     

   113 protected:

   114     

   115     /**

   116      * Starts fetching all the thumbnails in fetch list. Create flag is 

   117      * disabled. Thumbnail manager signals to thumbnailReadySlot. If thumbnail 

   118      * fetch fails with -1 the fetch is added to thumbnail creation list, 

   119      * otherwise signal thumbnailReady signal emitted.

   120      * 

   121      */

   122     void startThumbnailFetches();

   123     

   124     /**

   125      * Starts fetching thumbnail with highest priority from creation list. 

   126      * Create flag is enabled. Thumbnail manager signals to thumbnailReadySlot,

   127      * from there signal thumbnailReady is emitted.

   128      *  

   129      */

   130     void startThumbnailCreation();

   131     

   132 signals:

   133     

   134     /**

   135      * Signaled after signal from thumbnail manager has been processed and

   136      * thumbnail fetch process is complete.

   137      *

   138      * @param tnData thumbnail

   139      * @param internal internal data to identify the request

   140      * @param error possible error code from thumbnail manager ( 0 == ok )

   141      * 

   142      */

   143     void thumbnailReady(QPixmap tnData, void *internal, int error);

   144 

   145     /**

   146      * Signaled when all the fetches have been done.

   147      * 

   148      */

   149     void allThumbnailsFetched();

   150     

   151 private slots:

   152     

   153     /**

   154      * Thumbnail manager signals this slot when thumbnail is ready

   155      * for some item.

   156      *

   157      * @param tnData thumbnail

   158      * @param internal internal data to identify the request

   159      * @param requestId thumbnail manager request id

   160      * @param error: possible error code from thumbnail manager ( 0 == ok )

   161      *

   162      */

   163     void thumbnailReadySlot(QPixmap tnData, void *internal, int requestId, int error);

   164 

   165 private: // Data

   166 

   167     /**

   168      * Thumbnail manager object.

   169      */

   170     ThumbnailManager                *mThumbnailManager;

   171     

   172     /**

   173      * List containing not started thumbnail fetches.

   174      */

   175     QList<ThumbnailFetchData *>     mFetchList;

   176     

   177     /**

   178      * Hash containing ongoing thumbnail fetches.

   179      * 

   180      * key is thumbnail request id.

   181      * value is thumbnail fetch data.  

   182      */

   183     QHash<int, ThumbnailFetchData *> mStartedFetchList;

   184     

   185     /**

   186      * List containing thumbnails that have not been created yet.

   187      */

   188     QList<ThumbnailFetchData *>      mCreationList;    

   189     

   190     /**

   191      * Flag indicating if fetching has been paused.

   192      */

   193     bool                             mPaused;

   194     

   195     /**

   196      * Flag indicating if thumbnail creation is enabled.

   197      */

   198     bool                             mTbnCreationEnabled;

   199 };

   200 

   201 #endif // __VIDEOTHUMBNAILDATAFETCHER_H__