1 /*

     2 * Copyright (c) 2007 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:

    15 *

    16 */

    17 

    18 package com.nokia.mj.impl.properties.mobilemedia;

    19 

    20 import com.nokia.mj.impl.rt.support.SystemPropertyProvider;

    21 import javax.microedition.media.Manager;

    22 

    23 /**

    24  * A class for handling dynamic system properties of MobileMedia API.

    25  */

    26 public class DynamicPropertyHandler implements SystemPropertyProvider

    27 {

    28 

    29     /*

    30      * Constants for identifying the asked property.

    31      */

    32     private static String AUDIO_ENCODINGS = "audio.encodings";

    33     private static String SUPPORTS_VIDEO_CAPTURE = "supports.video.capture";

    34     private static String VIDEO_ENCODINGS = "video.encodings";

    35 

    36     // start of the audio content types

    37     private static final String AUDIO = "audio";

    38 

    39     // special audio encoding strings which are defined in the JSR

    40     private static final String AUDIO_ENCODINGS_JSR =

    41         " encoding=pcm encoding=ulaw encoding=gsm";

    42 

    43     // start of the video content types

    44     private static final String VIDEO = "video";

    45 

    46 

    47     /* (non-Javadoc)

    48      * @see com.nokia.mj.impl.rt.DynamicProperty#getProperty(com.nokia.mj.impl.rt.DynamicPropertyInfo)

    49      */

    50     public String getProperty(String propertyName)

    51     {

    52         String propertyValue = null;

    53 

    54         if (propertyName.equals(AUDIO_ENCODINGS))

    55         {

    56             propertyValue = getSupportedCaptureEncodings(AUDIO) +

    57                             AUDIO_ENCODINGS_JSR;

    58         }

    59         else if (propertyName.equals(SUPPORTS_VIDEO_CAPTURE))

    60         {

    61             propertyValue = getSupportedCaptureEncodings(VIDEO);

    62             // video capture is supported only if there is supported encodings

    63             propertyValue = String.valueOf(propertyValue != null);

    64         }

    65         else if (propertyName.equals(VIDEO_ENCODINGS))

    66         {

    67             propertyValue = getSupportedCaptureEncodings(VIDEO);

    68         }

    69         return propertyValue;

    70     }

    71 

    72     public boolean isStatic(String key)

    73     {

    74         // All property values of MobileMedia API do not change during the

    75         // lifetime of the application.

    76         return true;

    77     }

    78 

    79     // capture protocol

    80     private static final String CAPTURE = "capture";

    81 

    82     // encoding for media strings

    83     private static final String ENCODING = "encoding=";

    84 

    85     /**

    86      * Returns supported capture encodings.

    87      * @param aPrefix Capture format type.

    88      * @return the supported capture encodings.

    89      */

    90     private String getSupportedCaptureEncodings(String aPrefix)

    91     {

    92         // get supported content types from all capture:// protocols

    93         String[] cTypes = Manager.getSupportedContentTypes(CAPTURE);

    94 

    95         StringBuffer sBuffer = new StringBuffer();

    96 

    97         // go through all types

    98         for (int i = 0; i < cTypes.length; i++)

    99         {

   100             if (cTypes[ i ].startsWith(aPrefix))

   101             {

   102                 // if video type appent to buffer encoding= + content type

   103                 sBuffer.append(ENCODING + cTypes[ i ] + " ");

   104             }

   105         }

   106         String encodings = null;

   107 

   108         // if no types was found null must be returned

   109         if (sBuffer.length() > 0)

   110         {

   111             // substring is taken to remove last empty space added in previous

   112             // for loop

   113             encodings = sBuffer.toString().substring(0,

   114                         sBuffer.length() - 1);

   115         }

   116         return encodings;

   117     }

   118 }