/*

* Copyright (c) 2007 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:

*

*/

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

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

import javax.microedition.media.Manager;

/**

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

 */

public class DynamicPropertyHandler implements SystemPropertyProvider

{

    /*

     * Constants for identifying the asked property.

     */

    private static String AUDIO_ENCODINGS = "audio.encodings";

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

    private static String VIDEO_ENCODINGS = "video.encodings";

    // start of the audio content types

    private static final String AUDIO = "audio";

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

    private static final String AUDIO_ENCODINGS_JSR =

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

    // start of the video content types

    private static final String VIDEO = "video";

    /* (non-Javadoc)

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

     */

    public String getProperty(String propertyName)

    {

        String propertyValue = null;

        if (propertyName.equals(AUDIO_ENCODINGS))

        {

            propertyValue = getSupportedCaptureEncodings(AUDIO) +

                            AUDIO_ENCODINGS_JSR;

        }

        else if (propertyName.equals(SUPPORTS_VIDEO_CAPTURE))

        {

            propertyValue = getSupportedCaptureEncodings(VIDEO);

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

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

        }

        else if (propertyName.equals(VIDEO_ENCODINGS))

        {

            propertyValue = getSupportedCaptureEncodings(VIDEO);

        }

        return propertyValue;

    }

    public boolean isStatic(String key)

    {

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

        // lifetime of the application.

        return true;

    }

    // capture protocol

    private static final String CAPTURE = "capture";

    // encoding for media strings

    private static final String ENCODING = "encoding=";

    /**

     * Returns supported capture encodings.

     * @param aPrefix Capture format type.

     * @return the supported capture encodings.

     */

    private String getSupportedCaptureEncodings(String aPrefix)

    {

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

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

        StringBuffer sBuffer = new StringBuffer();

        // go through all types

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

        {

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

            {

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

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

            }

        }

        String encodings = null;

        // if no types was found null must be returned

        if (sBuffer.length() > 0)

        {

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

            // for loop

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

                        sBuffer.length() - 1);

        }

        return encodings;

    }

}