1 // Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

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

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 //

    15 

    16 #include "browsingframe.h"

    17 

    18 

    19 /** Verifies the length of a frame is correct.  Checking:

    20 1) Header is present

    21 2) Data length indicated is present

    22 

    23 This does not semantically check that the data expected for

    24 the PDU ID is present.

    25 

    26 @param aFrame The frame to verify

    27 @leave KErrCorrupt if the length of the frame is incorrect

    28 */

    29 void AvrcpBrowsing::BrowsingFrame::VerifyFrameL(const TDesC8& aFrame)

    30 	{

    31 	if((aFrame.Length() < AvrcpBrowsing::KHeaderLength) ||

    32 	  (aFrame.Length() < (AvrcpBrowsing::KHeaderLength + ParamLength(aFrame))))

    33 		{

    34 		User::Leave(KErrCorrupt);

    35 		}

    36 	}

    37 

    38 

    39 /** Retreives the PDU ID from this frame.

    40 

    41 @pre The integrity of the frame must have been verified (@see 

    42 	 BrowsingFrame::VerifyFrameL) as the length is not checked

    43 	 before retrieving the PDU ID.

    44 @param aFrame The frame to retrieve the PDU ID for.

    45 @return The PDU ID of aFrame

    46 */

    47 AvrcpBrowsing::TPduId AvrcpBrowsing::BrowsingFrame::PduId(const TDesC8& aFrame)

    48 	{

    49 	return aFrame[0];

    50 	}

    51 

    52 /** Retreives the parameter length from this frame.

    53 

    54 @pre The integrity of the frame must have been verified (@see 

    55 	 BrowsingFrame::VerifyFrameL) as the length is not checked

    56 	 before retrieving the parameter length.

    57 @param aFrame The frame to retrieve the parameter length for.

    58 @return The parameter length of aFrame

    59 */

    60 TInt AvrcpBrowsing::BrowsingFrame::ParamLength(const TDesC8& aFrame)

    61 	{

    62 	TInt paramLength = 0;

    63 	paramLength += aFrame[2];

    64 	paramLength += ((TUint)aFrame[1]) << 8;

    65 	

    66 	return paramLength;

    67 	}

    68 

    69 /** Retreives the payload from this frame.

    70 

    71 @pre The integrity of the frame must have been verified (@see 

    72 	 BrowsingFrame::VerifyFrameL) as the length is not checked

    73 	 before retrieving the payload.

    74 @param aFrame The frame to retrieve the payload for.

    75 @param aPayload On return the payload of aFrame

    76 */

    77 void AvrcpBrowsing::BrowsingFrame::Payload(const TDesC8& aFrame, TPtrC8& aPayload)

    78 	{

    79 	aPayload.Set(aFrame.Mid(AvrcpBrowsing::KHeaderLength, AvrcpBrowsing::BrowsingFrame::ParamLength(aFrame)));

    80 	}

    81