/*

 * Copyright (c) 2003-2009 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:

 * Name          : SdpAttributeField.h

 * Part of       : SDP Codec

 * Interface     : SDK API, SDP Codec API

 * Version       : 1.0

 *

 */

 #ifndef CSDPATTRIBUTEFIELD_H

 #define CSDPATTRIBUTEFIELD_H

 //  INCLUDES

 #include <e32base.h>

 #include <stringpool.h>

 #include "sdpcodecstringconstants.h"

 // FORWARD DECLARATIONS

 class RReadStream;

 class RWriteStream;

 class CSdpFmtAttributeField;

 class CSdpAttributeFieldPtrs;

 // CLASS DECLARATION

 /**

  *  @publishedAll

  *  @released

  *

  *	This class encapsulates the attribute field of Session Description Protocol

  *	for media and session level attributes. Media format/payload type level

  *  attributes are supported by the CSdpFmtAttributeField class. 

  * 

  *	The normative reference for correct formatting and values is

  *	draft-ietf-mmusic-sdp-new-14 unless specified otherwise in

  *  member documentation. The implementation supports this normative

  *  reference, but does not enforce it fully. 

  *

  *  @lib sdpcodec.lib

  */

 class CSdpAttributeField : public CBase

 	{

     public:     // Constructors and destructor

         /**

          *	Constructs a new attribute field.

 		 *			 

          *	@param aText A string containing a correctly 

          *         formatted field value terminated by a CRLF.

          *	@return a new instance.

          */

 		IMPORT_C static CSdpAttributeField* DecodeL( const TDesC8& aText );

         /**

          *	Constructs a new attribute field and adds the pointer to the 

          *  cleanup stack.

 		 *		 

          *	@param aTest A string containing a correctly 

          *         formatted field value terminated by a CRLF.

          *	@return a new instance.

          */

 		IMPORT_C static CSdpAttributeField* DecodeLC( const TDesC8& aText );

         /**

          *	Constructs a new attribute field. 

 		 *

          *	@param aAttribute The attribute name. It can be a pre-

          *         defined name in the SDP string pool or defined by the 

          *         client.

          *	@param aValue A valid attribute value or an empty 

          *         descriptor to omit the value part.

          *	@return a new instance.

 		 */

 		IMPORT_C static CSdpAttributeField* NewL(

             RStringF aAttribute, const TDesC8& aValue );

         /**

          *	Constructs a new attribute field and adds the pointer to the 

          *  cleanup stack. 

 		 *

          *	@param aAttribute The attribute name. It can be a pre-defined 

          *         name in the SDP string pool or defined by the client.

          *	@param aValue A valid attribute value or an empty 

          *         descriptor to omit the value part.

          *	@return a new instance.

 		 */

 		IMPORT_C static CSdpAttributeField* NewLC(

             RStringF aAttribute, const TDesC8& aValue );

  		/**

 		 *	Deletes the resources held by the instance.

 		 */

 		IMPORT_C ~CSdpAttributeField();

     public:     // New functions

     	/**

 		 *	Outputs the field formatted according to SDP syntax and including

 		 *  the terminating CRLF.

 		 * 

 		 *	@param aStream Stream used for output. On return the 

          *         stream includes correctly formatted attribute field.

 		 */

 		IMPORT_C void EncodeL( RWriteStream& aStream ) const;

 		/**

 		 *	Creates a new instance that is equal to the target.

 		 *

 		 *	@return a new instance.

 		 */

 		IMPORT_C CSdpAttributeField* CloneL() const;

 		/**	

 		 *	Compares this instance to another for equality.

 		 *

 		 *	@param aObj: The instance to compare to.

 		 *	@return ETrue if equal, EFalse if not.

 		 */

 		IMPORT_C TBool operator == ( const CSdpAttributeField& aObj ) const;

 		/**

 		 *	Gets the attribute name.

 		 *	

 		 *	@return	The attribute name. The name can be pre-defined 

          *          name in the SDP string table or defined by the client.

 		 */

 		IMPORT_C RStringF Attribute() const;

 		/**

 		 *	Gets the attribute.

 		 *

  		 *	@return	The value or an empty descriptor if there is no value part.

 		 */

 		IMPORT_C const TDesC8& Value() const;

 		/**

 		 *	Sets the attribute and attribute value.

 		 *

          *	@param aAttribute A valid attribute name. It can be a 

          *         pre-defined name in the SDP string pool or 

          *         defined by the client.

          *	@param aValue A valid attribute value or an empty 

          *         descriptor to omit the value part.

 		 *  @leave KErrSdpCodecAttributeField if the attribute part is not 

 		 *         pre-defined EAttributeFmtp or EAttributeRtpmap.

 		 */

 		IMPORT_C void SetL( RStringF aAttribute, const TDesC8& aValue );

 		/**

  		 *	Assigns attribute to the format level attribute.

  		 *  In the final output the attribute will placed after format level

 		 *  attribute.

  		 *

  		 *	@param aFmtAttribute A format level 

  		 *         attribute this attribute is assigned to.

  		 */

  		IMPORT_C void AssignTo(const CSdpFmtAttributeField& aFmtAttribute);

 		/**

 		 *	Test if the attribute belongs to the given format level attribute.

 		 *  Note, that the check can be true for the media level paremeter if

 		 *  it appears after the last format level attribute.

 		 *

 		 *	@param  aFmtAttribute: A format level 

 		 *          attribute this attribute belongs to.

 		 *	@return	ETrue if attribute belongs to the format level attribute, 

 		 *          EFalse otherwise.

 		 */

 		IMPORT_C TBool BelongsTo(const CSdpFmtAttributeField& aFmtAttribute) const;

     public:     // Internal to codec

         /**

          *  Externalizes the object to stream

          *

          *  @param aStream Stream where the object's state will be stored

          */

 		void ExternalizeL( RWriteStream& aStream ) const;

         /**

          *  Creates object from the stream data

          *

          *  @param aStream Stream where the object's state will be read

          *  @return Initialized object

          */

         static CSdpAttributeField* InternalizeL( RReadStream& aStream );

         /**

          *  Informs if the attribute belongs to any format level attribute.

          *

          *  @return ETrue if attribute belongs to any format level 

 		 *			attribute, EFalse otherwise.

          */

         TBool IsFmtAttribute();

 	private:    // Constructors

         /**

          *  Constructor

          */

 		CSdpAttributeField();

         /**

          *  Second phase constructor

          *

          *  @param aText Text string ending to LF character

          */

         void ConstructL( const TDesC8& aText );

         /**

          *  Second phase constructor

          *

          *  @param aAttribute Attribute identifier

          *  @param aValue Value of the attribute of KNullDesC8

          */

         void ConstructL( RStringF aAttribute, const TDesC8& aValue );

     private:    // Internal

         /**

          *  Verifies that attribute is valid property attribute and initializes

          *  the member variables of class accordingly

          *

          *  @param aAttribute Attribute in descriptor

          */

         void FormatProperyAttributeL( const TDesC8& aAttribute );

         /**

          *  Verifies that attribute is valid value attribute and initializes

          *  the member variables of class accordingly

          *

          *  @param aArray Array of the attributes

          */

         void FormatValueAttributeL( const TDesC8& aAttribute,

                                     const TDesC8& aValue );

         /**

          *  Verifies that the value is valid for the attribute

          *

          *  @param aAttribute The attribute

          *  @param aArray Array containing the values (and attribute)

          */

         void VerifyValueAttributeL( SdpCodecStringConstants::TStrings aString,

                                     const TDesC8& aValue );

         /**

          *  Forms attribute and value strings out of the token array

          *  and pushes both (aAttribute & aValue) into cleanup stack

          *

          *  @param aArray Token array

          *  @param aAttribute Attribute string (in cleanup stack)

          *  @param aValue Value string (in cleanup stack)

          */

         void CreateAttributeAndValueStringsLC( RArray<TPtrC8>& aArray,

                                                HBufC8*& aAttribute,

                                                HBufC8*& aValue );

         /**

          *  Checks if the value is among the valid orient attributes

          *

          *  @param aValue Value string

          */

         void CheckValidOrientL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid language attribute as

          *  specified in RFC 3066

          *

          *  @param aValue Value string

          */

         void CheckValidLangStrL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid framerate attribute

          *

          *  @param aValue Value string

          */

         void CheckValidFrameRateL( const TDesC8& aValue );

         /**

          *  Checks if the value is among valid uri value for control attribute

          *

          *  @param aValue Value string

          */       

         void CheckValidControlL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid value for group attribute as

          *  specified in RFC 3388

          *

          *  @param aValue Value string

          */       

         void CheckValidGroupL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid value for des attribute as

          *  specified in RFC 3312

          *

          *  @param aValue Value string

          */       

         void CheckValidDesL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid value for curr and conf attribute as

          *  specified in RFC 3312

          *

          *  @param aValue Value string

          */       

         void CheckValidCurrAndConfL( const TDesC8& aValue );

         /**

          *  Checks if value is included in the list of predefined values

          *

          *  @param aItemsCount Predefined values count

          *  @param aValuesList List of predefined values

          *  @param aValue Value string

          */       

         void ValidValueInListL( TInt aItemsCount, 

                                 const TText8* const aValuesList[], 

                                 const TDesC8& aValue );

         /**

          *  Checks if the value is valid value for range attribute as

          *  specified in RFC 2326

          *

          *  @param aValue Value string

          */       

         void CheckValidRangeL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid rtpmap string

          *

          *  @param aValue Value string

          */   

         void CheckValidRtpmapL( const TDesC8& aValue );

         /**

          *  Checks if the value is valid fmtp string

          *

          *  @param aValue Value string

          */   

         void CheckValidFmtpL( const TDesC8& aValue );

         /**

          *  Set attribute and values. Attribute is not one of predefined ones.

          *

          *  @param aAttribute Attribute string (in cleanup stack)

          *  @param aValue Value string

          */   

         void SetNotPredefinedAttributeL( const TDesC8& aAttribute, 

                                          const TDesC8& aValue );

         void CreateAttributeFieldPtrsL();

         inline CSdpAttributeFieldPtrs& AttributeFieldPtrs();      

         inline const CSdpAttributeFieldPtrs& AttributeFieldPtrs() const;

 		void __DbgTestInvariant() const;

     private:    // Data

         // String pool

         RStringPool iPool;

         // Attribute name

         RStringF iAttribute;

         // Flag indicating if the attribute is a property attribute

         TBool iPropertyAttribute;

         // Value field

         HBufC8* iValue;

 	};

 #endif // CSDPATTRIBUTEFIELD_H