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CnvUtfConverter Class Reference

class CnvUtfConverter

Converts text between Unicode (UCS-2) and the two Unicode transformation formats UTF-7 and UTF-8. There are no functions to convert directly between UTF-7 and UTF-8.

Objects of this class do not need to be created because all the member functions are static. The four functions are passed text in the second argument and output the resulting text in the first argument. Sixteen-bit descriptors are used to hold text encoded in UCS-2 (i.e. normal 16 bit Unicode), and eight-bit descriptors are used to hold text encoded in either of the transformation formats.

The conversion functions return the number of characters which were not converted because the output descriptor was not long enough to hold all of the converted text. This allows users of this class to perform partial conversions on an input descriptor, handling the case when the input descriptor is truncated mid way through a multi-byte character. The caller does not have to guess how big to make the output descriptor for a given input descriptor- they can simply do the conversion in a loop using a small output descriptor. The ability to handle truncated descriptors is particularly useful if the caller is receiving information in chunks from an external source.

Public Member Functions
IMPORT_C TInt	ConvertFromUnicodeToUtf7(TDes8 &, const TDesC16 &, TBool)
TInt	ConvertFromUnicodeToUtf7(TDes8 &, const TDesC16 &, TBool, TBool)
IMPORT_C HBufC8 *	ConvertFromUnicodeToUtf7L(const TDesC16 &, TBool)
IMPORT_C TInt	ConvertFromUnicodeToUtf8(TDes8 &, const TDesC16 &)
TInt	ConvertFromUnicodeToUtf8(TDes8 &, const TDesC16 &, TBool)
IMPORT_C HBufC8 *	ConvertFromUnicodeToUtf8L(const TDesC16 &)
IMPORT_C TInt	ConvertToUnicodeFromUtf7(TDes16 &, const TDesC8 &, TInt &)
TInt	ConvertToUnicodeFromUtf7(TDes16 &, const TDesC8 &, TBool, TInt &)
IMPORT_C HBufC16 *	ConvertToUnicodeFromUtf7L(const TDesC8 &)
IMPORT_C TInt	ConvertToUnicodeFromUtf8(TDes16 &, const TDesC8 &)
TInt	ConvertToUnicodeFromUtf8(TDes16 &, const TDesC8 &, TBool)
TInt	ConvertToUnicodeFromUtf8(TDes16 &, const TDesC8 &, TBool, TInt &, TInt &)
IMPORT_C HBufC16 *	ConvertToUnicodeFromUtf8L(const TDesC8 &)

Public Member Enumerations
enum	TError { EErrorIllFormedInput = KErrCorrupt }

Member Functions Documentation

ConvertFromUnicodeToUtf7(TDes8 &, const TDesC16 &, TBool)

IMPORT_C TInt	ConvertFromUnicodeToUtf7	(	TDes8 &	aUtf7,
			const TDesC16 &	aUnicode,
			TBool	aEncodeOptionalDirectCharactersInBase64
		)	[static]

Converts Unicode text into UTF-7 encoding.

Parameters

TDes8 & aUtf7	On return, contains the UTF-7 encoded output string.
const TDesC16 & aUnicode	A UCS-2 encoded input string.
TBool aEncodeOptionalDirectCharactersInBase64	If ETrue then characters from UTF-7 set O (optional direct characters) are encoded in Modified Base64. If EFalse the characters are encoded directly, as their ASCII equivalents.

ConvertFromUnicodeToUtf7(TDes8 &, const TDesC16 &, TBool, TBool)

TInt	ConvertFromUnicodeToUtf7	(	TDes8 &	aUtf7,
			const TDesC16 &	aUnicode,
			TBool	aIsImapUtf7,
			TBool	aEncodeOptionalDirectCharactersInBase64
		)	[static]

Parameters

TDes8 & aUtf7
const TDesC16 & aUnicode
TBool aIsImapUtf7
TBool aEncodeOptionalDirectCharactersInBase64

ConvertFromUnicodeToUtf7L(const TDesC16 &, TBool)

IMPORT_C HBufC8 *	ConvertFromUnicodeToUtf7L	(	const TDesC16 &	aUnicode,
			TBool	aEncodeOptionalDirectCharactersInBase64
		)	[static]

Converts Unicode text into UTF-7 encoding. The fucntion leaves with KErrCorrupt if the input string is corrupt.

Parameters

const TDesC16 & aUnicode	A UCS-2 encoded input string.
TBool aEncodeOptionalDirectCharactersInBase64	If ETrue then characters from UTF-7 set O (optional direct characters) are encoded in Modified Base64. If EFalse the characters are encoded directly, as their ASCII equivalents.

ConvertFromUnicodeToUtf8(TDes8 &, const TDesC16 &)

IMPORT_C TInt	ConvertFromUnicodeToUtf8	(	TDes8 &	aUtf8,
			const TDesC16 &	aUnicode
		)	[static]

Converts Unicode text into UTF-8 encoding.

Parameters

TDes8 & aUtf8	On return, contains the UTF-8 encoded output string.
const TDesC16 & aUnicode	The Unicode-encoded input string.

ConvertFromUnicodeToUtf8(TDes8 &, const TDesC16 &, TBool)

TInt	ConvertFromUnicodeToUtf8	(	TDes8 &	aUtf8,
			const TDesC16 &	aUnicode,
			TBool	aGenerateJavaConformantUtf8
		)	[static]

Converts Unicode text into UTF-8 encoding.

Surrogate pairs can be input which will result in a valid 4 byte UTF-8 value.

The variant of UTF-8 used internally by Java differs slightly from standard UTF-8. The TBool argument controls the UTF-8 variant generated by this function.

Parameters

TDes8 & aUtf8	On return, contains the UTF-8 encoded output string.
const TDesC16 & aUnicode	A UCS-2 encoded input string.
TBool aGenerateJavaConformantUtf8	EFalse for orthodox UTF-8. ETrue for Java UTF-8. The default is EFalse.

ConvertFromUnicodeToUtf8L(const TDesC16 &)

IMPORT_C HBufC8 *

ConvertFromUnicodeToUtf8L

(

const TDesC16 &

aUnicode

)

[static]

Converts Unicode text into UTF-8 encoding.

The variant of UTF-8 used internally by Java differs slightly from standard UTF-8. The TBool argument controls the UTF-8 variant generated by this function. This function leaves with a KErrCorrupt if the input string is corrupt.

Parameters

const TDesC16 & aUnicode

A UCS-2 encoded input string.

ConvertToUnicodeFromUtf7(TDes16 &, const TDesC8 &, TInt &)

IMPORT_C TInt	ConvertToUnicodeFromUtf7	(	TDes16 &	aUnicode,
			const TDesC8 &	aUtf7,
			TInt &	aState
		)	[static]

Converts text encoded using the Unicode transformation format UTF-7 into the Unicode UCS-2 character set.

If the conversion is achieved using a series of calls to this function, where each call starts off where the previous call reached in the input descriptor, the state of the conversion is stored. The initial value of the state variable should be set as KStateDefault when the conversion is started, and afterwards simply passed unchanged into each function call.

Parameters

TDes16 & aUnicode	On return, contains the Unicode encoded output string.
const TDesC8 & aUtf7	The UTF-7 encoded input string.
TInt & aState	For the first call of the function set to KStateDefault. For subsequent calls, pass in the variable unchanged.

ConvertToUnicodeFromUtf7(TDes16 &, const TDesC8 &, TBool, TInt &)

TInt	ConvertToUnicodeFromUtf7	(	TDes16 &	aUnicode,
			const TDesC8 &	aUtf7,
			TBool	aIsImapUtf7,
			TInt &	aState
		)	[static]

Parameters

TDes16 & aUnicode
const TDesC8 & aUtf7
TBool aIsImapUtf7
TInt & aState

ConvertToUnicodeFromUtf7L(const TDesC8 &)

IMPORT_C HBufC16 *

ConvertToUnicodeFromUtf7L

(

const TDesC8 &

aUtf7

)

[static]

Converts text encoded using the Unicode transformation format UTF-7 into the Unicode UCS-2 character set.

Parameters

const TDesC8 & aUtf7

The UTF-7 encoded input string.

ConvertToUnicodeFromUtf8(TDes16 &, const TDesC8 &)

IMPORT_C TInt	ConvertToUnicodeFromUtf8	(	TDes16 &	aUnicode,
			const TDesC8 &	aUtf8
		)	[static]

Converts text encoded using the Unicode transformation format UTF-8 into the Unicode UCS-2 character set.

Parameters

TDes16 & aUnicode	On return, contains the Unicode encoded output string.
const TDesC8 & aUtf8	The UTF-8 encoded input string

ConvertToUnicodeFromUtf8(TDes16 &, const TDesC8 &, TBool)

TInt	ConvertToUnicodeFromUtf8	(	TDes16 &	aUnicode,
			const TDesC8 &	aUtf8,
			TBool	aGenerateJavaConformantUtf8
		)	[static]

Converts text encoded using the Unicode transformation format UTF-8 into the Unicode UCS-2 character set.

Parameters

TDes16 & aUnicode	On return, contains the Unicode encoded output string.
const TDesC8 & aUtf8	The UTF-8 encoded input string
TBool aGenerateJavaConformantUtf8	EFalse for orthodox UTF-8. ETrue for Java

ConvertToUnicodeFromUtf8(TDes16 &, const TDesC8 &, TBool, TInt &, TInt &)

TInt	ConvertToUnicodeFromUtf8	(	TDes16 &	aUnicode,
			const TDesC8 &	aUtf8,
			TBool	aGenerateJavaConformantUtf8,
			TInt &	aNumberOfUnconvertibleCharacters,
			TInt &	aIndexOfFirstByteOfFirstUnconvertibleCharacter
		)	[static]

Converts text encoded using the Unicode transformation format UTF-8 into the Unicode UCS-2 character set. Surrogate pairs can be created when a valid 4 byte UTF-8 is input.

The variant of UTF-8 used internally by Java differs slightly from standard UTF-8. The TBool argument controls the UTF-8 variant generated by this function.

Parameters

TDes16 & aUnicode	On return, contains the Unicode encoded output string.
const TDesC8 & aUtf8	The UTF-8 encoded input string
TBool aGenerateJavaConformantUtf8	EFalse for orthodox UTF-8. ETrue for Java UTF-8. The default is EFalse.
TInt & aNumberOfUnconvertibleCharacters	On return, contains the number of bytes which were not converted.
TInt & aIndexOfFirstByteOfFirstUnconvertibleCharacter	On return, the index of the first byte of the first unconvertible character. For instance if the first character in the input descriptor (aForeign) could not be converted, then this parameter is set to the first byte of that character, i.e. zero. A negative value is returned if all the characters were converted.

ConvertToUnicodeFromUtf8L(const TDesC8 &)

IMPORT_C HBufC16 *

ConvertToUnicodeFromUtf8L

(

const TDesC8 &

aUtf8

)

[static]

Converts text encoded using the Unicode transformation format UTF-8 into the Unicode UCS-2 character set. This function leaves with an error code of the input string is corrupted.

Parameters

const TDesC8 & aUtf8

The UTF-8 encoded input string

Member Enumerations Documentation

Enum TError

Conversion error flags. At this stage there is only one error flag

others may be added in the future.

Enumerators

EErrorIllFormedInput = KErrCorrupt

The input descriptor contains a single corrupt character. This might occur when the input descriptor only contains some of the bytes of a single multi-byte character.