#include <e32des16.h>
class TDesC16 |
Public Member Enumerations | |
---|---|
enum | TPrefix { EIsPrefix, EMightBePrefix, EIsNotPrefix } |
Protected Member Functions | |
---|---|
TDesC16() | |
TDesC16(TInt, TInt) | |
IMPORT_C const TUint16 & | AtC(TInt) |
void | DoSetLength(TInt) |
TInt | Type() |
Abstract base class for 16-bit descriptors.
The class encapsulates the data member containing the length of data represented by a 16-bit descriptor. It also provides member functions through which the data can be accessed, but not modified.
Data represented by this class is treated as a contiguous set of 16-bit (i.e. double byte) values or data items.
This class cannot be instantiated as it is intended to form part of a class hierarchy; it provides a well defined part of descriptor behaviour. It can, however, be passed as an argument type for functions which want access to descriptor data but do not need to modify that data.
A value returned by a call to HasPrefixC().
See also: TDesC16::HasPrefixC
IMPORT_C HBufC16 * | Alloc | ( | ) | const |
Creates a new 16-bit heap descriptor and initialises it with a copy of this descriptor's data.
Returns: A pointer to the new 16-bit heap descriptor, if creation is successful. NULL, if creation of the descriptor fails.
IMPORT_C HBufC16 * | AllocL | ( | ) | const |
Creates a new 16-bit heap descriptor and initialises it with a copy of this descriptor's data.
The function leaves, if creation of the descriptor fails.
Returns: A pointer to the 16-bit heap descriptor, if creation is successful.
IMPORT_C HBufC16 * | AllocLC | ( | ) | const |
Creates a new 16-bit heap descriptor, initialises it with a copy of this descriptor's data, and puts a pointer to the descriptor onto the cleanup stack.
The function leaves, if creation of the descriptor fails.
Returns: A pointer to the 16-bit heap descriptor, if creation is successful. The pointer is also put onto the cleanup stack.
Compares this descriptor's data with the specified descriptor's data.
The comparison proceeds on a double-byte for double byte basis. The result of the comparison is based on the difference of the first pair of bytes to disagree.
Two descriptors are equal if they have the same length and content. Where two descriptors have different lengths and the shorter descriptor's data matches the first part of the longer descriptor's data, the shorter is considered to be less than the longer.
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor whose data is to be compared with this descriptor's data. |
Returns: Positive. if this descriptor is greater than the specified descriptor. Negative. if this descriptor is less than the specified descriptor. Zero, if both descriptors have the same length and the their contents are the same.
Compares this descriptor's data with the specified descriptor's data using the standard collation method appropriate to the current locale.
See also: TDesC16::Compare()
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor whose data is to be compared with this descriptor's data. |
Returns: Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified descriptor. Zero, if the content of both descriptors match.
IMPORT_C TInt | CompareC | ( | const TDesC16 & | aDes, |
TInt | aMaxLevel, | |||
const TCollationMethod * | aCollationMethod | |||
) | const |
Compares this descriptor's data with the specified descriptor's data to the specified maximum collation level and using the specified collation method.
If no collation method is supplied, a default method is used that uses a locale-independent collation table. This means that sorting and matching will not be based on the current locale.
This function is only defined for 16-bit (Unicode) build variants. This means that the function is not defined for 8-bit build variants, even when an explicit 16-bit descriptor is used.
Strings may match even if the lengths of their respective descriptors are different.
See also: Mem::CollationMethodByIndex() Mem::CollationMethodById() TDesC16::Compare()
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor whose data is to be compared with this descriptor's data. |
aMaxLevel | The maximum collation level. This is an integer with values: 0, 1, 2 or 3, which, effectively, determines how 'tight' the matching should be. Level 3 is always used if the aim is to sort strings. |
aCollationMethod | A pointer to the collation method or NULL. Collation methods can be retrieved by calls to Mem::CollationMethodByIndex() and Mem::CollationMethodById(). Specifying NULL means that the default method is used. |
Returns: Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified descriptor. Zero, if the content of both descriptors match.
Compares this descriptor's folded data with the specified descriptor's folded data.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding is in any way culturally appropriate, and should not be used for comparing strings in natural language; use CompareC() for this.
See also: TDesC16::Compare()
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor whose data is to be compared with this descriptor's data. |
Returns: Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified descriptor. Zero, if both descriptors have the same length and the their contents are the same.
Searches for the first occurrence of the specified data sequence within this descriptor.
Searching always starts at the beginning of this descriptor's data.
Parameter | Description |
---|---|
aDes | The 16-bit non-modifiable descriptor containing the data sequence to be searched for. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found.
Searches for the first occurrence of the specified data sequence within this descriptor.
Searching always starts at the beginning of this descriptor's data.
Parameter | Description |
---|---|
aBuf | A pointer to a location containing the data sequence to be searched for. |
aLen | The length of the data sequence to be searched for. This value must not be negative, otherwise the function raises a panic. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found.
Searches for the first occurrence of the specified collated data sequence within this descriptor's collated data.
Searching always starts at the beginning of this descriptor's data. The function uses the standard collation method appropriate to the current locale.
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor containing the data sequence to be searched for. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found.
Searches for the first occurrence of the specified collated data sequence within this descriptor's collated data.
Searching always starts at the beginning of this descriptor's data. The function uses the standard collation method appropriate to the current locale.
Parameter | Description |
---|---|
aBuf | A pointer to a location containing the data sequence to be searched for. |
aLen | The length of the data sequence to be searched for. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found.
Searches for the first occurrence of the specified collated data sequence within this descriptor's collated data to the specified maximum collation level.
Parameter | Description |
---|---|
aText | A pointer to a location containing the data sequence to be searched for. |
aLength | The length of the data sequence to be searched for. |
aMaxLevel | The maximum collation level. This is an integer with values: 0, 1, 2 or 3, which, effectively, determines how 'tight' the matching should be. Level 3 is always used if the aim is to sort strings. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found.
IMPORT_C TInt | FindC | ( | const TDesC16 & | aDes, |
TInt & | aLengthFound, | |||
const TCollationMethod & | aMethod, | |||
TInt | aMaxLevel | |||
) | const |
Searches for the first occurrence of the specified collated data sequence within this descriptor's collated data.
Searching always starts at the beginning of this descriptor's data. The function uses the standard collation method appropriate to the current locale.
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor containing the data sequence to be searched for. |
aLengthFound | A refernce to the maximal length of the match found in the candidate string. KErrNotFound, if the data sequence cannot be found. |
aMaxLevel | The maximum collation level. This is an integer with values: 0, 1, 2 or 3, which, effectively, determines how 'tight' the matching should be. Level 3 is always used if the aim is to sort strings. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found.
Searches for the first occurrence of the specified folded data sequence within this descriptor's folded data.
Searching always starts at the beginning of this descriptor's data.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding is in any way culturally appropriate, and should not be used for finding strings in natural language; use FindC() for this.
See also: TDesC16::FindC()
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor containing the data sequence to be searched for. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found. Zero, if the length of the search data sequence is zero.
Searches for the first occurrence of the specified folded data sequence within this descriptor's folded data.
Searching always starts at the beginning of this descriptor's data.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding is in any way culturally appropriate, and should not be used for finding strings in natural language; use FindC() for this.
See also: TDesC16::FindC()
Parameter | Description |
---|---|
aBuf | A pointer to a location containing the data sequence to be searched for. |
aLen | The length of the data sequence to be searched for. This value must not be negative, otherwise the function raises a panic. |
Returns: The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be found. Zero, if the length of the search data sequence is zero.
IMPORT_C HBufC8 * | GetCollationKeysL | ( | TInt | aMaxLevel, |
const TCollationMethod * | aCollationMethod | |||
) | const |
Parameter | Description |
---|---|
aMaxLevel | The maximum collation level. This is an integer with values: 0, 1, 2 or 3. Level 3 is always used if the aim is to sort strings. |
aCollationMethod | A pointer to the collation method or NULL. Collation methods can be retrieved by calls to Mem::CollationMethodByIndex() and Mem::CollationMethodById(). Specifying NULL means that the default method is used. |
Returns: A pointer to the 8-bit heap buffer containing the collation keys if creation is succesful
IMPORT_C HBufC16 * | GetFoldedDecomposedFormL | ( | ) | const |
Returns: A pointer to the 16-bit heap buffer containing folded decomposed form if creation is succesful
IMPORT_C HBufC16 * | GetNormalizedDecomposedFormL | ( | ) | const |
Returns: A pointer to the 16-bit heap buffer containing normalized decomposed form if creation is successful
IMPORT_C TPrefix | HasPrefixC | ( | const TDesC16 & | aPossiblePrefix, |
TInt | aLevel, | |||
const TCollationMethod * | aCollationMethod | |||
) | const |
Compares aPossiblePrefix against the start of the descriptor, using a collated comparison.
0: Only check character identities.
1: Check accents as well.
2: Check case as well.
3: Check Unicode values.
Currently only level 0 is supported.
Parameter | Description |
---|---|
aLevel | The maximum level at which to perform the collation. |
aCollationMethod | The collation method to be used for the matching. |
Returns: EIsPrefix, if aPossiblePrefix can be extended to be equivalent to the text at the start of this descriptor. EIsNotPrefix if aPossiblePrefix cannot be extended to be equivalent to the text at the start of this descriptor. EMightBePrefix if it currently does not seem to be a prefix, but it is possible that it could be extended to become equivalent to text at the start of this descriptor. EMightBePrefix is returned in cases where it would be expensive to determine for sure.
Extracts the leftmost part of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the leftmost part of the data.
Parameter | Description |
---|---|
aLength | The length of the data to be extracted. If this value is greater than the length of the descriptor, the function extracts the whole of the descriptor. |
Returns: The 16-bit non-modifiable pointer descriptor representing the leftmost part of the data.
TInt | Length | ( | ) | const [inline] |
Gets the length of the data.
This is the number of 16-bit values or data items represented by the descriptor.
Returns: The length of the data represented by the descriptor.
Searches for the first occurrence of a character within this descriptor's data.
The search starts at the beginning of the data, i.e. at the leftmost position.
Parameter | Description |
---|---|
aChar | The character to be found. |
Returns: The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
Searches for the first occurrence of a folded character within this descriptor's folded data.
The search starts at the beginning of the data, i.e. at the leftmost position.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding is in any way culturally appropriate, and should not be used for searching strings in natural language.
Parameter | Description |
---|---|
aChar | The character to be found. |
Returns: The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
Searches for the first occurrence of a character within this descriptor's data, searching from the end of the data.
The search starts at the rightmost position.
Parameter | Description |
---|---|
aChar | The character to be found. |
Returns: The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
Searches for the first occurrence of a folded character within this descriptor's folded data, searching from the end of the data.
The search starts at the rightmost position.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding is in any way culturally appropriate, and should not be used for searching strings in natural language.
Parameter | Description |
---|---|
aChar | The character to be found |
Returns: The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
Searches this descriptor's data for a match with the match pattern supplied in the specified descriptor.
The match pattern can contain the wildcard characters "*" and "?", where "*" matches zero or more consecutive occurrences of any character and "?" matches a single occurrence of any character.
Note that there is no 'escape character', which means that it is not possible to match either the "*" character itself or the "?" character itself using this function.
Parameter | Description |
---|---|
aDes | A 16-bit non-modifable descriptor containing the match pattern. |
Returns: If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
Searches this descriptor's collated data for a match with the collated match pattern supplied in the specified descriptor.
The function uses the standard collation method appropriate to the current locale.
The match pattern can contain the wildcard characters "*" and "?", where "*" matches zero or more consecutive occurrences of any character and "?" matches a single occurrence of any character.
Note that there is no 'escape character', which means that it is not possible to match either the "*" character itself or the "?" character itself using this function.
Parameter | Description |
---|---|
aDes | A 16-bit non-modifable descriptor containing the match pattern. |
Returns: If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
IMPORT_C TInt | MatchC | ( | const TDesC16 & | aPattern, |
TInt | aWildChar, | |||
TInt | aWildSequenceChar, | |||
TInt | aEscapeChar, | |||
TInt | aMaxLevel = 3, | |||
const TCollationMethod * | aCollationMethod = NULL | |||
) | const |
Searches this descriptor's collated data for a match with the collated match pattern supplied in the specified descriptor.
The function uses the standard collation method appropriate to the current locale.
The match pattern can contain the wildcard characters specified by aWildChar and aWildSequenceChar parameters, where aWildSequenceChar matches zero or more consecutive occurrences of any character and aWildChar matches a single occurrence of any character.
Parameter | Description |
---|---|
aPattern | A 16-bit non-modifable descriptor containing the match pattern. |
aWildChar | Wild card character which may be specified for aSearchTerm. |
aWildSequenceChar | Wild card sequence character which may be specified for aSearchTerm. |
aEscapeChar | The escape character, or 0 if there is to be none. The escape character removes any special meaning from the subsequent character. For example, if the escape, wild card and wild sequence characters are \, ? And * respectively, the search term "\?\*\\" matches only the candidate string "?*\"; |
aMaxLevel | Determines the tightness of the collation. At level 0, only character identities are distinguished. At level 1 accents are distinguished as well. At level 2 case is distinguishes as well. At level 3 all valid different Unicode characters are considered different. |
aCollationMethod | A pointer to the collation method or NULL. Collation methods can be retrieved by calls to Mem::CollationMethodByIndex() and Mem::CollationMethodById(). Specifying NULL means that the default method is used. |
Returns: If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
IMPORT_C TInt | MatchC | ( | const TDesC16 & | aPattern, |
const TCollationMethod * | aCollationMethod, | |||
TInt | aMaxLevel = 3, | |||
TInt | aWildChar = '?', | |||
TInt | aWildSequenceChar = '*', | |||
TInt | aEscapeChar = 0 | |||
) | const |
Searches this descriptor's collated data for a match with the collated match pattern supplied in the specified descriptor.
The function uses the standard collation method appropriate to the current locale.
The match pattern can contain the wildcard characters specified by aWildChar and aWildSequenceChar parameters, where aWildSequenceChar matches zero or more consecutive occurrences of any character and aWildChar matches a single occurrence of any character.
See also: TCollationFlag
See also: TCollationMethod
Parameter | Description |
---|---|
aPattern | A 16-bit non-modifable descriptor containing the match pattern. |
aCollationMethod | A pointer to the collation method. Collation methods can be retrieved by calls to Mem::CollationMethodByIndex(), Mem::CollationMethodById() or by custom defined name. Flags can be set on definition of the custom TCollationMethod, or by const_cast-ing the returned pointer and setting the iFlags field directly. |
aMaxLevel | Determines the tightness of the collation. Defaulted to 3 if omitted. At level 0, only character identities are distinguished. At level 1 accents are distinguished as well. At level 2 case is distinguishes as well. At level 3 all valid different Unicode characters are considered different. |
aWildChar | Wild card character which may be specified for aSearchTerm. Defaulted to '?' if omitted. |
aWildSequenceChar | Wild card sequence character which may be specified for aSearchTerm. Defaulted to '*' if omitted. |
aEscapeChar | The escape character, or 0 if there is to be none. The escape character removes any special meaning from the subsequent character. For example, if the escape, wild card and wild sequence characters are \, ? And * respectively, the search term "\?\*\\" matches only the candidate string "?*\". Defaulted to 0 if omitted. |
Returns: If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
Searches this descriptor's folded data for a match with the folded match pattern supplied in the specified descriptor.
The match pattern can contain the wildcard characters "*" and "?", where "*" matches zero or more consecutive occurrences of any character and "?" matches a single occurrence of any character.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding is in any way culturally appropriate, and should not be used for matching strings in natural language; use MatchC() for this.
Note that there is no 'escape character', which means that it is not possible to match either the "*" character itself or the "?" character itself using this function.
See also: TDesC16::MatchC()
Parameter | Description |
---|---|
aDes | A 16-bit non-modifable descriptor containing the match pattern. |
Returns: If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
Extracts a portion of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the defined portion.
The portion is identified by its starting position and by the length of the remainder of the data starting from the specified position.
Parameter | Description |
---|---|
aPos | The starting position of the data to be extracted. This is an offset value; a zero value refers to the leftmost data position. |
Returns: The 16-bit non-modifiable pointer descriptor representing the specified portion of the data.
Extracts a portion of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the defined portion.
The portion is identified by its starting position and by its length.
Parameter | Description |
---|---|
aPos | The starting position of the data to be extracted. This is an offset value; a zero value refers to the leftmost data position. |
aLength | The length of data to be extracted. |
Returns: The 16-bit non-modifiable pointer descriptor representing the specified portion of the data.
IMPORT_C const TUint16 * | Ptr | ( | ) | const |
Gets a pointer to the data represented by the descriptor.
The data cannot be changed through the returned pointer.
Returns: A pointer to the data
Extracts the rightmost part of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the rightmost part of the data.
Parameter | Description |
---|---|
aLength | The length of data to be extracted. If this value is greater than the length of the descriptor, the function extracts the whole of the descriptor. |
Returns: The 16-bit non-modifiable pointer descriptor representing the rightmost part of the data.
TInt | Size | ( | ) | const [inline] |
Gets the size of the data.
This is the number of bytes occupied by the data represented by the descriptor.
Returns: The size of the data represented by the descriptor. This is always twice the length.
Determines whether this descriptor's data is not equal to the specified descriptor's data.
The comparison is implemented using the Compare() member function.
See also: TDesC16::Compare
Parameter | Description |
---|---|
aDes | The 16-bit non-modifiable descriptor whose data is to be compared with this descriptor's data. |
Returns: True if not equal, false otherwise.
Determines whether this descriptor's data is less than the specified descriptor's data.
The comparison is implemented using the Compare() member function.
See also: TDesC16::Compare
Parameter | Description |
---|---|
aDes | The 16-bit non-modifable descriptor whose data is to be compared with this descriptor's data. |
Returns: True if less than, false otherwise.
Determines whether this descriptor's data is less than or equal to the specified descriptor's data.
The comparison is implemented using the Compare() member function.
See also: TDesC16::Compare
Parameter | Description |
---|---|
aDes | The 16-bit non- modifiable descriptor whose data is to be compared with this descriptor's data. |
Returns: True if less than or equal, false otherwise.
Determines whether this descriptor's data is equal to the specified descriptor's data.
The comparison is implemented using the Compare() member function.
See also: TDesC16::Compare
Parameter | Description |
---|---|
aDes | The 16-bit non-modifiable descriptor whose data is to be compared with this descriptor's data. |
Returns: True if equal, false otherwise.
Determines whether this descriptor's data is greater than the specified descriptor's data.
The comparison is implemented using the Compare() member function.
See also: TDesC16::Compare
Parameter | Description |
---|---|
aDes | The 16-bit non-modifiable descriptor whose data is to be compared with this descriptor's data. |
Returns: True if greater than, false otherwise.
Determines whether this descriptor's data is greater than or equal to the specified descriptor's data.
The comparison is implemented using the Compare() member function.
See also: TDesC16::Compare
Parameter | Description |
---|---|
aDes | The 16-bit non-modifiable descriptor whose data is to be compared with this descriptor's data. |
Returns: True if greater than or equal, false otherwise.
Gets a reference to a single data item within this descriptor's data.
Parameter | Description |
---|---|
anIndex | The position of the individual data item within the descriptor's data. This is an offset value; a zero value refers to the leftmost data position. |
Returns: A reference to the data item.