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 » Developer Library » API Reference » C++ API reference » Descriptor Arrays » CDesC8Array

Location: badesca.h
Link against: bafl.lib

Class CDesC8Array

CDesC8Array

Support

Supported from 5.0

Description

An implementation base class for 8 bit descriptor arrays.

It provides some of the behaviour for 8 bit descriptor arrays. The class is abstract and cannot be instantiated.

Derivation

CArrayFixBaseBase class for arrays of fixed length objects
CBaseBase class for all classes to be instantiated on the heap
CDesC8ArrayAn implementation base class for 8 bit descriptor arrays
MDesC8ArrayInterface class for 8 bit descriptor arrays

Defined in CDesC8Array:
AppendL(), Delete(), Find(), FindIsq(), InsertIsqAllowDuplicatesL(), InsertIsqL(), InsertL(), MdcaCount(), MdcaPoint(), Reset(), Sort(), operator[], ~CDesC8Array()

Inherited from CArrayFixBase:
Compress(), Count(), Length()

Inherited from CBase:
operator new()

Destruction

~CDesC8Array()

~CDesC8Array();

Description

Frees all resources owned by the object, prior to its destruction. In particular, it deletes all descriptors from the array and frees the memory allocated to the array buffer.

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Basic information

MdcaCount()

TInt MdcaCount() const;

Description

Returns the number of descriptor elements in the array. The function implements the interface MDesC8Array::MdcaCount().

Return value

TInt

The number of descriptor elements.

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Array housekeeping

Reset()

void Reset();

Description

Deletes all descriptors from the array and frees the memory allocated to the array buffer.

See also:

Sort()

void Sort(TKeyCmpText aTextComparisonType=ECmpFolded);

Description

Sorts the descriptor elements into sequence.

The sequence is determined by comparing descriptors using one of the member functions of the descriptor base class TDesC.

Parameters

TKeyCmpText aTextComparisonType

An enumeration which defines the type of comparison to be made between descriptors. By default the comparison type is ECmpFolded.

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Deleting elements

Delete()

void Delete(TInt aPos);
void Delete(TInt aPos,TInt aCount);

Description

Deletes one or more logically contiguous descriptor elements from the array. The deletion starts at the specified position.

Deleting descriptor elements from the array frees the memory occupied by the associated heap descriptors and removes their pointers from the array buffer but does not cause the array buffer to be automatically compressed. Call the Compress() function to return excess space in the array buffer to the heap.

Parameters

TInt aPos

The starting position in the array from which descriptor elements are to be deleted. The position is relative to zero, i.e. zero implies the first descriptor element. This value must not be negative and must not be greater than the number of descriptor elements currently in the array, otherwise the functions raise an E32USER-CBase 21 panic.

TInt aCount

If specified, the number of contiguous descriptor elements to be deleted from the array. This value must not be negative otherwise the function raises an E32USER-CBase 22 panic. This value plus the value of the starting position must not be greater than the number of descriptor elements in the array, otherwise the function raises an E32USER-CBase 29 panic. This value must not be negative otherwise the function raises an E32USER-CBase 22 panic. This value plus the value of the starting position must not be greater than the number of descriptor elements in the array, otherwise the function raises an E32USER-CBase 29 panic. If not specified, one element is assumed.

See also:

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Inserting elements

InsertL()

void InsertL(TInt aPos,const TDesC8& aPtr);

Description

Inserts a descriptor into the array at the specified position.

If the specified position is the same as the current number of descriptor elements in the array, this has the effect of appending the element.

Parameters

TInt aPos

The position within the array where the descriptor element is to be inserted. The position is relative to zero, i.e. zero implies the first descriptor element. This value must not be negative and must not be greater than the number of descriptor elements currently in the array, otherwise the function rasises an E32USER-CBase 21 panic.

const TDesC8& aPtr

The descriptor to be inserted into the array.

Leave codes

KErrNoMemory

There is insufficient memory available. If the function leaves, the array is left in the state it was in before the call.

InsertIsqL()

TInt InsertIsqL(const TDesC8& aPtr,TKeyCmpText aTextComparisonType=ECmpFolded);

Description

Inserts a descriptor into the array at a position which maintains the sequence of the descriptors.

The sequence is determined by comparing descriptors using one of the TDesC comparison functions. The enumeration aTextComparisonType governs how the descriptors are to be compared.

The array should already be in sequence, otherwise the position of the new descriptor element is unpredictable. Descriptor elements which are the same are not permitted.

Parameters

const TDesC8& aPtr

A reference to the descriptor to be inserted into the array.

TKeyCmpText aTextComparisonType

An enumeration which determines the type of comparison to be made between descriptors for the purpose of choosing the insertion position. If no parameter is explicitly passed, ECmpFolded is used by default.

Return value

TInt

The position within the array of the inserted descriptor.

Leave codes

KErrAlreadyExists

A descriptor with the same data (i.e. the same length and the same content) already exists within the array.
KErrNoMemory

There is insufficient memory available. If the function leaves, the array is left in the state it was in before the call.

InsertIsqAllowDuplicatesL()

TInt InsertIsqAllowDuplicatesL(const TDesC8& aPtr,TKeyCmpText aTextComparisonType=ECmpFolded);

Description

Inserts a descriptor into the array at a position which maintains the sequence of the descriptors — allows duplicates.

The sequence is determined by comparing descriptors using one of the TDesC comparison functions. The enumeration aTextComparisonType governs how the descriptors are to be compared.

The array should already be in sequence, otherwise the position of the new descriptor element is unpredictable. Descriptor elements which are the same are permitted; if the descriptor aPtr is a duplicate of an existing descriptor within the array, then the new descriptor element is positioned after the existing descriptor element.

Parameters

const TDesC8& aPtr

A reference to the descriptor to be inserted into the array.

TKeyCmpText aTextComparisonType

An enumeration which determines the type of comparison to be made between descriptors for the purpose of choosing the insertion position. If no parameter is explicitly passed, ECmpFolded is used by default.

Return value

TInt

The position within the array of the inserted descriptor.

Leave codes

KErrNoMemory

There is insufficient memory available. If the function leaves, the array is left in the state it was in before the call.

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Appending elements

AppendL()

void AppendL(const TDesC8& aPtr);

Description

Appends a descriptor onto the end of any existing descriptor elements in the array.

Parameters

const TDesC8& aPtr

A reference to the descriptor to be appended to the array.

Leave codes

KErrNoMemory

There is insufficient memory available. If the function leaves, the array is left in the state it was in before the call.

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Finding elements

Find()

TInt Find(const TDesC8& aPtr,TInt& aPos,TKeyCmpText aTextComparisonType=ECmpFolded) const;

Description

Finds the position of a descriptor element within the array which matches the specified descriptor using a sequential search.

The array is searched sequentially for a matching descriptor element, starting with the first descriptor element in the array. Descriptors are compared using one of the TDesC comparison functions. The enumeration aTextComparisonType governs how the descriptors are to be compared.

Where an array has duplicate descriptor elements, the function only supplies the position of the first descriptor element.

Parameters

const TDesC8& aPtr

A reference to a descriptor to be used for comparison.

TInt& aPos

If the descriptor element is found, this reference is set to the position of that descriptor element within the array. The position is relative to zero, (i.e. the first descriptor element in the array is at position 0). If the descriptor element is not found and the array is not empty, then the value of the reference is set to the number of descriptor elements in the array. If the descriptor element is not found and the array is empty, then the reference is set to zero.

TKeyCmpText aTextComparisonType=ECmpFolded

An enumeration which determines the type of comparison to be made between descriptors. If no parameter is explicitly passed, ECmpFolded is used by default.

Return value

TInt

Zero, if a matching descriptor element is found. Non-zero, if no matching descriptor element can be found.

FindIsq()

TInt FindIsq(const TDesC8& aPtr,TInt& aPos,TKeyCmpText aTextComparisonType=ECmpFolded) const;

Description

Finds the position of a descriptor element within the array which matches the specified descriptor — using a binary search technique. The array must be in sequence, otherwise the outcome is unpredictable.

Descriptors are compared using one of the TDesC comparison functions. The enumeration aTextComparisonType governs how the descriptors are to be compared.

Where an array has duplicate descriptor elements, the function cannot guarantee which matching descriptor element it will return; except that it will find one of them.

Parameters

const TDesC8& aPtr

A reference to a descriptor to be used for comparison.

TInt& aPos

If the descriptor element is found, the reference is set to the position of that descriptor element within the array. The position is relative to zero, (i.e. the first descriptor element in the array is at position 0). If the descriptor element is not found and the array is not empty, then the reference is set to the position of the first descriptor element in the array whose content is greater than the content of aPtr. If the descriptor element is not found and the array is empty, then the reference is set to zero.
TKeyCmpText aTextComparisonType

An enumeration which determines the type of comparison to be made between descriptors. If no parameter is explicitly passed, ECmpFolded is used by default.

Return value

TInt

Zero, if a matching descriptor element is found. Non-zero, if no matching descriptor element can be found.

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Indexing into the array

MdcaPoint()

TPtrC8 MdcaPoint(TInt aIndex) const;

Description

Indexes into a descriptor array. The function implements the interface MDesC8Array::MdcaPoint().

Parameters

TInt aIndex

The position of the descriptor element within the array. The position is relative to zero; i.e. zero implies the first descriptor element in the array. This value must be non-negative and less than the number of descriptors currently within the array otherwise the operator panics with EArrayIndexOutOfRange.

Return value

TPtrC8

A non-modifiable pointer descriptor representing the descriptor element located at position aIndex within the array.

operator[]

TPtrC8 operator[](TInt aIndex);

Description

Returns a non-modifiable descriptor to represent the descriptor element located at the specified index within the array.

Parameters

TInt aIndex

The position of the descriptor element within the array. The position is relative to zero; i.e. zero implies the first descriptor element in the array. This value must be non-negative and less than the number of descriptors currently within the array otherwise the operator panics with EArrayIndexOutOfRange.

Return value

TPtrC8

An 8 bit non-modifiable pointer descriptor.

©2002 Symbian Ltd.

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