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TDblQueBase Class Reference

class TDblQueBase

A base class that provides implementation for the doubly linked list header.

It also encapsulates the offset value of a link object.

The class is abstract and is not intended to be instantiated.

Public Member Functions
IMPORT_C TBool	IsEmpty ()
IMPORT_C void	Reset ()
IMPORT_C void	SetOffset ( TInt )

Protected Member Functions
	TDblQueBase ()
	TDblQueBase ( TInt )
IMPORT_C void	DoAddFirst ( TAny *)
IMPORT_C void	DoAddLast ( TAny *)
IMPORT_C void	DoAddPriority ( TAny *)
IMPORT_C void	__DbgTestEmpty ()

Private Member Functions
	TDblQueBase (const TDblQueBase &)
TDblQueBase &	operator= (const TDblQueBase &)

Protected Attributes
TDblQueLink	iHead
TInt	iOffset

Constructor & Destructor Documentation

TDblQueBase()

IMPORT_C

TDblQueBase

(

)

[protected]

Default constructor.

It sets:

1. iHead to point to this object in both the forwards and backwards direction.

2. iOffset to zero.

iHead iOffset

TDblQueBase(TInt)

IMPORT_C

TDblQueBase

(

TInt

aOffset

)

[protected]

Constructor with specified offset.

It sets:

1. iHead to point to this object in both the forwards and backwards direction.

2. iOffset to the specified value.

panic: USER 78, if aOffset is not divisible by four

iHead iOffset

Parameters

TInt aOffset

The offset of a link object within an element.

TDblQueBase(const TDblQueBase &)

TDblQueBase

(

const TDblQueBase &

aQue

)

[private]

Parameters

const TDblQueBase & aQue

Member Functions Documentation

DoAddFirst(TAny *)

IMPORT_C void

DoAddFirst

(

TAny *

aPtr

)

[protected]

Implements the insertion of the specified list element at the front of the doubly linked list.

This function is called by TDblQue::AddFirst() .

TDblQue::AddFirst

Parameters

TAny * aPtr

An untyped pointer to the element to be inserted.

DoAddLast(TAny *)

IMPORT_C void

DoAddLast

(

TAny *

aPtr

)

[protected]

Implements the insertion of the specified list element at the back of the doubly linked list.

This function is called by TDblQue::AddLast() .

TDblQue::AddLast

Parameters

TAny * aPtr

An untyped pointer to the element to be inserted.

DoAddPriority(TAny *)

IMPORT_C void

DoAddPriority

(

TAny *

aPtr

)

[protected]

Implements the insertion of the specified list element in priority order.

This function is called by TPriQue::Add() .

TPriQue::Add

Parameters

TAny * aPtr

An untyped pointer to the element to be inserted.

IsEmpty()

IMPORT_C TBool

IsEmpty

(

)

const

Tests whether the doubly linked list is empty, i.e. has no list elements.

Reset()

IMPORT_C void

Reset

(

)

Empties the doubly linked list.

After a call to this function, there are no elements queued from the header; the elements are orphaned. Special care must be taken when list elements are CBase derived objects, i.e. are allocated on the heap.

SetOffset(TInt)

IMPORT_C void

SetOffset

(

TInt

aOffset

)

Sets the offset of the link object from the start of a doubly linked list element.

panic: USER 78, if aOffset is not divisible by four.

TDblQue

Parameters

TInt aOffset

The offset of the link object from the start of a doubly linked list element.

__DbgTestEmpty()

IMPORT_C void

__DbgTestEmpty

(

)

const [protected]

Tests whether the queue is empty.

The function is implemented as an __ASSERT_DEBUG.

panic: USER 79, if the assertion fails.

operator=(const TDblQueBase &)

TDblQueBase &

operator=

(

const TDblQueBase &

aQue

)

[private]

Parameters

const TDblQueBase & aQue

Member Data Documentation

TDblQueLink iHead

TDblQueLink

iHead

[protected]

The head, or anchor point of the queue.

TInt iOffset

TInt

iOffset

[protected]

The offset of a component link object within elements that form the list.