TDblQueBase Class Reference

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

#include <e32std.h>

Inheritance diagram for TDblQueBase:

Public Member Functions
IMPORT_C TBool	IsEmpty () const
	Tests whether the doubly linked list is empty, i.e.
IMPORT_C void	SetOffset (TInt aOffset)
	Sets the offset of the link object from the start of a doubly linked list element.
IMPORT_C void	Reset ()
	Empties the doubly linked list.

Protected Member Functions
IMPORT_C	TDblQueBase ()
	Default constructor.
IMPORT_C	TDblQueBase (TInt aOffset)
	Constructor with specified offset.
IMPORT_C void	DoAddFirst (TAny *aPtr)
	Implements the insertion of the specified list element at the front of the doubly linked list.
IMPORT_C void	DoAddLast (TAny *aPtr)
	Implements the insertion of the specified list element at the back of the doubly linked list.
IMPORT_C void	DoAddPriority (TAny *aPtr)
	Implements the insertion of the specified list element in priority order.
IMPORT_C void	__DbgTestEmpty () const
	Tests whether the queue is empty.

Protected Attributes
TDblQueLink	iHead
	The head, or anchor point of the queue.
TInt	iOffset
	The offset of a component link object within elements that form the list.

Friends
class	TDblQueIterBase

Detailed Description

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.

See also

TDblQue

API status

Published to all clients. Released API.

Definition at line 328 of file e32std.h.

Constructor & Destructor Documentation

TDblQueBase() [1/2]

IMPORT_C TDblQueBase::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

(generated from Symbian Developer Library)

TDblQueBase() [2/2]

IMPORT_C TDblQueBase::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.

Parameters

aOffset

The offset of a link object within an element.

Panic condition: USER 78, if aOffset is not divisible by four

(generated from Symbian Developer Library)

Member Function Documentation

__DbgTestEmpty()

IMPORT_C void TDblQueBase::__DbgTestEmpty ( ) const

protected

Tests whether the queue is empty.

The function is implemented as an __ASSERT_DEBUG.

Panic condition: USER 79, if the assertion fails.

(generated from Symbian Developer Library)

DoAddFirst()

IMPORT_C void TDblQueBase::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

aPtr	An untyped pointer to the element to be inserted.

(generated from Symbian Developer Library)

DoAddLast()

IMPORT_C void TDblQueBase::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

aPtr	An untyped pointer to the element to be inserted.

(generated from Symbian Developer Library)

DoAddPriority()

IMPORT_C void TDblQueBase::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

aPtr	An untyped pointer to the element to be inserted.

(generated from Symbian Developer Library)

IsEmpty()

IMPORT_C TBool TDblQueBase::IsEmpty

(

)

const

Tests whether the doubly linked list is empty, i.e.

has no list elements.

(generated from Symbian Developer Library)

Reset()

IMPORT_C void TDblQueBase::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.

(generated from Symbian Developer Library)

SetOffset()

IMPORT_C void TDblQueBase::SetOffset

(

TInt

aOffset

)

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

Parameters

aOffset

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

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

(generated from Symbian Developer Library)

Friends And Related Symbol Documentation

TDblQueIterBase

friend class TDblQueIterBase

friend

Definition at line 354 of file e32std.h.

Member Data Documentation

iHead

TDblQueLink TDblQueBase::iHead

protected

The head, or anchor point of the queue.

Definition at line 345 of file e32std.h.

iOffset

TInt TDblQueBase::iOffset

protected

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

Definition at line 350 of file e32std.h.

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The documentation for this class was generated from the following files:

• e32std.h
• e32std.h.dox