TPriQue Class Reference

#include <e32std.h>

Link against: libm.lib

class TPriQue : public TDblQueBase

Inherits from

TPriQue
- TDblQueBase

Public Member Functions
	TPriQue()
	TPriQue(TInt)
void	Add(T &)
T *	First()
TBool	IsFirst(const T *)
TBool	IsHead(const T *)
TBool	IsLast(const T *)
T *	Last()

Inherited Attributes
	TDblQueBase::iHead
	TDblQueBase::iOffset

Inherited Functions
	TDblQueBase::DoAddFirst(TAny *)
	TDblQueBase::DoAddLast(TAny *)
	TDblQueBase::DoAddPriority(TAny *)
	TDblQueBase::IsEmpty()const
	TDblQueBase::Reset()
	TDblQueBase::SetOffset(TInt)
	TDblQueBase::TDblQueBase()
	TDblQueBase::TDblQueBase(TInt)
	TDblQueBase::__DbgTestEmpty()const

Detailed Description

A templated class that provides the behaviour for managing a doubly linked list in which the elements are added in descending priority order.

Priority is defined by the value of the TPriQueLink::iPriority member of the link element.

The template parameter defines the type of element that forms the doubly linked list and is the class that acts as host to the link object.

Constructor & Destructor Documentation

TPriQue ( )

TPriQue

(

)

[inline]

Default constructor.

Constructs an empty list header and sets the offset value of the link object to zero.

In practice, never assume that the offset of the link object from the start of a list element is zero, even if the link object is declared as the first data member in the list element class.

If this default constructor is used, then call the SetOffset() function of the base class to ensure that the offset value is set correctly.

TPriQue ( TInt )

TPriQue

(

TInt

aOffset

)

[inline, explicit]

Constructs an empty list header and sets the offset of the link object to the specified value.

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

Parameter	Description
aOffset	The offset of the link object from the start of a list element. The macro _FOFF can be used to calculate this value.

Member Function Documentation

Add ( T & )

void

Add

(

T &

aRef

)

[inline]

Inserts the specified list element in descending priority order.

If there is an existing list element with the same priority, then the new element is added after the existing element.

Parameter	Description
aRef	The list element to be inserted.

First ( )

T *

First

(

)

const [inline]

Gets a pointer to the first list element in the linked list.

Returns: A pointer to the first list element in the linked list. If the list is empty, this pointer is not necessarily NULL and must not be assumed to point to a valid object.

IsFirst ( const T * )

TBool

IsFirst

(

const T *

aPtr

)

const [inline]

Tests whether the specified element is the first in the linked list.

Parameter	Description
aPtr	A pointer to the element whose position in the list is to be checked.

Returns: True, if the element is the first in the list; false, otherwise.

IsHead ( const T * )

TBool

IsHead

(

const T *

aPtr

)

const [inline]

Tests whether the end of a list has been reached.

A doubly linked list is circular; in following the chain of elements in a list (e.g. using the iterator operator++ or operator--), the chain eventually reaches the end of the list and aPtr corresponds to the header (although it will not point to a valid T object).

Parameter	Description
aPtr	The pointer value to be checked.

Returns: True, if the end of the list has been reached. False, if the end of the list has not been reached; aPtr points to an element in the list.

IsLast ( const T * )

TBool

IsLast

(

const T *

aPtr

)

const [inline]

Tests whether the specified element is the last in the linked list.

Parameter	Description
aPtr	A pointer to the element whose position in the list is to be checked.

Returns: True, if the element is the last in the list; false, otherwise.

Last ( )

T *

Last

(

)

const [inline]

Gets a pointer to the last list element in the linked list.

Returns: A pointer to the last list element in the linked list. If the list is empty, this pointer is not necessarily NULL and must not be assumed to point to a valid object.