A templated class that provides the behaviour for managing a doubly linked list in which elements represent values which are increments, or deltas, on the value represented by a preceding element. More...

#include <e32std.h>

Inheritance diagram for TDeltaQue< T >:

Public Member Functions
	TDeltaQue ()
	Constructs an empty list header and sets the offset value of the link object to zero.

	TDeltaQue (TInt aOffset)
	Constructs an empty list header and sets the offset of the link object to the specified value.

void	Add (T &aRef, TInt aDelta)
	Adds the specified list element, having the specified 'distance' from the nominal zero point, into the list.

void	Remove (T &aRef)
	Removes the specified list element from the linked list.

T *	RemoveFirst ()
	Removes the first list element from the linked list if its delta value is zero or negative.

Public Member Functions inherited from TDeltaQueBase
IMPORT_C TBool	CountDown ()
	Decrements the delta value of the first element by one, and returns true if the result is negative or zero.

IMPORT_C TBool	CountDown (TInt aValue)
	Decrements the delta value of the first element by the specified value, and returns true if the result is negative or zero.

IMPORT_C TBool	FirstDelta (TInt &aValue)
	Gets the delta value of the first list element.

IMPORT_C void	Reset ()
	Empties the doubly linked list, and resets the first delta pointer.

Public Member Functions inherited from TDblQueBase
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.

Additional Inherited Members
Protected Member Functions inherited from TDeltaQueBase
IMPORT_C	TDeltaQueBase ()
	Default constructor.

IMPORT_C	TDeltaQueBase (TInt aOffset)
	Constructor with specified offset.

IMPORT_C void	DoAddDelta (TAny *aPtr, TInt aDelta)
	Implements the addition of the specified list element into the list.

IMPORT_C void	DoRemove (TAny *aPtr)
	Implements the removal of the specified list element from the list.

IMPORT_C TAny *	DoRemoveFirst ()
	Implements the removal of the first list element from the linked list if its delta value is zero or negative.

Protected Member Functions inherited from TDblQueBase
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 inherited from TDeltaQueBase
TInt *	iFirstDelta
	Pointer to the delta value in the first link element.

Protected Attributes inherited from TDblQueBase
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.

Detailed Description

template<class T>
class TDeltaQue< T >

A templated class that provides the behaviour for managing a doubly linked list in which elements represent values which are increments, or deltas, on the value represented by a preceding element.

The list is ordered so that the head of the queue represents a nominal zero point.

The delta value of a new element represents its 'distance' from the nominal zero point. The new element is added into the list, and the delta values of adjacent elements (and of the new element, if necessary) are adjusted, so that the sum of all deltas, up to and including the new element, is the same as the new element's intended 'distance' from the nominal zero point.

A common use for a list of this type is as a queue of timed events, where the delta values represent the intervals between the events.

The delta value is defined by the value of the TDeltaQueLink::iDelta 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.

See also: TDeltaQueLink; TDeltaQueLink::iDelta

API status: Published to all clients. Released API.

Definition at line 530 of file e32std.h.

Constructor & Destructor Documentation

◆ TDeltaQue() [1/2]

template<class T >

TDeltaQue< T >::TDeltaQue ( )

inline

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 TDblQueBase::SetOffset() function in the base class to ensure that the offset value is set correctly.

TDeltaQueBase::iFirstDelta is set to NULL.

TDblQueBase::SetOffset

(generated from Symbian Developer Library)

◆ TDeltaQue() [2/2]

template<class T >

TDeltaQue< T >::TDeltaQue ( TInt aOffset )

inlineexplicit

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

TDeltaQueBase::iFirstDelta is set to NULL.

Parameters

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

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

(generated from Symbian Developer Library)

Member Function Documentation

◆ Add()

template<class T >

void TDeltaQue< T >::Add	(	T &	aRef,
		TInt	aDelta
	)

inline

Adds the specified list element, having the specified 'distance' from the nominal zero point, into the list.

The element is added into the list, the adjacent delta values adjusted, and a suitable delta value assigned to the new element, so that the new element is at the specified 'distance' from the nominal zero point.

Parameters

aRef	The list element to be inserted.
aDelta	The 'distance' from the nominal zero point.

(generated from Symbian Developer Library)

◆ Remove()

template<class T >

void TDeltaQue< T >::Remove ( T & aRef )

inline

Removes the specified list element from the linked list.

The delta value of the element following the removed element is adjusted so that its 'distance' from the nominal zero point remains the same.

Parameters

aRef	The list element to be removed.

(generated from Symbian Developer Library)

◆ RemoveFirst()

template<class T >

T * TDeltaQue< T >::RemoveFirst ( )

inline

Removes the first list element from the linked list if its delta value is zero or negative.

(generated from Symbian Developer Library)

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TDeltaQue() [1/2]

◆ TDeltaQue() [2/2]

Member Function Documentation

◆ Add()

◆ Remove()

◆ RemoveFirst()