TDeltaQueBase Class Reference

#include <e32std.h>

class TDeltaQueBase : public TDblQueBase

Inherits from

TDeltaQueBase
- TDblQueBase

Protected Attributes
TInt *	iFirstDelta

Public Member Functions
IMPORT_C TBool	CountDown()
IMPORT_C TBool	CountDown(TInt)
IMPORT_C TBool	FirstDelta(TInt &)
IMPORT_C void	Reset()

Protected Member Functions
	TDeltaQueBase()
	TDeltaQueBase(TInt)
IMPORT_C void	DoAddDelta(TAny *, TInt)
IMPORT_C void	DoRemove(TAny *)
IMPORT_C TAny *	DoRemoveFirst()

Inherited Attributes
	TDblQueBase::iHead
	TDblQueBase::iOffset

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

Detailed Description

A base class that provides implementation for the TDeltaQue template class.

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

Member Attribute Documentation

iFirstDelta

TInt *

iFirstDelta

[protected]

Pointer to the delta value in the first link element.

Constructor & Destructor Documentation

TDeltaQueBase ( )

IMPORT_C

TDeltaQueBase

(

)

[protected]

Default constructor.

It sets iFirstDelta to NULL.

TDeltaQueBase ( TInt )

IMPORT_C

TDeltaQueBase

(

TInt

aOffset

)

[protected]

Constructor with specified offset.

It sets:

1. iFirstDelta to NULL

2. TDblQueBase::iOffset to the specified value, through a call to the base class constructor.

Parameter	Description
aOffset	The offset of a link object within an element.

Member Function Documentation

CountDown ( )

IMPORT_C TBool

CountDown

(

)

Decrements the delta value of the first element by one, and returns true if the result is negative or zero.

Returns: True, if the resulting delta value is negative or zero; false, if the value is positive, or there is no first element.

CountDown ( TInt )

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.

Parameter	Description
aValue	The amount by which the delta value is to be reduced.

Returns: True, if the resulting delta value is negative or zero; false, if the value is positive, or there is no first element.

DoAddDelta ( TAny *, TInt )

IMPORT_C void	DoAddDelta	(	TAny *	aPtr,
			TInt	aDelta
		)	[protected]

Implements the addition of the specified list element into the list.

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

Parameter	Description
aPtr	Pointer to the list element to be inserted.
aDelta	The 'distance' from the nominal zero point.

DoRemove ( TAny * )

IMPORT_C void

DoRemove

(

TAny *

aPtr

)

[protected]

Implements the removal of the specified list element from the list.

This function is called by TDeltaQue::Remove().

Parameter	Description
aPtr	Pointer to the list element to be removed.

DoRemoveFirst ( )

IMPORT_C TAny *

DoRemoveFirst

(

)

[protected]

Implements the removal of the first list element from the linked list if its delta value is zero or negative.

This function is called by TDeltaQue::RemoveFirst().

FirstDelta ( TInt & )

IMPORT_C TBool

FirstDelta

(

TInt &

aValue

)

Gets the delta value of the first list element.

Parameter	Description
aValue	On return, contsins the delta value of the first element. Note that this remains unchanged if there is no first element.

Returns: True, if there is a first element; false, otherwise.

Reset ( )

IMPORT_C void

Reset

(

)

Reimplemented from TDblQueBase::Reset()

Empties the doubly linked list, and resets the first delta pointer.