CAsyncCallBack Class Reference

#include <e32base.h>

Link against: euser_v5.lib

class CAsyncCallBack : public CAsyncOneShot

Inherits from

CAsyncCallBack
- CAsyncOneShot
  - CActive
    - CBase

Protected Attributes
TCallBack	iCallBack

Public Member Functions
	CAsyncCallBack(TInt)
	CAsyncCallBack(const TCallBack &, TInt)
virtual	~CAsyncCallBack()
IMPORT_C void	CallBack()
IMPORT_C void	Set(const TCallBack &)

Protected Member Functions
virtual void	RunL()

Inherited Attributes
	CActive::iStatus

Inherited Enumerations
	CActive:TPriority

Inherited Functions
	CActive::CActive(TInt)
	CActive::Cancel()
	CActive::Deque()
	CActive::Extension_(TUint,TAny &,TAny )
	CActive::IsActive()const
	CActive::IsAdded()const
	CActive::Priority()const
	CActive::RunError(TInt)
	CActive::SetActive()
	CActive::SetPriority(TInt)
	CActive::~CActive()
	CAsyncOneShot::CAsyncOneShot(TInt)
	CAsyncOneShot::Call()
	CAsyncOneShot::DoCancel()
	CAsyncOneShot::Thread()
	CAsyncOneShot::~CAsyncOneShot()
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()

Detailed Description

An active object that performs its processing through an associated call back function, and which is only performed once.

Member Attribute Documentation

iCallBack

TCallBack

iCallBack

[protected]

The callback object that encapsulates the callback function.

Constructor & Destructor Documentation

CAsyncCallBack ( TInt )

IMPORT_C

CAsyncCallBack

(

TInt

aPriority

)

Constructor taking a priority value.

Specifically, the constructor sets this active object's priority value through a call to the base class constructor in its ctor list.

No call back is set, which means that it must be set subsequently through a call to the Set() function.

Parameters
aPriority	The active object priority value. CActive::TPriority defines a standard set of priorities.

CAsyncCallBack ( const TCallBack &, TInt )

IMPORT_C	CAsyncCallBack	(	const TCallBack &	aCallBack,
			TInt	aPriority
		)

Constructor taking a priority value and a callback.

Specifically, the constructor:

1. sets this active object's priority value through a call to the base class constructor in its ctor list

2. sets the callback; the function encapsulated by the callback is called when this active object is scheduled to run.

Parameters
aCallBack	A reference to a callback object encapsulating a function which is called when this active object is ready to run. The constructor takes a copy of this callback object, which means that it can be safely discarded after construction.
aPriority	The active object priority value.

~CAsyncCallBack ( )

IMPORT_C

~CAsyncCallBack

(

)

[virtual]

Destructor.

Member Function Documentation

CallBack ( )

IMPORT_C void

CallBack

(

)

Queues this active object to be run, if it is not already queued.

RunL ( )

void

RunL

(

)

[protected, virtual]

Reimplemented from CActive::RunL()

Calls the callback function.

Set ( const TCallBack & )

IMPORT_C void

Set

(

const TCallBack &

aCallBack

)

Sets the call back.

Parameters
aCallBack	A reference to a callback object encapsulating a function which is called when this active object is ready to run.

Panic Codes
E32USER-CBase	1 if the active object is currently active.