CTextField Class Reference

#include <fldbase.h>

Link against: field.lib

class CTextField : public CBase, public CBase

Inherits from

CTextField
- CBase
- CBase

Public Member Functions
virtual IMPORT_C void	ExternalizeL(RWriteStream &)
pure virtual void	InternalizeL(RReadStream &)
virtual IMPORT_C void	RestoreL(const CStreamStore &, TStreamId)
virtual IMPORT_C TStreamId	StoreL(CStreamStore &)
pure virtual TUid	Type()
pure virtual TInt	Value(TPtr &)

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	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

Abstract class: derive from this to instantiate a particular type of field (eg date etc) Abstract base class for all field types.

A field contains information which relates to a text object and can be automatically updated, e.g. page number or current date and time. Fields must implement the pure virtual functions defined in this class, including Value() which should calculate and return the field's new value, and Type() which returns the field's type UID. The type UID identifies the field type to the field factory (see class MTextFieldFactory).

Member Function Documentation

ExternalizeL ( RWriteStream & )

IMPORT_C void

ExternalizeL

(

RWriteStream &

aStream

)

const [virtual]

Externalises the field data. Called by StoreL().

Calling this default implementation raises a panic. Concrete field classes with persistent data must provide their own implementation of this function. Concrete field classes with no persistent data must provide a StoreL() implementation that just returns KNullStreamId.

Parameters
aStream	Not used.

InternalizeL ( RReadStream & )

void

InternalizeL

(

RReadStream &

aStream

)

[pure virtual]

Internalises the field data. Called by RestoreL().

Parameters
aStream	Stream from which the field data should be internalised.

RestoreL ( const CStreamStore &, TStreamId )

IMPORT_C void	RestoreL	(	const CStreamStore &	aStore,
			TStreamId	aId
		)	[virtual]

Restores the field data from a stream store. Concrete field types with no persistent data should override this function to do nothing.

Parameters
aStore	Stream store containing the field data to restore.
aId	The ID of the stream store in which the field data was previously stored.

StoreL ( CStreamStore & )

IMPORT_C TStreamId

StoreL

(

CStreamStore &

aStore

)

const [virtual]

Stores the field data to a stream store. Concrete field types with no persistent data should override this function to return KNullStreamId.

Parameters
aStore	Stream store to which the field data is written.

Return Value: The ID of the stream store.

Type ( )

TUid

Type

(

)

const [pure virtual]

Returns the field's type UID.

Return Value: The field's type UID.

Value ( TPtr & )

TInt

Value

(

TPtr &

aValueText

)

[pure virtual]

Sets aValueText to the current field value if the buffer is large enough. If not, aValueText is not changed, and the function returns the length which is required to hold the field's value.

Parameters
aValueText	Descriptor which on return contains the field's updated value.

Return Value: Zero on success, otherwise, the length of the buffer which is required to hold the field's updated value.