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MFepAttributeStorer Class Reference

class MFepAttributeStorer

Protocol for storing, restoring and synchronising FEP attributes.

An abstract base class for CCoeFep, so FEPs must implement the pure virtual functions declared in this class.

Rather than using a single device-wide instance of a FEP, each application has its own instance of the FEP. MFepAttributeStorer provides a framework for synchronising FEP attributes across each running instance of the same FEP. For this to happen, the FEP must implement MFepAttributeStorer::WriteAttributeDataToStreamL() and MFepAttributeStorer::ReadAttributeDataFromStreamL().

Attributes are FEP-specific, and are identified by a UID which can be accessed using AttributeAtIndex(). An example of a FEP attribute might be whether inline editing is enabled or disabled.

Public Member Functions
TUid	AttributeAtIndex(TInt)
TInt	NumberOfAttributes()
IMPORT_C void	ReadAllAttributesL(CCoeEnv &)
void	ReadAttributeDataFromStreamL(TUid, RReadStream &)
IMPORT_C void	WriteAttributeDataAndBroadcastL(CCoeEnv &, TUid)
IMPORT_C void	WriteAttributeDataAndBroadcastL(CCoeEnv &, const TArray< TUid > &)
void	WriteAttributeDataToStreamL(TUid, RWriteStream &)

Private Member Functions
IMPORT_C void	MFepAttributeStorer_Reserved_1()
IMPORT_C void	MFepAttributeStorer_Reserved_2()
TInt	NumberOfOccurrencesOfAttributeUid(TUid)

Member Functions Documentation

AttributeAtIndex(TInt)

TUid

AttributeAtIndex

(

TInt

aIndex

)

const [pure virtual]

Returns the UID of the FEP attribute at the index specified.

Parameters

TInt aIndex

An array index.

MFepAttributeStorer_Reserved_1()

IMPORT_C void

MFepAttributeStorer_Reserved_1

(

)

[private, virtual]

MFepAttributeStorer_Reserved_2()

IMPORT_C void

MFepAttributeStorer_Reserved_2

(

)

[private, virtual]

NumberOfAttributes()

TInt

NumberOfAttributes

(

)

const [pure virtual]

Returns the total number of FEP attributes.

NumberOfOccurrencesOfAttributeUid(TUid)

TInt

NumberOfOccurrencesOfAttributeUid

(

TUid

aAttributeUid

)

const [private]

Parameters

TUid aAttributeUid

ReadAllAttributesL(CCoeEnv &)

IMPORT_C void

ReadAllAttributesL

(

CCoeEnv &

aConeEnvironment

)

Reads all of the FEP's attributes from the system settings.

Calls the implementation of ReadAttributeDataFromStreamL() for each attribute.

This function has identical behaviour to CCoeFep::ReadAllAttributesL().

Parameters

CCoeEnv & aConeEnvironment

Not used.

ReadAttributeDataFromStreamL(TUid, RReadStream &)

void	ReadAttributeDataFromStreamL	(	TUid	aAttributeUid,
			RReadStream &	aStream
		)	[pure virtual]

Reads the value of the attribute identified by the UID specified in aAttributeUid from the specified read stream.

You should take appropriate action if the attribute has changed, e.g. if inline editing has been disabled, you might cancel the current transaction.

This function is called by MFepAttributeStorer::ReadAllAttributesL() for all attributes. It is also called when the FEP receives a message that an attribute has been changed by another running instance of the FEP (using WriteAttributeDataAndBroadcastL()).

Parameters

TUid aAttributeUid	Identifies the attribute whose value should be read.
RReadStream & aStream	Read stream from which to read the attribute's value.

WriteAttributeDataAndBroadcastL(CCoeEnv &, TUid)

IMPORT_C void	WriteAttributeDataAndBroadcastL	(	CCoeEnv &	aConeEnvironment,
			TUid	aAttributeUid
		)

Call this function after changing the value of an attribute that needs to be synchronised.

Writes the new value to the system-wide settings and causes all other running instances of the FEP to be notified of the change.

A panic occurs if aAttributeUid is not one of the FEP's attributes.

capability: WriteDeviceData

Parameters

CCoeEnv & aConeEnvironment	The FEP's control environment.
TUid aAttributeUid	The UID of the attribute whose value has changed.

WriteAttributeDataAndBroadcastL(CCoeEnv &, const TArray< TUid > &)

IMPORT_C void	WriteAttributeDataAndBroadcastL	(	CCoeEnv &	aConeEnvironment,
			const TArray< TUid > &	aAttributeUids
		)

Call this function after changing the value of multiple attributes that need to be synchronised.

Writes the new values to the system settings, and causes all other running instances of the FEP to be notified of the change.

A panic occurs if any of the attributes contained in aAttributeUids are not among the FEP's attributes.

capability: WriteDeviceData To prevent corruption of FEP settings.

Parameters

CCoeEnv & aConeEnvironment	Not used.
const TArray< TUid > & aAttributeUids	Array of UIDs of the attribute whose values have changed.

WriteAttributeDataToStreamL(TUid, RWriteStream &)

void	WriteAttributeDataToStreamL	(	TUid	aAttributeUid,
			RWriteStream &	aStream
		)	const [pure virtual]

Writes the value of the attribute specified to the specified write stream.

Called by MFepAttributeStorer::WriteAttributeDataAndBroadcastL() for each attribute passed to it.

Parameters

TUid aAttributeUid	UID of the attribute to write to the stream.
RWriteStream & aStream	The stream to which to write the attribute.