MFepAttributeStorer Class Reference

#include <mw/fepbconfig.h>

Link against: fepbase.lib

class MFepAttributeStorer

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

Detailed Description

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.

Member Function Documentation

AttributeAtIndex ( TInt )

TUid

AttributeAtIndex

(

TInt

aIndex

)

const [pure virtual]

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

Parameters
aIndex	An array index.

Return Value: The UID of the FEP attribute at aIndex.

NumberOfAttributes ( )

TInt

NumberOfAttributes

(

)

const [pure virtual]

Returns the total number of FEP attributes.

Return Value: The number of FEP attributes.

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
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
aAttributeUid	Identifies the attribute whose value should be read.
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.

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

Capability
WriteDeviceData

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.

Parameters
aConeEnvironment	Not used.
aAttributeUids	Array of UIDs of the attribute whose values have changed.

Capability
WriteDeviceData	To prevent corruption of FEP settings.

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