Class RChangeNotifier

class RChangeNotifier : public RHandleBase;

Description

A handle to a change notifier.

The change notifier itself is a kernel object.

Derivation

• RHandleBase - A handle to an object.

• RChangeNotifier - A handle to a change notifier.

Members

Defined in RChangeNotifier:

• Create()Creates a change notifier, and opens this handle to that change notifier.
• Logon(TRequestStatus &)constIssues a request for notification when changes occur in the environment.
• LogonCancel()constCancels an outstanding change notification request.

Inherited from RHandleBase:

• Attributes()const
• BTraceId()constReturns a unique object identifier for use with BTrace
• Close()Closes the handle.
• Duplicate(const RThread &,TOwnerType)Creates a valid handle to the kernel object for which the specified thread alrea...
• FullName()constGets the full name of the handle.
• FullName(TDes &)constGets the full name of the handle.
• Handle()constRetrieves the handle-number of the object associated with this handle.
• HandleInfo(THandleInfo *)Gets information about the handle.
• Name()constGets the name of the handle.
• Open(const TFindHandleBase &,TOwnerType)Opens a handle to a kernel side object found using a find-handle object.
• RHandleBase(TInt)Copy constructor.
• SetHandle(TInt)Sets the handle-number of this handle to the specified value.
• SetHandleNC(TInt)Sets the handle-number of this handle to the specified value, and marks it as no...
• SetReturnedHandle(TInt)Sets the handle-number of this handle to the specified value.
• iHandle

IMPORT_C TInt Create();

Description

Creates a change notifier, and opens this handle to that change notifier.

Ownership of this change notifier is vested in the current process.

Return value

TInt KErrNone if successful, otherwise one of the other system-wide error codes.

IMPORT_C TInt Logon(TRequestStatus &aStatus) const;

Description

Issues a request for notification when changes occur in the environment.

A switch in locale, or crossing over past midnight, are examples of changes that are reported.

When a change in the environment occurs, the request completes and the TRquestStatus object will contain one or more of the bit values defined by the TChanges enum.

Alternatively, if an outstanding request is cancelled by a call to this handle's RChangeNotifier::LogonCancel()const member function, then the request completes with a KErrCancel.

Note that if this is the first notification request after creation of the change notifier, then this request completes immediately.

Parameters

TRequestStatus &aStatus A reference to the request status object.

Return value

TInt KErrInUse, if there is an outstanding request; KErrNone otherwise.

See also:

• TChanges...
• RChangeNotifier::Logon(TRequestStatus &)constIssues a request for notification when changes occur in the environment.

IMPORT_C TInt LogonCancel() const;

Description

Cancels an outstanding change notification request.

Return value

TInt KErrGeneral, if there is no outstanding request; KErrNone otherwise.

See also:

• RChangeNotifier::Logon(TRequestStatus &)constIssues a request for notification when changes occur in the environment.