// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// Client observer class
// 
//

#include "UD_STD.H"

// Class RDbNotifier

EXPORT_C TInt RDbNotifier::Open(RDbDatabase& aDatabase)
/** Opens a DBMS change notifier on a database.

Note that a notifier cannot be opened on a client side database.

@param aDatabase The database to be observed.
@return KErrNone if successful, otherwise another of the system-wide error 
codes. */
	{
	TRAPD(r,iNotifier=aDatabase.iDatabase->NotifierL());
	return r;
	}
 
EXPORT_C void RDbNotifier::Close()
/** Closes a DBMS change notifier. Any outstanding notification request is automatically 
cancelled.

Note that this function can be called on a DBMS change notifier that has already 
been closed. */
	{
	iNotifier.Close();
	}

LOCAL_C void Notify(RDbHandle<CDbNotifier>& aNotifier,TRequestStatus& aStatus,CDbNotifier::TType aType)
	{
	aNotifier->Notify(aType,aStatus);
	}

EXPORT_C void RDbNotifier::NotifyUnlock(TRequestStatus& aStatus)
/** Makes an asynchronous request for notification of a database event. All events, 
including the release of all read locks, are reported.

When a database event occurs, the request completes and the TRequestStatus 
objectcontains one of the enumerators defined by the TEvent enumeration member.

Alternatively, if an outstanding request is cancelled by a call to the Cancel() 
member function of this class, then the request completes with KErrCancel.

Only one notification request can be outstanding on this notifier at any one 
time.

Note that if further database events occur while a client is handling a request 
completion, the notifier records the most significant database event and this 
is signalled as soon as the client issues the next NotifyUnlock() or NotifyChange() 
request.

@param aStatus The request status object. If the request is cancelled, this 
is set to KErrCancel. If the request completes normally, this is set to one 
of the enumerator values defined by the TEvent enumeration member. */
	{
	::Notify(iNotifier,aStatus,CDbNotifier::EUnlock);
	}

EXPORT_C void RDbNotifier::NotifyChange(TRequestStatus& aStatus)
/** Makes an asynchronous request for notification of changes to the database.

All events which indicate a change to the database are reported; in practice, 
this means all database events except RDbNotifier::EUnlock.

When a change event occurs, the request completes and the TRequestStatus object 
contains one of the appropriate enumerators defined by the TEvent enumeration 
member.

Alternatively, if an outstanding request is cancelled by a call to the Cancel() 
member function of this class, then the request completes with KErrCancel.

Only one notification request can be outstanding on this notifier at any one 
time.

Note that if further database events occur while a client is handling a request 
completion, the notifier records the most significant database event and this 
is signalled as soon as the client issues the next NotifyUnlock() or NotifyChange() 
request.

@param aStatus The request status object. If the request is cancelled, this 
is set to KErrCancel. If the request completes normally, this is set to one 
of the enumerator values defined by the TEvent enumeration member. */
	{
	::Notify(iNotifier,aStatus,CDbNotifier::EChange);
	}

EXPORT_C void RDbNotifier::Cancel()
/** Cancels any outstanding notification request to this DBMS notifier.

The outstanding request completes with a KErrCancel. */
	{
	iNotifier->Cancel();
	}