sl@0: // Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // Started by BLB, October 1996
sl@0: // Active object for tracking changes in TLocale
sl@0: // 
sl@0: //
sl@0: 
sl@0: #include <bacntf.h>
sl@0: 
sl@0: inline CEnvironmentChangeNotifier::CEnvironmentChangeNotifier(TInt aPriority)
sl@0: 	: CActive(aPriority)
sl@0: 	{__DECLARE_NAME(_S("CEnvironmentChangeNotifier"));}
sl@0: 
sl@0: 
sl@0: EXPORT_C CEnvironmentChangeNotifier* CEnvironmentChangeNotifier::NewL(TInt aPriority,const TCallBack& aCallBack)
sl@0: /** Constructs a new environment change notifier object with the specified active 
sl@0: object priority and callback function.
sl@0: 
sl@0: The function requires a priority value for this active object and a reference 
sl@0: to a TCallBack object encapsulating a pointer to the call back function which 
sl@0: is to run when change events occur.
sl@0: 
sl@0: As part of its implementation, the function:
sl@0: 
sl@0: creates a Kernel side change notifier and opens a handle (an RChangeNotifier) 
sl@0: to it.
sl@0: 
sl@0: adds this active object to the current active scheduler.
sl@0: 
sl@0: Note that construction of the environment change notifier does not issue any 
sl@0: requests for change events.
sl@0: 
sl@0: @param aPriority The priority of this active object. Priority values determine 
sl@0: the order in which an active scheduler handles completed active object requests.
sl@0: @param aCallBack A reference to a callback object which the caller must construct 
sl@0: to encapsulate the callback function. 
sl@0: @return A pointer to the new environment change notifier object.
sl@0: @see CEnvironmentChangeNotifier::Start()
sl@0: @see CActive::TPriority */
sl@0: 	{
sl@0: 	CEnvironmentChangeNotifier* This=new(ELeave) CEnvironmentChangeNotifier(aPriority);
sl@0: 	This->iChangeNotifier.Create();
sl@0: 	This->Set(aCallBack);
sl@0: 	CActiveScheduler::Add(This);
sl@0: 	return(This);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C CEnvironmentChangeNotifier::~CEnvironmentChangeNotifier()
sl@0: /** Destructor. Frees all resources owned by the object, prior to its destruction.
sl@0: 
sl@0: In particular, it cancels any outstanding request to the Kernel side change 
sl@0: notifier before closing the handle to it. */
sl@0: 	{
sl@0: 	Cancel();
sl@0: 	iChangeNotifier.Close();
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void CEnvironmentChangeNotifier::Start()
sl@0: /** Issues a request for change events.
sl@0: 
sl@0: The request completes when change events occur, as signalled by the Kernel 
sl@0: side change notifier service. The request may also complete if it is cancelled 
sl@0: by calling the Cancel() member function of this active object.
sl@0: 
sl@0: When change events occur, the callback function is called.
sl@0: 
sl@0: Note that after the first call to this function, the callback function is 
sl@0: called immediately; this is because of the way the underlying change notifier 
sl@0: is implemented. The changes reported are all those defined by the TChanges 
sl@0: enum.
sl@0: 
sl@0: @see CActive::Cancel()
sl@0: @see TChanges */
sl@0: 	{
sl@0: 	SetActive();
sl@0: 	iChangeNotifier.Logon(iStatus);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt CEnvironmentChangeNotifier::Set(const TCallBack& aCallBack)
sl@0: /** Sets the callback function.
sl@0: 
sl@0: A callback is normally set when this active object is constructed through 
sl@0: the NewL() function. This function replaces any existing callback object with 
sl@0: the specified callback object.
sl@0: 
sl@0: @param aCallBack A reference to the call back object encapsulating the call 
sl@0: back function. 
sl@0: @return KErrNone if successful, KErrInUse if this active object currently has 
sl@0: an outstanding request for change events, or another of the system-wide error-codes. */
sl@0: 	{
sl@0: 	if (IsActive())
sl@0: 		return(KErrInUse);
sl@0: 	iCallBack=aCallBack;
sl@0: 	return(KErrNone);
sl@0: 	}
sl@0: 
sl@0: void CEnvironmentChangeNotifier::RunL()
sl@0: //
sl@0: //	Active framework: Call the callback function
sl@0: //
sl@0: 	{
sl@0: 	iChange=iStatus.Int();
sl@0: 	Start();
sl@0: 	if (iChange!=0)
sl@0: 		{
sl@0: 		iCallBack.CallBack();
sl@0: 		iChange=0;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void CEnvironmentChangeNotifier::DoCancel()
sl@0: //
sl@0: //	Active framework: Cancel the current request
sl@0: //	
sl@0: 	{
sl@0: 	iChangeNotifier.LogonCancel();
sl@0: 	}
sl@0: