NewLC - Symbian Active Object Framework - A Classic Example for Open Closed Principle - Comments

Re: Symbian Active Object Framework - A Classic

Numpty Alert — Mon, 02 Jun 2008 23:34:08 +0200

"We should not be setting the istatus variable with the value as set above. Is it right(correct me if not)?"

It is the asynchronous function that is being called that should be setting the status to KRequestPending.

Re: Symbian Active Object Framework - A Classic Example for Open

satishkhatri — Mon, 31 Mar 2008 09:35:13 +0200

Hi,

I also a beginner in this active objects and i have watched ur replies. Can u send me a simple
example for understanding active objects.

Thanks and regards,
Satish Khatri

Symbian Active Object Framework - A Classic Example

jobin.tech — Mon, 06 Aug 2007 08:36:33 +0200

Hi,

I also a beginner in this active objects and i have watched ur replies. Can u send me a simple
example for understanding active objects.

Thanks and regards,

Jobin

Symbian Active Object Framework - A Classic Example for Open Clo

Anonymous — Mon, 26 Mar 2007 21:28:08 +0200

This is a very bad example of the use of active objects if the intention is to try and help beginners know how to use them.

The reason is its stopping the active scheduler. An active object shouldn't start or stop the active scheduler (and if it does its a very advanced case and you must definatly know exactly what you are doing any why before doing that).

A test active object can start and stop the active scheduler, but a production active object shouldn't. So for any beginners reading this article, please don't think this is a good example.

Symbian Active Object Framework - A Classic Example for Open Clo

Anonymous — Thu, 08 Feb 2007 10:40:11 +0100

I am very new in Symbian but i have question here on the code example. In the function

CMyActiveObject::RequestFunction( TRequestType aRequest ) iRequest = aRequest; iStatus = KRequestPending;

We should not be setting the istatus variable with the value as set above. Is it right(correct me if not)?

Could someone post an working example code for active objects please(.h .cpp, and client code which uses these)

Thanks in advance... Sreenn

Symbian Active Object Framework - A Classic Example for Open Clo

Anonymous — Mon, 27 Nov 2006 12:01:09 +0100

In the header file above, a tilde is missing from the destructor prototype.

> Symbian Active Object Framework - A Classic Example for Open C

Alok — Fri, 05 Aug 2005 03:54:44 +0200

I figured out the problem with my code.. and it was something stupid.. Basically in the header file for The LIne status monitoring I had declared a TRequestStatus iStatus variable... which was confusing that Active Object as to which iState variable would be used. Dumb... but it tok me a day and a half to figure it out.. hope that helps anybody else who runs into something similar..

> Symbian Active Object Framework - A Classic Example for Open C

Alok — Fri, 05 Aug 2005 00:31:06 +0200

Hi, Read through your tutorial and have this strange problem with using multiple Active Objects. Two to be precise. I have two active objects, 1 to monitor the recent call log and the other to monitor the Line status of the phone. I am posting the .cpp code for both below.

For the Line Manager

CStatusManager* CStatusManager::NewL(MStatusManagerObserver* aObserver, TInt aTimeout) { CStatusManager* self = new (ELeave) CStatusManager(aObserver, aTimeout); CleanupStack::PushL(self); self->ConstructL(); CleanupStack::Pop(self); return self; } CStatusManager::CStatusManager(MStatusManagerObserver* aObserver, TInt aTimeout) : CActive(CActive::EPriorityHigh), iObserver(aObserver), iTimeout(aTimeout) { CActiveScheduler::Add(this); } CStatusManager::~CStatusManager() { Cancel(); iTimer.Close(); delete iObserver; //Added this iLine.Close(); iPhone.Close(); iTelServer.Close(); //End Add } void CStatusManager::ConstructL() { TInt ret; ret=iTelServer.Connect(); TInt Numberphones; ret=iTelServer.EnumeratePhones(Numberphones); if(Numberphones>0) { GetDefaultTSY(); TInt ret=iTelServer.LoadPhoneModule(iTsyName); if(ret!=KErrNone) { return; } } else { User::After(5000000); return; } //Creating a phone connected to server RTelServer::TPhoneInfo PhoneInfo; iTelServer.GetPhoneInfo(0,PhoneInfo); iPhone.Open(iTelServer,PhoneInfo.iName); TInt aCount; iPhone.EnumerateLines(aCount); if(aCount>0) { RPhone::TLineInfo LineInfo; iPhone.GetLineInfo(0,LineInfo); TInt ret=iLine.Open(iPhone,LineInfo.iName); //iObserver->DispInt(ret); } } void CStatusManager::Reset() { Cancel(); Start(); } void CStatusManager::DoCancel() { iLine.NotifyStatusChangeCancel(); } void CStatusManager::Start() { if (!IsActive()) { Cancel();//Just in case iLine.NotifyStatusChange(iStatus,iLineStatus); SetActive(); } } void CStatusManager::RunL() { TBuf<99> Msg; char a[99]; if (iStatus == KErrNone) { switch(iLineStatus) { //Monitor different line status here } iLine.NotifyStatusChange(iStatus,iLineStatus); SetActive(); } else { //this is debuggin code iObserver->StatusChange(this,"Crap"); TInt a=iStatus.Int(); iObserver->DispInt(a); User::After(5000000); this->Deque(); ConstructL(); Start(); } } void CStatusManager::GetDefaultTSY() { TUint32 modemId = 0; CCommsDatabase* db = CCommsDatabase::NewL(EDatabaseTypeUnspecified); CleanupStack::PushL(db); db->GetGlobalSettingL(TPtrC(MODEM_DATA_FAX), modemId); // Now read the TSY name from the modem table record CCommsDbTableView* tableView = db->OpenViewMatchingUintLC (TPtrC(MODEM),TPtrC(COMMDB_ID),modemId); User::LeaveIfError(tableView->GotoFirstRecord()); tableView->ReadTextL(TPtrC(MODEM_TSY_NAME),iTsyName); CleanupStack::PopAndDestroy(tableView); CleanupStack::PopAndDestroy(db); } void MStatusManagerObserver::AccessCallLog() { } void MStatusManagerObserver::StatusChange(CStatusManager* aStatusManager,char *status) { } void MStatusManagerObserver::StatusDetected(CStatusManager* aStatusManager) { } void MStatusManagerObserver::InStatusDetected(CStatusManager* aStatusManager) { } void MStatusManagerObserver::DispInt(TInt &aArg) { }

For Accessing the Call Logs

CInCallNumber* CInCallNumber::NewL(MNumberObserver* aObserver) { CInCallNumber* self = new (ELeave) CInCallNumber(aObserver); CleanupStack::PushL(self); self->ConstructL(); CleanupStack::Pop(self); return self; } CInCallNumber::CInCallNumber(MNumberObserver* aObserver) : CActive(CActive::EPriorityHigh), iObserver(aObserver) { CActiveScheduler::Add(this); } CInCallNumber::~CInCallNumber() { Cancel(); delete iObserver; } void CInCallNumber::ConstructL() { RFs aFs; aFs.Connect(); iLogClient = CLogClient::NewL(aFs); User::LeaveIfNull(iLogClient); iLogViewRecent = CLogViewRecent::NewL(*iLogClient); User::LeaveIfNull(iLogViewRecent); iLogFilter = CLogFilter::NewL(); User::LeaveIfNull(iLogFilter); iLogFilter->SetEventType(KLogCallEventTypeUid); //SetupFilterL(iLogViewRecent,iLogFilter); _LIT(Error,"Ended ConstructL of CallLg"); TBuf<50> temp; temp.Copy(Error); iObserver->DisplayNumber(temp); } void CInCallNumber::DoCancel() { iLogClient->NotifyChangeCancel(); } void CInCallNumber::SetupNotify() { if (!IsActive()) { iLogViewRecent->SetRecentListL(KLogNullRecentList,*iLogFilter,iStatus); SetActive(); } } void CInCallNumber::RunL() { if(iStatus==KErrNone) { // User::After(1000000); iNumCall=iLogViewRecent->CountL(); //iObserver->DisplayInt(iNumCall); if(iNumCall>0) { iObserver->StatusChange(this,"dialling"); const CLogEvent& event=iLogViewRecent->Event(); TBuf<20> icallno=event.Number(); iObserver->DisplayNumber(icallno); WForNot=EFalse; } else { iObserver->StatusChange(this,"idd"); } } else { _LIT(Error,"got an error from get number"); TBuf<30> temp; temp.Copy(Error); iObserver->DisplayNumber(temp); } } void MNumberObserver::StatusChange(CInCallNumber* aStatusManager,char *status) { } void MNumberObserver::StatusDetected(CInCallNumber* aStatusManager) { } void MNumberObserver::InStatusDetected(CInCallNumber* aStatusManager) { } void MNumberObserver::DisplayNumber(TDesC &aArg) { }

and this is how I am calling them from a Main Function.

CActiveScheduler *sched = new (ELeave) CActiveScheduler(); CleanupStack::PushL(sched); CActiveScheduler::Install(sched); //For getting the Number NumObserver=new (ELeave) MNumberObserver(); CleanupStack::PushL(NumObserver); ExNumber=CInCallNumber::NewL(NumObserver); CleanupStack::Pop(NumObserver); ExNumber->SetupNotify(); //Observing the line status CStatusManager* iStatusManager; MStatusManagerObserver *iStatusManagerObserver; iStatusManagerObserver = new (ELeave) MStatusManagerObserver(); CleanupStack::PushL(iStatusManagerObserver); iStatusManager = CStatusManager::NewL(iStatusManagerObserver, 10); CleanupStack::Pop(iStatusManagerObserver); iStatusManager->Start(); CActiveScheduler::Start();

Ok so after this really long code, just wanted to add that I am developing a console application. Now When i run this application of an Nokia 6620 phone, the RunL of the Line status function executes, but the iStatus is KRequestPending. Both of these AOs work fine independently.. so I am not sure what to do in order to figure out what the problem is. The issue seems to be with the time when both the asynchronus requests are isseud. Any guidance would be apprieciated.. Thanks
alok

> Symbian Active Object Framework - A Classic Example for Open C

eric — Wed, 03 Aug 2005 09:42:41 +0200

You have to use ... tags around your code to make it looks like code !!! I have copy pasted your code at the end of the article.

> Symbian Active Object Framework - A Classic Example for Open C

Anonymous — Tue, 02 Aug 2005 07:03:55 +0200

Hi Girish,

Thanks for the help i will try with ur code.If incase Iam unable to get the desired output i will contact you.

Thanks for the help.

> Symbian Active Object Framework - A Classic Example for Open C

Girish Shetty — Tue, 02 Aug 2005 06:52:59 +0200

Hi,

I could not get any way of attaching files with this thread. So, I am adding code with this only. May be you can mail me at Girish.Shetty@nokia.com if in case you are still not sure about the implementation and usage of Active Object so that I can mail you the code..

I am copy-pasting the working code directly, so formatting of the text/code may look very bad in this!

Here it goes:

=======================================================

//In Header File: MyActiveObject.h

#ifndef MYACTIVEOBJECT_H #define MYACTIVEOBJECT_H

#include <e32base.h>

class CMyActiveObject : public CActive public: enum TRequestType ECount, EStop ; public: CMyActiveObject( TRequestType aRequest = ECount, TInt aPriority = EPriorityStandard ); void DoCancel(); void RunL(); void RequestFunction( TRequestType aRequest ); void ReadyToGo(); void SetIncrementCounter( TInt aCount = 1 ); TUint CountValue () const; ~CMyActiveObject(); private: TUint iCount; TUint iIncrementCount; TRequestType iRequest; ;

#endif //MYACTIVEOBJECT_H

=======================================================

//Corresponding .cpp file //MyActiveObject.cpp

#include "MyActiveObject.h"

// ----------------------------------------------------------------------------- // CMyActiveObject::CMyActiveObject // Description: CMyActiveObject constructer // ----------------------------------------------------------------------------- // CMyActiveObject::CMyActiveObject( TRequestType aRequest, TInt aPriority ) : CActive( aPriority ), iCount( 0 ), iIncrementCount( 1 ), iRequest( aRequest ) CActiveScheduler::Add( this ); // ----------------------------------------------------------------------------- // CMyActiveObject::~CMyActiveObject // Description: CMyActiveObject Destructer // ----------------------------------------------------------------------------- // CMyActiveObject::~CMyActiveObject() Cancel();

// ----------------------------------------------------------------------------- // CMyActiveObject::RequestFunction // Description: Request Function for CMyActiveObject // ----------------------------------------------------------------------------- // void CMyActiveObject::RequestFunction( TRequestType aRequest ) iRequest = aRequest; iStatus = KRequestPending; if( !IsActive() ) SetActive();

// ----------------------------------------------------------------------------- // CMyActiveObject::ReadyToGo // Description: This calls CMyActiveObject's RunL // ----------------------------------------------------------------------------- // void CMyActiveObject::ReadyToGo() TRequestStatus* status = &iStatus; User::RequestComplete( status, KErrNone );

// ----------------------------------------------------------------------------- // CMyActiveObject::DoCancel // Description: This calls CActive's Cancel // ----------------------------------------------------------------------------- // void CMyActiveObject::DoCancel()

// ----------------------------------------------------------------------------- // CMyActiveObject::SetIncrementCounter // Description: Sets Increment Counter of CMyActiveObject // ----------------------------------------------------------------------------- // void CMyActiveObject::SetIncrementCounter( TInt aCount) iIncrementCount = aCount;

// ----------------------------------------------------------------------------- // CMyActiveObject::RunL // Description: CActive::RunL implementation which will either stop the // Scheduler or increment the count // ----------------------------------------------------------------------------- // void CMyActiveObject::RunL() switch(iRequest) case ECount: iCount += iIncrementCount; break; case EStop: CActiveScheduler::Stop(); break; default: break;

// ----------------------------------------------------------------------------- // CMyActiveObject::CountValue // Description: Returns Count Value of CMyActiveObject // ----------------------------------------------------------------------------- // TUint CMyActiveObject::CountValue () const return iCount;

======================================================= //Usage... SomeOtherCpp.cpp

#include "MyActiveObject.h"

const TInt KErrActiveObjCount = -1001;

TInt UseMyActiveObjectL( TUint aCount ) TInt retVal ( KErrNone );

//Create one Active Object for Count purpose CMyActiveObject* object1 = new( ELeave ) CMyActiveObject; object1->SetIncrementCounter( aCount); object1->RequestFunction( CMyActiveObject::ECount ); CleanupStack::PushL( object1 );

//Create one Active Object for Stopping Scheduler CMyActiveObject* object2 = new( ELeave ) CMyActiveObject; object2->RequestFunction( CMyActiveObject::EStop ); //Issue the Request object1->ReadyToGo(); object2->ReadyToGo();

//Start the Scheduler CActiveScheduler::Start(); if( object1->CountValue() != aCount ) retVal = KErrActiveObjCount; delete object2; CleanupStack::PopAndDestroy( object1 ); return retVal;

I hope you might have got some idea now...

Regards Girish

> Symbian Active Object Framework - A Classic Example for Open C

Anonymous — Tue, 02 Aug 2005 05:13:42 +0200

hi, The article is informative one.Iam a novoice user of symbian,and Iam developing an application which involves active object,I tryed but Iam not getting the desired output.Can you send an example (if possible both header and cpp) which includes use of Active Objects

Thanks

Symbian Active Object Framework - A Classic Example for Open Closed Principle

girishshetty — Mon, 01 Aug 2005 17:32:42 +0200

Some light on C++ OCP Design principle and Symbian Active Object Framework