FAQ-0499 How can I launch an application and wait until it's finished to do something?


FAQ-0499 How can I launch an application and wait until it's finished to do something?

» Symbian OS » Developer Knowledgebase » FAQ-0499

Classification:	C++	Category:	Threads & Processes
Created:	06/23/2000	Modified:	01/16/2002
Number:	FAQ-0499
Platform:	ER5, Symbian OS v6.0, Symbian OS v6.1

Question:
How can I launch an application and wait until it's finished to do something?

Answer:
This can be done via a simple Active Object. Consider this class:

//
// CThreadLogon
//
class CEikBusyMsgWin;
class CExampleAppUi;
class CThreadLogon : public CActive

{

public:

CThreadLogon(CExampleAppUi& aAppUi);

~CThreadLogon();

void ConstructL();

void Request(const TThreadId& aId);

private:

void DoCancel();

void RunL();

private:

RThread iThread;

CExampleAppUi& iAppUi;

CEikBusyMsgWin* iBusyMsg;

HBufC* iBusyText;

};

CThreadLogon::CThreadLogon(CExampleAppUi& aAppUi)

: CActive(EActivePriorityIpcEventsHigh), iAppUi(aAppUi)

{

}

CThreadLogon::~CThreadLogon()

{

Cancel();

delete iBusyMsg;

User::Free(iBusyText);

}

void CThreadLogon::ConstructL()

{

CEikonEnv* eikonEnv=CEikonEnv::Static();

iBusyMsg=new(ELeave) CEikBusyMsgWin(*eikonEnv);

iBusyMsg->ConstructL(eikonEnv->RootWin());

iBusyText=eikonEnv->AllocReadResourceL(R_EXAMPLE_WAITING_FOR_APP);

CActiveScheduler::Add(this);

}

void CThreadLogon::DoCancel()

{

iBusyMsg->CancelDisplay();

iThread.LogonCancel(iStatus);

iThread.Close();

}

void CThreadLogon::RunL()

{

iBusyMsg->CancelDisplay();

iThread.Close();

iAppUi.LogonCallBackL();

}

void CThreadLogon::Request(const TThreadId& aId)

{

TInt err=iThread.Open(aId);

if (err)

{

TRequestStatus* pS=&iStatus;

User::RequestComplete(pS,err);

}

else

iThread.Logon(iStatus);

SetActive();

iBusyMsg->StartDisplay(iBusyText->Des(),EHRightVBottom);

}

All you now need to to is add a CThreadLogon* iThreadLogon member to your AppUi, do:

iThreadLogon=new(ELeave) CThreadLogon(*this);

iThreadLogon->ConstructL();

in the AppUi's constructor and finally construct a callback procedure in your AppUI. For example, this will bring your application to the foreground and show a simple message:

void CExampleAppUi::LogonCallBackL()

{

iEikonEnv->SetBusy(EFalse);

RWsSession& ws = iEikonEnv->WsSession();

RWindowGroup& rw = iEikonEnv->RootWin();

TInt winId = rw.Identifier();

TApaTask tApatsk(ws);

tApatsk.SetWgId(winId);

tApatsk.BringToForeground();

iEikonEnv->InfoWinL(R_EXAMPLE_APP_FINISHED);

}

When launching the app initially, you need to ensure the thread id is passed to the iThreadLogon AO. This could be done as follows:

iThreadLogon->Request(EikDll::StartAppL(*cmdLine));

iEikonEnv->SetBusy(ETrue);