Call Hold Tutorial

This tutorial describes how to place a call on hold with the telephony API for applications.

Steps

create a new instance of CTelephony
use CTelephony::GetCallDynamicCaps() to check if the device supports hold function
use CTelephony::Hold() to place a call on hold Pass it the ID of the call to hold. The ID is the CTelephony::TCallId returned when you dialled or answered the call.
pass the enumeration CTelephony::EHoldCancel to cancel the asynchronous request

Call hold example

#include <e32base.h>
#include <Etel3rdParty.h>

class CClientApp : public CActive
    { 

private:
    CTelephony* iTelephony;
    CTelephony::TCallId iCallId;

public:
    CClientApp(CTelephony* aTelephony, CTelephony::TCallId aCallId);
    TInt SomeFunction();

private:
    /*
       These are the pure virtual methods from CActive that  
       MUST be implemented by all active objects
       */
    void RunL();
    void DoCancel();
   };

CClientApp::CClientApp(CTelephony* aTelephony, CTelephony::TCallId aCallId)
    : CActive(EPriorityStandard),
      iTelephony(aTelephony),
      iCallId(aCallId)
    {
    //default constructor
    }

TInt CClientApp::SomeFunction()
    {
    // Check that the phone supports holding calls.
    CTelephony::TCallCapsV1 callCapsV1;
    CTelephony::TCallCapsV1Pckg callCapsV1Pckg(callCapsV1);
    iTelephony->GetCallDynamicCaps(iCallId, callCapsV1Pckg);

    if( callCapsV1.iControlCaps & CTelephony::KCapsHold )
       {
       // The call represented by 'iCallId' can be put on hold
       iTelephony->Hold(iStatus, iCallId);
       SetActive();
       return KErrNone;
       }
    else
       {
       // The call cannot be put on hold; 
       // return an error indicate this.
       return KErrNotSupported;
       }
    }

void CClientApp::RunL()
    {
    if(iStatus==KErrNone)
       {} // The call has been held successfully;
    }

void CClientApp::DoCancel()
    {
    iTelephony->CancelAsync(CTelephony::EHoldCancel);
    }