1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

     3 <!-- This component and the accompanying materials are made available under the terms of the License 

     4 "Eclipse Public License v1.0" which accompanies this distribution, 

     5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

     9 -->

    10 <!DOCTYPE task

    11   PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">

    12 <task xml:lang="en" id="GUID-D6334249-E61D-55E7-9D0E-95231DC3621F"><title>Answer a Call Tutorial</title><shortdesc>This tutorial describes how to detect and answer an inbound call with the telephony API for applications. </shortdesc><prolog><metadata><keywords/></metadata></prolog><taskbody> <steps id="GUID-00FE5186-EF10-5AFB-B633-D6A09A988E28"> <step id="GUID-1E64BB78-64C9-5CEE-8242-75DF3B93CA45"><cmd/><info>create a new instance of <xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony</apiname></xref>  </info> </step> <step id="GUID-CE695413-811F-5089-8701-A78FB58CDA35"><cmd/><info>Use <xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::NotifyChange()</apiname></xref> to detect changes in the voice line's status. <codeph>NotifyChange()</codeph> can be used to detect a variety of changes, but in this case you are only interested in the status of the voice line. Pass a notification event, in this case <xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::EVoiceLineStatusChange</apiname></xref>. Also pass it an empty <xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::TCallStatusV1Pckg</apiname></xref>. </info> <info>Possible status values are Idle, Ringing, On-Hold. When the voice line status is Ringing(<codeph>CTelephony::EStatusRinging</codeph>) there is an incoming voice call to be answered. </info> </step> <step id="GUID-367A68B1-9149-561A-9AC1-3EFF30415319"><cmd/><info>answer a call with <xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::AnswerIncomingCall()</apiname></xref>. You can only answer a call when the voice line status is Ringing(<xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::EStatusRinging</apiname></xref>) </info> </step> <step id="GUID-72EBECDA-178A-541C-B05A-F560F113480C"><cmd/><info>pass the enumeration <xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::EAnswerIncomingCallCancel</apiname></xref> to cancel the operation. </info> </step> </steps> <example id="GUID-5F63DA49-52D4-5E10-81E1-BE71CD5BA923"><title>Answer a call example</title> <codeblock id="GUID-42AE93F9-40C4-5751-8677-DC12D42EC378" xml:space="preserve">#include &lt;e32base.h&gt;

    13 #include <Etel3rdParty.h>

    14 

    15 class CClientApp : public CActive

    16     { 

    17 

    18 private:

    19     CTelephony* iTelephony;

    20     CTelephony::TCallId iCallId;

    21 

    22 public:

    23     CClientApp(CTelephony* aTelephony);

    24     void SomeFunction();

    25 

    26 private:

    27     /*

    28        These are the pure virtual methods from CActive that  

    29        MUST be implemented by all active objects

    30        */

    31     void RunL();

    32     void DoCancel();

    33    };

    34 

    35 CClientApp::CClientApp(CTelephony* aTelephony)

    36     : CActive(EPriorityStandard),

    37       iTelephony(aTelephony)

    38     {

    39     //default constructor

    40     }

    41 

    42 void CClientApp::SomeFunction()

    43     {

    44     iTelephony->AnswerIncomingCall(iStatus, iCallId);

    45     SetActive();

    46     }

    47 

    48 void CClientApp::RunL()

    49     {

    50     if(iStatus==KErrNone)

    51        {} // The call has been answered successfully;

    52           // iCallId contains the call's ID, needed when controlling the call.

    53     }

    54 

    55 void CClientApp::DoCancel()

    56     {

    57     iTelephony->CancelAsync(CTelephony::EAnswerIncomingCallCancel);

    58     }

    59 </codeblock> </example> <postreq id="GUID-19AC29A6-3A34-57E8-A0BE-8242CF60BF86"><p>This describes how to answer a second call while another is in progress. </p> <ol id="GUID-6E342500-D7DA-5DD9-89A6-120B2C8FCC0F"><li id="GUID-66CB266C-96CF-58A3-AAEA-00949C356545"><p>Put the first call on hold. </p> <p>This is the same as holding a call in <xref href="GUID-1907CF0B-2F4B-50F6-B676-7B7059B7FF74.dita">Call Hold Tutorial</xref>. </p> <p>If the other call was not dialled or answered by you then you cannot control it, and so you cannot put it on hold. If it is not on hold already (<xref href="GUID-97D402C8-B4B7-385A-92B3-D3FCC0CA575A.dita"><apiname>CTelephony::EStatusHold</apiname></xref>) then you cannot answer the call. </p> </li> <li id="GUID-90CFC6A4-CA1B-593C-937F-B189630DCB0C"><p>Answer the second call. </p> <p>This is the same as answering the first call. <codeph>AnswerIncomingCall()</codeph> will return a different call ID from the first call. </p> </li> <li id="GUID-E278B859-89BE-5C90-94CE-21D66335CEBD"><p>If the operation fails, remember to resume the original call. </p> </li> </ol> <p>As a result, the first call is on-hold and the second call is active. </p> </postreq> </taskbody></task>