<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
<!-- This component and the accompanying materials are made available under the terms of the License 
"Eclipse Public License v1.0" which accompanies this distribution, 
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
<!-- Initial Contributors:
    Nokia Corporation - initial contribution.
Contributors: 
-->
<!DOCTYPE task
  PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">
<task id="GUID-133999E8-0ACB-5929-949E-82BB16F8E267" xml:lang="en"><title>Writing
a UI MTM </title><abstract><p>This section explains the initial set up steps to be performed
to write a UI MTM. It does not explain the implementation of all <xref href="GUID-EB76BA4B-D6A2-5651-A310-647E1D2CDEBC.dita">UI
MTM functionality</xref>, however, you can see the <xref href="GUID-385BB488-5C32-58A7-8401-F3F0A0707DD9.dita">UI
MTM example</xref>for detailed implementation steps.</p></abstract><prolog><metadata><keywords/></metadata></prolog><taskbody>
<context><p>The most basic functionality required in a UI MTM is to open a
message (for viewing or editing) and close it again. The <xref href="GUID-A5982338-A057-3870-8832-F503AEAC470A.dita#GUID-A5982338-A057-3870-8832-F503AEAC470A/GUID-0DD6B979-0473-3AAD-AE14-F1B0AC1E73C5"><apiname>CBaseMtmUi::OpenL()</apiname></xref> function
opens the current context; the actual behaviour is dependent on the entry
that the context points at. </p> <p>The base class of UI MTM, <xref href="GUID-2AD22359-BB98-31D2-8138-4E5F17A4BFE7.dita"><apiname>CBaseUiMtm</apiname></xref>,
defines functions that return <xref href="GUID-AF724192-6580-3DE3-9287-3A005C0AA932.dita"><apiname>CMsvOperation</apiname></xref> objects for
control of asynchronous operations. Implementers of these functions are required
to provide suitable classes that are derived from <xref href="GUID-AF724192-6580-3DE3-9287-3A005C0AA932.dita"><apiname>CMsvOperation</apiname></xref>.
For example, if <xref href="GUID-2AD22359-BB98-31D2-8138-4E5F17A4BFE7.dita#GUID-2AD22359-BB98-31D2-8138-4E5F17A4BFE7/GUID-59FD3DB0-9F10-3052-B4F6-F9CF59854B8B"><apiname>CBaseUiMtm::EditL()</apiname></xref> is implemented to provide
message editing, a derived <xref href="GUID-AF724192-6580-3DE3-9287-3A005C0AA932.dita"><apiname>CMsvOperation</apiname></xref> class must be
provided that completes when the editing operation is complete. </p> </context>
<steps id="GUID-DD170CFC-0DD8-5B20-856C-E9269FD98F29">
<step id="GUID-23F7AF46-A909-5802-8168-8416EF531AF1"><cmd/>
<info>Derive a class from the <xref href="GUID-A5982338-A057-3870-8832-F503AEAC470A.dita"><apiname>CBaseMtmUi</apiname></xref> class. </info>
</step>
<step id="GUID-A37BCDA1-14CB-5FF2-931D-F32A8B92478B"><cmd/>
<info>Register it using the <xref href="GUID-0D5D7FAC-4F14-3046-92FB-873B8350FF4C.dita"><apiname>CRegisteredMtmDll</apiname></xref> parameter. </info>
</step>
<step id="GUID-694A8171-AD7B-5671-86AA-87CC470213CE"><cmd/>
<info>Create the <xref href="GUID-AF724192-6580-3DE3-9287-3A005C0AA932.dita"><apiname>CMsvOperation</apiname></xref> -based classes for performing
the different operations that are required for your Messaging protocol. </info>
</step>
</steps>
<example><title>UI MTM example</title><codeblock xml:space="preserve">//
// CTextMtmUi: User Interface MTM
//

CTextMtmUi* CTextMtmUi::NewL(CBaseMtm&amp; aBaseMtm, CRegisteredMtmDll&amp; aRegisteredMtmDll)
    {
    CTextMtmUi* self=new(ELeave) CTextMtmUi(aBaseMtm, aRegisteredMtmDll);
    CleanupStack::PushL(self);
    self-&gt;ConstructL();
    CleanupStack::Pop();
    return self;
    }

CTextMtmUi::CTextMtmUi(CBaseMtm&amp; aBaseMtm, CRegisteredMtmDll&amp; aRegisteredMtmDll)
    :   CBaseMtmUi(aBaseMtm, aRegisteredMtmDll)
    {
 
   }</codeblock> <p>For more details on implementing all the
UI MTM functions, see <xref href="GUID-385BB488-5C32-58A7-8401-F3F0A0707DD9.dita">example
code</xref>. </p> </example>
</taskbody><related-links>
<link href="GUID-59217FA7-3078-53CA-88B3-78D6FB788271.dita"><linktext>MTM overview</linktext>
</link>
<link href="GUID-EB76BA4B-D6A2-5651-A310-647E1D2CDEBC.dita"><linktext>User Interface
MTM</linktext></link>
</related-links></task>