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<concept id="GUID-868C1A38-3CD0-4082-8106-DC3EE1F815D8" xml:lang="en"><title>System

events</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>System events are enumerated in <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Application_Architecture/APGTASK.HGlobals.html#%3a%3aTApaSystemEvent" format="application/java-archive"><parmname>TApaSystemEvent</parmname></xref>, which is defined in the <parmname>apgtask.h</parmname> header.

You must override <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeAppUiClass.html#%3a%3aCCoeAppUi%3a%3aHandleSystemEventL%28const%20TWsEvent%20%26amp%3b%29" format="application/java-archive"><parmname>CCoeAppUI::HandleSystemEventL()</parmname></xref> to handle

these events, which should be done in the UI controller. The default implementation

is empty. The possible events are as follows:</p>

<codeblock id="GUID-F0606F71-729A-4D6B-AAC6-876A526DDFAC" xml:space="preserve">enum TApaSystemEvent

    {

    EApaSystemEventShutdown = 1,

    EApaSystemEventBackupStarting,

    EApaSystemEventBackupComplete,

    EApaSystemEventBroughtToForeground

    };

</codeblock>

<p>The following is a code example of system event handling:</p>

<codeblock id="GUID-86877508-AD28-4576-B9D5-55565B0F4A4A" xml:space="preserve">void CExampleAppUI::HandleSystemEvent( const TWsEvent&amp; aEvent )

    {

    switch( *( TApaSystemEvent* )( aEvent.EventData() ) )

        {

        case EApaSystemEventBackupStarting:

            {

            // Handle backup starting

            //...

            break;

            }

        case EApaSystemEventBackupComplete:

            {

            // Handle backup complete

            //...

            break;

            }

        case EApaSystemEventShutdown:

            {

            // Handle shutdown

            //...

            break;

            }

        }

        // Call the base class implementation

        CAknAppUi::HandleSystemEvent( aEvent );

    }

</codeblock>

</conbody></concept>