<?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 concept

  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

<concept id="GUID-E402616A-7ED8-45AC-B836-99C3A3760B33" xml:lang="en"><title>Key events</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<fig id="GUID-9A1FDF4B-5FD8-4113-8D8E-E879B4C7C255"><title>Key presses generate key events</title><image href="GUID-C9429505-EEE7-4E64-BE0A-BC5D57D5B42C_d0e42810_href.png"/></fig>

<p>Key events are generated when a device user presses one or more device

key buttons. The application framework delivers the event to the application

that has focus. The <parmname>TKeyEvent</parmname> structure is used to contain

the key event details delivered to the application. For more information on <parmname>TKeyEvent</parmname>,

see <xref href="GUID-0F8FA6A3-F172-36E4-9CF5-60814ABCD562.dita"><apiname>TKeyEvent</apiname></xref>. </p>

<p>The structure is as follows:</p>

<codeblock id="GUID-467AB9BB-948F-49B6-A243-206314E90242" xml:space="preserve">struct TKeyEvent

    {

    TUint iCode;

    TInt iScanCode;

    TUint iModifiers; // State of modifier keys

    TInt iRepeats; // Count of auto repeats generated

    };

</codeblock>

<p>The following events are generated by means of a single key press and

release:</p>

<codeblock id="GUID-5FE1F179-8F7A-4653-9604-3CFC4B66AE33" xml:space="preserve">EEventKeyDown

EEventKey

EEventKeyUp

</codeblock>

<p>The first event indicates that a key has been pressed down. The second

event indicates that a character has been received from the keyboard. The

third event is sent when the button has been released. These events are described

in the <parmname>iCode</parmname> and <parmname>iSCanCode</parmname> members

of <parmname>TKeyEvent</parmname>.</p>

<p>For more information on possible data contained in <parmname>EEventKey</parmname>,

see <xref href="GUID-B67B6ED5-6C8F-3B36-934C-B47A109A515F.dita"><apiname>TKeyCode</apiname></xref>.</p>

<p>Key presses may be interpreted by a Front End Processor (FEP) and tied

to specific key events. For example, if a device user presses the <parmname>2</parmname> key

twice, an active FEP could generate a key event code of <parmname>b</parmname>.</p>

<p> For more information on FEPs, see <xref href="GUID-FCEDC338-61CA-5D10-A8DB-E44A3EBBDE5E-GENID-1-8-1-3-1-1-9-1-3-1.dita">Front

End Processor overview</xref>.</p>

</conbody></concept>