<?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-1FCD0312-7B28-47F9-BE54-822B74A8934C" xml:lang="en"><title>Designing

applications for touch UI</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-98B5BA8E-A71D-44C3-B7F3-91FBF9599E0B"> <p>In S60 5th edition,

the software platform supports traditional keypads, and touch screen UI. Touch

screen enables direct manipulation of content and objects, allowing for far

more natural interaction with the device. This means a completely different

user experience and interaction style compared to using a hardware keypad.</p><fig id="GUID-0895B1BD-27D2-4824-A02C-F89137A16E53">

<image href="GUID-59F26729-3FFB-48AE-91FB-4B9AC2955A06_d0e46754_href.png" scale="60" placement="inline"/>

</fig><p>All S60 5th edition applications should be touch-enabled, meaning

they can be used with the touch screen alone, regardless of the presence of

a keypad. There are only three mandatory hardware keys in touch devices based

on the Symbian platform: Send, End, and Multitasking key.</p><p>However, the

touch UI is by no means the definitive feature of the whole platform. Any

knowledge gained from previous Symbian development is still relevant. The

core of the Symbian platform still remains its scalability, wide range of

options, the wealth of multimedia features, and language support. </p><p><b>The

application features must follow the platform support for different hardware.</b> When

designing a touch-enabled Symbian application, the UI must be designed so

that everything can be accomplished by using the touch screen interface, as

the potential target devices may or may not have a hardware keyboard.  </p> <p>The

touch UI in the Symbian platform is based on the use of resistive and capacitive

touch screens. In <b>resistive touch screen</b> technology, two conductive

and resistive layers are separated by a thin space. When an object touches

this kind of touch panel, the layers are connected at a certain point, and

a touch event is registered. This allows efficient stylus control, in addition

to finger touch - unlike capacitive panels, which usually register only finger

touch. Additionally, resistive touch screen offers a higher resolution and

more durability. In <b>capacitive touch screen</b> technology, the panel consists

of an insulator such as glass, coated with a transparent conductor (such as

indium tin oxide (ITO)). When an object touches the surface of the screen,

it results in a distortion of the local electrostatic field, measurable as

a change in capacitance. Then a touch controller measures the frequency variations

to ascertain the co-ordinates of the object's touch.</p><p>The

hardware is supported by a number of </p><ul>

<li><p>touch-specific components (see <xref href="GUID-BB8B3A11-0BBC-4759-A7F4-A28C9E70573F.dita">Touch

support for common UI components</xref>)</p></li>

<li><p>component and UI behavior changes</p></li>

<li><p>layout changes, and</p></li>

<li><p>additions to the interaction style.</p></li>

</ul><p>The touch UI is designed to enable full task flow with touch, with

minimal need to switch to hardware keys. Thus, the design ensures that users

can complete a task with the chosen interaction method from start to finish. </p><p>When

designing and implementing applications for touch screen devices based on

the Symbian platform, consider which interactions benefit the most from the

touch UI.  </p> <p>If you can apply direct manipulation of the UI, for example

when moving items from one place to another, or scrolling a page, do not confine

the user with unnecessary scroll bars or have the user resort to options list

commands.</p> <p>Instead, enable the user to view pages larger than a screen

by panning them directly, and dragging and dropping items rather than marking

them and using menu options. </p><ul>

<li><p>Remember that the most intuitive touch screen interactions that can

be performed using a finger are tapping, stroking up/down/left/right, and

the long tap. </p></li>

<li><p>Utilize strokes that are easily discovered to the users in the given

context. It should be explicit to the user where strokes can be performed. </p></li>

<li><p>Design to ensure that users can complete a task with the same interaction

method from start to finish: touch or hardware keys, stylus, or finger, and

using one hand or both hands.</p></li>

<li><p>Aim to optimize system performance and battery consumption to provide

a fluid and reliable touch user experience. </p></li>

</ul><p>In this section:</p><ul>

<li><p><xref href="GUID-41A36790-CB11-4620-A2D5-1981077E5753.dita">Touch strategies</xref></p></li>

<li><p><xref href="GUID-F4F3A37A-AB0C-47B8-A538-C05F1CA73BF3.dita">Touch-enabled

vs. touch-optimized</xref></p></li>

</ul></section>

</conbody></concept>