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

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

<p>Both touch screens and hybrid devices are supported by Symbian platform.

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_d0e102557_href.png" scale="60" placement="inline"/>

</fig>

<p>All applications must be touch-enabled, which means that 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 Multi-tasking key.</p>

<p>The application features must follow the platform support for different

hardware. 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. Capacitive

touch screen supports <xref href="GUID-17C64C2F-9426-4B41-9F0A-23060289D644.dita">multi-touch</xref>.</p>

<p>The hardware is supported by various:</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>While designing and implementing applications for touch screen devices

based on the Symbian platform, consider interactions that 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 scrollbars 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><b>See Also</b>:</p>

</conbody></concept>