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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_d0e99597_href.png" scale="60" placement="inline">

</image>

</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. In Symbian platform-based touch devices, the important hardware

keys are Send, End, Multi-tasking and Power 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">multiple 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>