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  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_d0e71729_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>