Symbian3/SDK/Source/GUID-5486EFD3-4660-4C19-A007-286DE48F6EEF.dita
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+<?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-5486EFD3-4660-4C19-A007-286DE48F6EEF" xml:lang="en"><title>Scale
+and positioning of controls</title><prolog><metadata><keywords/></metadata></prolog><conbody>
+<section id="GUID-EF8CA4BE-130F-4117-9722-3F652DD1D244"> <p>Interface elements
+a user has to select and manipulate should not be smaller than the smallest
+average finger pad, that is, no smaller than 1 cm (0.4") in diameter or a
+1 cm × 1 cm square.</p> <p>In the Symbian OS, UI style defines
+the target minimum sizes for a UI element considered as finger usable:</p><ul>
+<li><p>7 x 7 mm with 1 mm gaps for index finger usage</p></li>
+<li><p>8 x 8 mm with 2 mm gaps for thumb usage</p></li>
+<li><p>List type of components should have minimum of 5 mm line spacing</p></li>
+</ul><p>The width of a finger limits the density of items on screen. If the
+items are too close, the user will not be able to choose a single one.</p><p>As
+the user is more likely to touch higher on the button by mistake than either
+side, button and icon sizes can be increased vertically.</p><p>Essential information
+or features, such as a label, instructions, or sub-controls should never be
+placed below an interface element that can be touched, as it may be hidden
+by the user's own body.</p><fig id="GUID-FF8225A9-0D9F-4E8F-8B19-32FAECEFE47C">
+<image href="GUID-FD85921E-AC9F-481F-8A58-0D03D56661C0_d0e47154_href.png" scale="60" placement="inline"/>
+</fig><ul>
+<li><p>With interfaces with traditional input devices, it makes sense to place
+targets like menu items on the edges of screens: the user cannot overshoot
+the target, as the cursor stops at the edge of the screen. </p></li>
+<li><p>When using a touch screen, a user seldom drags his finger across the
+screen as he would with a cursor. Instead, they most likely lift their finger
+and place it on a new target. Users may have difficulties in reaching the
+objects located on the edges of the screen, especially if the physical device
+has protruding edges around the touch screen panel. Additionally, with some
+devices, the screen edges may be less sensitive to register the touch input.</p></li>
+</ul> </section>
+</conbody></concept>
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