--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/SDK/Source/GUID-EDAF2886-5296-53BD-B847-0E0D9B5FBF7E.dita	Wed Mar 31 11:11:55 2010 +0100
@@ -0,0 +1,55 @@
+<?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-EDAF2886-5296-53BD-B847-0E0D9B5FBF7E" xml:lang="en"><title>Special
+requirements</title><prolog><metadata><keywords/></metadata></prolog><conbody>
+<section id="GUID-FAEE5A94-6E06-4991-AA1C-ED8AAAF2CBA7"><title>Performance</title> <p>Since text objects are potentially
+both large and complex, editing them can involve complex operations. It is
+important on the one hand that text views have high performance, and on the
+other that they require little memory, and have a usable API.</p> <p>Memory
+use is minimised by the format band and by using only minimal format information
+for purposes which require it — such as pagination, and print preview.</p> <p>One
+key measure of perceived performance is responsiveness to user input. The
+Text Views API support this by using background-priority active objects to
+maintain the formatting of text in two contexts. Firstly, the formatting of
+the format band is handled, where possible, using an active object which is
+invisible to the user of the API. Secondly, pagination is handled, where required,
+using an active object which is visibly part of the API.</p> </section>
+<section id="GUID-5DEC7434-0626-468F-93DE-DCCCA760F8ED"><title>High-level GUI support</title> <p>For many purposes, such
+as editing short text objects, a GUI-provided high-level editor provides a
+convenient interface. </p> </section>
+<section id="GUID-9855C622-5788-4873-A54B-306443CBBC1F"><title>Text content interfaces</title> <p>The <xref href="GUID-51B3C34F-2F8E-3181-93C4-00F073B1207C.dita"><apiname>MLayDoc</apiname></xref> interface
+is used to convey layout information from a text object to the text layout
+and views. Within the Symbian platform text content model, global
+text and rich text implement this interface. Using such a narrow interface
+between content and views allows each to be optimized separately and is good
+object-oriented design.</p> <p>A further benefit is that any content model
+may be equipped with an <codeph>MLayDoc</codeph> interface. For instance,
+an HTML browser would require formatting that could be specified through the <codeph>MLayDoc</codeph> interface,
+but for various reasons it may wish to use a substantially different content
+model. One important reason is that HTML is essentially read-only. Other applications,
+especially for data browsing, may also benefit from the flexibility of the <codeph>MLayDoc</codeph> interface.</p> </section>
+<section id="GUID-98AA8A05-676D-44E6-AB34-C9C9AF4D5F0B"><title>Detailed view control</title> <p>The first requirement of
+text views is that they honor all the specifications of a text object and
+its formatting information. However, in addition to this, text views provides
+many flexible features for controlling the display of text.</p> <ul>
+<li id="GUID-21B3BAB1-3C84-5E62-8766-9860C00A0E1D"><p>the visibility of non-printing
+characters (paragraph marks, blanks, non-breaking blanks) can be controlled</p> </li>
+<li id="GUID-EC249206-5F64-599C-9271-6C31EE04194F"><p>background colour can
+be specified, and text colour overridden from that in the document, in accordance
+with user preferences (e.g., in order to display yellow text on a dark blue
+screen instead of the default black on white)</p> </li>
+<li id="GUID-C8B6EFC2-4808-584A-82B4-1A386175CEB6"><p>text can have highlighting
+applied to it, these highlights may have round corners</p> </li>
+<li id="GUID-60812D34-065A-5418-9456-3CCB340ED18B"><p>pictures may have frames,
+with or without grab handles, when selected</p> </li>
+</ul> </section>
+</conbody></concept>
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