--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/SDK/Source/GUID-0174CE72-AEF6-5DA9-A9C5-074781BD544F.dita	Thu Jan 21 18:18:20 2010 +0000
@@ -0,0 +1,57 @@
+<?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-0174CE72-AEF6-5DA9-A9C5-074781BD544F" xml:lang="en"><title>Window
+Server Sessions</title><shortdesc>Each application uses a Window Server session to communicate with
+the Window Server. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
+<p>Through the session, the application may control and interrogate </p>
+<ul>
+<li id="GUID-81DEE250-87BC-5C47-91E5-B8E480884111"><p>its own windows </p> </li>
+<li id="GUID-7F8F429D-AD79-5634-A815-CE7DB12F2866"><p>which events it wishes
+to receive </p> </li>
+<li id="GUID-E86BCF17-F124-5CE5-B07B-704BBD020F97"><p>all other window groups
+connected to the Window Server </p> </li>
+</ul>
+<p>The Window Server session provides a low-level interface for application
+programs’ use, using asynchronous services. To support an application framework,
+these services should be made higher-level, and the asynchronous services
+should be encapsulated into active objects. This function is performed by
+the UI control framework. The control framework is the basis for the GUI.
+Each event is then handled by the <xref href="GUID-067293BF-B28C-3CEC-92F4-1351A795EA7F.dita"><apiname>CActive::RunL()</apiname></xref> member
+function of an active object. </p>
+<p>The <xref href="GUID-067293BF-B28C-3CEC-92F4-1351A795EA7F.dita"><apiname>RWsSession</apiname></xref> class represents a <keyword>session</keyword> from
+the client to the Window Server. Through an <codeph>RWsSession</codeph>, the
+client program controls all its own windows, issues asynchronous requests
+for up to three types of event, and may in addition control certain system-wide
+Window Server behavior. </p>
+<p>The <codeph>RWsSession</codeph> is a client-server session derived from <codeph>RSessionBase</codeph>.
+In a typical application, an <codeph>RWsSession</codeph> owns a single <keyword>window
+group</keyword>, but the Window Server architecture allows more than one window
+group per session. An application owns several windows. See <xref href="GUID-D68E0A64-0E8A-5C52-9C5B-93BA3B80C200.dita">Window
+Groups and Applications</xref>. </p>
+<p>The Window Server session delivers events to the application via three
+event streams. A typical application handles each stream using an active object.
+See <xref href="GUID-08427065-B8E5-5194-B095-3B5213836BED.dita">Window Server Client-Side
+Events</xref>. </p>
+<p>The application draws to its windows using a <xref href="GUID-067293BF-B28C-3CEC-92F4-1351A795EA7F.dita"><apiname>CWindowGc</apiname></xref>.
+Draw functions are buffered in a client-side buffer in order to minimize client/server
+context switches. This buffer is flushed in certain circumstances by the Window
+Server and can also be flushed explicitly by the application. The <codeph>Flush()</codeph> and <codeph>SetAutoFlush()</codeph> functions
+are part of the <codeph>RWsSession</codeph> API. The <codeph>RWsBuffer</codeph> is
+privately owned by an <codeph>RWsSession</codeph> and is not as such part
+of the API. See <xref href="GUID-E5CDDA05-CD86-5C44-B9DA-3249D9C14396.dita">Client-Side
+Buffer</xref>  </p>
+</conbody><related-links>
+<link href="GUID-890F06C6-DE32-5EB1-BF0F-D41794F47AE1.dita"><linktext>Active objects</linktext>
+</link>
+<link href="GUID-1F9A47CE-7F4C-52BD-8823-25D5D1BEF42F.dita"><linktext>Window Server
+Client-Side Library                 Concepts</linktext></link>
+</related-links></concept>
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