Symbian3/SDK/Source/GUID-7250950C-5502-5ACE-864B-0EFD5C253053-GENID-1-8-1-6-1-1-4-1-6-1-10-1.dita
changeset 8 ae94777fff8f
parent 7 51a74ef9ed63
child 9 59758314f811
--- a/Symbian3/SDK/Source/GUID-7250950C-5502-5ACE-864B-0EFD5C253053-GENID-1-8-1-6-1-1-4-1-6-1-10-1.dita	Wed Mar 31 11:11:55 2010 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,76 +0,0 @@
-<?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-7250950C-5502-5ACE-864B-0EFD5C253053-GENID-1-8-1-6-1-1-4-1-6-1-10-1" xml:lang="en"><title>How
-to create a singleton</title><prolog><metadata><keywords/></metadata></prolog><conbody>
-<p>The <xref href="GUID-F0C084E2-C683-39E2-A131-77FE3206A02C.dita"><apiname>CCoeStatic</apiname></xref> class allows singleton classes to be
-created and stored by the environment (<xref href="GUID-12A9389D-363B-3F54-857F-89EE0EDCDF40.dita"><apiname>CCoeEnv</apiname></xref>) in Thread
-Local Storage (TLS). This provides a means of creating writeable global static
-data. </p>
-<p> <filepath>MySingleton.h</filepath>  </p>
-<codeblock id="GUID-B526F5B3-FBC7-5563-8F5C-37B01A0EC28D-GENID-1-8-1-6-1-1-4-1-6-1-10-1-2-3" xml:space="preserve">
-class CMySingleton : public CCoeStatic
-    {
-public:
-    static CMySingleton* SelfL() ;                // Slightly slower
-    static CMySingleton* SelfL( CCoeEnv* aCoeEnv ) ;    // Slightly faster
-    ...
-private:
-    CMySingleton() ;
-    ~CMySingleton() ;
-    } ;
-</codeblock>
-<p> <filepath>MySingleton.cpp</filepath>  </p>
-<codeblock id="GUID-FD7053EB-8769-5C04-98E2-3C8EC8589A10-GENID-1-8-1-6-1-1-4-1-6-1-10-1-2-5" xml:space="preserve">
-const TUid KUidMySingleton = {0x10204232} ;
-
-CMySingleton::CMySingleton() : CCoeStatic( KUidMySingleton, CCoeStatic::EThread /*or EApp*/ )
-    {
-    }
-
-CMySingleton* CMySingleton::SelfL()
-    {
-    CMySingleton* self = static_cast&lt;CMySingleton*&gt;( CCoeStatic::Static( KUidMySingleton ) ) ; 
-    if(!self)
-        {
-        self = new( ELeave ) CMySingleton() ;
-        }
-    return self ;
-    }
-
-CMySingleton* CMySingleton::SelfL( CCoeEnv* aCoeEnv )
-    {
-    CMySingleton* self = static_cast&lt;CMySingleton*&gt;( aCoeEnv-&gt;FindStatic( KUidMySingleton ) ) ;
-    if( !self )
-        {
-        self = new( ELeave ) CMySingleton() ;
-        }
-    return self ;
-    }
-</codeblock>
-<p>A singleton must be given a UID. When it is instantiated for the first
-time the base class constructor adds it to the list of singletons in the environment.
-Any subsequent attempts to instantiate the same singleton will result in a
-panic. </p>
-<p>Singletons may be given a <b>destruction priority</b> and a <b>scope</b>. </p>
-<p>The <b>destruction priority</b> determines when the singleton is destroyed
-relative to any other singletons in the environment's list and relative to
-the App Ui. The default priority, <codeph>EDefaultDestructionPriority</codeph>,
-is 100. The higher the priority, the earlier the singleton will be destroyed.
-A negative value indicates that the singleton should be destroyed after the
-AppUi. The more negative the value, the later the destruction. </p>
-<p>The <b>scope</b> may be <codeph>EThread</codeph> (the default) or <codeph>EApp</codeph> and
-determines the visibility of the singleton. </p>
-<p>Once a singleton has been created it may be accessed through the <xref href="GUID-12A9389D-363B-3F54-857F-89EE0EDCDF40.dita"><apiname>CCoeEnv</apiname></xref> API. </p>
-<codeblock id="GUID-7B6E1AE6-30E6-585C-84AC-5C385F0894D3-GENID-1-8-1-6-1-1-4-1-6-1-10-1-2-11" xml:space="preserve">// Singleton access
-IMPORT_C static CCoeStatic* Static( TUid aUid ) ;
-IMPORT_C CCoeStatic* FindStatic( TUid aUid ) ;</codeblock>
-</conbody></concept>
\ No newline at end of file