TB9.2 Example Applications: examples/Base/IPC/pubsub/subscribespec.cpp Source File

00001 // Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
+00002 // All rights reserved.
+00003 // This component and the accompanying materials are made available
+00004 // under the terms of "Eclipse Public License v1.0"
+00005 // which accompanies this distribution, and is available
+00006 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
+00007 //
+00008 // Initial Contributors:
+00009 // Nokia Corporation - initial contribution.
+00010 //
+00011 // Contributors:
+00012 //
+00013 // Description:
+00014 // Demonstrates the speculative pattern of subscribing to a byte-array property
+00015 //
+00016 
+00017 
+00018 
+00023 #include "subscribe.h"
+00024 LOCAL_D CConsoleBase* console;
+00025 
+00029 CArrayPropertyWatch::CArrayPropertyWatch():CActive(EPriority)
+00030         {
+00031         }
+00032 
+00037 void CArrayPropertyWatch::ConstructL(CConsoleBase* aConsole)
+00038         {
+00039         User::LeaveIfError(iProperty.Attach(KMyPropertyCat,KMyPropertyName));
+00040         iConsole = aConsole;
+00041         CActiveScheduler::Add(this);
+00042         }
+00043 
+00049 CArrayPropertyWatch* CArrayPropertyWatch::NewL(CConsoleBase* aConsole)
+00050         {
+00051         CArrayPropertyWatch* self = new (ELeave) CArrayPropertyWatch;
+00052         CleanupStack::PushL(self);
+00053         self->ConstructL(aConsole);
+00054         CleanupStack::Pop(self);
+00055         return self;
+00056         }
+00057 
+00061 CArrayPropertyWatch::~CArrayPropertyWatch()
+00062         {
+00063         iProperty.Close();
+00064         // Delete the property as it is no longer required by the subscriber
+00065         RProperty::Delete(KMyPropertyCat, KMyPropertyName);
+00066         Cancel();
+00067         }
+00068 
+00072 void CArrayPropertyWatch::DoCancel()
+00073         {
+00074         iProperty.Cancel();
+00075         }
+00076 
+00081 void CArrayPropertyWatch::RunL()
+00082         {
+00083         // Get the value of the property
+00084         TBuf16<KArraySize> buf;
+00085         TInt err = iProperty.Get(buf);
+00086         if(err == KErrNotFound)
+00087                 {
+00088                 // Leave the function if the property is not defined
+00089                 CActiveScheduler::Stop();
+00090                 User::Leave(err);
+00091                 }
+00092         else
+00093                 {
+00094                 // Print the value of the property
+00095                 PrintProperty(buf);
+00096                 if(buf == KStop)
+00097                         {
+00098                         CActiveScheduler::Stop();
+00099                         }
+00100                 else
+00101                         {
+00102                         // Re-subscribe to the property
+00103                         iProperty.Subscribe(iStatus);
+00104                         SetActive();
+00105                         }
+00106                 }
+00107         }
+00108 
+00113 void CArrayPropertyWatch::PrintProperty(TDes16& aBuf)
+00114         {
+00115         iConsole->Printf(KTxtArray);
+00116         TInt bufLength = aBuf.Length();
+00117         for(TInt ix = 0; ix < bufLength;ix++)
+00118                 {
+00119                 iConsole->Printf(KTxtArrayElement,aBuf[ix]);
+00120                 }
+00121         iConsole->Printf(KTxtNewLine);
+00122         }
+00123 
+00127 void CArrayPropertyWatch::DefinePropertyL()
+00128         {
+00129         iConsole->Printf(KTxtDefine);
+00130         // Define the property
+00131         TInt err = RProperty::Define(KMyPropertyCat, KMyPropertyName,RProperty::EByteArray,KAllowAllPolicy,KAllowAllPolicy,KArraySize);
+00132         if(err == KErrAlreadyExists || err == KErrNone)
+00133                 {
+00134                 // Ignore the KErrAlreadyExists error code
+00135                 TBuf16<KArraySize> buf;
+00136                 // Returns the default value of the property
+00137                 // Ignore this value
+00138                 err = iProperty.Get(buf);
+00139                 User::LeaveIfError(err);
+00140                 // Subscribe to the property and maintain an outstanding request
+00141                 iProperty.Subscribe(iStatus);
+00142                 SetActive();
+00143                 }
+00144         else
+00145                 {
+00146                 // Leave in case of errors other than KErrAlreadyExists
+00147                 User::Leave(err);
+00148                 }
+00149         }
+00150 
+00151 void DoExampleL()
+00152         {
+00153         CActiveScheduler* scheduler = new (ELeave) CActiveScheduler();
+00154         CleanupStack::PushL(scheduler);
+00155         CActiveScheduler::Install(scheduler);
+00156 
+00157         console->Printf(KTxtSpecSub);
+00158 
+00159         // Create the byte-array property watch active object
+00160         CArrayPropertyWatch* obj = CArrayPropertyWatch::NewL(console);
+00161         CleanupStack::PushL(obj);
+00162 
+00163         // Subscribe to the property and start the scheduler
+00164         obj->DefinePropertyL();
+00165         CActiveScheduler::Start();
+00166 
+00167         CleanupStack::PopAndDestroy(obj);
+00168         CleanupStack::PopAndDestroy(scheduler);
+00169         }
+00170 
+00171 GLDEF_C TInt E32Main()
+00172         {
+00173         __UHEAP_MARK;
+00174         CTrapCleanup* cleanup = CTrapCleanup::New();
+00175 
+00176         TRAPD(createError, console = Console::NewL(KTextConsoleTitle, TSize(KConsFullScreen,KConsFullScreen)));
+00177         if (createError)
+00178                 return createError;
+00179 
+00180         TRAPD(mainError, DoExampleL());
+00181         if (mainError)
+00182                 console->Printf(KTextFailed, mainError);
+00183         console->Printf(KTextPressAnyKey);
+00184         console->Getch();
+00185 
+00186         delete console;
+00187         delete cleanup;
+00188         __UHEAP_MARKEND;
+00189         return KErrNone;
+00190         }
+