menucontentsrv/inc/menubuf.h
changeset 0 79c6a41cd166
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/menucontentsrv/inc/menubuf.h	Thu Dec 17 08:54:17 2009 +0200
@@ -0,0 +1,120 @@
+/*
+* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "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:
+*
+* Description:  Definition of client side stream buffer
+*
+*/
+
+
+#ifndef __MENUBUF_H__
+#define __MENUBUF_H__
+
+#include "menusrvdef.h"
+#include <e32base.h>
+#include <s32buf.h>
+
+class RMenu;
+
+/**
+ *  Client side stream buffer. Not seekable.
+ *  @lib mcsmenu.lib
+ *  @since S60 v5.0
+ */
+NONSHARABLE_CLASS( RMenuBuf ): public RSubSessionBase, public TStreamBuf
+    {
+
+public:
+
+    /**
+    * Close the object.
+    */
+    void Close();
+
+    /**
+    * Open the object (initially empty).
+    * @param aMenu Session to be used.
+    * @return Error code.
+    */
+    TInt Open( RMenu& aMenu );
+
+    /**
+    * Open this object using other object.
+    * @param aHandle Handle used to open this object.
+    * @param aFunction Function.
+    * @param aArgs Arguments. Use arg 0 and 1 only;
+    * arg 2 and 3 are used internally.
+    * @return Error code.
+    */
+    TInt Open( RMenu& aMenu, TInt aFunction, TIpcArgs& aArgs );
+
+private:
+
+    /**
+    * Read data from server.
+    * @param aLength The number of bytes read.
+    */
+    void IpcReadL( TInt& aLength );
+
+    /**
+    * Write data to server.
+    */
+    void IpcWriteL();
+
+    /**
+    * Get read lag (number of bytes transferred from server side but not
+    * yet read).
+    * @return Read lag.
+    */
+    inline TInt Lag( TRead aArea ) const;
+
+    /**
+    * Get write lag (number of bytes written but not yet transferred to
+    * server side).
+    * @return Write lag.
+    */
+    inline TInt Lag( TWrite aArea ) const;
+
+// from base class TStreamBuf
+
+    /**
+    * Re-fill the intermediate buffer and reset the start and end points
+    * of the read area.
+    * @param aMaxLength The maximum amount of data required.
+    * @return The amount of data available.
+    */
+    TInt UnderflowL( TInt aMaxLength );
+
+    /**
+    * Empty the intermediate buffer and resets the start and end points
+    * of the write area.
+    */
+    void OverflowL();
+
+    /**
+    * Synchronise the stream buffer with the stream. In effect, this
+    * ensures that buffered data is delivered to the stream.
+    * Write lag flushed.
+    * Read lag leaves with KErrNotSupported.
+    */
+    void DoSynchL();
+
+private:    // Data
+
+    TMenuBuf iBuf; ///< Data buffer.
+
+    };
+
+#include "menubuf.inl"
+
+#endif // __MENUBUF_H__
+