diff -r 000000000000 -r 1e05558e2206 usbengines/usbotgwatcher/inc/cusbbusactivityobserver.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/usbengines/usbotgwatcher/inc/cusbbusactivityobserver.h	Thu Dec 17 09:14:30 2009 +0200
@@ -0,0 +1,140 @@
+/*
+* Copyright (c) 2008-2009 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:  Monitors USB activity
+ *
+*/
+
+
+#ifndef C_USBBUSACTIVITYOBSERVER_H
+#define C_USBBUSACTIVITYOBSERVER_H
+
+#include <e32base.h>
+#include <e32property.h>
+
+/**
+ *  This interface has to be implemented by observer
+ *  to receive notifications from USB bus activity property
+ */
+NONSHARABLE_CLASS(MUsbBusActivityObserver)
+    {
+public:
+
+    /**
+     * Called when bus turn to idle
+     */
+    virtual void BusIdleL() = 0;
+
+    /**
+     * Called when when bus is in Idle, and some activity appears on the bus
+     */
+    virtual void BusActiveL() = 0;
+    
+    /**
+      * Called when when error happened
+      * @param aError errorcode
+      */
+     virtual void BusActivityErrorL(TInt aError) = 0;   
+    
+    };
+
+/**
+ *  Class observes USB OTG State property
+ *
+ */
+NONSHARABLE_CLASS(CUsbBusActivityObserver) : public CActive
+    {
+
+public:
+
+    enum TBusActivity
+        {
+        EBusIdle = 0, EBusActive = 1
+        };
+
+    /**
+     * Two-phased constructor.
+     */
+    static CUsbBusActivityObserver* NewL();
+
+    /**
+     * Destructor.
+     */
+    virtual ~CUsbBusActivityObserver();
+
+    /**
+     * Returns bus activity state
+     * @return bus activity
+     */
+    TBusActivity BusActivity();
+
+    /**
+     * Adds subscriber for the notification
+     * @param aObserver Observer
+     */
+    void SubscribeL(MUsbBusActivityObserver* aObserver);
+
+    /**
+     * Removes observer
+     * @param aObserver Observer
+     */
+    void UnsubscribeL(MUsbBusActivityObserver* aObserver);
+
+private:
+
+    // From CActive
+    /**
+     * Called when request on bus activity completed
+     */
+    void RunL();
+
+    /**
+     * Called by framwork, when canceling outstanding request
+     */
+    void DoCancel();
+
+    /**
+     * Called when RunL leaves
+     * @param aError error code
+     */
+    TInt RunError(TInt aError);
+
+private:
+
+    /**
+     * Default constructor
+     */
+    CUsbBusActivityObserver();
+
+    /**
+     * 2nd phase construction
+     */
+    void ConstructL();
+
+private:
+    // data
+
+    /**
+     * The observer reports state changes to own observers
+     * Owns
+     */
+    RPointerArray<MUsbBusActivityObserver> iObservers;
+
+    /**
+     * The observer observes property change
+     */
+    RProperty iBusActivity;
+
+    };
+
+#endif //  C_USBOTGSTATEOBSERVER_H