1 /*

     2  * Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

     3  * All rights reserved.

     4  * This component and the accompanying materials are made available

     5  * under the terms of "Eclipse Public License v1.0"

     6  * which accompanies this distribution, and is available

     7  * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8  *

     9  * Initial Contributors:

    10  * Nokia Corporation - initial contribution.

    11  *

    12  * Contributors:

    13  *

    14  * Description:  Implements VBus observer

    15  *

    16  */

    17 

    18 #ifndef C_USBVBUSOBSERVER_H

    19 #define C_USBVBUSOBSERVER_H

    20 

    21 #include <e32base.h>

    22 #include <e32property.h>

    23 

    24 /**

    25  * Observers of this class have to implement this interface

    26  * to get call back on VBus events

    27  */

    28 NONSHARABLE_CLASS( MUsbVBusObserver)

    29     {

    30 public:

    31 

    32     /**

    33      * VBus down event received

    34      */

    35     virtual void VBusDownL() = 0;

    36     /**

    37      * VBus up event received

    38      */

    39     virtual void VBusUpL() = 0;

    40     /**

    41      * error handler

    42      * @param aError error code

    43      */

    44     virtual void VBusObserverErrorL(TInt aError)=0;

    45 

    46     };

    47 

    48 /**

    49  *  Class observes VBUS property

    50  *

    51  */

    52 NONSHARABLE_CLASS( CUsbVBusObserver ) : public CActive

    53     {

    54 

    55 public:

    56     enum TState

    57         {

    58         EVBusDown = 0, EVBusUp = 1

    59 

    60         };

    61 

    62     /**

    63      * Two-phased constructor.

    64      */

    65     static CUsbVBusObserver* NewL();

    66 

    67     /**

    68      * Destructor.

    69      */

    70     virtual ~CUsbVBusObserver();

    71 

    72     /**

    73      * VBus state getter

    74      * @return VBus state

    75      */

    76     TState VBus() /* not const. read comment in impl*/;

    77 

    78     /**

    79      * Adds observer to a list

    80      * @param aObserver observer

    81      */

    82     void SubscribeL(MUsbVBusObserver& aObserver);

    83 

    84     /**

    85      * removes observer from list

    86      * @param aObserver observer

    87      */

    88     void UnsubscribeL(MUsbVBusObserver& aObserver);

    89 

    90 private:

    91 

    92     // From CActive

    93     /**

    94      * Called when request completed

    95      *

    96      */

    97     void RunL();

    98 

    99     /**

   100      * Called when request is cancelled

   101      *

   102      */

   103     void DoCancel();

   104 

   105     /**

   106      * Called when RunL leaves

   107      * @param aError error code

   108      * @return error code

   109      *

   110      */

   111     TInt RunError(TInt aError);

   112 

   113 private:

   114 

   115     /**

   116      * Default constructor

   117      */

   118     CUsbVBusObserver();

   119 

   120     /**

   121      * 2nd phase constructor

   122      */

   123     void ConstructL();

   124 

   125 private:

   126     // data

   127 

   128     /**

   129      * The observer reports state changes to own observers

   130      * Not owns

   131      */

   132     RPointerArray<MUsbVBusObserver> iObservers;

   133 

   134     /**

   135      * The observer observes property change

   136      */

   137     RProperty iVBus;

   138 

   139     };

   140 

   141 #endif //  C_USBVBUSOBSERVER_H