1 /*

     2 * Copyright (c) 2005 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:  

    15 *

    16 */

    17 

    18 

    19 #ifndef MUSUICALLBACKSERVICE_H

    20 #define MUSUICALLBACKSERVICE_H

    21 

    22 #include "musuidefinitions.h"

    23 #include <e32base.h>

    24 

    25 class MMusUiCallbackObserver;

    26 

    27 

    28 /**

    29  * Callback Service used to pass asynchronous events

    30  */

    31 class CMusUiCallbackService : public CActive

    32     {

    33 

    34 public: // Constructors and destructor

    35 

    36     /**

    37     * Two-phased constructor.

    38     * @param aCallbackObserver the observer that will receive the callbacks.

    39     * @return new instance of CMusUiCallbackService.

    40     */

    41     static CMusUiCallbackService* NewL( 

    42                             MMusUiCallbackObserver& aCallbackObserver );

    43     

    44     /**

    45     * Destructor.

    46     */

    47     ~CMusUiCallbackService();

    48 

    49 private: // Constructors

    50 

    51     /**

    52     * C++ default constructor.

    53     * @param aCallbackObserver the observer that will receive the callbacks.

    54     */

    55     CMusUiCallbackService( MMusUiCallbackObserver& aCallbackObserver );

    56     

    57     /**

    58     * By default Symbian 2nd phase constructor is private.

    59     */

    60     void ConstructL();

    61 

    62 

    63 public: // New functions

    64 

    65     /**

    66     * Buffer a request to trigger an event.

    67     * @param aEventId    Id of the event

    68     */

    69     void AsyncEventL( TMusUiAsyncEvent aEventId );

    70 

    71     /**

    72     * Called when the notifier has been deactivated so resources can be 

    73     * freed and outstanding messages completed.

    74     */

    75     void Cancel();

    76     

    77     /**

    78     * Check what event is currently pending

    79     * @return EMusUiAsyncUninitialized is no events are pending

    80     */

    81     TMusUiAsyncEvent CurrentEvent() const;

    82 

    83 

    84 public: // Functions from CActive base class

    85     

    86     /**

    87     * From CActive.  Called when a request completes.

    88     */

    89     void RunL();

    90 

    91     /**

    92     * From CActive.  Called when a leave occurres in RunL.

    93     * @param aError Symbian OS errorcode.

    94     * @return Error Code.

    95     */

    96     TInt RunError(TInt aError);

    97     

    98     /**

    99     * From CActive.  Called when a request is cancelled.

   100     */

   101     void DoCancel();  

   102 

   103 

   104 private: // New functions

   105 

   106     /**

   107     * Activate the object.

   108     */

   109     void Activate();

   110 

   111 

   112 private:    // Data

   113 

   114     /**  Handle to callback observer. */

   115     MMusUiCallbackObserver& iCallbackObserver;

   116 

   117     /**  Event ID to pass through. */

   118     TMusUiAsyncEvent iEventId;

   119 

   120     };

   121 

   122 #endif // MUSUICALLBACKSERVICE_H