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:  Header for Base class for log busses.

    15 *

    16 */

    17 

    18 

    19 #ifndef HSPS_LOGBUS_H

    20 #define HSPS_LOGBUS_H

    21 

    22 // INCLUDES

    23 #include <e32std.h>

    24 #include <e32base.h>

    25 

    26 // CLASS DECLARATION

    27 

    28 /**

    29  * Base class for log busses. Not instanciable.

    30  * 

    31  * @lib hspsTools.lib

    32  * @since S60 5.0

    33  * @ingroup group_homescreenpluginservice_tools

    34  */

    35 class ChspsLogBus : public CBase, TDes16Overflow, TDes8Overflow

    36     {

    37 public:

    38     /**

    39      * Destructor.

    40      */

    41     IMPORT_C ~ChspsLogBus();

    42 

    43     /**

    44      * Log formattable 16bit string.

    45      * 

    46      * @since S60 5.0

    47      * @param aFmt  String to be logged. May contain format specifiers, but

    48      *              those must match with additional arguments given.

    49      *        ...   Data to be inserted to formatted string.

    50      */    

    51     IMPORT_C void LogText( TRefByValue<const TDesC16> aFmt, ... );

    52 

    53     /**

    54      * Log formattable 8bit string.

    55      * 

    56      * @since S60 5.0

    57      * @param aFmt  String to be logged. May contain format specifiers, but

    58      *              those must match with additional arguments given.

    59      *        ...   Data to be inserted to formatted string.

    60      */    

    61     IMPORT_C void LogText( TRefByValue<const TDesC8> aFmt, ... );    

    62     

    63 protected:

    64     /**

    65      * This method must be overwritten in inherited class (implementation).

    66      * Implementation must log given string using logging channel of

    67      * it's choice.

    68      * 

    69      * @param aMessage Message to be logged.

    70      */    

    71     virtual void _LogText( const TDesC& aMessage ) = 0;

    72 

    73     /**

    74      * This method is used to query max. line length from inheriting object.

    75      * Default implementation returns 128.

    76      * This value is used to crop descriptors before _LogText is called.

    77      * 

    78      * @return  TInt    Max line length supported by this log bus.

    79      */    

    80     virtual TInt MaxLineLen() const;    

    81     

    82     /**

    83      * Constructor for performing 1st stage construction.

    84      */

    85     IMPORT_C ChspsLogBus();    

    86     

    87 private: // Methods.

    88     /**

    89      * Create a heap descriptor using given arguments.

    90      * 

    91      * @param   aFmt    Descriptor

    92      * @param   aList   Variable length argument list.

    93      * @return  HBufC*  Pointer to created heap descriptor. OWNERSHIP TRANSFERRED

    94      *                  TO CALLER.

    95      */    

    96     HBufC* FormatMessage( TRefByValue<const TDesC16> aFmt, VA_LIST aList );

    97 

    98     /**

    99      * From TDes16Overflow.

   100      * 

   101      * Handles the overflow.

   102     

   103      * This function is called when the TDes16::AppendFormat() 

   104      * variant that takes an overflow handler argument, fails.    

   105      * 

   106      * @param aDes  The 16-bit modifiable descriptor whose overflow results in the 

   107      *              call to this overflow handler.

   108      * 

   109      */    

   110     void Overflow( TDes16& aDes );    

   111 

   112     /**

   113      * Create a heap descriptor using given arguments.

   114      * 

   115      * @param   aFmt    Descriptor

   116      * @param   aList   Variable length argument list.

   117      * @return  HBufC*  Pointer to created heap descriptor. OWNERSHIP TRANSFERRED

   118      *                  TO CALLER.

   119      */    

   120     HBufC* FormatMessage( TRefByValue<const TDesC8> aFmt, VA_LIST aList );

   121 

   122     /**

   123      * From TDes8Overflow.

   124      * 

   125      * Handles the overflow.

   126     

   127      * This function is called when the TDes16::AppendFormat() 

   128      * variant that takes an overflow handler argument, fails.    

   129      * 

   130      * @param aDes  The 16-bit modifiable descriptor whose overflow results in the 

   131      *              call to this overflow handler.

   132      * 

   133      */    

   134     void Overflow( TDes8& aDes );     

   135 

   136     /**

   137      * Crops text according to max line and then calls

   138      * inherited class' _LogText. 

   139      * 

   140      * @param   aText   Message to be logged.

   141      */

   142     void CropAndLogText( const TDesC& aText );

   143     

   144 private: // Data.    

   145     /**

   146      * Internal flag to indicate possible overflow.

   147      */

   148     TBool iOverflow;

   149     };

   150 

   151 #endif // HSPS_LOGBUS_H