1 /*

     2 * Copyright (c) 2007-2008 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:  CCFCount class declaration.

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef C_CFCOUNT_H

    21 #define C_CFCOUNT_H

    22 

    23 // INCLUDES

    24 #include "cfcontextoperation.h"

    25 

    26 // FORWARD DECLARATIONS

    27 class CCFContextObject;

    28 

    29 // CLASS DECLARATION

    30 

    31 /**

    32 *  This class implements count -operation on Context Framework Scripts.

    33 *

    34 *  @lib CFScriptEngine

    35 *  @since S60 v5.0

    36 */

    37 NONSHARABLE_CLASS( CCFCount ): public CCFContextOperation

    38     {

    39 public: // Public types

    40 

    41     /** Count types. */

    42     enum TCountType {

    43         ECountTypeRemain, /** Count value remains true after operation is evaluated to true. */

    44         ECountTypeChange, /** Count value is changed back from true to false after receiving the next counted context. */

    45         ECountTypeTrigger /** Count triggers one evaluation when count's value is true, after which count changes it's value back to false. */

    46     };

    47 

    48 public: // Constructors and destructor

    49 

    50     /**

    51     * Creates and parses a CCFCount instance from an xml node.

    52     * @param aServices is the operation services interface for nodes.

    53     * @param aParent is the parent of this node or NULL if this is a root.

    54     *   The ownership of the parent is not transferred.

    55     * @param aNode is the node to be parsed.

    56     * @return a pointer to the created instance of CCFCount, or NULL if the node

    57     *   is not this count node. May leave with any system wide error code.

    58     */

    59     static CCFCount* ParseL( MCFOperationServices& aServices,

    60             CCFOperationNode* aParent,

    61             CMDXMLNode& aNode );

    62 

    63     /**

    64     * Destructor.

    65     */

    66     ~CCFCount();

    67 

    68 public: // From CCFOperationNode

    69 

    70     /**

    71     * Internalizes operation.

    72     * @param aStream Read stream.

    73     * @return None.

    74     */

    75     void InternalizeL( RReadStream& aStream );

    76 

    77     /**

    78     * Externalizes operation.

    79     * @param aStream Write stream.

    80     * @return None.

    81     */

    82     void ExternalizeL( RWriteStream& aStream );

    83 

    84     /**

    85     * Cleanup deletes possible persistent data file.

    86     * This is called by the context framework when the script is uninstalled

    87     * from the system.

    88     * @return None.

    89     */ 

    90     void Cleanup();

    91 

    92 protected: // From CCFContextOperation

    93 

    94     /**

    95     * Tests if this listener requires notification of all contexts.

    96     * Count type trigger requires all contexts, other types do not.

    97     * @returns ETrue if this listener is interested in all contexts,

    98     *   EFalse otherwise.

    99     */

   100     TBool IsAllRequired() const;

   101 

   102     /**

   103     * Evaluates a node with a context.

   104     * @param aContext is the context for evaluation.

   105     * @param aContextLevelDelay contains the context level delay defined by

   106     *  contextRef after the call.

   107     * @return ETrue if the operation was evaluated, EFalse otherwise.

   108     */

   109     TBool Evaluate( const CCFContextObject& aContext,

   110             TInt& aContextLevelDelay );

   111 

   112 protected: // From CCFOperationNode

   113 

   114     /**

   115     * Activates this node by subscribing to a context.

   116     * Overrides base class implementation because count must discard the

   117     * possible cached context used to pre-evaluate operations during subscribe

   118     * context. Otherwise count might be increased based on the cached context.

   119     * @return None.

   120     */

   121     void ActivateL();

   122 

   123     /**

   124     * Deactivates this node by removing context subscription.

   125     * @return None.

   126     */

   127     void Deactivate();

   128 

   129 protected:

   130 

   131     /**

   132     * C++ default constructor.

   133     */

   134     CCFCount( MCFOperationServices& aServices,

   135             CCFOperationNode* aParent,

   136             HBufC* aName,

   137             HBufC* aSource,

   138             const CCFContextOperation::TCmpType aType,

   139             const TUint aCount,

   140             const TCountType aCountType );

   141 

   142     /**

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

   144     */

   145     void ConstructL( const TDesC& aCmpVal );

   146 

   147 private: // New functions

   148 

   149     /**

   150     * Evaluates a node with a context.

   151     * @param aContext is the context for evaluation.

   152     * @return ETrue if the operation was evaluated, EFalse otherwise.

   153     */

   154     TBool DoEvaluateL( const CCFContextObject& aContext );

   155 

   156     /**

   157     * Counts a context if appropriate.

   158     * @param aContext is the context for counting.

   159     * @return ETrue if the context was counted, otherwise EFalse.

   160     */

   161     TBool CountContextL( const CCFContextObject& aContext );

   162 

   163 protected: // Data

   164 

   165     CCFContextOperation::TCmpType iType;

   166     TUint                         iCurrentCount;

   167     TBool                         iActive;

   168     TBool                         iFinished;

   169     TUint                         iCmpCount;

   170     TCountType                    iCountType;

   171     HBufC*                        iCmpValue;

   172     HBufC*                        iPersistencyFile;

   173     TBool                         iReEvaluateFromNextContext;

   174     };

   175 

   176 

   177 #endif // C_CFCOUNT_H