1 /*

     2 * Copyright (c) 2004-2008 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:  CCFContextChanged class declaration.

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef C_CFCONTEXTCHANGED_H

    21 #define C_CFCONTEXTCHANGED_H

    22 

    23 // INCLUDES

    24 #include "cfcontextoperation.h"

    25 

    26 #include <e32base.h>

    27 

    28 // FORWARD DECLARATIONS

    29 class CCFContextObject;

    30 

    31 // CLASS DECLARATION

    32 

    33 /**

    34 *  This class implements ContextChanged context object event.

    35 *

    36 *  @lib CFScriptEngine

    37 *  @since Series 60 2.6

    38 */

    39 NONSHARABLE_CLASS( CCFContextChanged ): public CCFContextOperation

    40     {

    41 public: // Constructors and destructor

    42 

    43     /**

    44     * Two-phased constructor.

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

    46     * @param aParent is parent node for this node.

    47     * @param aName is name of the context object this operation operates on.

    48     * @param aSource is the source of the context object this operation

    49     *   operates on.

    50     * @param aValue is the expected value of the context object this operation

    51     *   operates on. Use KNullDesC if no particular value is expected.

    52     */

    53     static CCFContextChanged* NewL( MCFOperationServices& aServices,

    54             CCFOperationNode* aParent,

    55             const TDesC& aName,

    56             const TDesC& aSource,

    57             const TDesC& aValue );

    58 

    59     /**

    60     * Two-phased constructor that leaves the class into CleanupStack.

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

    62     * @param aParent is parent node for this node.

    63     * @param aName is name of the context object this operation operates on.

    64     * @param aSource is the source of the context object this operation

    65     *   operates on.

    66     * @param aValue is the expected value of the context object this operation

    67     *   operates on. Use KNullDesC if no particular value is expected.

    68     */

    69     static CCFContextChanged* NewLC( MCFOperationServices& aServices,

    70             CCFOperationNode* aParent,

    71             const TDesC& aName,

    72             const TDesC& aSource,

    73             const TDesC& aValue );

    74 

    75     /**

    76     * Creates and parses a CCFContextChanged instance from an xml node.

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

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

    79     *   The ownership of the parent is not transferred.

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

    81     * @return a pointer to the created instance of CCFContextChanged, or NULL if

    82     *   the node is not this context changed node. May leave with any system

    83     *   wide error code.

    84     */

    85     static CCFContextChanged* ParseL( MCFOperationServices& aServices,

    86             CCFOperationNode* aParent,

    87             CMDXMLNode& aNode );

    88 

    89     /**

    90     * Destructor.

    91     */

    92     ~CCFContextChanged();

    93 

    94 private:

    95 

    96     /**

    97     * C++ default constructor.

    98     */

    99     CCFContextChanged( MCFOperationServices& aServices,

   100             CCFOperationNode* aParent,

   101             HBufC* aName,

   102             HBufC* aSource );

   103 

   104     /**

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

   106     * @param aValue is the expected value of the context object this operation

   107     *   operates on. Use KNullDesC if no particular value is expected.

   108     */

   109     void ConstructL( const TDesC& aValue );

   110 

   111 protected: // From CFContextOperation

   112 

   113     /**

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

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

   116     *   EFalse otherwise.

   117     */

   118     TBool IsAllRequired() const;

   119 

   120     /**

   121     * Evaluates a node with a context.

   122     * @param aContext is the context for evaluation.

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

   124     *  contextRef after the call.

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

   126     */

   127     virtual TBool Evaluate( const CCFContextObject& aContext,

   128             TInt& aContextLevelDelay );

   129 

   130     /**

   131     * Method that returns whether or not this this operation is true.

   132     * @returns ETrue if this operation is true, EFalse otherwise

   133     */

   134     TBool IsTrueL( const CCFContextObject& aContextObject );

   135 

   136 private: // Data

   137 

   138     // Flag for context used with previous truth check (call to isTrueL),

   139     // tells whether it was the referenced context or not.

   140     TBool iPreviousTruthCheckWithReferencedContext;

   141 

   142     // When set, the required context value for making the operation true.

   143     HBufC* iCmpValue;

   144     };

   145 

   146 #endif // C_CFCONTEXTCHANGED_H