/*

* Copyright (c) 2003-2005 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

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

* which accompanies this distribution, and is available

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

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:       Variant data type for LIW generic parameters.

*

*/

#ifndef LIW_VARIANT_H

#define LIW_VARIANT_H

// INCLUDES

#include <e32std.h>

#include <s32strm.h>

#include <f32file.h>

#include "liwvarianttype.hrh"

// FORWARD DECLARATIONS

class CLiwGenericParamList;

class MLiwNotifyCallback;

// New variant types

class CLiwContainer;

class CLiwIterable;

class CLiwList;

class CLiwMap;

class MLiwInterface;

class CLiwBuffer;

// CLASS DECLARATION

/**

* Variant data class to hold a value of a TLiwGenericParam instance.

* The variant contains a data type and a value. This class is attached to

* TLiwGenericParam instance which holds the semantic type of the value.

*

* @lib ServiceHandler.lib

* @since Series 60 2.6

* @see TLiwGenericParam

*/

class TLiwVariant

    {

    public:  // Constructors

        /**

        * Default constructor. Initializes this variant to be empty.

        *

        * @post IsEmpty()

        */

        inline TLiwVariant();

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */

        inline TLiwVariant(TInt32 aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */

        inline TLiwVariant(TInt64 aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */

        inline TLiwVariant(TUint aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */

        inline TLiwVariant(TBool aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const TUid& aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const TTime& aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const TDesC& aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const HBufC* aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const TDesC8& aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const RFile& aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const CLiwList* aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const CLiwMap* aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const MLiwInterface* aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */        

        inline TLiwVariant(const CLiwIterable* aValue);

		/**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */

        inline TLiwVariant(TReal aValue);

        /**

        * Constructor from a value.

        *

        * @param aValue The value to set for this variant object.

        */

        inline TLiwVariant(const CLiwBuffer* aValue);

        /**

        * Copy constructor. Does not take ownership of data.

        *

        * @param aSrc The source object.

        */

        IMPORT_C TLiwVariant(const TLiwVariant& aSrc);

        /**

        * Assignment operator. Does not take ownership of data.

        *

        * @param aValue The source object.

        */

        IMPORT_C TLiwVariant& TLiwVariant::operator=(const TLiwVariant& aValue);

        // This class does not need a destructor because memory allocation

        // policy for variant class has been implemented by TLiwGenericParam

        // class.

    public:  // Interface

        /**

        * Returns the type id of data this variant object is holding.

        */

        inline LIW::TVariantTypeId TypeId() const;

        /**

        * Returns ETrue if this variant is empty (it does not hold any value).

        */

        inline TBool IsEmpty() const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */

        IMPORT_C TBool Get(TInt32& aValue) const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */

        IMPORT_C TBool Get(TInt64& aValue) const;

		/**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(TUid& aValue)   const;

        /**

        * Retrieves the boolean value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */

        IMPORT_C TBool Get(TUint& aValue) const;

        /**

        * Retrieves the boolean value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */

        IMPORT_C TBool Get(TBool& aValue) const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(TPtrC& aValue)  const;

        //needed at least temporarily for data binding integration...

        //inline TBool Get(const TPtrC** aValue)  const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(TTime& aValue)  const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(TPtrC8& aValue) const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(RFile& aValue) const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(CLiwList& aValue) const;

        /**

        * Retrieves the value held by this variant.

        *

        * @param aValue If this variant's type does not match the

        *               parameter type, the parameter will not be modified.

        * @return ETrue if aValue was set, EFalse if types did not match.

        */        

        IMPORT_C TBool Get(CLiwMap& aValue) const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */

        IMPORT_C TInt32 AsTInt32() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */

        IMPORT_C TInt64 AsTInt64() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */

        IMPORT_C TBool AsTBool() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */

        IMPORT_C TBool AsTUint() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */        

        IMPORT_C TUid AsTUid() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */        

        IMPORT_C TPtrC AsDes() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */        

        IMPORT_C TTime AsTTime() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */        

        IMPORT_C TPtrC8 AsData() const; 

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function, the default initialized data is returned.

        */        

        IMPORT_C RFile AsFileHandle() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function default initialized data is returned.

        */        

        IMPORT_C const CLiwList* AsList() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function default initialized data is returned.

        */        

        IMPORT_C const CLiwMap* AsMap() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function default initialized data is returned.

        */        

        IMPORT_C MLiwInterface* AsInterface() const;

        /**

        * Returns the value held by this variant.

        *

        * @return The value held by this variant. If the data type does not

        *         match the function default initialized data is returned.

        */        

        IMPORT_C CLiwIterable* AsIterable() const;

        /**

        * Deletes possibly set value and resets this variant to empty.

        *

        * @post IsEmpty()

        */

        IMPORT_C void Reset();

        /**

        * Sets integer value to this variant. The previous value is overwritten.

        *

        * @param aValue Value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(TInt32 aValue);

        /**

        * Sets integer value to this variant. The previous value is overwritten.

        *

        * @param aValue Value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(TInt64 aValue);

        /**

        * Sets Boolean value to this variant. The previous value is overwritten.

        *

        * @param aValue Value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(TBool aValue);

        /**

        * Sets Boolean value to this variant. The previous value is overwritten.

        *

        * @param aValue Value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(TUint aValue);

        /**

        * Sets unique ID value to this variant. The previous value is overwritten.

        *

        * @param aValue Value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(const TUid& aValue);

        /**

        * Sets date and time value to this variant. The previous value is overwritten.

        *

        * @param aValue Value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(const TTime& aValue);

        /**

        * Sets constant text reference to this variant. 

        *

        * @param aValue Text value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(const TDesC& aValue);

        /**

        * Sets constant text reference to this variant. 

        *

        * @param aValue Text value for this variant object to hold. 

        *               Ownership is not taken.

        */

        inline void Set(const HBufC* aValue);

        /**

        * Sets constant 8-bit text reference to this variant.

        * 

        * @param aValue Text value for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(const TDesC8& aValue);

        /**

        * Sets RFile file handle to this variant.

        *

        * @param aValue File handle for this variant object to hold.

        * @post *this == aValue

        */

        IMPORT_C void Set(const RFile& aValue);

        /**

        * Sets list of variants to this variant.

        *

        * @param aValue Array of variants for this variant object to hold.

        * @postcond *this == aValue

        */

        IMPORT_C void Set(const CLiwList* aValue);

        /**

        * Sets map of variants to this variant.

        *

        * @param aValue Dictionary of variants for this variant object to hold.

        * @postcond *this == aValue

        */

        IMPORT_C void Set(const CLiwMap* aValue);

        /**

        * Sets interface pointer to this variant.

        *

        * @param aValue Interface pointer for this variant object to hold.

        * @postcond *this == aValue

        */

        IMPORT_C void Set(const MLiwInterface* aValue);

        /**

        * Sets list of variants to this variant.

        *