/*

* Copyright (c) 2004-2007 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "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:  An interface for the field of the store contact

*

*/

#ifndef MVPBKSTORECONTACTFIELD_H

#define MVPBKSTORECONTACTFIELD_H

// INCLUDES

#include <e32std.h>

// CONSTANTS

/// A constant that indicates that the store doesn't set limits

/// to the length of the label

const TInt KVPbkUnlimitedLabelLength = -1;

// FORWARD DECLARATIONS

class MVPbkContactLink;

// CLASS DECLARATIONS

/**

 * An interface for the field of the store contact.

 *

 * Client can access the contact field using this interface. The field

 * can have a label and a data.

 *

 * A new field can be created using the MVPbkStoreContact interface.

 * For looping the contact fields see MVPbkStoreContactFieldCollection.

 * The parent of the field in the object hierarchy is the store contact.

 *

 * @see CVPbkContactFieldTypeIterator

 * @see CVPbkFieldTypeSelector

 */

class MVPbkStoreContactField : public MVPbkBaseContactField,

                               public MVPbkObjectHierarchy

    {

    public:  // Destructor

        /**

         * Destructor

         */

        virtual ~MVPbkStoreContactField() { }

    public: // From MVPbkBaseContactField

        virtual const MVPbkContactFieldData& FieldData() const = 0;

    public:  // New functions

        /**

         * Returns ETrue if the field supports label.

         *

         * Overwrites the global setting in MVPbkContactStoreProperties.

         * This must be confirmed before using SetFieldLabelL or

         * MaxLabelLength.

         *

         * @return ETrue if the field supports label. Otherwise EFalse.

         */

        virtual TBool SupportsLabel() const = 0;

        /**

         * Returns the label of the field or KNullDesC if there is no field

         * label.

         *

         * @return The label of the field or KNullDesC

         */

        virtual TPtrC FieldLabel() const = 0;

        /**

         * Sets this field's label.

         *

         * SupportsLabel must be true for using this.

         *

         * @param aText The label for the field.

         */

        virtual void SetFieldLabelL( const TDesC& aText ) = 0;

        /**

         * Gets the maximum length of the label.

         *

         * SupportsLabel must be true for using this.

         *

         * @return The maximum length of the label or KVPbkUnlimitedLabelLength

         *         if the store has no limits. Zero should be returned in other

         *         cases though this shouldn't be called if labels are

         *         not supported.

         */

        virtual TInt MaxLabelLength() const = 0;

        /**

         * Returns the data storage (read-write) of the field.

         *

         * The data type depends on the field and it's client's responsibility

         * to check the type before casting the type.

         *

         * @return The data storage of the field.

         * @see MVPbkContactFieldTextData::Cast

         * @see MVPbkContactFieldDateTimeData::Cast

         * @see MVPbkContactFieldBinaryData::Cast

         */

        virtual MVPbkContactFieldData& FieldData() = 0;

        /**

         * Clones the field.

         *

         * Pushes the created copy to the cleanup stack.

         *

         * @return A copy of the field.

         * @see MVPbkStoreContactFieldCollection::FieldAt

         */

        virtual MVPbkStoreContactField* CloneLC() const = 0;

        /**

         * Creates a link representing the contact and the field.

         *

         * The field can be later retrieved using the RetrieveField of

         * MVPbkStoreContactFieldCollection interface.

         *

         * NOTE: implementations of stores are possibly using an index

         *       of the field as an identifier so clients should prefer not

         *       to save field links permanently. E.g modifying the contact

         *       can invalidate the link in some store implementations.

         *       A field link is practical in use cases where the link is

         *       created and immediately given to another component.

         *

         * @return A link representing the contact and the field or NULL

         *         if the contact doesn't exist in the store. E.g a new

         *         contact that hasn't been committed has no unique

         *         identifier yet.

         *         NULL is not put into the CleanupStack.

         */

        virtual MVPbkContactLink* CreateLinkLC() const = 0;

        /**

         * Returns an extension point for this interface or NULL.

         *

         * @param aExtensionUid no extensions defined currently.

         * @return An extension point for this interface or NULL.

         */

        virtual TAny* StoreContactFieldExtension( TUid /*aExtensionUid*/ )

            { return NULL; }

    };

#endif  // MVPBKSTORECONTACTFIELD_H

// End of file