/*

* Copyright (c) 2008-2009 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:  Defines an ECOM interface for third parties to customize

*               contact related icons in certain platform applications.

*/

#ifndef CCONTACTICONCUSTOMPLUGINBASE_H

#define CCONTACTICONCUSTOMPLUGINBASE_H

// INCLUDES

#include <e32base.h>

#include <ecom/ecom.h>

#include <ContactCustomIconPluginDefs.h>

// FORWARD DECLARATIONS

class CGulIcon;

class CCustomIconIdMap;

class CCustomIconDecisionData;

class MCustomIconChangeObserver;

// CONSTANTS

/**

*  Interface UID for ECOM plug-ins, which inherit from this interface.

*  This is used in plug-in registration resource file (interface_uid). Example:

*

*   RESOURCE REGISTRY_INFO cs_ecom_reg_info

*       {

*       dll_uid = <UID_OF_ECOM_DLL>;

*       interfaces =

*           {

*           INTERFACE_INFO

*               {

*               // Make sure to use KContactIconCustomizationInterfaceUidValue

*               interface_uid = 0x2001E2DA;

*

*               implementations =

*                   {

*                   IMPLEMENTATION_INFO

*                       {

*                       implementation_uid = <...>; //  maps to IMPLEMENTATION_PROXY_ENTRY in CPP exporting plugin factory functions

*                       version_no = 1;

*                       display_name = "CMyContactIconCustomizationPlugin";

*                       default_data = "";

*                       opaque_data = "";

*                       }

*                   };

*               }

*           };

*       }

*/

const TInt KContactIconCustomizationInterfaceUidValue = 0x2001E2DA;

const TUid KContactIconCustomizationInterfaceUid =

    { KContactIconCustomizationInterfaceUidValue };

// CLASS DECLARATION

/**

*  Base class for contact related icon customization ECOM plugins.

*

*  This API allows customizing contact related icons of certain

*  applications at runtime.

*

*  The API defines two roles:

*  - Customizable entity is typically an application supporting icon

*    customization. It is a caller of this API.

*  - Customizer is an entity implementing ecom plug-in, a callee.

*

*  As a concrete example, Logs application has 'Dialled calls' view

*  where it by default shows in each listbox row a call specific icon.

*  Plugin can change each of the icons by implementing this API.

*

*  The customizer needs only one plug-in implementation, which affects

*  multiple applications at a same time. This means the API cannot define

*  application specific info.

*

*  Note that customizable entity - typically an application - has to provide

*  a connection to Font and Bitmap server. The plug-in may fail to provide

*  the icon (KErrCouldNotConnect), if the connection does not exist.

*/

class CContactCustomIconPluginBase : public CBase

    {

    public: // API to be implemented by ECOM plug-in

        /**

         * An icon size hint from application to plug-in. Plug-in

         * may use this to load icons of appropriate size.

         * @see IconsL

         */

        enum TIconSizeHint

            {

            EReallySmall,

            ESmall,

            EMedium,

            EMediumLarge,

            ELarge

            };

        /**

         * Calling application uses this method to register itself as an observer

         * for the plug-in state change notifications.

         *

         * Plug-in uses observer interface for notifying calling application

         * about icon related changes.

         *

         * @param aObserver     Observer interface, implemented by calling client

         *                      code. Ownership of the object is not transferred.

         */

        virtual void AddObserverL(

                MCustomIconChangeObserver* aObserver ) = 0;

        /**

         * Calling application uses this method to deregister itself as an observer

         * from the plug-in state change notifications.

         *

         * @param aObserver     Observer interface, implemented by calling client

         *                      code. Ownership of the object is not transferred.

         */

        virtual void RemoveObserver(

                MCustomIconChangeObserver* aObserver ) = 0;

        /**

         * Gets an array of custom icons from the plug-in.

         *

         * Application calls this method typically in its initialization phase

         * to prepare for replacing its default icons. When it is time to show

         * the icons, calling application may call IconChoiceL.

         *

         * ECOM plug-in implementation should fill in the potential icons

         * and give each icon an identifier, which it can use later to refer

         * to a certain icon it wants to use as replacement for application's

         * default icon.

         *

         * @see CCustomIconIdMap.h

         * @param aContext  Context of the function call. For more information

         *                  about context semantics see CCustomIconDecisionData

         *                  documentation.

         * @param aSizeHint Hint for plug-in to load icons of appropriate size.

         * @return  Icon-to-id map.

         * @leave On typical leave level problems. Application should handle

         *        this by ignoring ECOM plug-in functionality and continue

         *        using its default icons.

         */

        virtual CCustomIconIdMap* IconsL(

                TUid aContext,

                TIconSizeHint aSizeHint ) = 0;

        /**

         * Application uses this method to make a choice of the icon to be

         * displayed in certain UI condition.

         *

         * Note that application should have always had called the IconsL

         * function before this gets called.

         *

         * ECOM plug-in implementation should use aHint parameter to make a decision

         * which icon it wants to use.

         *

         * @param aHint     Hint from the application to the plug-in, which tells

         *                  what kind of icon is being replaced. For example, the

         *                  plug-in may want to choose the icon based on the

         *                  phonenumber. For more details see

         *                  CCustomIconDecisionData.h.

         *                  Plug-in must not take ownership of the object's

         *                  members. The instance and its members are guaranteed to

         *                  be valid only during the method call.

         *

         *                  Caller must fill at least one of the members, otherwise

         *                  plug-in can and should leave with KErrArgument.

         *

         * @param aIdResult Icon reference value filled by the ECOM plug-in. The id

         *                  should be one of the ids, which were used to build the

         *                  CCustomIconIdMap object in IconsL function. If the

         *                  calling application cannot find an icon by aIdResult

         *                  from the map, it should use application's default icon.

         *

         * @return  Return value indicating if the decision could be made.

         *          ETrue, if the icon choice decision could be made.

         *          EFalse, if the icon choice could not be made.

         *          This is an indication from plug-in to application that

         *          application should use its default icon.

         *

         * @leave On typical leave level problems like database access failure

         *        or condition where application may not be able to provide the

         *        requested functionality. It is up to application how it

         *        handles leave from the plug-in. Recommendation is that it

         *        ignores plug-in's functionality and uses default icons.

         */

        virtual TBool IconChoiceL(

                const CCustomIconDecisionData& aHint,

                TCustomIconId& aIdResult ) = 0;

        /**

         * Application uses this method when it dynamically needs to replace

         * its default icon. This can typically happen at any time of the

         * application runtime.

         *

         * Application should favor using the IconsL/IconChoiceL pair, if it

         * is likely to use multiple icons and several times. This function is

         * useful if the application needs only couple of icons only couple

         * of times. This is discouraged for use in frequent draw requests.

         *

         * The plug-in implementation should use the aHint to make a decision

         * which icon it wants to use.

         *

         * @param aHint     Hint from application to plug-in, which tells what

         *                  kind of icon is being replaced. For example, the

         *                  plug-in may want to choose the icon based on the

         *                  phonenumber. For more details see

         *                   CCustomIconDecisionData.h

         *                  Plug-in must not take ownership of the object or its

         *                  members. The instance and its members are guaranteed to

         *                  be valid only during the method call.

         *                  Caller must fill at least one of the members, otherwise

         *                  plug-in can and should leave with KErrArgument.

         *

         * @param aSizeHint Hint for plug-in to load icon of appropriate size.

         *

         * @return  Icon instance. NULL, if plug-in wants to indicate it is

         *          not willing to replace caller's default icon.

         */

        virtual CGulIcon* IconL(

                const CCustomIconDecisionData& aHint,

                TIconSizeHint aSizeHint ) = 0;

        /**

         * Application uses this method when it dynamically needs to update

         * previously loaded custom icon. Typically this happens after

         * application has received update notification from plug-in.

         *

         * @param aContext   Context of the function call. While this override

         *                   provides known icon id rather than

         *                   CCustomIconDecisionData, the context is given here

         *                   separately. For more information about context

         *                   semantics see CCustomIconDecisionData

         *                   documentation.

         *

         * @param aIconId   Specifies the icon for the client to provide. This is

         *                   valid when a known custom icon has changed and is

         *                   being replaced.

         *

         * @param aSizeHint Hint for plug-in to load icon of appropriate size.

         *

         * @return  Icon instance. NULL, if plug-in wants to indicate it is

         *          not willing to replace application's default icon.

         */

        virtual CGulIcon* IconL(

                TUid aContext,

                TCustomIconId aIconId,

                TIconSizeHint aSizeHint ) = 0;

        /**

         * Factory function for getting access to extended API functionality.

         * Uid defines the extension interface being used.

         *

         * @param aExtensionUid     Identifier for extension API class.

         * @return  Extension API class, casted to one of M-interfaces defined

         *         by this API (later). Ownership of the object is not transferred.

         */

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

            {

            return NULL;

            }

    public:

        /**

         * ~CContactIconCustomPluginBase

         *

         * Cleans up resources, specifically notify ECOM server that this

         * instance is being deleted.

         */

        inline virtual ~CContactCustomIconPluginBase()

            {

            REComSession::DestroyedImplementation( iDtorKey );

            }

    public:

        /// Own: Key UID

        TUid iDtorKey;

    };

#endif // CCONTACTICONCUSTOMPLUGINBASE_H

// End of File