/*

* Copyright (c) 2010 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:  THIS FILE IS NOT INCLUDED INTO ECLIPSE CVS DELIVERY

*               Provides a way to invoke some functionality

*               which can run in ESWT thread only

*

*/

#ifndef SWTDCOBSERVER_H

#define SWTDCOBSERVER_H

// Using MSwtDcEventConsumer

#include "swtdceventconsumer.h"

// Using RPointerArray

#include <e32std.h>

// Using RMsgQueue

#include <e32msgqueue.h>

// Forward declarations

class MUiEventConsumer;

class CCoeControl;

/**

 * Provides a way to make calls to functions which are able

 * to run in ESWT thread only and

 * which may origin in non-ESWT thread (MMAPI for instance).

 *

 * The calls are kept in queue and processed serially.

 *

 * If the call works with some CCoeControl instance,

 * ther control must be registered by RegisterControl().

 *

 * Some events may invoke a callback into specified callback interface.

 * The receiver of this callback must not be deleted if there is

 * a possibility of having some events, which will call this, in queue.

 *

 * The callback receiver can for example implement

 * its instance deletion via event using this observer,

 * so this deletion event will be the last one for that receiver.

 *

 * @lib    eswtdirectcontent.dll

 * @since  S60 v5.2

 */

{

public:

    /**

     * Constructor.

     */

    CSwtDcObserver();

    /**

     * Destructor.

     */

    ~CSwtDcObserver();

    /**

     * Asynchronously sends an event into a consumer.

     * The call may origin in other than ESWT thread.

     *

     * @since S60 5.2

     * @param aConsumer Consumer which gets event asynchronously.

     * @param aType An data indicating event type for consumer.

     */

    virtual void InvokeDcEvent(MSwtDcEventConsumer& aConsumer, TInt aType);

    /**

     * Invokes aConsumer->MdcDSAResourcesCallback from ESWT thread.

     * The call may origin in other than ESWT thread.

     *

     * @since S60 5.2

     * @param aControl Control used to get DSA resources from.

     * @param aConsumer Consumer of the callback.  The instance

     *                  must not be deleted before the event processed.

     */

    void InvokeDSAResourcesCallback(

        CCoeControl& aControl,

        MUiEventConsumer& aConsumer);

    /**

     * Invokes aConsumer->MdcUICallback( aCallbackId ) from ESWT thread.

     * The call may origin in other than ESWT thread.

     *

     * @since S60 5.2

     * @param aConsumer Consumer of the callback.

     * @param aCallbackId Id which is provided to the callback

     */

    void InvokeUICallback(MUiEventConsumer& aConsumer, TInt aCallbackId);

private:

    /** CSwtDcObserver event datatype */

    enum TDcEventType

    {

        EDcEvent,

        EDSAResourcesCallbackEvent,

        EUICallbackEvent

    };

    /** CSwtDcObserver event content datatype */

    struct TDcEventData

    {

        TDcEventType iType;

        void* iConsumer;

        void* iParam;

    };

    /**

     * Sends an event into a consumer.

     *

     * @since S60 5.2

     * @param aConsumer Consumer of the event.

     * @param aType Type of event given to the invoke method.

     */

    void DoDcEvent(MSwtDcEventConsumer* aConsumer, TInt aType);

    /**

     * Invokes callback aConsumer->MdcDSAResourcesCallback.

     *

     * @since S60 5.2

     * @param aControl Control used to get DSA resources from.

     * @param aConsumer Consumer of the callback.

     */

    void DoInvokeDSAResourcesCallback(

        CCoeControl* aControl,

        MUiEventConsumer *aConsumer);

    /**

     * Invokes callback aConsumer->MdcUICallback.

     *

     * @since S60 5.2

     * @param aConsumer Consumer of the callback.

     * @param aCallbackId Id which is provided to the callback

     */

    void DoInvokeUICallback(

        MUiEventConsumer *aConsumer,

        TInt aCallbackId);

// from base class CActive

    /**

     * From CActive.

     * Handles an active object’s request completion event.

     * Processes the first available event in queue.

     *

     * @since S60 5.2

     */

    virtual void RunL();

    /**

     * From CActive.

     * Implements cancellation of an outstanding request.

     *

     * @since S60 5.2

     */

    virtual void DoCancel();

private:

    /**

     * Event queue to store the call requests

     * Own.

     */

    RMsgQueue<TDcEventData> iEventQueue;

};

#endif // SWTDCOBSERVER_H