/*

* ==============================================================================

*  Name        : %name: hgpreviewprovider.h %

*  Part of     : Hg fast swap preview provider plugin

*  Description : Preview provider API

*  Version     : %version: sa1spcx1#2 %

*

*  Copyright (c) 2008 Nokia Corporation.

*  This material, including documentation and any related

*  computer programs, is protected by copyright controlled by

*  Nokia Corporation. All rights are reserved. Copying,

*  including reproducing, storing, adapting or translating, any

*  or all of this material requires the prior written consent of

*  Nokia Corporation. This material also contains confidential

*  information which may not be disclosed to others without the

*  prior written consent of Nokia Corporation.

* ==============================================================================

*/

#ifndef HGPREVIEWPROVIDER_H

#define HGPREVIEWPROVIDER_H

// INCLUDES

#include <e32base.h>

#include <gdi.h>

// FORWARD DECLARATIONS

class CHgFastSwapPreviewProviderClient;

class MHgFastSwapPreviewObserver;

/**

 * Preview provider API class. Applications (window groups) must be

 * registered before screenshots can be received. Also, closed apps

 * should be unregistered to save resources.

 * TakePreview() can be called to take a screenshot right away.

 * A client needing notifications has to create an instance

 * so that screenshots can be delivered to it via MHgFastSwapPreviewObserver.

 *

 * @see MHgFastSwapPreviewObserver

 * @lib hgpreviewprovider.lib

 */

NONSHARABLE_CLASS( CHgFastSwapPreviewProvider ) : public CBase

    {

public:

    /**

     * Two phased constructor.

     * @see MHgFastSwapPreviewObserver

     *

     * @param aObs Observer.     

     */   

    IMPORT_C static CHgFastSwapPreviewProvider* NewL(

        MHgFastSwapPreviewObserver& aObs );

    /**

     * Destructor.

     */   

    IMPORT_C ~CHgFastSwapPreviewProvider();

    /**

     * Registers window group for screenshots.

     *

     * @param aWgId Window group id.

     * @return Error code.     

     */       

    IMPORT_C TInt Register( TInt aWgId );

    /**

     * Unregisters window group.

     *

     * @param aWgId Window group id.

     * @return Error code.     

     */       

    IMPORT_C TInt Unregister( TInt aWgId );

    /**

     * Change screen.

     *

     * @param aScreenId Screen id.

     * @return Error code.     

     */       

    IMPORT_C TInt ChangeScreen( TInt aScreenId );

    /**

     * Defines the dimensions and format of the screenshots.

     * @see TDisplayMode.

     *

     * @param aSize Size to be used for the preview screenshots.

     * @param aMode Color depth to be used for the preview screenshots.

     * @return Error code.

     */       

    IMPORT_C TInt SetPreviewParam( const TSize& aSize, TDisplayMode aMode );

    /**

     * Takes a screenshot.

     * 

     * @return Error code.     

     */       

    IMPORT_C TInt TakePreview();

    /**

     * Ack preview ready message

     */

    IMPORT_C void AckPreview( TInt aPreviewId );

private:

    /**

     * C++ constructor.

     */   

    CHgFastSwapPreviewProvider();

    /**

     * 2nd phase constructor.

     *

     * @param aObs Observer.

     */       

    void ConstructL( MHgFastSwapPreviewObserver& aObs );

private:    

    /**

     * Implementation class.

     */   

    CHgFastSwapPreviewProviderClient* iClient;

    };

#endif // HGPREVIEWPROVIDER_H

// End of file