/*

* Copyright (c) 2008 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:  Preview provider ECOM plugin

*

*/

#ifndef PREVIEWPROVIDERCRP_H

#define PREVIEWPROVIDERCRP_H

// INCLUDES

#include <w32std.h>

#include <graphics/wsgraphicdrawerinterface.h>

#include <graphics/wsgraphicdrawer.h>

// Number of screenshots used at the same time,

// each window group change will cause a screenshot

// to one of these, the index for the current one is

// switched after each screenshot capture. (this is needed

// to prevent overwriting screenshots before the client could

// make a copy of them)

const TInt KMaxShots = 4;

/**

 * Preview provider window server ECOM plugin class.

 */

NONSHARABLE_CLASS( CPreviewProviderCRP ) : public CWsGraphicDrawer, 

                                           public MWsEventHandler 

    {

public:

    /**

     * Creates a new instance of the plguin.

     *

     * @return Created instance.

     */ 

    static CWsGraphicDrawer* CreateL();

    /**

     * Destructor

     */ 

    ~CPreviewProviderCRP();

private:

    /**

     * From CWsGraphicDrawer.

     *

     * @param aGc

     * @param aRect

     * @param aData

     */ 

    void DoDraw( MWsGc& aGc, const TRect& aRect, const TDesC8& aData ) const;

    /**

     * Handles message from PreviewProviderClient.

     *

     * @param aData Message data.

     */ 

    void HandleMessage( const TDesC8& aData );

    /**

     * 2nd phase constructor.

     *

     * @param aEnv

     * @param aId

     * @param aOwner

     * @param aData

     */     

    void ConstructL( MWsGraphicDrawerEnvironment& aEnv, 

                     const TGraphicDrawerId& aId, 

                     MWsClient& aOwner, 

                     const TDesC8& aData );

    /**

     * From MWsEventHandler.

     * 

     * Observer for TWservCrEvent::EWindowGroupChanged to take the screenshot

     * when application changes.

     *

     * @param aEvent

     */     

    void DoHandleEvent( const TWservCrEvent& aEvent );

private:

    /**

     * 2nd phase constructor.

     */ 

    void ConstructL();

    /**

     * Handles application registration.

     *

     * @param aWgId Window group id.

     */ 

    void Register( TInt aWgId );

    /**

     * Handler application unregistration.

     *

     * @param aWgId Window group id.

     */     

    void Unregister( TInt aWgId );

    /*

     * Allocate resources and take screenshot

     */

    void ScreenshotL();

    /**

     * Takes the screenshot.

     */     

    void ScreenshotL( CFbsBitmap& aBitmap );

    /**

     * Remove bitmap reference fom list

     */

    void RemoveScreenshot( TInt aBitmapHandle );

    /**

     * Remove all bitmaps overflow

     */

    void CheckOverflow();

    /**

     * Handles message from PreviewProviderClient.

     *

     * @param aData Message data.

     */     

    void DoHandleMessageL( const TDesC8& aData );

    /**

     * Notifies the PreviewProviderClient when screenshot is ready for copying.

     */     

    void ScaleCompleteL(const CFbsBitmap& aBitmap);

    /**

     * Notifies the PreviewProviderClient when an application has been exited.

     */

    void UnregisterComplete( TInt aWgId );

    /**

     * Uses window server front buffer to create a screenshot.

     * @param aFront preallocated destination bitmap

     * @param aFront Front buffer. 

     * @param aSrcSize Size of the source front buffer in pixels.

     * @param aSrcStride Source stride.

     */

    void FrontBufferScreenShot(

        CFbsBitmap& aBitmap,

        MWsFrontBuffer& aFront, const TSize& aSrcSize, TInt aSrcStride );  

private:

    TInt iScreen;

    TInt iPrevId;

    TInt iPrevReg; // to work around the problem with wgid not set when app brought 

                   // to foreground first time

    RPointerArray<CFbsBitmap> iScreenshots;

    TSize iScreenshotSize;

    TDisplayMode iScreenshotMode;

    RArray<TInt> iWgIds;

    };

#endif // PREVIEWPROVIDERCRP_H

// End of file