/*

* Copyright (c) 2002 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: 

*     Phonebook image reader class definition.

*

*/

#ifndef __CPbkImageReader_H__

#define __CPbkImageReader_H__

//  INCLUDES

#include <e32base.h>    // CBase

#include "TPbkImageLoadParameters.h"

// FORWARD DECLARATIONS

class MPbkImageReaderObserver;

class CImageDecoder;

class CBitmapScaler;

class TFrameInfo;

// CLASS DECLARATIONS

/**

 * Phonebook image file or buffer -> bitmap reader.

 */

NONSHARABLE_CLASS(CPbkImageReader) : 

        public CActive

    {

    public: // interface

        /**

         * Creates a new instance of this class.

         *

         * @param aObserver observer to notify about progress of this 

         *        operation.

         */

        static CPbkImageReader* NewL(MPbkImageReaderObserver& aObserver);

        /**

         * Destructor. Cancels any executing read operation and destroys this

         * object. Observer is not notified about the cancellation.

         */

        ~CPbkImageReader();

        /**

         * Reads bitmap from file. Cancels any previously executing read 

         * operation. Observer is not notified about the cancellation.

         *

         * @param aFileName name of the image file to read

         * @param aParams   optional parameters, @see TPbkImageLoadParameters

         */

        void ReadFromFileL

            (const TDesC& aFileName, 

            const TPbkImageLoadParameters* aParams=NULL);

        /**

         * Reads bitmap from buffer. Cancels any previously executing read 

         * operation. Observer is not notified about the cancellation.

         *

         * @param aBuffer   the buffer to read the image from. Caller must keep

         *                  the buffer alive as long as this reader is 

         *                  executing

         * @param aParams   optional parameters, @see TPbkImageLoadParameters

         */

        void ReadFromBufferL

            (const TDesC8& aBuffer, 

            const TPbkImageLoadParameters* aParams=NULL);

        /**

         * Recognizes image format in a file.

         *

         * @param aFileName file to recognize image format from.

         * @see ImageFormat().

         */

        void RecognizeFormatFromFileL(const TDesC& aFileName);

        /**

         * Recognizes image format in a buffer.

         *

         * @param aBuffer buffer to recognize image format from.

         * @see ImageFormat().

         */

        void RecognizeFormatFromBufferL(const TDesC8& aBuffer);

        /**

         * Returns Mime string of the recognized format. Recognizing

         * function has to be called before this, otherwise Mime string

         * is not known and NULL descriptor will be returned.

         *

         * @return Mime string of the recognized format.

         */

        const TDesC8& MimeString() const;

        /**

         * Returns information about a frame of the image.

         * Can be called after this object calls ImageOpenComplete to its

         * observer.

         *

         * @param aFrame    number of the frame to get inforamtion of.

         * @param aInfo     frame information is written to this parameter.

         * @precond aFrame>=0 && aFrame<FrameCount()

         * @see CImageDecoder::FrameInfo

         */

        void FrameInfo(TInt aFrame, TFrameInfo& aInfo) const;

        /**

         * Returns the frame count of the image.

         * Can be called after this object calls ImageOpenComplete to its

         * observer.

         *

         * @see CImageDecoder::FrameCount

         */

        TInt FrameCount() const;

        /**

         * This is overridden from CActive because 

         * observers may be called from RunL. If observers then call

         * Cancel method, the CActive implementation does not call DoCancel.

         * However, in this case it has to be called so that resources 

         * are freed immediately in case of Cancel.

         */

        void Cancel();

    private: // From CActive

        void RunL();

        TInt RunError(TInt aError);

        void DoCancel();

    private: // implementation

        CPbkImageReader(MPbkImageReaderObserver& aObserver);

        void ConstructL();

        void NextStateL();

        void ConvertImageToBitmapL();

        void ScaleBitmapL();

        void Complete();

        void InitReadL(const TPbkImageLoadParameters* aParams);

        void CloseImage();

    private: // data members

        /// Ref: observer

        MPbkImageReaderObserver& iObserver;

        /// Own: currect asynchronous step

        TInt iState;

        /// Own: reading parameters

        TPbkImageLoadParameters iParams;

        /// Own: file server session

        RFs iFsSession;

        /// Own: image decoder

        CImageDecoder* iImageDecoder;        

        /// Own: read bitmap

        CFbsBitmap* iBitmap;

        /// Own: bitmap scaler

        CBitmapScaler* iBitmapScaler;

        /// Own: Mime string of the read image

        HBufC8* iMimeString;

    };

#endif // __CPbkImageReader_H__

// End of File