/*

* 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:  Document class, CCalcDocument

*                Derived from CEikDocument

*                The history of inputted data is held.

*                The memory of four-arithmetical-operations operation 

*                or a calculation result is held.

*                The last result and memory are saved at a file and 

*                it restores.

*

*/

#ifndef     CALCDOC_H

#define     CALCDOC_H

//  INCLUDES

#include <eikdoc.h>

#include "CalcEditline.h"

#include "CalcView.h"

//  CONSTANTS

const TInt KCalcErrEditorSpaceFull(-10000); 

//  FORWARD DECLARATIONS

class  CEikAppUi;

class  CCalcHistory;

class  CCalcAppEnv;

//  CLASS DEFINITIONS 

/**

CCalcDocument : 'Document' class

*/

class   CCalcDocument 

        :public CEikDocument

    {

    public:  // Constructors and destructor  

        /**

        * Two-phased constructor.

        * @param aApp : Reference of CEikApplication class 

        */

        static CCalcDocument* NewL(CEikApplication& aApp);

        /**

        * Destructor.

        */

        virtual ~CCalcDocument();

    public:  // New functions

		/**

        * Set the pointer to CalcAppEnv. 

        */

		void SetAppEnv(CCalcAppEnv* aCalcAppEnv);

        /**

        * Set the pointer to CalcAppEnv. 

        */		

        void SetCalcView( CCalcView* aCCalcView );

		/**

        * Make calculation, and add result to calcluation history.

        * Leave may occur, causes KErrOverflow or KErrDivideByZero or KErrNotSupported (negative value with square root).

        * @param aOperand : operand.

        * @param aLine : inputted edit line

        * @return TReal64: Provisional result.

        */

        TReal64 CalculateAndAddHistoryL(

                TReal64 aOperand,

               const TCalcEditLine& aLine);  

		/**

        * Make calculation, nothing is added to the calculation history.

        * Leave may occur, causes KErrOverflow or KErrDivideByZero or KErrNotSupported (negative value with square root).

        * @param aOperand : operand.

        * @param aLine : inputted edit line

        * @return TReal64: Provisional result.

        */

		TReal64 CalculateAndNoHistoryL(

				TReal64 aOperand,

               const TCalcEditLine& aLine);  

		/**

        * Make calculation, and modify the operator

		* before adding anything to the calculation history.

        * Leave may occur, causes KErrOverflow or KErrDivideByZero or KErrNotSupported (negative value with square root).

        * @param aOperand : operand.

        * @param aLine : inputted edit line

        * @return TReal64: Provisional result.

        */

		TReal64 CalculateAndModifyHistoryL(

				TReal64 aOperand,

               TCalcEditLine& aLine,

			   TCalcEditLine::TCalcOperatorType aOperator); 

        /**

        * Add a line which is "= (provisional result)" to calculation history.

        * And Last Result is updated to provisional result

        */

        void AddEqualLineAndUpdateLastResultL();

        /**

        * Empty line is added to calculation history.

        */

        void AddEmptyLine();

        /**

        * Memory is saved.

        * @param aNewMemory : New memory, current operand.

        */

        void MemorySaveL(TReal64 aNewMemory); 

        /**

        * Memory is saved.

        * @param aLine : Current value of editor

        */

        TBool HasMemory() const;

        /**

        * Return current memory.

        * @return TReal64 : current memory.

        */

        TReal64 Memory() const; 

        /**

        * Clear memory.

        */

        void MemoryClearL();

        /**

        * Return last result

        * @param TReal64 : Last result.

        */

        TReal64 LastResult() const;  

        /**

        * Return provisional result

        * @param aLine : For getting provisional result.

        */

        TReal64 ProvisionalResult() const;

        /**

        * Return pointer of CCalcHistory class. 

        * @return Pointer of CCalcHistory class

        */

        CCalcHistory* History() const;

        /**

        * Restore memory and last result

        */

        void LoadStateL();

        /**

        * Store memory and last result

        */

		void SaveStateL();

    private:   //  New functions

        /**

        * By default constructor is private.

        * @param aApp: Reference of CEikApplication class

        */

        CCalcDocument(CEikApplication& aApp); 

        /**

        * Second-phase constructor

        */

        void ConstructL();

        /**

        * Make calculation by using argument aLine 

        * Leave may occur, causes KErrOverflow or KErrDivideByZero.

        * @param aOperand : operand

        * @param aOperator : Operator type enum.

        * @return Result of calculation

        */

        TReal64 CalculateL(TReal64 aOperand,

            TCalcEditLine::TCalcOperatorType aOperator);

        /**

        * Check overflow and underflow 

        * Leave may occur, causes KErrOverflow

        * @param aResult : result of calculation

        */

        void CheckResultL(TReal64* aResult);  

        /**

        * Write last result and memory to document file.

        * @param aStream : Interface of write steam

        */

        void ExternalizeL(RWriteStream& aStream) const;

        /**

        * Read last result and memory from document file.

        * @param aStream : Interface of read steam

        */

        void InternalizeL(RReadStream& aStream);

    private:  // Functions from base classes  

        /**

        * From CEikDocument : Create CCalcAppUi object

        */

        CEikAppUi* CreateAppUiL();  

    private:    // Data

	    CCalcAppEnv* iCalcAppEnv;  // Not own

        TReal64 iProvisionalResult; // Provisional result

        TReal64 iMemory;        // Memory

        TReal64 iLastResult;    // Last result

        CCalcHistory* iHistory; // History

        CCalcView* iCCalcView;  // Not own

    };

#endif      //  CALCDOC_H

// End of File