// bufferbase.h

// 

// Copyright (c) 2009 - 2010 Accenture. All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the "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:

// Accenture - Initial contribution

//

#ifndef BUFFERBASE_H_

#define BUFFERBASE_H_

#include <e32base.h>

#include "common.h"

enum TEncodingType

	{

	EEncodingUnknown,

	EEncodingNarrow,

	EEncodingUtf8,

	EEncodingUtf16LE,

	EEncodingUtf16BE,

#ifdef __BIG_ENDIAN__ // I know Symbian doesn't actually define the endian macros (afaics) but if they do, we'll do the right thing(TM)

	EEncodingUtf16Native = EEncodingUtf16BE,

	EEncodingUtf16Switched = EEncodingUtf16LE,

#else

	// Assume little-endian unless specifically told otherwise

	EEncodingUtf16Native = EEncodingUtf16LE,

	EEncodingUtf16Switched = EEncodingUtf16BE,

#endif

	};

enum TDelimiterType

	{

	EDelimNotYetKnown = 0,

	EDelimLF, // Unix

	EDelimCRLF, // DOS

	EDelimCR, // old school mac

	EDelimUnicode, // KUnicodeLineBreak - really doubt we'll see many of these!

	};

class CFileBlock;

//Parent class for all memory buffers which can be used by appropriate views to read/write data and show it on the screen

class CFedBufferBase : public CActive, public MSharedCacheProvider

{

protected:

	CFedBufferBase();

public:

	TInt RefCount() const;

	void PushL(); // Pushes a cleanup stack item that does a DecRef()

	void IncRef();

	TInt DecRef();

	~CFedBufferBase();

public: // From MSharedCacheProvider

	TInt RegisterClient(MSharedCacheClient& aClient, TPtrC& aDes, TRange& aRange, TInt& aRangeStartLineNumber);

	void UnregisterClient(MSharedCacheClient& aClient);

public: // CActive (noops in this class, override if you actually use the CActive-ness

	void DoCancel();

	void RunL();

public:

	virtual const TDesC& Title() const = 0;

	virtual TBool Modified() const;

	virtual TBool Editable() const;

	virtual TDelimiterType DelimiterType() const = 0;

	virtual TEncodingType Encoding() const = 0;

	virtual TBool IsOpen() const;

	virtual TInt GetData(MSharedCacheClient& aClient, TInt aDocumentPosition) = 0; // "Get me the block containing aDocumentPosition".

	virtual TInt SeekFromOffset(MSharedCacheClient& aClient, TInt aOffset, TInt aNumLinesFromOffset, TInt aLineLength) = 0; 

	virtual TBool DocumentPositionIsEof(TInt aDocumentPosition) const = 0; // The block containing aDocumentPosition MUST have already have been loaded (otherwise we could not guarantee const-ness)

	virtual TInt Find(TInt aStartingPosition, const TDesC& aSearchString, TBool aBackwards) = 0;

	virtual void InsertTextL(TInt aDocumentPosition, const TDesC& aText);

	virtual void DeleteTextL(TRange aRange);

	virtual void SaveL(const TDesC& aName, TBool aReplace);

protected:

	TInt FindClientRequest(MSharedCacheClient& aClient);

	class TClientRequest

		{

	public:

		TClientRequest(MSharedCacheClient* aClient, TPtrC& aDes, TRange& aRange, TInt& aRangeStartLineNumber)

			: iClient(aClient), iDes(aDes), iRange(aRange), iLastRequestedBlock(NULL), iRangeStartLineNumber(aRangeStartLineNumber)

			{}

	public:

		MSharedCacheClient* iClient;

		TPtrC& iDes;

		TRange& iRange; // iRange is the document range for whatever's in iDes (used for something else during seeking)

		CFileBlock* iLastRequestedBlock;

		TInt& iRangeStartLineNumber;

		};

private:

	TInt iRefCount;

protected:

	RArray<TClientRequest> iClientRequests;

};

class CConstDataBuffer : public CFedBufferBase

	{

public:

	CConstDataBuffer(const TDesC& aTitle, const TDesC& aText);

	CConstDataBuffer(const TDesC& aTitle, HBufC* aTextPtr);

	~CConstDataBuffer();

	const TDesC& Title() const;

	TDelimiterType DelimiterType() const;

	TEncodingType Encoding() const;

	TInt GetData(MSharedCacheClient& aClient, TInt aDocumentPosition);

	TInt SeekFromOffset(MSharedCacheClient& aClient, TInt aOffset, TInt aNumLinesFromOffset, TInt aLineLength); 

	TBool DocumentPositionIsEof(TInt aDocumentPosition) const;

	TInt Find(TInt aStartingPosition, const TDesC& aSearchString, TBool aBackwards);

private:

	const TDesC& iTitle;

	TPtrC iText;

	HBufC* iOwnedTextPtr;

	};

#endif /*BUFFERBASE_H_*/