/*

* Copyright (c) 2006-2010 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: 

*

*/

#ifndef __OPENFONTS_PRIVATE_H__

#define __OPENFONTS_PRIVATE_H__

#include <hextree.h>

class COpenFontShaperCacheEntry;

/* MSB is set to indicate a glyph code rather than a unicode value

   This is used for extracting the code value */

#define GLYPH_CODE(code) (code & 0x7fffffff)

/** COpenFontFile owned container for extra data. May be extended without affecting Binary Compatibility.

 @internalComponent

 */

class TOpenFontFileData

	{

public:

	CFontStore* iFontStore;			// pointer to the CFontStore instance that loaded the COpenFontFile

	};

/**

 Note: this class must be self-contained, since instances are added to an RHexTree,

 that is, it must be possible to destroy instances simply with RHeap::Free().

 @internalComponent

 */

class COpenFontGlyph

	{

public:

    static COpenFontGlyph* New(RHeap* aHeap, TInt aCode, TInt aGlyphIndex,

                               const TOpenFontCharMetrics& aMetrics, const TDesC8& aBitmap);

	inline static void Delete(RHeap* aHeap, COpenFontGlyph* aGlyph);

	inline const TUint8* Bitmap() const;

protected:

	COpenFontGlyph(TInt aCode, TInt aGlyphIndex, const TOpenFontCharMetrics& aMetrics)

		: iCode(aCode), iGlyphIndex(aGlyphIndex), iMetrics(aMetrics), iBitmapOffset(0) {}

	~COpenFontGlyph() {}

	void SetBitmap(const TAny* aBitmap);

public:

	const TInt iCode;						// the Unicode value of the character

	const TInt iGlyphIndex;					// the glyph index

	const TOpenFontCharMetrics iMetrics;	// the metrics

private:

	// an offset from this COpenFontGlyph object to a pointer to the run-length-encoded bitmap, 

	// calculated as (bitmapPointer)-(this)

	TInt iBitmapOffset;

	};

/**

 * Template for offset implementation of pointer array

 @internalComponent

 */

template<class T>

class ROffsetArray

    {

public:

    ROffsetArray();

    TInt Create(RHeap* aHeap, TInt aCount);

    void Close(RHeap* aHeap);

    TInt Count() const;

    T* operator[](TInt aIndex) const;

    void SetAt(TInt aIndex, T* aEntry);

private:

    TInt iOffset;

    TInt iCount;

    };

/**

 The per-font glyph cache. For now, just the members that used to be directly in

 COpenFont. Now it is a private class it can be elaborated to do character-to-glyph-index

 mapping when that is needed.

 @internalComponent

 */

class COpenFontGlyphCache

	{

public:

	COpenFontGlyphCache(RHeap* aHeap)

	  : iGlyphTreeById(aHeap),

		iGlyphTreeByUnicode(aHeap),

		iGlyphCacheMemory(0),

		iShaperCacheSentinel(NULL),

		iShapingInfoCacheMemory(0),

		iNumberOfShaperCacheEntries(0)

		{}

	TShapeHeader* SearchShaperCache(TInt aSessionHandle, TFontShapeFunctionParameters*& aParams);

	TShapeHeader* Insert(TInt aSessionHandle, RHeap* aHeap, CShaper::TInput aInput, TShapeHeader* aShapeHeader, TInt& aAddedBytes);

	TInt DeleteLeastRecentlyUsedEntry(RHeap* aHeap);

	TBool ShaperCacheIsEmpty();

public:

	RHexTree<COpenFontGlyph> iGlyphTreeById;				// a hex tree of glyphs indexed by glyph ID

	RHexTree<COpenFontGlyph> iGlyphTreeByUnicode;			// a hex tree of glyphs indexed by Unicode code point

	TInt iGlyphCacheMemory;									// memory used by the glyph tree in bytes

	COpenFontShaperCacheEntry* iShaperCacheSentinel;

	TInt iShapingInfoCacheMemory;

	TInt iNumberOfShaperCacheEntries;	

	};

/**

 @internalComponent

 */

class COpenFontSessionCacheEntry: public COpenFontGlyph

	{

public:

	static COpenFontSessionCacheEntry* New(RHeap* aHeap, const COpenFont* aFont, TInt aCode, TInt aGlyphIndex,

										   const TOpenFontCharMetrics& aMetrics, const TDesC8& aBitmap);

	inline static void Delete(RHeap* aHeap, COpenFontSessionCacheEntry* aEntry);

	inline const COpenFont* Font()const;

private:

	inline COpenFontSessionCacheEntry(const COpenFont* aFont, TInt aCode, TInt aGlyphIndex, const TOpenFontCharMetrics& aMetrics);

	~COpenFontSessionCacheEntry();

public:

    TInt iLastAccess;               // serial number of the last access to the glyph

private: 

    TInt iFontOffset;          // offset of the font that contains this glyph, (not owned by this class!)    

	};

/**

 A glyph cache for a particular session.

 Because session caches are not shared they can shrink as well as grow.

 @internalComponent

 */

class COpenFontSessionCache

    {

public:

    static COpenFontSessionCache* NewL(RHeap* aHeap, TInt aSessionHandle, TInt aEntries);

    void Delete(RHeap* aHeap);

    TInt SessionHandle() { return iSessionHandle; }

    const COpenFontGlyph* Glyph(const COpenFont* aFont, TInt aCode, TInt& aIndex);

    void Insert(RHeap* aHeap, COpenFontSessionCacheEntry* aEntry, TInt aIndex);

private:

    COpenFontSessionCache(TInt aSessionHandle);

    ~COpenFontSessionCache();

public:

    TInt iSessionHandle;    

    TInt iLastAccess;

    ROffsetArray<COpenFontSessionCacheEntry> iEntryArray;

    };

// inline functions

inline void COpenFontGlyph::Delete(RHeap* aHeap, COpenFontGlyph* aGlyph)

	{

	aHeap->Free(aGlyph);

	}

/**

@return A pointer to the bitmap data stored with this glyph, or NULL

if no bitmap has been stored with this glyph.

 */

inline const TUint8* COpenFontGlyph::Bitmap() const

	{

	if (iBitmapOffset)

		{

		return reinterpret_cast<const TUint8*>(PtrAdd(this, iBitmapOffset));

		}

	return NULL;

	}

inline COpenFontSessionCacheEntry::COpenFontSessionCacheEntry(const COpenFont* aFont, TInt aCode, TInt aGlyphIndex,const TOpenFontCharMetrics& aMetrics) :

    COpenFontGlyph(aCode, aGlyphIndex, aMetrics)

    {

    iFontOffset = aFont ? reinterpret_cast<TInt>(aFont) - reinterpret_cast<TInt>(this) : 0;

    }

inline void COpenFontSessionCacheEntry::Delete(RHeap* aHeap, COpenFontSessionCacheEntry* aEntry)

	{

	COpenFontGlyph::Delete(aHeap, aEntry);

	}

inline const COpenFont* COpenFontSessionCacheEntry::Font() const

    {

    if (iFontOffset)

        {

        return reinterpret_cast<const COpenFont*> (PtrAdd(this, iFontOffset));

        }

    return NULL;

    }

#endif	// __OPENFONTSPRIVATE_H__