/*
 * Copyright 2003-2010, Haiku, Inc.
 * Distributed under the terms of the MIT License.
 */
#ifndef __WIDTHBUFFER_H
#define __WIDTHBUFFER_H


#include <Locker.h>
#include <TextView.h>

#include "TextViewSupportBuffer.h"


class BFont;


namespace BPrivate {


class TextGapBuffer;


struct _width_table_ {
        BFont font;                             // corresponding font
        int32 hashCount;                // number of hashed items
        int32 tableCount;               // size of table
        void* widths;                   // width table
};


class WidthBuffer : public _BTextViewSupportBuffer_<_width_table_> {
public:
                                                                WidthBuffer();
        virtual                                         ~WidthBuffer();

                        float                           StringWidth(const char* inText,
                                                                        int32 fromOffset, int32 length,
                                                                        const BFont* inStyle);
                        float                           StringWidth(TextGapBuffer& gapBuffer,
                                                                        int32 fromOffset, int32 length,
                                                                        const BFont* inStyle);

private:
                        bool                            FindTable(const BFont* font, int32* outIndex);
                        int32                           InsertTable(const BFont* font);

                        bool                            GetEscapement(uint32 value, int32 index,
                                                                        float* escapement);
                        float                           HashEscapements(const char* chars,
                                                                        int32 numChars, int32 numBytes,
                                                                        int32 tableIndex, const BFont* font);

        static  uint32                          Hash(uint32);

private:
                        BLocker                         fLock;
};


extern WidthBuffer* gWidthBuffer;


} // namespace BPrivate


using BPrivate::WidthBuffer;


#if __GNUC__ < 3
//! NetPositive binary compatibility support

class _BWidthBuffer_ : public _BTextViewSupportBuffer_<BPrivate::_width_table_> {
        _BWidthBuffer_();
        virtual ~_BWidthBuffer_();
};

extern
_BWidthBuffer_* gCompatibilityWidthBuffer;

#endif // __GNUC__ < 3


#endif // __WIDTHBUFFER_H