/*
 * Copyright 2001-2006, Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Marc Flerackers (mflerackers@androme.be)
 */
#ifndef __TEXTGAPBUFFER_H
#define __TEXTGAPBUFFER_H


#include <SupportDefs.h>
#include <TextView.h>


class BFile;


namespace BPrivate {


class TextGapBuffer {
public:
                                                                TextGapBuffer();
                                                                ~TextGapBuffer();

                        void                            InsertText(const char* inText, int32 inNumItems,
                                                                        int32 inAtIndex);
                        bool                            InsertText(BFile* file, int32 fileOffset,
                                                                        int32 amount, int32 atIndex);
                        void                            RemoveRange(int32 start, int32 end);

                        bool                            FindChar(char inChar, int32 fromIndex,
                                                                        int32* ioDelta);

                        const char*                     Text();
                        const char*                     RealText();
                        int32                           Length() const;

                        const char*                     GetString(int32 fromOffset, int32* numBytes);
                        void                            GetString(int32 offset, int32 length,
                                                                        char* buffer);

                        char                            RealCharAt(int32 offset) const;

                        bool                            PasswordMode() const;
                        void                            SetPasswordMode(bool);

private:
                        void                            _MoveGapTo(int32 toIndex);
                        void                            _EnlargeGapTo(int32 inCount);
                        void                            _ShrinkGapTo(int32 inCount);

                        int32                           fItemCount;                     // logical count
                        char*                           fBuffer;                        // allocated memory
                        int32                           fBufferCount;           // physical count
                        int32                           fGapIndex;                      // gap position
                        int32                           fGapCount;                      // gap count
                        char*                           fScratchBuffer;         // for GetString
                        int32                           fScratchSize;           // scratch size
                        bool                            fPasswordMode;
};


inline int32
TextGapBuffer::Length() const
{
        return fItemCount;
}


inline char
TextGapBuffer::RealCharAt(int32 index) const
{
        if (index < 0 || index >= fItemCount) {
                if (index != fItemCount)
                        debugger("RealCharAt: invalid index supplied");
                return 0;
        }

        return index < fGapIndex ? fBuffer[index] : fBuffer[index + fGapCount];
}


} // namespace BPrivate


#endif //__TEXTGAPBUFFER_H