gecko-dev/gfx/thebes/gfxScriptItemizer.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * This file is based on usc_impl.c from ICU 4.2.0.1, slightly adapted
 * for use within Mozilla Gecko, separate from a standard ICU build.
 *
 * The original ICU license of the code follows:
 *
 * ICU License - ICU 1.8.1 and later
 *
 * COPYRIGHT AND PERMISSION NOTICE
 * 
 * Copyright (c) 1995-2009 International Business Machines Corporation and
 * others
 *
 * All rights reserved.
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 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, provided that the above copyright notice(s) and this
 * permission notice appear in all copies of the Software and that both the
 * above copyright notice(s) and this permission notice appear in supporting
 * documentation.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
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 */

#ifndef GFX_SCRIPTITEMIZER_H
#define GFX_SCRIPTITEMIZER_H

#include <stdint.h>
#include "nsUnicodeScriptCodes.h"

#define PAREN_STACK_DEPTH 32

class gfxScriptItemizer
{
public:
    typedef mozilla::unicode::Script Script;

    gfxScriptItemizer(const char16_t *src, uint32_t length);

    void SetText(const char16_t *src, uint32_t length);

    bool Next(uint32_t& aRunStart, uint32_t& aRunLimit,
              Script& aRunScript);

protected:
    void reset() {
        scriptStart = 0;
        scriptLimit = 0;
        scriptCode  = Script::INVALID;
        parenSP     = -1;
        pushCount   =  0;
        fixupCount  =  0;
    }

    void push(uint32_t endPairChar, Script newScriptCode);
    void pop();
    void fixup(Script newScriptCode);

    struct ParenStackEntry {
        uint32_t endPairChar;
        Script  scriptCode;
    };

    const char16_t *textPtr;
    uint32_t textLength;

    uint32_t scriptStart;
    uint32_t scriptLimit;
    Script  scriptCode;

    struct ParenStackEntry parenStack[PAREN_STACK_DEPTH];
    uint32_t parenSP;
    uint32_t pushCount;
    uint32_t fixupCount;
};

#endif /* GFX_SCRIPTITEMIZER_H */