khtml/rendering/bidi.h

   1 /*
   2  * This file is part of the html renderer for KDE.
   3  *
   4  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
   5  * Copyright (C) 2003 Apple Computer, Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public License
  18  * along with this library; see the file COPYING.LIB.  If not, write to
  19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20  * Boston, MA 02110-1301, USA.
  21  *
  22  */
  23 #ifndef BIDI_H
  24 #define BIDI_H
  25
  26 #include <QtCore/QString>
  27
  28 namespace khtml {
  29     class RenderArena;
  30         class RenderObject;
  31     class InlineBox;
  32
  33     class BidiContext {
  34     public:
  35         BidiContext(unsigned char level, QChar::Direction embedding, BidiContext *parent = 0, bool override = false);
  36         ~BidiContext();
  37
  38         void ref() const;
  39         void deref() const;
  40
  41         unsigned char level;
  42         bool override : 1;
  43         QChar::Direction dir : 5;
  44         QChar::Direction basicDir : 5;
  45
  46         BidiContext *parent;
  47
  48
  49         // refcounting....
  50         mutable int count;
  51     };
  52
  53     struct BidiRun {
  54         BidiRun(int _start, int _stop, RenderObject *_obj, BidiContext *context, QChar::Direction dir)
  55             :  start( _start ), stop( _stop ), obj( _obj ), box(0), nextRun(0)
  56         {
  57             if(dir == QChar::DirON) dir = context->dir;
  58
  59             level = context->level;
  60
  61             // add level of run (cases I1 & I2)
  62             if( level % 2 ) {
  63                 if(dir == QChar::DirL || dir == QChar::DirAN || dir == QChar::DirEN)
  64                     level++;
  65             } else {
  66                 if( dir == QChar::DirR )
  67                     level++;
  68                 else if( dir == QChar::DirAN || dir == QChar::DirEN)
  69                     level += 2;
  70             }
  71         }
  72
  73         void detach(RenderArena* renderArena);
  74
  75         // Overloaded new operator.
  76         void* operator new(size_t sz, RenderArena* renderArena) throw();
  77
  78         // Overridden to prevent the normal delete from being called.
  79         void operator delete(void* ptr, size_t sz);
  80
  81 private:
  82         // The normal operator new is disallowed.
  83         void* operator new(size_t sz) throw();
  84
  85 public:
  86         int start;
  87         int stop;
  88
  89         RenderObject *obj;
  90         InlineBox* box;
  91
  92         // explicit + implicit levels here
  93         uchar level;
  94
  95         bool compact : 1;
  96
  97         BidiRun* nextRun;
  98     };
  99
 100     struct BidiIterator;
 101     struct BidiState;
 102
 103     struct BidiStatus {
 104         BidiStatus() : eor(QChar::DirON), lastStrong(QChar::DirON), last(QChar::DirON) {}
 105
 106         QChar::Direction eor;
 107         QChar::Direction lastStrong;
 108         QChar::Direction last;
 109     };
 110
 111 }
 112
 113 #endif