src/Bidi.cpp

   1 /**
   2  * \file Bidi.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Dekel Tsur
   7  *
   8  * Full author contact details are available in file CREDITS.
   9  */
  10
  11 #include <config.h>
  12
  13 #include "Bidi.h"
  14 #include "Buffer.h"
  15 #include "BufferView.h"
  16 #include "Cursor.h"
  17 #include "Font.h"
  18 #include "Row.h"
  19 #include "LyXRC.h"
  20 #include "Paragraph.h"
  21
  22
  23 namespace lyx {
  24
  25
  26 pos_type Bidi::log2vis(pos_type pos) const
  27 {
  28         return (start_ == -1) ? pos : log2vis_list_[pos - start_];
  29 }
  30
  31
  32 pos_type Bidi::vis2log(pos_type pos) const
  33 {
  34         return (start_ == -1) ? pos : vis2log_list_[pos - start_];
  35 }
  36
  37
  38 pos_type Bidi::level(pos_type pos) const
  39 {
  40         return (start_ == -1) ? 0 : levels_[pos - start_];
  41 }
  42
  43
  44 bool Bidi::inRange(pos_type pos) const
  45 {
  46         return start_ == -1 || (start_ <= pos && pos <= end_);
  47 }
  48
  49 bool Bidi::same_direction() const
  50 {
  51         return same_direction_;
  52 }
  53
  54
  55 void Bidi::computeTables(Paragraph const & par,
  56         Buffer const & buf, Row const & row)
  57 {
  58         same_direction_ = true;
  59         if (!lyxrc.rtl_support) {
  60                 start_ = -1;
  61                 return;
  62         }
  63
  64         if (par.ownerCode() == ERT_CODE || par.ownerCode() == LISTINGS_CODE) {
  65                 start_ = -1;
  66                 return;
  67         }
  68
  69         start_ = row.pos();
  70         end_ = row.endpos() - 1;
  71
  72         if (start_ > end_) {
  73                 start_ = -1;
  74                 return;
  75         }
  76
  77         if (end_ + 2 - start_ >
  78             static_cast<pos_type>(log2vis_list_.size())) {
  79                 pos_type new_size =
  80                         (end_ + 2 - start_ < 500) ?
  81                         500 : 2 * (end_ + 2 - start_);
  82                 log2vis_list_.resize(new_size);
  83                 vis2log_list_.resize(new_size);
  84                 levels_.resize(new_size);
  85         }
  86
  87         vis2log_list_[end_ + 1 - start_] = -1;
  88         log2vis_list_[end_ + 1 - start_] = -1;
  89
  90         BufferParams const & bufparams = buf.params();
  91         pos_type stack[2];
  92         bool const rtl_par = par.isRTL(bufparams);
  93         int lev = 0;
  94         bool rtl = false;
  95         bool rtl0 = false;
  96         pos_type const body_pos = par.beginOfBody();
  97
  98         for (pos_type lpos = start_; lpos <= end_; ++lpos) {
  99                 bool is_space = false;
 100                 // We do not handle spaces around an RTL segment in a special way anymore.
 101                 // Neither do we do so when generating the LaTeX, so setting is_space
 102                 // to false makes the view in the GUI consistent with the output of LaTeX
 103                 // later. The old setting was:
 104                 //bool is_space = par.isLineSeparator(lpos);
 105                 // FIXME: once we're sure that this is what we really want, we should just
 106                 // get rid of this variable...
 107                 pos_type const pos =
 108                         (is_space && lpos + 1 <= end_ &&
 109                          !par.isLineSeparator(lpos + 1) &&
 110                          !par.isNewline(lpos + 1))
 111                         ? lpos + 1 : lpos;
 112                 Font font = par.getFontSettings(bufparams, pos);
 113                 if (pos != lpos && 0 < lpos && rtl0 && font.isRightToLeft() &&
 114                     font.fontInfo().number() == FONT_ON &&
 115                     par.getFontSettings(bufparams, lpos - 1).fontInfo().number()
 116                     == FONT_ON) {
 117                         font = par.getFontSettings(bufparams, lpos);
 118                         is_space = false;
 119                 }
 120
 121                 bool new_rtl = font.isVisibleRightToLeft();
 122                 bool new_rtl0 = font.isRightToLeft();
 123                 int new_level;
 124
 125                 if (lpos == body_pos - 1
 126                     && row.pos() < body_pos - 1
 127                     && is_space) {
 128                         new_level = rtl_par ? 1 : 0;
 129                         new_rtl0 = rtl_par;
 130                         new_rtl = rtl_par;
 131                 } else if (new_rtl0) {
 132                         new_level = new_rtl ? 1 : 2;
 133                 } else {
 134                         new_level = rtl_par ? 2 : 0;
 135                 }
 136
 137                 if (is_space && new_level >= lev) {
 138                         new_level = lev;
 139                         new_rtl = rtl;
 140                         new_rtl0 = rtl0;
 141                 }
 142
 143                 int new_level2 = new_level;
 144
 145                 if (lev == new_level && rtl0 != new_rtl0) {
 146                         --new_level2;
 147                         log2vis_list_[lpos - start_] = rtl ? 1 : -1;
 148                 } else if (lev < new_level) {
 149                         log2vis_list_[lpos - start_] = rtl ? -1 : 1;
 150                         if (new_level > 0 && !rtl_par)
 151                                 same_direction_ = false;
 152                 } else {
 153                         log2vis_list_[lpos - start_] = new_rtl ? -1 : 1;
 154                 }
 155                 rtl = new_rtl;
 156                 rtl0 = new_rtl0;
 157                 levels_[lpos - start_] = new_level;
 158
 159                 while (lev > new_level2) {
 160                         pos_type old_lpos = stack[--lev];
 161                         int delta = lpos - old_lpos - 1;
 162                         if (lev % 2)
 163                                 delta = -delta;
 164                         log2vis_list_[lpos - start_] += delta;
 165                         log2vis_list_[old_lpos - start_] += delta;
 166                 }
 167                 while (lev < new_level)
 168                         stack[lev++] = lpos;
 169         }
 170
 171         while (lev > 0) {
 172                 pos_type const old_lpos = stack[--lev];
 173                 int delta = end_ - old_lpos;
 174                 if (lev % 2)
 175                         delta = -delta;
 176                 log2vis_list_[old_lpos - start_] += delta;
 177         }
 178
 179         pos_type vpos = start_ - 1;
 180         for (pos_type lpos = start_; lpos <= end_; ++lpos) {
 181                 vpos += log2vis_list_[lpos - start_];
 182                 vis2log_list_[vpos - start_] = lpos;
 183                 log2vis_list_[lpos - start_] = vpos;
 184         }
 185 }
 186
 187
 188 // This method requires a previous call to computeTables()
 189 bool Bidi::isBoundary(Buffer const & buf, Paragraph const & par,
 190         pos_type pos) const
 191 {
 192         if (!lyxrc.rtl_support || pos == 0)
 193                 return false;
 194
 195         if (!inRange(pos - 1)) {
 196                 // This can happen if pos is the first char of a row.
 197                 // Returning false in this case is incorrect!
 198                 return false;
 199         }
 200
 201         bool const rtl = level(pos - 1) % 2;
 202         bool const rtl2 = inRange(pos)
 203                 ? level(pos) % 2
 204                 : par.isRTL(buf.params());
 205         return rtl != rtl2;
 206 }
 207
 208
 209 bool Bidi::isBoundary(Buffer const & buf, Paragraph const & par,
 210         pos_type pos, Font const & font) const
 211 {
 212         if (!lyxrc.rtl_support)
 213                 return false;    // This is just for speedup
 214
 215         bool const rtl = font.isVisibleRightToLeft();
 216         bool const rtl2 = inRange(pos)
 217                 ? level(pos) % 2
 218                 : par.isRTL(buf.params());
 219         return rtl != rtl2;
 220 }
 221
 222
 223 bool reverseDirectionNeeded(Cursor const & cur)
 224 {
 225         /*
 226          * We determine the directions based on the direction of the
 227          * bottom() --- i.e., outermost --- paragraph, because that is
 228          * the only way to achieve consistency of the arrow's movements
 229          * within a paragraph, and thus avoid situations in which the
 230          * cursor gets stuck.
 231          */
 232         return cur.bottom().paragraph().isRTL(cur.bv().buffer().params());
 233 }
 234
 235
 236 bool isWithinRtlParagraph(Cursor const & cur)
 237 {
 238         return cur.innerParagraph().isRTL(cur.bv().buffer().params());
 239 }
 240
 241 } // namespace lyx