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// Copyright (C) 2003 Mooffie <mooffie@typo.co.il>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
#include <config.h>
#include "bidi.h"
#include "dbg.h"
static ctype_t fribidi_dir(direction_t dir)
{
switch (dir) {
case dirLTR: return FRIBIDI_TYPE_LTR;
case dirRTL: return FRIBIDI_TYPE_RTL;
default: return FRIBIDI_TYPE_ON;
}
}
void BiDi::get_embedding_levels(unichar *str, idx_t len,
direction_t dir,
level_t *levels,
int line_breaks_count,
idx_t *line_breaks,
bool disable_bidi)
{
if (disable_bidi) {
for (idx_t i = len-1; i >= 0; i--)
levels[i] = (dir == dirRTL) ? 1 :0;
} else {
ctype_t base_dir = fribidi_dir(dir);
fribidi_log2vis_get_embedding_levels(str, len, &base_dir, levels);
}
// Do rule L1.4 of TR9: wspaces at end of lines.
level_t para_embedding_level = (dir == dirRTL ? 1 : 0);
int prev_line_break = 0;
for (int i = 0; i < line_breaks_count; i++) {
int pos = (int)line_breaks[i] - 1;
while (pos >= prev_line_break && is_space(str[pos])) {
levels[pos] = para_embedding_level;
pos--;
}
prev_line_break = line_breaks[i];
}
}
static void xsimple_log2vis(unichar *str, idx_t len, direction_t dir,
unichar *dest)
{
ctype_t base_dir = fribidi_dir(dir);
fribidi_log2vis(str, len, &base_dir, dest, NULL, NULL, NULL);
}
void BiDi::simple_log2vis(unistring &str, direction_t dir, unistring &dest)
{
dest.resize(str.size() + 1); // fribidi_log2vis needs "+1" !!!!!!!!!!!!!
xsimple_log2vis(str.begin(), str.size(), dir, dest.begin());
dest.resize(str.size());
}
// determine_base_dir() - determines the base direction of a string.
// We provide the user with several algorithms. algoUnicode is described
// in P2,3 of TR9.
//
// algoContext's implementation is divided into two: half is here and
// the other half is in EditBox::calc_contextual_dirs(). See documentation
// there.
direction_t BiDi::determine_base_dir(unichar *str, idx_t len,
diralgo_t dir_algo)
{
ctype_t ctype;
switch (dir_algo) {
case algoContextRTL:
{
// - if there's any RTL letter, set direction to LTR;
// - else: if there's any LTR letter, set direction to LTR;
// - else: set direction to neutral.
bool found_LTR = false;
for (idx_t i = 0; i < len; i++) {
ctype = fribidi_get_type(str[i]);
if (FRIBIDI_IS_LETTER(ctype)) {
if (FRIBIDI_IS_RTL(ctype))
return dirRTL;
else
found_LTR = true;
}
}
if (found_LTR)
return dirLTR;
else
return dirN;
}
case algoUnicode:
case algoContextStrong:
{
// directionality is determined by the first strong letter.
for (idx_t i = 0; i < len; i++) {
ctype = fribidi_get_type(str[i]);
if (FRIBIDI_IS_LETTER(ctype)) {
if (FRIBIDI_IS_RTL(ctype))
return dirRTL;
else
return dirLTR;
}
}
if (dir_algo == algoContextStrong)
return dirN;
else
return dirLTR;
}
case algoForceRTL:
return dirRTL;
case algoForceLTR:
default:
return dirLTR;
};
}
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