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Diffstat (limited to 'pango2/pango-script.c')
| -rw-r--r-- | pango2/pango-script.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/pango2/pango-script.c b/pango2/pango-script.c new file mode 100644 index 00000000..e65c6265 --- /dev/null +++ b/pango2/pango-script.c @@ -0,0 +1,373 @@ +/* Pango2 + * pango-script.c: Script tag handling + * + * Copyright (C) 2002 Red Hat Software + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + * Implementation of pango2_script_iter is derived from ICU: + * + * icu/sources/common/usc_impl.c + * + ********************************************************************** + * Copyright (C) 1999-2002, International Business Machines + * Corporation and others. All Rights Reserved. + ********************************************************************** + * + * 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. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR + * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL + * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING + * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, + * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION + * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + * Except as contained in this notice, the name of a copyright holder + * shall not be used in advertising or otherwise to promote the sale, use + * or other dealings in this Software without prior written authorization + * of the copyright holder. + */ + +#include "config.h" +#include <stdlib.h> +#include <string.h> + +#include "pango-script.h" +#include "pango-script-private.h" + + +/**********************************************************************/ + +static Pango2ScriptIter *pango2_script_iter_copy (Pango2ScriptIter *iter); + +G_DEFINE_BOXED_TYPE (Pango2ScriptIter, + pango2_script_iter, + pango2_script_iter_copy, + pango2_script_iter_free) + +Pango2ScriptIter * +_pango2_script_iter_init (Pango2ScriptIter *iter, + const char *text, + int length) +{ + iter->text_start = text; + if (length >= 0) + iter->text_end = text + length; + else + iter->text_end = text + strlen (text); + + iter->script_start = text; + iter->script_end = text; + iter->script_code = G_UNICODE_SCRIPT_COMMON; + + iter->paren_sp = -1; + + pango2_script_iter_next (iter); + + return iter; +} + +/** + * pango2_script_iter_new: + * @text: a UTF-8 string + * @length: length of @text, or -1 if @text is nul-terminated + * + * Create a new `Pango2ScriptIter`, used to break a string of + * Unicode text into runs by Unicode script. + * + * No copy is made of @text, so the caller needs to make + * sure it remains valid until the iterator is freed with + * [method@Pango2.ScriptIter.free]. + * + * Return value: the new script iterator, initialized + * to point at the first range in the text, which should be + * freed with [method@Pango2.ScriptIter.free]. If the string is + * empty, it will point at an empty range. + */ +Pango2ScriptIter * +pango2_script_iter_new (const char *text, + int length) +{ + return _pango2_script_iter_init (g_slice_new (Pango2ScriptIter), text, length); +} + +static Pango2ScriptIter * +pango2_script_iter_copy (Pango2ScriptIter *iter) +{ + return g_slice_dup (Pango2ScriptIter, iter); +} + +void +_pango2_script_iter_fini (Pango2ScriptIter *iter) +{ +} + +/** + * pango2_script_iter_free: + * @iter: a `Pango2ScriptIter` + * + * Frees a `Pango2ScriptIter`. + */ +void +pango2_script_iter_free (Pango2ScriptIter *iter) +{ + _pango2_script_iter_fini (iter); + g_slice_free (Pango2ScriptIter, iter); +} + +/** + * pango2_script_iter_get_range: + * @iter: a `Pango2ScriptIter` + * @start: (out) (optional): location to store start position of the range + * @end: (out) (optional): location to store end position of the range + * @script: (out) (optional): location to store script for range + * + * Gets information about the range to which @iter currently points. + * + * The range is the set of locations p where *start <= p < *end. + * (That is, it doesn't include the character stored at *end) + */ +void +pango2_script_iter_get_range (Pango2ScriptIter *iter, + const char **start, + const char **end, + GUnicodeScript *script) +{ + if (start) + *start = iter->script_start; + if (end) + *end = iter->script_end; + if (script) + *script = iter->script_code; +} + +static const gunichar paired_chars[] = { + 0x0028, 0x0029, /* ascii paired punctuation */ + 0x003c, 0x003e, + 0x005b, 0x005d, + 0x007b, 0x007d, + 0x00ab, 0x00bb, /* guillemets */ + 0x0f3a, 0x0f3b, /* tibetan */ + 0x0f3c, 0x0f3d, + 0x169b, 0x169c, /* ogham */ + 0x2018, 0x2019, /* general punctuation */ + 0x201c, 0x201d, + 0x2039, 0x203a, + 0x2045, 0x2046, + 0x207d, 0x207e, + 0x208d, 0x208e, + 0x27e6, 0x27e7, /* math */ + 0x27e8, 0x27e9, + 0x27ea, 0x27eb, + 0x27ec, 0x27ed, + 0x27ee, 0x27ef, + 0x2983, 0x2984, + 0x2985, 0x2986, + 0x2987, 0x2988, + 0x2989, 0x298a, + 0x298b, 0x298c, + 0x298d, 0x298e, + 0x298f, 0x2990, + 0x2991, 0x2992, + 0x2993, 0x2994, + 0x2995, 0x2996, + 0x2997, 0x2998, + 0x29fc, 0x29fd, + 0x2e02, 0x2e03, + 0x2e04, 0x2e05, + 0x2e09, 0x2e0a, + 0x2e0c, 0x2e0d, + 0x2e1c, 0x2e1d, + 0x2e20, 0x2e21, + 0x2e22, 0x2e23, + 0x2e24, 0x2e25, + 0x2e26, 0x2e27, + 0x2e28, 0x2e29, + 0x3008, 0x3009, /* chinese paired punctuation */ + 0x300a, 0x300b, + 0x300c, 0x300d, + 0x300e, 0x300f, + 0x3010, 0x3011, + 0x3014, 0x3015, + 0x3016, 0x3017, + 0x3018, 0x3019, + 0x301a, 0x301b, + 0xfe59, 0xfe5a, + 0xfe5b, 0xfe5c, + 0xfe5d, 0xfe5e, + 0xff08, 0xff09, + 0xff3b, 0xff3d, + 0xff5b, 0xff5d, + 0xff5f, 0xff60, + 0xff62, 0xff63 +}; + +static int +get_pair_index (gunichar ch) +{ + int lower = 0; + int upper = G_N_ELEMENTS (paired_chars) - 1; + + while (lower <= upper) + { + int mid = (lower + upper) / 2; + + if (ch < paired_chars[mid]) + upper = mid - 1; + else if (ch > paired_chars[mid]) + lower = mid + 1; + else + return mid; + } + + return -1; +} + +/* duplicated in pango-language.c */ +#define REAL_SCRIPT(script) \ + ((script) > G_UNICODE_SCRIPT_INHERITED && (script) != G_UNICODE_SCRIPT_UNKNOWN) + +#define SAME_SCRIPT(script1, script2) \ + (!REAL_SCRIPT (script1) || !REAL_SCRIPT (script2) || (script1) == (script2)) + +#define IS_OPEN(pair_index) (((pair_index) & 1) == 0) + +/** + * pango2_script_iter_next: + * @iter: a `Pango2ScriptIter` + * + * Advances a `Pango2ScriptIter` to the next range. + * + * If @iter is already at the end, it is left unchanged + * and %FALSE is returned. + * + * Return value: %TRUE if @iter was successfully advanced + */ +gboolean +pango2_script_iter_next (Pango2ScriptIter *iter) +{ + int start_sp; + + if (iter->script_end == iter->text_end) + return FALSE; + + start_sp = iter->paren_sp; + iter->script_code = G_UNICODE_SCRIPT_COMMON; + iter->script_start = iter->script_end; + + for (; iter->script_end < iter->text_end; iter->script_end = g_utf8_next_char (iter->script_end)) + { + gunichar ch = g_utf8_get_char (iter->script_end); + GUnicodeScript sc; + int pair_index; + + sc = g_unichar_get_script (ch); + if (sc != G_UNICODE_SCRIPT_COMMON) + pair_index = -1; + else + pair_index = get_pair_index (ch); + + /* + * Paired character handling: + * + * if it's an open character, push it onto the stack. + * if it's a close character, find the matching open on the + * stack, and use that script code. Any non-matching open + * characters above it on the stack will be poped. + */ + if (pair_index >= 0) + { + if (IS_OPEN (pair_index)) + { + /* + * If the paren stack is full, empty it. This + * means that deeply nested paired punctuation + * characters will be ignored, but that's an unusual + * case, and it's better to ignore them than to + * write off the end of the stack... + */ + if (++iter->paren_sp >= PAREN_STACK_DEPTH) + iter->paren_sp = 0; + + iter->paren_stack[iter->paren_sp].pair_index = pair_index; + iter->paren_stack[iter->paren_sp].script_code = iter->script_code; + } + else if (iter->paren_sp >= 0) + { + int pi = pair_index & ~1; + + while (iter->paren_sp >= 0 && iter->paren_stack[iter->paren_sp].pair_index != pi) + iter->paren_sp--; + + if (iter->paren_sp < start_sp) + start_sp = iter->paren_sp; + + if (iter->paren_sp >= 0) + sc = iter->paren_stack[iter->paren_sp].script_code; + } + } + + if (SAME_SCRIPT (iter->script_code, sc)) + { + if (!REAL_SCRIPT (iter->script_code) && REAL_SCRIPT (sc)) + { + iter->script_code = sc; + + /* + * now that we have a final script code, fix any open + * characters we pushed before we knew the script code. + */ + while (start_sp < iter->paren_sp) + iter->paren_stack[++start_sp].script_code = iter->script_code; + } + + /* + * if this character is a close paired character, + * pop it from the stack + */ + if (pair_index >= 0 && !IS_OPEN (pair_index) && iter->paren_sp >= 0) + { + iter->paren_sp--; + + if (iter->paren_sp < start_sp) + start_sp = iter->paren_sp; + } + } + else + { + /* Different script, we're done */ + break; + } + } + + return TRUE; +} + +/********************************************************** + * End of code from ICU + **********************************************************/ |