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author | Vincent Sanders <vince@kyllikki.org> | 2021-01-31 10:49:13 +0000 |
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committer | Vincent Sanders <vince@kyllikki.org> | 2021-01-31 10:49:13 +0000 |
commit | 83ebc3bb8ee84284e68e2cb87873c1934e1b92b5 (patch) | |
tree | 00e7e0d40282e107d5c95b6746a08fa565842c49 /content/handlers/html/list_counter_style.c | |
parent | 13c1b11317d0153af235f1f2d15798a9cd942358 (diff) | |
download | netsurf-83ebc3bb8ee84284e68e2cb87873c1934e1b92b5.tar.gz netsurf-83ebc3bb8ee84284e68e2cb87873c1934e1b92b5.tar.bz2 |
split counter style handling out of the box code
Diffstat (limited to 'content/handlers/html/list_counter_style.c')
-rw-r--r-- | content/handlers/html/list_counter_style.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/content/handlers/html/list_counter_style.c b/content/handlers/html/list_counter_style.c new file mode 100644 index 000000000..a5ce3ae64 --- /dev/null +++ b/content/handlers/html/list_counter_style.c @@ -0,0 +1,312 @@ +/* + * Copyright 2021 Vincent Sanders <vince@netsurf-browser.org> + * + * This file is part of NetSurf, http://www.netsurf-browser.org/ + * + * NetSurf 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; version 2 of the License. + * + * NetSurf 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, see <http://www.gnu.org/licenses/>. + */ + +/** + * \file + * Implementation of css list counter styling + */ + +#include <stddef.h> +#include <stdio.h> + +#include "css/select.h" + +#include "html/list_counter_style.h" + + +/** + * maps alphabet values to output values with a symbol table + * + * Takes a list of alphabet values and for each one outputs the + * compete symbol (in utf8) to an output buffer. + * + * \param buf The oputput buffer + * \param buflen the length of \a buf + * \param aval array of alphabet values + * \param alen The number of values in \a alen + * \param symtab The symbol table + * \param symtablen The number of symbols in \a symtab + * \return The number of bytes needed in the output buffer whichmay be + * larger than \a buflen but the buffer will not be overrun + */ +static int +map_aval_to_symbols(char *buf, const size_t buflen, + const uint8_t *aval, const size_t alen, + const char symtab[][4], const size_t symtablen) +{ + size_t oidx; + size_t aidx; + int sidx; + + oidx = 0; + for (aidx=0; aidx < alen; aidx++) { + sidx=0; + while ((sidx < 4) && + (symtab[aval[aidx]][sidx] != 0)) { + if (oidx < buflen) { + buf[oidx] = symtab[aval[aidx]][sidx]; + } + oidx++; + sidx++; + } + } + return oidx; +} + + +/** + * generate alphabet symbol values for latin and greek labelling + * + * fills array with alphabet values suitable for the input value + * + * \param ares Buffer to recive the converted values + * \param alen the length of \a ares buffer + * \param value The value to convert + * \param slen The number of symbols in the alphabet + * \return The length a complete conversion which may be larger than \a alen + */ +static size_t +calc_alphabet_values(uint8_t *ares, + const size_t alen, + int value, + unsigned char slen) +{ + size_t idx = 0; + uint8_t *first; + uint8_t *last; + + /* generate alphabet values in ascending order */ + while (value > 0) { + --value; + if (idx < alen) ares[idx] = value % slen; + idx++; + value = value / slen; + } + + /* put the values in decending order */ + first = ares; + if (idx < alen) { + last = first + (idx - 1); + } else { + last = first + (alen - 1); + } + while (first < last) { + *first ^= *last; + *last ^= *first; + *first ^= *last; + first++; + last--; + } + + return idx; +} + + +/** + * Roman numeral conversion + * + * \return The number of characters that are nesesary for full output + */ +static int +ntoromannumeral(char *buf, const size_t maxlen, int value, const char *C) +{ + const int S[] = { 0, 2, 4, 2, 4, 2, 4 }; + const int D[] = { 1000, 500, 100, 50, 10, 5, 1 }; + const size_t L = sizeof(D) / sizeof(int) - 1; + size_t k = 0; /* index into output buffer */ + unsigned int i = 0; /* index into maps */ + int r, r2; + + while (value > 0) { + if (D[i] <= value) { + r = value / D[i]; + value = value - (r * D[i]); + if (i < L) { + /* lookahead */ + r2 = value / D[i+1]; + } + if (i < L && r2 >= S[i+1]) { + /* will violate repeat boundary on next pass */ + value = value - (r2 * D[i+1]); + if (k < maxlen) buf[k++] = C[i+1]; + if (k < maxlen) buf[k++] = C[i-1]; + } else if (S[i] && r >= S[i]) { + /* violated repeat boundary on this pass */ + if (k < maxlen) buf[k++] = C[i]; + if (k < maxlen) buf[k++] = C[i-1]; + } else { + while (r-- > 0 && k < maxlen) { + buf[k++] = C[i]; + } + } + } + i++; + } + if (k < maxlen) { + buf[k] = '\0'; + } + return k; +} + + +/** + * lower case roman numeral + */ +static int ntolcromannumeral(char *buf, const size_t maxlen, int value) +{ + const char C[] = { 'm', 'd', 'c', 'l', 'x', 'v', 'i' }; + return ntoromannumeral(buf, maxlen, value, C); +} + +/** + * upper case roman numeral + */ +static int ntoucromannumeral(char *buf, const size_t maxlen, int value) +{ + const char C[] = { 'M', 'D', 'C', 'L', 'X', 'V', 'I' }; + return ntoromannumeral(buf, maxlen, value, C); +} + + + + +static int ntolcalpha(char *buf, const size_t buflen, int value) +{ + size_t alen; + uint8_t aval[20]; + const char symtab[][4] = { + "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", + "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", + "u", "v", "w", "x", "y", "z" + }; + const size_t symtablen = sizeof(symtab) / 4; + + alen = calc_alphabet_values(aval, sizeof(aval), value, symtablen); + if (alen >= sizeof(aval)) { + *buf = '?'; + return 1; + } + + return map_aval_to_symbols(buf, buflen, aval, alen, symtab, symtablen); +} + +static int ntoucalpha(char *buf, const size_t buflen, int value) +{ + size_t alen; + uint8_t aval[20]; + const char symtab[][4] = { + "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", + "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", + "U", "V", "W", "X", "Y", "Z" + }; + const size_t symtablen = sizeof(symtab) / 4; + + alen = calc_alphabet_values(aval, sizeof(aval), value, symtablen); + if (alen >= sizeof(aval)) { + *buf = '?'; + return 1; + } + + return map_aval_to_symbols(buf, buflen, aval, alen, symtab, symtablen); +} + +static int ntolcgreek(char *buf, const size_t buflen, int value) +{ + size_t alen; + uint8_t aval[20]; + const char symtab[][4] = { + "α", "β", "γ", "δ", "ε", "ζ", "η", "θ", "ι", "κ", + "λ", "μ", "ν", "ξ", "ο", "π", "ρ", "σ", "τ", "υ", + "φ", "χ", "ψ", "ω" + }; + const size_t symtablen = sizeof(symtab) / 4; + + alen = calc_alphabet_values(aval, sizeof(aval), value, symtablen); + if (alen >= sizeof(aval)) { + *buf = '?'; + return 1; + } + + return map_aval_to_symbols(buf, buflen, aval, alen, symtab, symtablen); +} + + +/** + * format value into a list marker with a style + * + * The value is a one based index into the list. This means for + * numeric printing the value must be incremented by one. + */ +size_t +list_counter_style_value(char *text, + size_t text_len, + enum css_list_style_type_e list_style_type, + unsigned int value) +{ + int res = -1; + + switch (list_style_type) { + case CSS_LIST_STYLE_TYPE_DECIMAL_LEADING_ZERO: + res = snprintf(text, text_len, "%02u", value); + break; + + case CSS_LIST_STYLE_TYPE_LOWER_ROMAN: + res = ntolcromannumeral(text, text_len, value); + break; + + case CSS_LIST_STYLE_TYPE_UPPER_ROMAN: + res = ntoucromannumeral(text, text_len, value); + break; + + case CSS_LIST_STYLE_TYPE_LOWER_ALPHA: + case CSS_LIST_STYLE_TYPE_LOWER_LATIN: + res = ntolcalpha(text, text_len, value); + break; + + case CSS_LIST_STYLE_TYPE_UPPER_ALPHA: + case CSS_LIST_STYLE_TYPE_UPPER_LATIN: + res = ntoucalpha(text, text_len, value); + break; + + case CSS_LIST_STYLE_TYPE_LOWER_GREEK: + res = ntolcgreek(text, text_len, value); + break; + + case CSS_LIST_STYLE_TYPE_ARMENIAN: + case CSS_LIST_STYLE_TYPE_GEORGIAN: + case CSS_LIST_STYLE_TYPE_DECIMAL: + default: + res = snprintf(text, text_len, "%u", value); + break; + } + + /* deal with error */ + if (res < 0) { + text[0] = 0; + return 0; + } + + /* deal with overflow */ + if ((size_t)res >= (text_len-2)) { + res = text_len-2; + } + text[res++] = '.'; + text[res++] = 0; + + return res; +} |