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elinks/src/intl/charsets.h
Witold Filipczyk faff6b9b63 ascii replacements for linux virtual terminals
Patch by sgerwk, slightly modified. Taken from Debian.
2022-10-03 17:55:20 +02:00

207 lines
7.7 KiB
C

#ifndef EL__INTL_CHARSETS_H
#define EL__INTL_CHARSETS_H
#ifdef __cplusplus
extern "C" {
#endif
struct hash;
/* The TRE check in configure.ac assumes unicode_val_T is uint32_t. */
typedef uint32_t unicode_val_T;
/* U+0020 SPACE. Normally the same as ' ' or L' ' but perhaps ELinks
* shouldn't rely on that. */
#define UCS_SPACE ((unicode_val_T) 0x0020)
/* U+00A0 NO-BREAK SPACE. */
#define UCS_NO_BREAK_SPACE ((unicode_val_T) 0x00A0)
/* U+00AD SOFT HYPHEN. */
#define UCS_SOFT_HYPHEN ((unicode_val_T) 0x00AD)
/* U+FFFD REPLACEMENT CHARACTER. Used when no Unicode mapping is
* known for a byte in a codepage, or when invalid UTF-8 is received
* from a terminal. After generating the character, ELinks then
* treats it like any other Unicode character. The user can also type
* this character directly, and it can occur in documents. */
#define UCS_REPLACEMENT_CHARACTER ((unicode_val_T) 0xFFFD)
/* A special value that fits in unicode_val_T but is outside the range
* of Unicode characters. utf8_to_unicode and cp_to_unicode return
* this if the input is too short. This is also used as a placeholder
* for the second cell of a double-cell character. */
#define UCS_NO_CHAR ((unicode_val_T) 0xFFFFFFFD)
#ifdef CONFIG_COMBINE
#define UCS_END_COMBINED ((unicode_val_T) 0xFFFFFFFC)
#define UCS_BEGIN_COMBINED ((unicode_val_T) (UCS_END_COMBINED - (unicode_val_T) 10000))
/* Base character and up to 5 combining characters. */
#define UCS_MAX_LENGTH_COMBINED 6
#endif /* CONFIG_COMBINE */
/* If ELinks should display a double-cell character but there is only
* one cell available, it displays this character instead. This must
* be a single-cell character but need not be unique. Possible values
* might be U+0020 SPACE or U+303F IDEOGRAPHIC HALF FILL SPACE.
*
* Some BFU widgets (at least input fields and list boxes) currently
* ignore this setting and use U+0020 instead. (They first draw spaces
* and then overwrite with text; look for utf8_cells2bytes calls.)
* We should fix that if we ever change the value. */
#define UCS_ORPHAN_CELL ((unicode_val_T) 0x20)
/*   replacement character. See u2cp().
* UTF-8 strings should use the encoding of U+00A0 instead. */
#define NBSP_CHAR ((unsigned char) 1)
#define NBSP_CHAR_STRING "\001"
/* How to convert a byte from a source charset. This is used in an
* array (struct conv_table[256]) indexed by the byte value. */
struct conv_table {
/* 0 if this is the final byte of a character, or 1 if more
* bytes are needed. */
int t;
union {
/* If @t==0: a null-terminated string that is the
* corresponding character in the target charset.
* Normally, the string is statically allocated.
* However, if the conversion table is to UTF-8, then
* the strings in elements 0x80 to 0xFF are allocated
* with @mem_alloc and owned by the table. */
const char *str;
/* If @t==1: a pointer to a nested conversion table
* (with 256 elements) that describes how to convert
* each possible subsequent byte. The conversion
* table owns the nested conversion table. */
struct conv_table *tbl;
} u;
int iconv_cp;
};
enum convert_string_mode {
CSM_DEFAULT, /* Convert any char. */
CSM_QUERY, /* Special handling of '&' and '=' chars. */
CSM_FORM, /* Special handling of '&' and '=' chars in forms. */
CSM_NONE, /* Convert nothing. */
};
/* How to translate U+00A0 NO-BREAK SPACE. If u2cp_ is converting to
* UTF-8, it ignores this choice and just encodes the U+00A0. */
enum nbsp_mode {
/* Convert to NBSP_CHAR. This lets the HTML renderer
* recognize nbsp even if the codepage doesn't support
* nbsp. (VISCII doesn't.) */
NBSP_MODE_HACK = 0,
/* Convert to normal ASCII space. */
NBSP_MODE_ASCII = 1
};
struct conv_table *get_translation_table(int, int);
const char *get_entity_string(const char *str,
const int strlen, int encoding);
/* The convert_string() name is also used by Samba (version 3.0.3), which
* provides libnss_wins.so.2, which is called somewhere inside
* _nss_wins_gethostbyname_r(). This name clash causes the elinks hostname
* lookup thread to crash so we need to rename the symbol. */
/* Reported by Derek Poon and filed as bug 453 */
#undef convert_string
#define convert_string convert_string_elinks
/* This routine converts a string from one charset to another according to the
* passed @convert_table, potentially also decoding SGML (HTML) entities along
* the way (according to @mode). It either returns dynamically allocated
* converted string of length @length, or if the @callback is non-NULL it calls
* it each few bytes instead and always returns NULL (@length is undefined).
* Note that it's ok not to care and pass NULL as @length. */
char *convert_string(struct conv_table *convert_table,
const char *chars, int charslen, int cp,
enum convert_string_mode mode, int *length,
void (*callback)(void *data, char *buf, int buflen),
void *callback_data);
int get_cp_index(const char *);
const char *get_cp_name(int);
const char *get_cp_config_name(int);
const char *get_cp_mime_name(int);
const uint16_t *get_cp_highhalf(const char *);
int is_cp_utf8(int);
void free_conv_table(void);
char *encode_utf8(unicode_val_T);
#ifdef CONFIG_UTF8
char *utf8_prevchar(char *, int, char *);
int utf8charlen(const char *);
int utf8_char2cells(const char *, char *);
int utf8_ptr2cells(const char *, char *);
int utf8_ptr2chars(char *, char *);
int utf8_cells2bytes(const char *, int, char *);
/* How utf8_step_forward and utf8_step_backward count steps. */
enum utf8_step {
/* Each step is one character, even if it is a combining or
* double-width character. */
UTF8_STEP_CHARACTERS,
/* Each step is one cell. If the specified number of steps
* would end in the middle of a double-width character, do not
* include the character. */
UTF8_STEP_CELLS_FEWER,
/* Each step is one cell. If the specified number of steps
* would end in the middle of a double-width character,
* include the whole character. */
UTF8_STEP_CELLS_MORE
};
char *utf8_step_forward(char *, char *,
int, enum utf8_step, int *);
char *utf8_step_backward(char *, char *,
int, enum utf8_step, int *);
int is_codepoint_supported(unicode_val_T u);
int codepoint_replacement(unicode_val_T u);
int unicode_to_cell(unicode_val_T);
unicode_val_T unicode_fold_label_case(unicode_val_T);
int strlen_utf8(char **);
#endif /* CONFIG_UTF8 */
unicode_val_T utf8_to_unicode(char **, const char *);
unicode_val_T cp_to_unicode(int, char **, const char *);
#ifdef CONFIG_COMBINE
extern unicode_val_T last_combined;
extern unicode_val_T **combined;
extern struct hash *combined_hash;
unicode_val_T get_combined(unicode_val_T *, int);
void free_combined();
#endif /* CONFIG_COMBINE */
unicode_val_T cp2u(int, unsigned char);
const char *cp2utf8(int, int);
const char *u2cp_(unicode_val_T, int, enum nbsp_mode);
#define u2cp(u, to) u2cp_(u, to, NBSP_MODE_HACK)
#define u2cp_no_nbsp(u, to) u2cp_(u, to, NBSP_MODE_ASCII)
void init_charsets_lookup(void);
void free_charsets_lookup(void);
/* UTF-16 encodes each Unicode character U+0000...U+FFFF as a single
* 16-bit code unit, and each character U+10000...U+10FFFF as a pair
* of two code units: a high surrogate followed by a low surrogate.
* The range U+D800...U+DFFF is reserved for these surrogates. */
#define is_utf16_surrogate(u) (((u) & 0xFFFFF800) == 0xD800)
#define is_utf16_high_surrogate(u) (((u) & 0xFFFFFC00) == 0xD800)
#define is_utf16_low_surrogate(u) (((u) & 0xFFFFFC00) == 0xDC00)
#define join_utf16_surrogates(high,low) (0x10000 + (((high) - 0xD800L) << 10) + ((low) - 0xDC00))
#define needs_utf16_surrogates(u) ((uint32_t) ((u) - 0x10000) < 0x100000)
#define get_utf16_high_surrogate(u) (0xD800 + (((u) - 0x10000) >> 10))
#define get_utf16_low_surrogate(u) (0xDC00 + ((u) & 0x3FF))
#ifdef __cplusplus
}
#endif
#endif