mirrors/fltk
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
0b6475d8d6
fltk/src/fl_utf.c
Greg Ercolano 4f4a8fc3c7 Modifications to all LGPL headers for STR #2685. 
(to clarify static exception LGPL by changing license references)



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@8864 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2011-07-19 04:49:30 +00:00

987 lines
32 KiB
C
Raw Blame History

/*
* "$Id$"
*
* This is the utf.c file from fltk2 adapted for use in my fltk1.1 port
*/
/* Copyright 2006-2011 by Bill Spitzak and others.
*
* This library is free software. Distribution and use rights are outlined in
* the file "COPYING" which should have been included with this file. If this
* file is missing or damaged, see the license at:
*
* http://www.fltk.org/COPYING.php
*
* Please report all bugs and problems on the following page:
*
* http://www.fltk.org/str.php
*/
/* Modified to obey rfc3629, which limits unicode to 0-0x10ffff */
#include <FL/fl_utf8.h>
#include <string.h>
#include <stdlib.h>
/** \addtogroup fl_unicode
@{
*/
#if 0
/**
\defgroup fl_unichar Unicode Character Functions
Global Functions Handling Single Unicode Characters
@{ */
/**
Converts a Unicode character into a utf-8 sequence.
\param[in] uc Unicode character
\param[out] text utf-8 sequence will be written here; if this pointer is
\c NULL, only the length of the utf-8 sequence is calculated
\return length of the sequence in bytes
*/
/* FL_EXPORT int fl_unichar_to_utf8(unsigned int uc, char *text); */
/** @} */
/**
\defgroup fl_utf8 Unicode String Functions
Global Functions Handling Unicode Text
@{ */
/**
Calculate the size of a utf-8 sequence for a Unicode character.
\param[in] uc Unicode character
\return length of the sequence in bytes
*/
/* FL_EXPORT int fl_utf8_size(unsigned int uc); */
/** @} */
#endif /* 0 */
/*!Set to 1 to turn bad UTF8 bytes into ISO-8859-1. If this is to zero
they are instead turned into the Unicode REPLACEMENT CHARACTER, of
value 0xfffd.
If this is on fl_utf8decode() will correctly map most (perhaps all)
human-readable text that is in ISO-8859-1. This may allow you
to completely ignore character sets in your code because virtually
everything is either ISO-8859-1 or UTF-8.
*/
#define ERRORS_TO_ISO8859_1 1
/*!Set to 1 to turn bad UTF8 bytes in the 0x80-0x9f range into the
Unicode index for Microsoft's CP1252 character set. You should
also set ERRORS_TO_ISO8859_1. With this a huge amount of more
available text (such as all web pages) are correctly converted
to Unicode.
*/
#define ERRORS_TO_CP1252 1
/*!A number of Unicode code points are in fact illegal and should not
be produced by a UTF-8 converter. Turn this on will replace the
bytes in those encodings with errors. If you do this then converting
arbitrary 16-bit data to UTF-8 and then back is not an identity,
which will probably break a lot of software.
*/
#define STRICT_RFC3629 0
#if ERRORS_TO_CP1252
/* Codes 0x80..0x9f from the Microsoft CP1252 character set, translated
* to Unicode:
*/
static unsigned short cp1252[32] = {
0x20ac, 0x0081, 0x201a, 0x0192, 0x201e, 0x2026, 0x2020, 0x2021,
0x02c6, 0x2030, 0x0160, 0x2039, 0x0152, 0x008d, 0x017d, 0x008f,
0x0090, 0x2018, 0x2019, 0x201c, 0x201d, 0x2022, 0x2013, 0x2014,
0x02dc, 0x2122, 0x0161, 0x203a, 0x0153, 0x009d, 0x017e, 0x0178
};
#endif
/*! Decode a single UTF-8 encoded character starting at \e p. The
resulting Unicode value (in the range 0-0x10ffff) is returned,
and \e len is set to the number of bytes in the UTF-8 encoding
(adding \e len to \e p will point at the next character).
If \p p points at an illegal UTF-8 encoding, including one that
would go past \e end, or where a code is uses more bytes than
necessary, then *(unsigned char*)p is translated as though it is
in the Microsoft CP1252 character set and \e len is set to 1.
Treating errors this way allows this to decode almost any
ISO-8859-1 or CP1252 text that has been mistakenly placed where
UTF-8 is expected, and has proven very useful.
If you want errors to be converted to error characters (as the
standards recommend), adding a test to see if the length is
unexpectedly 1 will work:
\code
if (*p & 0x80) { // what should be a multibyte encoding
code = fl_utf8decode(p,end,&len);
if (len<2) code = 0xFFFD; // Turn errors into REPLACEMENT CHARACTER
} else { // handle the 1-byte utf8 encoding:
code = *p;
len = 1;
}
\endcode
Direct testing for the 1-byte case (as shown above) will also
speed up the scanning of strings where the majority of characters
are ASCII.
*/
unsigned fl_utf8decode(const char* p, const char* end, int* len)
{
unsigned char c = *(unsigned char*)p;
if (c < 0x80) {
if (len) *len = 1;
return c;
#if ERRORS_TO_CP1252
} else if (c < 0xa0) {
if (len) *len = 1;
return cp1252[c-0x80];
#endif
} else if (c < 0xc2) {
goto FAIL;
}
if ( (end && p+1 >= end) || (p[1]&0xc0) != 0x80) goto FAIL;
if (c < 0xe0) {
if (len) *len = 2;
return
((p[0] & 0x1f) << 6) +
((p[1] & 0x3f));
} else if (c == 0xe0) {
if (((unsigned char*)p)[1] < 0xa0) goto FAIL;
goto UTF8_3;
#if STRICT_RFC3629
} else if (c == 0xed) {
/* RFC 3629 says surrogate chars are illegal. */
if (((unsigned char*)p)[1] >= 0xa0) goto FAIL;
goto UTF8_3;
} else if (c == 0xef) {
/* 0xfffe and 0xffff are also illegal characters */
if (((unsigned char*)p)[1]==0xbf &&
((unsigned char*)p)[2]>=0xbe) goto FAIL;
goto UTF8_3;
#endif
} else if (c < 0xf0) {
UTF8_3:
if ( (end && p+2 >= end) || (p[2]&0xc0) != 0x80) goto FAIL;
if (len) *len = 3;
return
((p[0] & 0x0f) << 12) +
((p[1] & 0x3f) << 6) +
((p[2] & 0x3f));
} else if (c == 0xf0) {
if (((unsigned char*)p)[1] < 0x90) goto FAIL;
goto UTF8_4;
} else if (c < 0xf4) {
UTF8_4:
if ( (end && p+3 >= end) || (p[2]&0xc0) != 0x80 || (p[3]&0xc0) != 0x80) goto FAIL;
if (len) *len = 4;
#if STRICT_RFC3629
/* RFC 3629 says all codes ending in fffe or ffff are illegal: */
if ((p[1]&0xf)==0xf &&
((unsigned char*)p)[2] == 0xbf &&
((unsigned char*)p)[3] >= 0xbe) goto FAIL;
#endif
return
((p[0] & 0x07) << 18) +
((p[1] & 0x3f) << 12) +
((p[2] & 0x3f) << 6) +
((p[3] & 0x3f));
} else if (c == 0xf4) {
if (((unsigned char*)p)[1] > 0x8f) goto FAIL; /* after 0x10ffff */
goto UTF8_4;
} else {
FAIL:
if (len) *len = 1;
#if ERRORS_TO_ISO8859_1
return c;
#else
return 0xfffd; /* Unicode REPLACEMENT CHARACTER */
#endif
}
}
/*! Move \p p forward until it points to the start of a UTF-8
character. If it already points at the start of one then it
is returned unchanged. Any UTF-8 errors are treated as though each
byte of the error is an individual character.
\e start is the start of the string and is used to limit the
backwards search for the start of a utf8 character.
\e end is the end of the string and is assumed to be a break
between characters. It is assumed to be greater than p.
This function is for moving a pointer that was jumped to the
middle of a string, such as when doing a binary search for
a position. You should use either this or fl_utf8back() depending
on which direction your algorithim can handle the pointer
moving. Do not use this to scan strings, use fl_utf8decode()
instead.
*/
const char* fl_utf8fwd(const char* p, const char* start, const char* end)
{
const char* a;
int len;
/* if we are not pointing at a continuation character, we are done: */
if ((*p&0xc0) != 0x80) return p;
/* search backwards for a 0xc0 starting the character: */
for (a = p-1; ; --a) {
if (a < start) return p;
if (!(a[0]&0x80)) return p;
if ((a[0]&0x40)) break;
}
fl_utf8decode(a,end,&len);
a += len;
if (a > p) return a;
return p;
}
/*! Move \p p backward until it points to the start of a UTF-8
character. If it already points at the start of one then it
is returned unchanged. Any UTF-8 errors are treated as though each
byte of the error is an individual character.
\e start is the start of the string and is used to limit the
backwards search for the start of a UTF-8 character.
\e end is the end of the string and is assumed to be a break
between characters. It is assumed to be greater than p.
If you wish to decrement a UTF-8 pointer, pass p-1 to this.
*/
const char* fl_utf8back(const char* p, const char* start, const char* end)
{
const char* a;
int len;
/* if we are not pointing at a continuation character, we are done: */
if ((*p&0xc0) != 0x80) return p;
/* search backwards for a 0xc0 starting the character: */
for (a = p-1; ; --a) {
if (a < start) return p;
if (!(a[0]&0x80)) return p;
if ((a[0]&0x40)) break;
}
fl_utf8decode(a,end,&len);
if (a+len > p) return a;
return p;
}
/*! Returns number of bytes that utf8encode() will use to encode the
character \p ucs. */
int fl_utf8bytes(unsigned ucs) {
if (ucs < 0x000080U) {
return 1;
} else if (ucs < 0x000800U) {
return 2;
} else if (ucs < 0x010000U) {
return 3;
} else if (ucs <= 0x10ffffU) {
return 4;
} else {
return 3; /* length of the illegal character encoding */
}
}
/*! Write the UTF-8 encoding of \e ucs into \e buf and return the
number of bytes written. Up to 4 bytes may be written. If you know
that \p ucs is less than 0x10000 then at most 3 bytes will be written.
If you wish to speed this up, remember that anything less than 0x80
is written as a single byte.
If ucs is greater than 0x10ffff this is an illegal character
according to RFC 3629. These are converted as though they are
0xFFFD (REPLACEMENT CHARACTER).
RFC 3629 also says many other values for \p ucs are illegal (in
the range 0xd800 to 0xdfff, or ending with 0xfffe or
0xffff). However I encode these as though they are legal, so that
utf8encode/fl_utf8decode will be the identity for all codes between 0
and 0x10ffff.
*/
int fl_utf8encode(unsigned ucs, char* buf) {
if (ucs < 0x000080U) {
buf[0] = ucs;
return 1;
} else if (ucs < 0x000800U) {
buf[0] = 0xc0 | (ucs >> 6);
buf[1] = 0x80 | (ucs & 0x3F);
return 2;
} else if (ucs < 0x010000U) {
buf[0] = 0xe0 | (ucs >> 12);
buf[1] = 0x80 | ((ucs >> 6) & 0x3F);
buf[2] = 0x80 | (ucs & 0x3F);
return 3;
} else if (ucs <= 0x0010ffffU) {
buf[0] = 0xf0 | (ucs >> 18);
buf[1] = 0x80 | ((ucs >> 12) & 0x3F);
buf[2] = 0x80 | ((ucs >> 6) & 0x3F);
buf[3] = 0x80 | (ucs & 0x3F);
return 4;
} else {
/* encode 0xfffd: */
buf[0] = 0xefU;
buf[1] = 0xbfU;
buf[2] = 0xbdU;
return 3;
}
}
/*! Convert a single 32-bit Unicode codepoint into an array of 16-bit
characters. These are used by some system calls, especially on Windows.
\p ucs is the value to convert.
\p dst points at an array to write, and \p dstlen is the number of
locations in this array. At most \p dstlen words will be
written, and a 0 terminating word will be added if \p dstlen is
large enough. Thus this function will never overwrite the buffer
and will attempt return a zero-terminated string if space permits.
If \p dstlen is zero then \p dst can be set to NULL and no data
is written, but the length is returned.
The return value is the number of 16-bit words that \e would be written
to \p dst if it is large enough, not counting any terminating
zero.
If the return value is greater than \p dstlen it indicates truncation,
you should then allocate a new array of size return+1 and call this again.
Unicode characters in the range 0x10000 to 0x10ffff are converted to
"surrogate pairs" which take two words each (in UTF-16 encoding).
Typically, setting \p dstlen to 2 will ensure that any valid Unicode
value can be converted, and setting \p dstlen to 3 or more will allow
a NULL terminated sequence to be returned.
*/
unsigned fl_ucs_to_Utf16(const unsigned ucs, unsigned short *dst, const unsigned dstlen)
{
/* The rule for direct conversion from UCS to UTF16 is:
* - if UCS > 0x0010FFFF then UCS is invalid
* - if UCS >= 0xD800 && UCS <= 0xDFFF UCS is invalid
* - if UCS <= 0x0000FFFF then U16 = UCS, len = 1
* - else
* -- U16[0] = ((UCS - 0x00010000) >> 10) & 0x3FF + 0xD800
* -- U16[1] = (UCS & 0x3FF) + 0xDC00
* -- len = 2;
*/
unsigned count; /* Count of converted UTF16 cells */
unsigned short u16[4]; /* Alternate buffer if dst is not set */
unsigned short *out; /* points to the active buffer */
/* Ensure we have a valid buffer to write to */
if((!dstlen) || (!dst)) {
out = u16;
} else {
out = dst;
}
/* Convert from UCS to UTF16 */
if((ucs > 0x0010FFFF) || /* UCS is too large */
((ucs > 0xD7FF) && (ucs < 0xE000))) { /* UCS in invalid range */
out[0] = 0xFFFD; /* REPLACEMENT CHARACTER */
count = 1;
} else if(ucs < 0x00010000) {
out[0] = (unsigned short)ucs;
count = 1;
} else if(dstlen < 2) { /* dst is too small for the result */
out[0] = 0xFFFD; /* REPLACEMENT CHARACTER */
count = 2;
} else {
out[0] = (((ucs - 0x00010000) >> 10) & 0x3FF) + 0xD800;
out[1] = (ucs & 0x3FF) + 0xDC00;
count = 2;
}
/* NULL terminate the output, if there is space */
if(count < dstlen) { out[count] = 0; }
return count;
} /* fl_ucs_to_Utf16 */
/*! Convert a UTF-8 sequence into an array of 16-bit characters. These
are used by some system calls, especially on Windows.
\p src points at the UTF-8, and \p srclen is the number of bytes to
convert.
\p dst points at an array to write, and \p dstlen is the number of
locations in this array. At most \p dstlen-1 words will be
written there, plus a 0 terminating word. Thus this function
will never overwrite the buffer and will always return a
zero-terminated string. If \p dstlen is zero then \p dst can be
null and no data is written, but the length is returned.
The return value is the number of 16-bit words that \e would be written
to \p dst if it were long enough, not counting the terminating
zero. If the return value is greater or equal to \p dstlen it
indicates truncation, you can then allocate a new array of size
return+1 and call this again.
Errors in the UTF-8 are converted as though each byte in the
erroneous string is in the Microsoft CP1252 encoding. This allows
ISO-8859-1 text mistakenly identified as UTF-8 to be printed
correctly.
Unicode characters in the range 0x10000 to 0x10ffff are converted to
"surrogate pairs" which take two words each (this is called UTF-16
encoding).
*/
unsigned fl_utf8toUtf16(const char* src, unsigned srclen,
unsigned short* dst, unsigned dstlen)
{
const char* p = src;
const char* e = src+srclen;
unsigned count = 0;
if (dstlen) for (;;) {
if (p >= e) {dst[count] = 0; return count;}
if (!(*p & 0x80)) { /* ascii */
dst[count] = *p++;
} else {
int len; unsigned ucs = fl_utf8decode(p,e,&len);
p += len;
if (ucs < 0x10000) {
dst[count] = ucs;
} else {
/* make a surrogate pair: */
if (count+2 >= dstlen) {dst[count] = 0; count += 2; break;}
dst[count] = (((ucs-0x10000u)>>10)&0x3ff) | 0xd800;
dst[++count] = (ucs&0x3ff) | 0xdc00;
}
}
if (++count == dstlen) {dst[count-1] = 0; break;}
}
/* we filled dst, measure the rest: */
while (p < e) {
if (!(*p & 0x80)) p++;
else {
int len; unsigned ucs = fl_utf8decode(p,e,&len);
p += len;
if (ucs >= 0x10000) ++count;
}
++count;
}
return count;
}
/**
Converts a UTF-8 string into a wide character string.
This function generates 32-bit wchar_t (e.g. "ucs4" as it were) except
on Windows where it is equivalent to fl_utf8toUtf16 and returns
UTF-16.
\p src points at the UTF-8, and \p srclen is the number of bytes to
convert.
\p dst points at an array to write, and \p dstlen is the number of
locations in this array. At most \p dstlen-1 wchar_t will be
written there, plus a 0 terminating wchar_t.
The return value is the number of wchar_t that \e would be written
to \p dst if it were long enough, not counting the terminating
zero. If the return value is greater or equal to \p dstlen it
indicates truncation, you can then allocate a new array of size
return+1 and call this again.
Notice that sizeof(wchar_t) is 2 on Windows and is 4 on Linux
and most other systems. Where wchar_t is 16 bits, Unicode
characters in the range 0x10000 to 0x10ffff are converted to
"surrogate pairs" which take two words each (this is called UTF-16
encoding). If wchar_t is 32 bits this rather nasty problem is
avoided.
Note that Windows includes Cygwin, i.e. compiled with Cygwin's POSIX
layer (cygwin1.dll, --enable-cygwin), either native (GDI) or X11.
*/
unsigned fl_utf8towc(const char* src, unsigned srclen,
wchar_t* dst, unsigned dstlen)
{
#if defined(WIN32) || defined(__CYGWIN__)
return fl_utf8toUtf16(src, srclen, (unsigned short*)dst, dstlen);
#else
const char* p = src;
const char* e = src+srclen;
unsigned count = 0;
if (dstlen) for (;;) {
if (p >= e) {
dst[count] = 0;
return count;
}
if (!(*p & 0x80)) { /* ascii */
dst[count] = *p++;
} else {
int len; unsigned ucs = fl_utf8decode(p,e,&len);
p += len;
dst[count] = (wchar_t)ucs;
}
if (++count == dstlen) {dst[count-1] = 0; break;}
}
/* we filled dst, measure the rest: */
while (p < e) {
if (!(*p & 0x80)) p++;
else {
int len; fl_utf8decode(p,e,&len);
p += len;
}
++count;
}
return count;
#endif
}
/*! Convert a UTF-8 sequence into an array of 1-byte characters.
If the UTF-8 decodes to a character greater than 0xff then it is
replaced with '?'.
Errors in the UTF-8 are converted as individual bytes, same as
fl_utf8decode() does. This allows ISO-8859-1 text mistakenly identified
as UTF-8 to be printed correctly (and possibly CP1512 on Windows).
\p src points at the UTF-8, and \p srclen is the number of bytes to
convert.
Up to \p dstlen bytes are written to \p dst, including a null
terminator. The return value is the number of bytes that would be
written, not counting the null terminator. If greater or equal to
\p dstlen then if you malloc a new array of size n+1 you will have
the space needed for the entire string. If \p dstlen is zero then
nothing is written and this call just measures the storage space
needed.
*/
unsigned fl_utf8toa(const char* src, unsigned srclen,
char* dst, unsigned dstlen)
{
const char* p = src;
const char* e = src+srclen;
unsigned count = 0;
if (dstlen) for (;;) {
unsigned char c;
if (p >= e) {dst[count] = 0; return count;}
c = *(unsigned char*)p;
if (c < 0xC2) { /* ascii or bad code */
dst[count] = c;
p++;
} else {
int len; unsigned ucs = fl_utf8decode(p,e,&len);
p += len;
if (ucs < 0x100) dst[count] = ucs;
else dst[count] = '?';
}
if (++count >= dstlen) {dst[count-1] = 0; break;}
}
/* we filled dst, measure the rest: */
while (p < e) {
if (!(*p & 0x80)) p++;
else {
int len;
fl_utf8decode(p,e,&len);
p += len;
}
++count;
}
return count;
}
/*! Turn "wide characters" as returned by some system calls
(especially on Windows) into UTF-8.
Up to \p dstlen bytes are written to \p dst, including a null
terminator. The return value is the number of bytes that would be
written, not counting the null terminator. If greater or equal to
\p dstlen then if you malloc a new array of size n+1 you will have
the space needed for the entire string. If \p dstlen is zero then
nothing is written and this call just measures the storage space
needed.
\p srclen is the number of words in \p src to convert. On Windows
this is not necessarily the number of characters, due to there
possibly being "surrogate pairs" in the UTF-16 encoding used.
On Unix wchar_t is 32 bits and each location is a character.
On Unix if a \p src word is greater than 0x10ffff then this is an
illegal character according to RFC 3629. These are converted as
though they are 0xFFFD (REPLACEMENT CHARACTER). Characters in the
range 0xd800 to 0xdfff, or ending with 0xfffe or 0xffff are also
illegal according to RFC 3629. However I encode these as though
they are legal, so that fl_utf8towc will return the original data.
On Windows "surrogate pairs" are converted to a single character
and UTF-8 encoded (as 4 bytes). Mismatched halves of surrogate
pairs are converted as though they are individual characters.
*/
unsigned fl_utf8fromwc(char* dst, unsigned dstlen,
const wchar_t* src, unsigned srclen) {
unsigned i = 0;
unsigned count = 0;
if (dstlen) for (;;) {
unsigned ucs;
if (i >= srclen) {dst[count] = 0; return count;}
ucs = src[i++];
if (ucs < 0x80U) {
dst[count++] = ucs;
if (count >= dstlen) {dst[count-1] = 0; break;}
} else if (ucs < 0x800U) { /* 2 bytes */
if (count+2 >= dstlen) {dst[count] = 0; count += 2; break;}
dst[count++] = 0xc0 | (ucs >> 6);
dst[count++] = 0x80 | (ucs & 0x3F);
#if defined(WIN32) || defined(__CYGWIN__)
} else if (ucs >= 0xd800 && ucs <= 0xdbff && i < srclen &&
src[i] >= 0xdc00 && src[i] <= 0xdfff) {
/* surrogate pair */
unsigned ucs2 = src[i++];
ucs = 0x10000U + ((ucs&0x3ff)<<10) + (ucs2&0x3ff);
/* all surrogate pairs turn into 4-byte utf8 */
#else
} else if (ucs >= 0x10000) {
if (ucs > 0x10ffff) {
ucs = 0xfffd;
goto J1;
}
#endif
if (count+4 >= dstlen) {dst[count] = 0; count += 4; break;}
dst[count++] = 0xf0 | (ucs >> 18);
dst[count++] = 0x80 | ((ucs >> 12) & 0x3F);
dst[count++] = 0x80 | ((ucs >> 6) & 0x3F);
dst[count++] = 0x80 | (ucs & 0x3F);
} else {
#if !(defined(WIN32) || defined(__CYGWIN__))
J1:
#endif
/* all others are 3 bytes: */
if (count+3 >= dstlen) {dst[count] = 0; count += 3; break;}
dst[count++] = 0xe0 | (ucs >> 12);
dst[count++] = 0x80 | ((ucs >> 6) & 0x3F);
dst[count++] = 0x80 | (ucs & 0x3F);
}
}
/* we filled dst, measure the rest: */
while (i < srclen) {
unsigned ucs = src[i++];
if (ucs < 0x80U) {
count++;
} else if (ucs < 0x800U) { /* 2 bytes */
count += 2;
#if defined(WIN32) || defined(__CYGWIN__)
} else if (ucs >= 0xd800 && ucs <= 0xdbff && i < srclen-1 &&
src[i+1] >= 0xdc00 && src[i+1] <= 0xdfff) {
/* surrogate pair */
++i;
#else
} else if (ucs >= 0x10000 && ucs <= 0x10ffff) {
#endif
count += 4;
} else {
count += 3;
}
}
return count;
}
/*! Convert an ISO-8859-1 (ie normal c-string) byte stream to UTF-8.
It is possible this should convert Microsoft's CP1252 to UTF-8
instead. This would translate the codes in the range 0x80-0x9f
to different characters. Currently it does not do this.
Up to \p dstlen bytes are written to \p dst, including a null
terminator. The return value is the number of bytes that would be
written, not counting the null terminator. If greater or equal to
\p dstlen then if you malloc a new array of size n+1 you will have
the space needed for the entire string. If \p dstlen is zero then
nothing is written and this call just measures the storage space
needed.
\p srclen is the number of bytes in \p src to convert.
If the return value equals \p srclen then this indicates that
no conversion is necessary, as only ASCII characters are in the
string.
*/
unsigned fl_utf8froma(char* dst, unsigned dstlen,
const char* src, unsigned srclen) {
const char* p = src;
const char* e = src+srclen;
unsigned count = 0;
if (dstlen) for (;;) {
unsigned char ucs;
if (p >= e) {dst[count] = 0; return count;}
ucs = *(unsigned char*)p++;
if (ucs < 0x80U) {
dst[count++] = ucs;
if (count >= dstlen) {dst[count-1] = 0; break;}
} else { /* 2 bytes (note that CP1252 translate could make 3 bytes!) */
if (count+2 >= dstlen) {dst[count] = 0; count += 2; break;}
dst[count++] = 0xc0 | (ucs >> 6);
dst[count++] = 0x80 | (ucs & 0x3F);
}
}
/* we filled dst, measure the rest: */
while (p < e) {
unsigned char ucs = *(unsigned char*)p++;
if (ucs < 0x80U) {
count++;
} else {
count += 2;
}
}
return count;
}
#ifdef WIN32
# include <windows.h>
#endif
/*! Return true if the "locale" seems to indicate that UTF-8 encoding
is used. If true the fl_utf8to_mb and fl_utf8from_mb don't do anything
useful.
<i>It is highly recommended that you change your system so this
does return true.</i> On Windows this is done by setting the
"codepage" to CP_UTF8. On Unix this is done by setting $LC_CTYPE
to a string containing the letters "utf" or "UTF" in it, or by
deleting all $LC* and $LANG environment variables. In the future
it is likely that all non-Asian Unix systems will return true,
due to the compatibility of UTF-8 with ISO-8859-1.
*/
int fl_utf8locale(void) {
static int ret = 2;
if (ret == 2) {
#ifdef WIN32
ret = GetACP() == CP_UTF8;
#else
char* s;
ret = 1; /* assume UTF-8 if no locale */
if (((s = getenv("LC_CTYPE")) && *s) ||
((s = getenv("LC_ALL")) && *s) ||
((s = getenv("LANG")) && *s)) {
ret = (strstr(s,"utf") || strstr(s,"UTF"));
}
#endif
}
return ret;
}
/*! Convert the UTF-8 used by FLTK to the locale-specific encoding
used for filenames (and sometimes used for data in files).
Unfortunately due to stupid design you will have to do this as
needed for filenames. This is a bug on both Unix and Windows.
Up to \p dstlen bytes are written to \p dst, including a null
terminator. The return value is the number of bytes that would be
written, not counting the null terminator. If greater or equal to
\p dstlen then if you malloc a new array of size n+1 you will have
the space needed for the entire string. If \p dstlen is zero then
nothing is written and this call just measures the storage space
needed.
If fl_utf8locale() returns true then this does not change the data.
*/
unsigned fl_utf8to_mb(const char* src, unsigned srclen,
char* dst, unsigned dstlen)
{
if (!fl_utf8locale()) {
#ifdef WIN32
wchar_t lbuf[1024];
wchar_t* buf = lbuf;
unsigned length = fl_utf8towc(src, srclen, buf, 1024);
unsigned ret;
if (length >= 1024) {
buf = (wchar_t*)(malloc((length+1)*sizeof(wchar_t)));
fl_utf8towc(src, srclen, buf, length+1);
}
if (dstlen) {
/* apparently this does not null-terminate, even though msdn
* documentation claims it does:
*/
ret =
WideCharToMultiByte(GetACP(), 0, buf, length, dst, dstlen, 0, 0);
dst[ret] = 0;
}
/* if it overflows or measuring length, get the actual length: */
if (dstlen==0 || ret >= dstlen-1)
ret =
WideCharToMultiByte(GetACP(), 0, buf, length, 0, 0, 0, 0);
if (buf != lbuf) free((void*)buf);
return ret;
#else
wchar_t lbuf[1024];
wchar_t* buf = lbuf;
unsigned length = fl_utf8towc(src, srclen, buf, 1024);
int ret;
if (length >= 1024) {
buf = (wchar_t*)(malloc((length+1)*sizeof(wchar_t)));
fl_utf8towc(src, srclen, buf, length+1);
}
if (dstlen) {
ret = wcstombs(dst, buf, dstlen);
if (ret >= dstlen-1) ret = wcstombs(0,buf,0);
} else {
ret = wcstombs(0,buf,0);
}
if (buf != lbuf) free((void*)buf);
if (ret >= 0) return (unsigned)ret;
/* on any errors we return the UTF-8 as raw text...*/
#endif
}
/* identity transform: */
if (srclen < dstlen) {
memcpy(dst, src, srclen);
dst[srclen] = 0;
} else {
/* Buffer insufficent or buffer query */
}
return srclen;
}
/*! Convert a filename from the locale-specific multibyte encoding
used by Windows to UTF-8 as used by FLTK.
Up to \p dstlen bytes are written to \p dst, including a null
terminator. The return value is the number of bytes that would be
written, not counting the null terminator. If greater or equal to
\p dstlen then if you malloc a new array of size n+1 you will have
the space needed for the entire string. If \p dstlen is zero then
nothing is written and this call just measures the storage space
needed.
On Unix or on Windows when a UTF-8 locale is in effect, this
does not change the data.
You may also want to check if fl_utf8test() returns non-zero, so that
the filesystem can store filenames in UTF-8 encoding regardless of
the locale.
*/
unsigned fl_utf8from_mb(char* dst, unsigned dstlen,
const char* src, unsigned srclen)
{
if (!fl_utf8locale()) {
#ifdef WIN32
wchar_t lbuf[1024];
wchar_t* buf = lbuf;
unsigned length;
unsigned ret;
length = MultiByteToWideChar(GetACP(), 0, src, srclen, buf, 1024);
if ((length == 0)&&(GetLastError()==ERROR_INSUFFICIENT_BUFFER)) {
length = MultiByteToWideChar(GetACP(), 0, src, srclen, 0, 0);
buf = (wchar_t*)(malloc(length*sizeof(wchar_t)));
MultiByteToWideChar(GetACP(), 0, src, srclen, buf, length);
}
ret = fl_utf8fromwc(dst, dstlen, buf, length);
if (buf != lbuf) free((void*)buf);
return ret;
#else
wchar_t lbuf[1024];
wchar_t* buf = lbuf;
int length;
unsigned ret;
length = mbstowcs(buf, src, 1024);
if (length >= 1024) {
length = mbstowcs(0, src, 0)+1;
buf = (wchar_t*)(malloc(length*sizeof(wchar_t)));
mbstowcs(buf, src, length);
}
if (length >= 0) {
ret = fl_utf8fromwc(dst, dstlen, buf, length);
if (buf != lbuf) free((void*)buf);
return ret;
}
/* errors in conversion return the UTF-8 unchanged */
#endif
}
/* identity transform: */
if (srclen < dstlen) {
memcpy(dst, src, srclen);
dst[srclen] = 0;
} else {
/* Buffer insufficent or buffer query */
}
return srclen;
}
/*! Examines the first \p srclen bytes in \p src and returns a verdict
on whether it is UTF-8 or not.
- Returns 0 if there is any illegal UTF-8 sequences, using the
same rules as fl_utf8decode(). Note that some UCS values considered
illegal by RFC 3629, such as 0xffff, are considered legal by this.
- Returns 1 if there are only single-byte characters (ie no bytes
have the high bit set). This is legal UTF-8, but also indicates
plain ASCII. It also returns 1 if \p srclen is zero.
- Returns 2 if there are only characters less than 0x800.
- Returns 3 if there are only characters less than 0x10000.
- Returns 4 if there are characters in the 0x10000 to 0x10ffff range.
Because there are many illegal sequences in UTF-8, it is almost
impossible for a string in another encoding to be confused with
UTF-8. This is very useful for transitioning Unix to UTF-8
filenames, you can simply test each filename with this to decide
if it is UTF-8 or in the locale encoding. My hope is that if
this is done we will be able to cleanly transition to a locale-less
encoding.
*/
int fl_utf8test(const char* src, unsigned srclen) {
int ret = 1;
const char* p = src;
const char* e = src+srclen;
while (p < e) {
if (*p & 0x80) {
int len; fl_utf8decode(p,e,&len);
if (len < 2) return 0;
if (len > ret) ret = len;
p += len;
} else {
p++;
}
}
return ret;
}
/* forward declare mk_wcwidth() as static so the name is not visible.
*/
static int mk_wcwidth(unsigned int ucs);
/* include the c source directly so it's contents are only visible here
*/
#include "xutf8/mk_wcwidth.c"
/** wrapper to adapt Markus Kuhn's implementation of wcwidth() for FLTK
\param [in] ucs Unicode character value
\returns width of character in columns
See http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c for Markus Kuhn's
original implementation of wcwidth() and wcswidth()
(defined in IEEE Std 1002.1-2001) for Unicode.
\b WARNING: this function returns widths for "raw" Unicode characters.
It does not even try to map C1 control characters (0x80 to 0x9F) to
CP1252, and C0/C1 control characters and DEL will return -1.
You are advised to use fl_width(const char* src) instead.
*/
int fl_wcwidth_(unsigned int ucs) {
return mk_wcwidth(ucs);
}
/** extended wrapper around fl_wcwidth_(unsigned int ucs) function.
\param[in] src pointer to start of UTF-8 byte sequence
\returns width of character in columns
Depending on build options, this function may map C1 control
characters (0x80 to 0x9f) to CP1252, and return the width of
that character instead. This is not the same behaviour as
fl_wcwidth_(unsigned int ucs) .
Note that other control characters and DEL will still return -1,
so if you want different behaviour, you need to test for those
characters before calling fl_wcwidth(), and handle them separately.
*/
int fl_wcwidth(const char* src) {
int len = fl_utf8len(*src);
int ret = 0;
unsigned int ucs = fl_utf8decode(src, src+len, &ret);
int width = fl_wcwidth_(ucs);
return width;
}
/** @} */
/*
* End of "$Id$".
*/
Reference in New Issue View Git Blame Copy Permalink