gri3-wm/libi3/ucs2_conversion.c

102 lines
3.3 KiB
C

/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
*
*/
#include "libi3.h"
#include <err.h>
#include <errno.h>
#include <iconv.h>
#include <stdlib.h>
#include <string.h>
static iconv_t utf8_conversion_descriptor = (iconv_t)-1;
static iconv_t ucs2_conversion_descriptor = (iconv_t)-1;
/*
* Converts the given string to UTF-8 from UCS-2 big endian. The return value
* must be freed after use.
*
*/
char *convert_ucs2_to_utf8(xcb_char2b_t *text, size_t num_glyphs) {
/* Allocate the output buffer (UTF-8 is at most 4 bytes per glyph) */
size_t buffer_size = num_glyphs * 4 + 1;
char *buffer = scalloc(buffer_size, 1);
/* We need to use an additional pointer, because iconv() modifies it */
char *output = buffer;
size_t output_size = buffer_size - 1;
if (utf8_conversion_descriptor == (iconv_t)-1) {
/* Get a new conversion descriptor */
utf8_conversion_descriptor = iconv_open("UTF-8", "UCS-2BE");
if (utf8_conversion_descriptor == (iconv_t)-1)
err(EXIT_FAILURE, "Error opening the conversion context");
} else {
/* Reset the existing conversion descriptor */
iconv(utf8_conversion_descriptor, NULL, NULL, NULL, NULL);
}
/* Do the conversion */
size_t input_len = num_glyphs * sizeof(xcb_char2b_t);
size_t rc = iconv(utf8_conversion_descriptor, (char **)&text,
&input_len, &output, &output_size);
if (rc == (size_t)-1) {
perror("Converting to UTF-8 failed");
free(buffer);
return NULL;
}
return buffer;
}
/*
* Converts the given string to UCS-2 big endian for use with
* xcb_image_text_16(). The amount of real glyphs is stored in real_strlen,
* a buffer containing the UCS-2 encoded string (16 bit per glyph) is
* returned. It has to be freed when done.
*
*/
xcb_char2b_t *convert_utf8_to_ucs2(char *input, size_t *real_strlen) {
/* Calculate the input buffer size (UTF-8 is strlen-safe) */
size_t input_size = strlen(input);
/* Calculate the output buffer size and allocate the buffer */
size_t buffer_size = input_size * sizeof(xcb_char2b_t);
xcb_char2b_t *buffer = smalloc(buffer_size);
/* We need to use an additional pointer, because iconv() modifies it */
size_t output_size = buffer_size;
xcb_char2b_t *output = buffer;
if (ucs2_conversion_descriptor == (iconv_t)-1) {
/* Get a new conversion descriptor */
ucs2_conversion_descriptor = iconv_open("UCS-2BE", "UTF-8");
if (ucs2_conversion_descriptor == (iconv_t)-1)
err(EXIT_FAILURE, "Error opening the conversion context");
} else {
/* Reset the existing conversion descriptor */
iconv(ucs2_conversion_descriptor, NULL, NULL, NULL, NULL);
}
/* Do the conversion */
size_t rc = iconv(ucs2_conversion_descriptor, (char **)&input,
&input_size, (char **)&output, &output_size);
if (rc == (size_t)-1) {
perror("Converting to UCS-2 failed");
free(buffer);
if (real_strlen != NULL)
*real_strlen = 0;
return NULL;
}
/* Return the resulting string's length */
if (real_strlen != NULL)
*real_strlen = (buffer_size - output_size) / sizeof(xcb_char2b_t);
return buffer;
}