gri3-wm/i3-input/ucs2_to_utf8.c

101 lines
3.0 KiB
C

/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
*
* ucs2_to_utf8.c: Converts between UCS-2 and UTF-8, both of which are used in
* different contexts in X11.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <err.h>
#include <iconv.h>
#include "libi3.h"
static iconv_t conversion_descriptor = 0;
static iconv_t conversion_descriptor2 = 0;
/*
* Returns the input string, but converted from UCS-2 to UTF-8. Memory will be
* allocated, thus the caller has to free the output.
*
*/
char *convert_ucs_to_utf8(char *input) {
size_t input_size = 2;
/* UTF-8 may consume up to 4 byte */
int buffer_size = 8;
char *buffer = scalloc(buffer_size);
size_t output_size = buffer_size;
/* We need to use an additional pointer, because iconv() modifies it */
char *output = buffer;
/* We convert the input into UCS-2 big endian */
if (conversion_descriptor == 0) {
conversion_descriptor = iconv_open("UTF-8", "UCS-2BE");
if (conversion_descriptor == 0)
errx(EXIT_FAILURE, "Error opening the conversion context");
}
/* Get the conversion descriptor back to original state */
iconv(conversion_descriptor, NULL, NULL, NULL, NULL);
/* Convert our text */
int rc = iconv(conversion_descriptor, (void*)&input, &input_size, &output, &output_size);
if (rc == (size_t)-1) {
free(buffer);
perror("Converting to UCS-2 failed");
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.
*
*/
char *convert_utf8_to_ucs2(char *input, int *real_strlen) {
size_t input_size = strlen(input) + 1;
/* UCS-2 consumes exactly two bytes for each glyph */
int buffer_size = input_size * 2;
char *buffer = smalloc(buffer_size);
size_t output_size = buffer_size;
/* We need to use an additional pointer, because iconv() modifies it */
char *output = buffer;
/* We convert the input into UCS-2 big endian */
if (conversion_descriptor2 == 0) {
conversion_descriptor2 = iconv_open("UCS-2BE", "UTF-8");
if (conversion_descriptor2 == 0)
errx(EXIT_FAILURE, "Error opening the conversion context");
}
/* Get the conversion descriptor back to original state */
iconv(conversion_descriptor2, NULL, NULL, NULL, NULL);
/* Convert our text */
int rc = iconv(conversion_descriptor2, (void*)&input, &input_size, &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;
}
if (real_strlen != NULL)
*real_strlen = ((buffer_size - output_size) / 2) - 1;
return buffer;
}