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bl_mcu_sdk/components/lvgl/misc/lv_txt.c

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/**
* @file lv_txt.c
*
*/
/*********************
* INCLUDES
*********************/
#include <stdarg.h>
#include "lv_txt.h"
#include "lv_txt_ap.h"
#include "lv_math.h"
#include "lv_log.h"
#include "lv_mem.h"
#include "lv_assert.h"
/*********************
* DEFINES
*********************/
#define NO_BREAK_FOUND UINT32_MAX
/**********************
* TYPEDEFS
**********************/
/**********************
* STATIC PROTOTYPES
**********************/
#if LV_TXT_ENC == LV_TXT_ENC_UTF8
static uint8_t lv_txt_utf8_size(const char * str);
static uint32_t lv_txt_unicode_to_utf8(uint32_t letter_uni);
static uint32_t lv_txt_utf8_conv_wc(uint32_t c);
static uint32_t lv_txt_utf8_next(const char * txt, uint32_t * i);
static uint32_t lv_txt_utf8_prev(const char * txt, uint32_t * i_start);
static uint32_t lv_txt_utf8_get_byte_id(const char * txt, uint32_t utf8_id);
static uint32_t lv_txt_utf8_get_char_id(const char * txt, uint32_t byte_id);
static uint32_t lv_txt_utf8_get_length(const char * txt);
#elif LV_TXT_ENC == LV_TXT_ENC_ASCII
static uint8_t lv_txt_iso8859_1_size(const char * str);
static uint32_t lv_txt_unicode_to_iso8859_1(uint32_t letter_uni);
static uint32_t lv_txt_iso8859_1_conv_wc(uint32_t c);
static uint32_t lv_txt_iso8859_1_next(const char * txt, uint32_t * i);
static uint32_t lv_txt_iso8859_1_prev(const char * txt, uint32_t * i_start);
static uint32_t lv_txt_iso8859_1_get_byte_id(const char * txt, uint32_t utf8_id);
static uint32_t lv_txt_iso8859_1_get_char_id(const char * txt, uint32_t byte_id);
static uint32_t lv_txt_iso8859_1_get_length(const char * txt);
#endif
/**********************
* STATIC VARIABLES
**********************/
/**********************
* GLOBAL VARIABLES
**********************/
#if LV_TXT_ENC == LV_TXT_ENC_UTF8
uint8_t (*_lv_txt_encoded_size)(const char *) = lv_txt_utf8_size;
uint32_t (*_lv_txt_unicode_to_encoded)(uint32_t) = lv_txt_unicode_to_utf8;
uint32_t (*_lv_txt_encoded_conv_wc)(uint32_t) = lv_txt_utf8_conv_wc;
uint32_t (*_lv_txt_encoded_next)(const char *, uint32_t *) = lv_txt_utf8_next;
uint32_t (*_lv_txt_encoded_prev)(const char *, uint32_t *) = lv_txt_utf8_prev;
uint32_t (*_lv_txt_encoded_get_byte_id)(const char *, uint32_t) = lv_txt_utf8_get_byte_id;
uint32_t (*_lv_txt_encoded_get_char_id)(const char *, uint32_t) = lv_txt_utf8_get_char_id;
uint32_t (*_lv_txt_get_encoded_length)(const char *) = lv_txt_utf8_get_length;
#elif LV_TXT_ENC == LV_TXT_ENC_ASCII
uint8_t (*_lv_txt_encoded_size)(const char *) = lv_txt_iso8859_1_size;
uint32_t (*_lv_txt_unicode_to_encoded)(uint32_t) = lv_txt_unicode_to_iso8859_1;
uint32_t (*_lv_txt_encoded_conv_wc)(uint32_t) = lv_txt_iso8859_1_conv_wc;
uint32_t (*_lv_txt_encoded_next)(const char *, uint32_t *) = lv_txt_iso8859_1_next;
uint32_t (*_lv_txt_encoded_prev)(const char *, uint32_t *) = lv_txt_iso8859_1_prev;
uint32_t (*_lv_txt_encoded_get_byte_id)(const char *, uint32_t) = lv_txt_iso8859_1_get_byte_id;
uint32_t (*_lv_txt_encoded_get_char_id)(const char *, uint32_t) = lv_txt_iso8859_1_get_char_id;
uint32_t (*_lv_txt_get_encoded_length)(const char *) = lv_txt_iso8859_1_get_length;
#endif
/**********************
* MACROS
**********************/
#define LV_IS_ASCII(value) ((value & 0x80U) == 0x00U)
#define LV_IS_2BYTES_UTF8_CODE(value) ((value & 0xE0U) == 0xC0U)
#define LV_IS_3BYTES_UTF8_CODE(value) ((value & 0xF0U) == 0xE0U)
#define LV_IS_4BYTES_UTF8_CODE(value) ((value & 0xF8U) == 0xF0U)
#define LV_IS_INVALID_UTF8_CODE(value) ((value & 0xC0U) != 0x80U)
/**********************
* GLOBAL FUNCTIONS
**********************/
void lv_txt_get_size(lv_point_t * size_res, const char * text, const lv_font_t * font, lv_coord_t letter_space,
lv_coord_t line_space, lv_coord_t max_width, lv_text_flag_t flag)
{
size_res->x = 0;
size_res->y = 0;
if(text == NULL) return;
if(font == NULL) return;
if(flag & LV_TEXT_FLAG_EXPAND) max_width = LV_COORD_MAX;
uint32_t line_start = 0;
uint32_t new_line_start = 0;
uint16_t letter_height = lv_font_get_line_height(font);
/*Calc. the height and longest line*/
while(text[line_start] != '\0') {
new_line_start += _lv_txt_get_next_line(&text[line_start], font, letter_space, max_width, NULL, flag);
if((unsigned long)size_res->y + (unsigned long)letter_height + (unsigned long)line_space > LV_MAX_OF(lv_coord_t)) {
LV_LOG_WARN("lv_txt_get_size: integer overflow while calculating text height");
return;
}
else {
size_res->y += letter_height;
size_res->y += line_space;
}
/*Calculate the longest line*/
lv_coord_t act_line_length = lv_txt_get_width(&text[line_start], new_line_start - line_start, font, letter_space,
flag);
size_res->x = LV_MAX(act_line_length, size_res->x);
line_start = new_line_start;
}
/*Make the text one line taller if the last character is '\n' or '\r'*/
if((line_start != 0) && (text[line_start - 1] == '\n' || text[line_start - 1] == '\r')) {
size_res->y += letter_height + line_space;
}
/*Correction with the last line space or set the height manually if the text is empty*/
if(size_res->y == 0)
size_res->y = letter_height;
else
size_res->y -= line_space;
}
/**
* Get the next word of text. A word is delimited by break characters.
*
* If the word cannot fit in the max_width space, obey LV_TXT_LINE_BREAK_LONG_* rules.
*
* If the next word cannot fit anything, return 0.
*
* If the first character is a break character, returns the next index.
*
* Example calls from lv_txt_get_next_line() assuming sufficient max_width and
* txt = "Test text\n"
* 0123456789
*
* Calls would be as follows:
* 1. Return i=4, pointing at breakchar ' ', for the string "Test"
* 2. Return i=5, since i=4 was a breakchar.
* 3. Return i=9, pointing at breakchar '\n'
* 4. Parenting lv_txt_get_next_line() would detect subsequent '\0'
*
* TODO: Returned word_w_ptr may overestimate the returned word's width when
* max_width is reached. In current usage, this has no impact.
*
* @param txt a '\0' terminated string
* @param font pointer to a font
* @param letter_space letter space
* @param max_width max width of the text (break the lines to fit this size). Set COORD_MAX to avoid line breaks
* @param flags settings for the text from 'txt_flag_type' enum
* @param[out] word_w_ptr width (in pixels) of the parsed word. May be NULL.
* @param cmd_state pointer to a txt_cmd_state_t variable which stores the current state of command processing
* @param force Force return the fraction of the word that can fit in the provided space.
* @return the index of the first char of the next word (in byte index not letter index. With UTF-8 they are different)
*/
static uint32_t lv_txt_get_next_word(const char * txt, const lv_font_t * font,
lv_coord_t letter_space, lv_coord_t max_width,
lv_text_flag_t flag, uint32_t * word_w_ptr, lv_text_cmd_state_t * cmd_state, bool force)
{
if(txt == NULL || txt[0] == '\0') return 0;
if(font == NULL) return 0;
if(flag & LV_TEXT_FLAG_EXPAND) max_width = LV_COORD_MAX;
uint32_t i = 0, i_next = 0, i_next_next = 0; /*Iterating index into txt*/
uint32_t letter = 0; /*Letter at i*/
uint32_t letter_next = 0; /*Letter at i_next*/
lv_coord_t letter_w;
lv_coord_t cur_w = 0; /*Pixel Width of transversed string*/
uint32_t word_len = 0; /*Number of characters in the transversed word*/
uint32_t break_index = NO_BREAK_FOUND; /*only used for "long" words*/
uint32_t break_letter_count = 0; /*Number of characters up to the long word break point*/
letter = _lv_txt_encoded_next(txt, &i_next);
i_next_next = i_next;
/*Obtain the full word, regardless if it fits or not in max_width*/
while(txt[i] != '\0') {
letter_next = _lv_txt_encoded_next(txt, &i_next_next);
word_len++;
/*Handle the recolor command*/
if((flag & LV_TEXT_FLAG_RECOLOR) != 0) {
if(_lv_txt_is_cmd(cmd_state, letter) != false) {
i = i_next;
i_next = i_next_next;
letter = letter_next;
continue; /*Skip the letter if it is part of a command*/
}
}
letter_w = lv_font_get_glyph_width(font, letter, letter_next);
cur_w += letter_w;
if(letter_w > 0) {
cur_w += letter_space;
}
/*Test if this character fits within max_width*/
if(break_index == NO_BREAK_FOUND && (cur_w - letter_space) > max_width) {
break_index = i;
break_letter_count = word_len - 1;
/*break_index is now pointing at the character that doesn't fit*/
}
/*Check for new line chars and breakchars*/
if(letter == '\n' || letter == '\r' || _lv_txt_is_break_char(letter)) {
/*Update the output width on the first character if it fits.
*Must do this here in case first letter is a break character.*/
if(i == 0 && break_index == NO_BREAK_FOUND && word_w_ptr != NULL) *word_w_ptr = cur_w;
word_len--;
break;
}
/*Update the output width*/
if(word_w_ptr != NULL && break_index == NO_BREAK_FOUND) *word_w_ptr = cur_w;
i = i_next;
i_next = i_next_next;
letter = letter_next;
}
/*Entire Word fits in the provided space*/
if(break_index == NO_BREAK_FOUND) {
if(word_len == 0 || (letter == '\r' && letter_next == '\n')) i = i_next;
return i;
}
#if LV_TXT_LINE_BREAK_LONG_LEN > 0
/*Word doesn't fit in provided space, but isn't "long"*/
if(word_len < LV_TXT_LINE_BREAK_LONG_LEN) {
if(force) return break_index;
if(word_w_ptr != NULL) *word_w_ptr = 0; /*Return no word*/
return 0;
}
/*Word is "long," but insufficient amounts can fit in provided space*/
if(break_letter_count < LV_TXT_LINE_BREAK_LONG_PRE_MIN_LEN) {
if(force) return break_index;
if(word_w_ptr != NULL) *word_w_ptr = 0;
return 0;
}
/*Word is a "long", but letters may need to be better distributed*/
{
i = break_index;
int32_t n_move = LV_TXT_LINE_BREAK_LONG_POST_MIN_LEN - (word_len - break_letter_count);
/*Move pointer "i" backwards*/
for(; n_move > 0; n_move--) {
_lv_txt_encoded_prev(txt, &i);
// TODO: it would be appropriate to update the returned word width here
// However, in current usage, this doesn't impact anything.
}
}
return i;
#else
if(force) return break_index;
if(word_w_ptr != NULL) *word_w_ptr = 0; /*Return no word*/
(void) break_letter_count;
return 0;
#endif
}
uint32_t _lv_txt_get_next_line(const char * txt, const lv_font_t * font,
lv_coord_t letter_space, lv_coord_t max_width,
lv_coord_t * used_width, lv_text_flag_t flag)
{
if(used_width) *used_width = 0;
if(txt == NULL) return 0;
if(txt[0] == '\0') return 0;
if(font == NULL) return 0;
lv_coord_t line_w = 0;
/*If max_width doesn't mater simply find the new line character
*without thinking about word wrapping*/
if((flag & LV_TEXT_FLAG_EXPAND) || (flag & LV_TEXT_FLAG_FIT)) {
uint32_t i;
for(i = 0; txt[i] != '\n' && txt[i] != '\r' && txt[i] != '\0'; i++) {
/*Just find the new line chars or string ends by incrementing `i`*/
}
if(txt[i] != '\0') i++; /*To go beyond `\n`*/
if(used_width) *used_width = -1;
return i;
}
if(flag & LV_TEXT_FLAG_EXPAND) max_width = LV_COORD_MAX;
lv_text_cmd_state_t cmd_state = LV_TEXT_CMD_STATE_WAIT;
uint32_t i = 0; /*Iterating index into txt*/
while(txt[i] != '\0' && max_width > 0) {
uint32_t word_w = 0;
uint32_t advance = lv_txt_get_next_word(&txt[i], font, letter_space, max_width, flag, &word_w, &cmd_state, i == 0);
max_width -= word_w;
line_w += word_w;
if(advance == 0) {
break;
}
i += advance;
if(txt[0] == '\n' || txt[0] == '\r') break;
if(txt[i] == '\n' || txt[i] == '\r') {
i++; /*Include the following newline in the current line*/
break;
}
}
/*Always step at least one to avoid infinite loops*/
if(i == 0) {
uint32_t letter = _lv_txt_encoded_next(txt, &i);
if(used_width != NULL) {
line_w = lv_font_get_glyph_width(font, letter, '\0');
}
}
if(used_width != NULL) {
*used_width = line_w;
}
return i;
}
lv_coord_t lv_txt_get_width(const char * txt, uint32_t length, const lv_font_t * font, lv_coord_t letter_space,
lv_text_flag_t flag)
{
if(txt == NULL) return 0;
if(font == NULL) return 0;
if(txt[0] == '\0') return 0;
uint32_t i = 0;
lv_coord_t width = 0;
lv_text_cmd_state_t cmd_state = LV_TEXT_CMD_STATE_WAIT;
if(length != 0) {
while(i < length) {
uint32_t letter;
uint32_t letter_next;
_lv_txt_encoded_letter_next_2(txt, &letter, &letter_next, &i);
if((flag & LV_TEXT_FLAG_RECOLOR) != 0) {
if(_lv_txt_is_cmd(&cmd_state, letter) != false) {
continue;
}
}
lv_coord_t char_width = lv_font_get_glyph_width(font, letter, letter_next);
if(char_width > 0) {
width += char_width;
width += letter_space;
}
}
if(width > 0) {
width -= letter_space; /*Trim the last letter space. Important if the text is center
aligned*/
}
}
return width;
}
bool _lv_txt_is_cmd(lv_text_cmd_state_t * state, uint32_t c)
{
bool ret = false;
if(c == (uint32_t)LV_TXT_COLOR_CMD[0]) {
if(*state == LV_TEXT_CMD_STATE_WAIT) { /*Start char*/
*state = LV_TEXT_CMD_STATE_PAR;
ret = true;
}
/*Other start char in parameter is escaped cmd. char*/
else if(*state == LV_TEXT_CMD_STATE_PAR) {
*state = LV_TEXT_CMD_STATE_WAIT;
}
/*Command end*/
else if(*state == LV_TEXT_CMD_STATE_IN) {
*state = LV_TEXT_CMD_STATE_WAIT;
ret = true;
}
}
/*Skip the color parameter and wait the space after it*/
if(*state == LV_TEXT_CMD_STATE_PAR) {
if(c == ' ') {
*state = LV_TEXT_CMD_STATE_IN; /*After the parameter the text is in the command*/
}
ret = true;
}
return ret;
}
void _lv_txt_ins(char * txt_buf, uint32_t pos, const char * ins_txt)
{
if(txt_buf == NULL || ins_txt == NULL) return;
size_t old_len = strlen(txt_buf);
size_t ins_len = strlen(ins_txt);
if(ins_len == 0) return;
size_t new_len = ins_len + old_len;
pos = _lv_txt_encoded_get_byte_id(txt_buf, pos); /*Convert to byte index instead of letter index*/
/*Copy the second part into the end to make place to text to insert*/
size_t i;
for(i = new_len; i >= pos + ins_len; i--) {
txt_buf[i] = txt_buf[i - ins_len];
}
/*Copy the text into the new space*/
lv_memcpy_small(txt_buf + pos, ins_txt, ins_len);
}
void _lv_txt_cut(char * txt, uint32_t pos, uint32_t len)
{
if(txt == NULL) return;
size_t old_len = strlen(txt);
pos = _lv_txt_encoded_get_byte_id(txt, pos); /*Convert to byte index instead of letter index*/
len = _lv_txt_encoded_get_byte_id(&txt[pos], len);
/*Copy the second part into the end to make place to text to insert*/
uint32_t i;
for(i = pos; i <= old_len - len; i++) {
txt[i] = txt[i + len];
}
}
char * _lv_txt_set_text_vfmt(const char * fmt, va_list ap)
{
/*Allocate space for the new text by using trick from C99 standard section 7.19.6.12*/
va_list ap_copy;
va_copy(ap_copy, ap);
uint32_t len = lv_vsnprintf(NULL, 0, fmt, ap_copy);
va_end(ap_copy);
char * text = 0;
#if LV_USE_ARABIC_PERSIAN_CHARS
/*Put together the text according to the format string*/
char * raw_txt = lv_mem_buf_get(len + 1);
LV_ASSERT_MALLOC(raw_txt);
if(raw_txt == NULL) {
return NULL;
}
lv_vsnprintf(raw_txt, len + 1, fmt, ap);
/*Get the size of the Arabic text and process it*/
size_t len_ap = _lv_txt_ap_calc_bytes_cnt(raw_txt);
text = lv_mem_alloc(len_ap + 1);
LV_ASSERT_MALLOC(text);
if(text == NULL) {
return NULL;
}
_lv_txt_ap_proc(raw_txt, text);
lv_mem_buf_release(raw_txt);
#else
text = lv_mem_alloc(len + 1);
LV_ASSERT_MALLOC(text);
if(text == NULL) {
return NULL;
}
text[len] = 0; /*Ensure NULL termination*/
lv_vsnprintf(text, len + 1, fmt, ap);
#endif
return text;
}
void _lv_txt_encoded_letter_next_2(const char * txt, uint32_t * letter, uint32_t * letter_next, uint32_t * ofs)
{
*letter = _lv_txt_encoded_next(txt, ofs);
*letter_next = *letter != '\0' ? _lv_txt_encoded_next(&txt[*ofs], NULL) : 0;
}
#if LV_TXT_ENC == LV_TXT_ENC_UTF8
/*******************************
* UTF-8 ENCODER/DECODER
******************************/
/**
* Give the size of an UTF-8 coded character
* @param str pointer to a character in a string
* @return length of the UTF-8 character (1,2,3 or 4), 0 on invalid code.
*/
static uint8_t lv_txt_utf8_size(const char * str)
{
if(LV_IS_ASCII(str[0]))
return 1;
else if(LV_IS_2BYTES_UTF8_CODE(str[0]))
return 2;
else if(LV_IS_3BYTES_UTF8_CODE(str[0]))
return 3;
else if(LV_IS_4BYTES_UTF8_CODE(str[0]))
return 4;
return 0;
}
/**
* Convert a Unicode letter to UTF-8.
* @param letter_uni a Unicode letter
* @return UTF-8 coded character in Little Endian to be compatible with C chars (e.g. 'Á', 'Ű')
*/
static uint32_t lv_txt_unicode_to_utf8(uint32_t letter_uni)
{
if(letter_uni < 128) return letter_uni;
uint8_t bytes[4];
if(letter_uni < 0x0800) {
bytes[0] = ((letter_uni >> 6) & 0x1F) | 0xC0;
bytes[1] = ((letter_uni >> 0) & 0x3F) | 0x80;
bytes[2] = 0;
bytes[3] = 0;
}
else if(letter_uni < 0x010000) {
bytes[0] = ((letter_uni >> 12) & 0x0F) | 0xE0;
bytes[1] = ((letter_uni >> 6) & 0x3F) | 0x80;
bytes[2] = ((letter_uni >> 0) & 0x3F) | 0x80;
bytes[3] = 0;
}
else if(letter_uni < 0x110000) {
bytes[0] = ((letter_uni >> 18) & 0x07) | 0xF0;
bytes[1] = ((letter_uni >> 12) & 0x3F) | 0x80;
bytes[2] = ((letter_uni >> 6) & 0x3F) | 0x80;
bytes[3] = ((letter_uni >> 0) & 0x3F) | 0x80;
}
else {
return 0;
}
uint32_t * res_p = (uint32_t *)bytes;
return *res_p;
}
/**
* Convert a wide character, e.g. 'Á' little endian to be UTF-8 compatible
* @param c a wide character or a Little endian number
* @return `c` in big endian
*/
static uint32_t lv_txt_utf8_conv_wc(uint32_t c)
{
#if LV_BIG_ENDIAN_SYSTEM == 0
/*Swap the bytes (UTF-8 is big endian, but the MCUs are little endian)*/
if((c & 0x80) != 0) {
uint32_t swapped;
uint8_t c8[4];
lv_memcpy_small(c8, &c, 4);
swapped = (c8[0] << 24) + (c8[1] << 16) + (c8[2] << 8) + (c8[3]);
uint8_t i;
for(i = 0; i < 4; i++) {
if((swapped & 0xFF) == 0)
swapped = (swapped >> 8); /*Ignore leading zeros (they were in the end originally)*/
}
c = swapped;
}
#endif
return c;
}
/**
* Decode an UTF-8 character from a string.
* @param txt pointer to '\0' terminated string
* @param i start byte index in 'txt' where to start.
* After call it will point to the next UTF-8 char in 'txt'.
* NULL to use txt[0] as index
* @return the decoded Unicode character or 0 on invalid UTF-8 code
*/
static uint32_t lv_txt_utf8_next(const char * txt, uint32_t * i)
{
/**
* Unicode to UTF-8
* 00000000 00000000 00000000 0xxxxxxx -> 0xxxxxxx
* 00000000 00000000 00000yyy yyxxxxxx -> 110yyyyy 10xxxxxx
* 00000000 00000000 zzzzyyyy yyxxxxxx -> 1110zzzz 10yyyyyy 10xxxxxx
* 00000000 000wwwzz zzzzyyyy yyxxxxxx -> 11110www 10zzzzzz 10yyyyyy 10xxxxxx
*/
uint32_t result = 0;
/*Dummy 'i' pointer is required*/
uint32_t i_tmp = 0;
if(i == NULL) i = &i_tmp;
/*Normal ASCII*/
if(LV_IS_ASCII(txt[*i])) {
result = txt[*i];
(*i)++;
}
/*Real UTF-8 decode*/
else {
/*2 bytes UTF-8 code*/
if(LV_IS_2BYTES_UTF8_CODE(txt[*i])) {
result = (uint32_t)(txt[*i] & 0x1F) << 6;
(*i)++;
if(LV_IS_INVALID_UTF8_CODE(txt[*i])) return 0;
result += (txt[*i] & 0x3F);
(*i)++;
}
/*3 bytes UTF-8 code*/
else if(LV_IS_3BYTES_UTF8_CODE(txt[*i])) {
result = (uint32_t)(txt[*i] & 0x0F) << 12;
(*i)++;
if(LV_IS_INVALID_UTF8_CODE(txt[*i])) return 0;
result += (uint32_t)(txt[*i] & 0x3F) << 6;
(*i)++;
if(LV_IS_INVALID_UTF8_CODE(txt[*i])) return 0;
result += (txt[*i] & 0x3F);
(*i)++;
}
/*4 bytes UTF-8 code*/
else if(LV_IS_4BYTES_UTF8_CODE(txt[*i])) {
result = (uint32_t)(txt[*i] & 0x07) << 18;
(*i)++;
if(LV_IS_INVALID_UTF8_CODE(txt[*i])) return 0;
result += (uint32_t)(txt[*i] & 0x3F) << 12;
(*i)++;
if(LV_IS_INVALID_UTF8_CODE(txt[*i])) return 0;
result += (uint32_t)(txt[*i] & 0x3F) << 6;
(*i)++;
if(LV_IS_INVALID_UTF8_CODE(txt[*i])) return 0;
result += txt[*i] & 0x3F;
(*i)++;
}
else {
(*i)++; /*Not UTF-8 char. Go the next.*/
}
}
return result;
}
/**
* Get previous UTF-8 character form a string.
* @param txt pointer to '\0' terminated string
* @param i start byte index in 'txt' where to start. After the call it will point to the previous
* UTF-8 char in 'txt'.
* @return the decoded Unicode character or 0 on invalid UTF-8 code
*/
static uint32_t lv_txt_utf8_prev(const char * txt, uint32_t * i)
{
uint8_t c_size;
uint8_t cnt = 0;
/*Try to find a !0 long UTF-8 char by stepping one character back*/
(*i)--;
do {
if(cnt >= 4) return 0; /*No UTF-8 char found before the initial*/
c_size = _lv_txt_encoded_size(&txt[*i]);
if(c_size == 0) {
if(*i != 0)
(*i)--;
else
return 0;
}
cnt++;
} while(c_size == 0);
uint32_t i_tmp = *i;
uint32_t letter = _lv_txt_encoded_next(txt, &i_tmp); /*Character found, get it*/
return letter;
}
/**
* Convert a character index (in an UTF-8 text) to byte index.
* E.g. in "AÁRT" index of 'R' is 2th char but start at byte 3 because 'Á' is 2 bytes long
* @param txt a '\0' terminated UTF-8 string
* @param utf8_id character index
* @return byte index of the 'utf8_id'th letter
*/
static uint32_t lv_txt_utf8_get_byte_id(const char * txt, uint32_t utf8_id)
{
uint32_t i;
uint32_t byte_cnt = 0;
for(i = 0; i < utf8_id && txt[byte_cnt] != '\0'; i++) {
uint8_t c_size = _lv_txt_encoded_size(&txt[byte_cnt]);
/* If the char was invalid tell it's 1 byte long*/
byte_cnt += c_size ? c_size : 1;
}
return byte_cnt;
}
/**
* Convert a byte index (in an UTF-8 text) to character index.
* E.g. in "AÁRT" index of 'R' is 2th char but start at byte 3 because 'Á' is 2 bytes long
* @param txt a '\0' terminated UTF-8 string
* @param byte_id byte index
* @return character index of the letter at 'byte_id'th position
*/
static uint32_t lv_txt_utf8_get_char_id(const char * txt, uint32_t byte_id)
{
uint32_t i = 0;
uint32_t char_cnt = 0;
while(i < byte_id) {
_lv_txt_encoded_next(txt, &i); /*'i' points to the next letter so use the prev. value*/
char_cnt++;
}
return char_cnt;
}
/**
* Get the number of characters (and NOT bytes) in a string. Decode it with UTF-8 if enabled.
* E.g.: "ÁBC" is 3 characters (but 4 bytes)
* @param txt a '\0' terminated char string
* @return number of characters
*/
static uint32_t lv_txt_utf8_get_length(const char * txt)
{
uint32_t len = 0;
uint32_t i = 0;
while(txt[i] != '\0') {
_lv_txt_encoded_next(txt, &i);
len++;
}
return len;
}
#elif LV_TXT_ENC == LV_TXT_ENC_ASCII
/*******************************
* ASCII ENCODER/DECODER
******************************/
/**
* Give the size of an ISO8859-1 coded character
* @param str pointer to a character in a string
* @return length of the UTF-8 character (1,2,3 or 4). O on invalid code
*/
static uint8_t lv_txt_iso8859_1_size(const char * str)
{
LV_UNUSED(str); /*Unused*/
return 1;
}
/**
* Convert a Unicode letter to ISO8859-1.
* @param letter_uni a Unicode letter
* @return ISO8859-1 coded character in Little Endian to be compatible with C chars (e.g. 'Á', 'Ű')
*/
static uint32_t lv_txt_unicode_to_iso8859_1(uint32_t letter_uni)
{
if(letter_uni < 256)
return letter_uni;
else
return ' ';
}
/**
* Convert wide characters to ASCII, however wide characters in ASCII range (e.g. 'A') are ASCII compatible by default.
* So this function does nothing just returns with `c`.
* @param c a character, e.g. 'A'
* @return same as `c`
*/
static uint32_t lv_txt_iso8859_1_conv_wc(uint32_t c)
{
return c;
}
/**
* Decode an ISO8859-1 character from a string.
* @param txt pointer to '\0' terminated string
* @param i start byte index in 'txt' where to start.
* After call it will point to the next UTF-8 char in 'txt'.
* NULL to use txt[0] as index
* @return the decoded Unicode character or 0 on invalid UTF-8 code
*/
static uint32_t lv_txt_iso8859_1_next(const char * txt, uint32_t * i)
{
if(i == NULL) return txt[0]; /*Get the next char*/
uint8_t letter = txt[*i];
(*i)++;
return letter;
}
/**
* Get previous ISO8859-1 character form a string.
* @param txt pointer to '\0' terminated string
* @param i start byte index in 'txt' where to start. After the call it will point to the previous UTF-8 char in 'txt'.
* @return the decoded Unicode character or 0 on invalid UTF-8 code
*/
static uint32_t lv_txt_iso8859_1_prev(const char * txt, uint32_t * i)
{
if(i == NULL) return *(txt - 1); /*Get the prev. char*/
(*i)--;
uint8_t letter = txt[*i];
return letter;
}
/**
* Convert a character index (in an ISO8859-1 text) to byte index.
* E.g. in "AÁRT" index of 'R' is 2th char but start at byte 3 because 'Á' is 2 bytes long
* @param txt a '\0' terminated UTF-8 string
* @param utf8_id character index
* @return byte index of the 'utf8_id'th letter
*/
static uint32_t lv_txt_iso8859_1_get_byte_id(const char * txt, uint32_t utf8_id)
{
LV_UNUSED(txt); /*Unused*/
return utf8_id; /*In Non encoded no difference*/
}
/**
* Convert a byte index (in an ISO8859-1 text) to character index.
* E.g. in "AÁRT" index of 'R' is 2th char but start at byte 3 because 'Á' is 2 bytes long
* @param txt a '\0' terminated UTF-8 string
* @param byte_id byte index
* @return character index of the letter at 'byte_id'th position
*/
static uint32_t lv_txt_iso8859_1_get_char_id(const char * txt, uint32_t byte_id)
{
LV_UNUSED(txt); /*Unused*/
return byte_id; /*In Non encoded no difference*/
}
/**
* Get the number of characters (and NOT bytes) in a string. Decode it with UTF-8 if enabled.
* E.g.: "ÁBC" is 3 characters (but 4 bytes)
* @param txt a '\0' terminated char string
* @return number of characters
*/
static uint32_t lv_txt_iso8859_1_get_length(const char * txt)
{
return strlen(txt);
}
#else
#error "Invalid character encoding. See `LV_TXT_ENC` in `lv_conf.h`"
#endif
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