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hekate/bdk/libs/lvgl/lv_misc/lv_txt.c
CTCaer 185526d134 Introducing Bootloader Development Kit (BDK) 
BDK will allow developers to use the full collection of drivers,
with limited editing, if any, for making payloads for Nintendo Switch.

Using a single source for everything will also help decoupling
Switch specific code and easily port it to other Tegra X1/X1+ platforms.
And maybe even to lower targets.

Everything is now centrilized into bdk folder.
Every module or project can utilize it by simply including it.

This is just the start and it will continue to improve.
2020-06-14 15:25:21 +03:00

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/**
* @file lv_text.c
*
*/
/*********************
* INCLUDES
*********************/
#include "lv_txt.h"
#include "lv_math.h"
/*********************
* DEFINES
*********************/
#define NO_BREAK_FOUND UINT32_MAX
#ifndef LV_TXT_LINE_BREAK_LONG_LEN
#define LV_TXT_LINE_BREAK_LONG_LEN 12 /* If a character is at least this long, will break wherever "prettiest" */
#endif
#ifndef LV_TXT_LINE_BREAK_LONG_PRE_MIN_LEN
#define LV_TXT_LINE_BREAK_LONG_PRE_MIN_LEN 3 /* Minimum number of characters of a word to put on a line before a break */
#endif
#ifndef LV_TXT_LINE_BREAK_LONG_POST_MIN_LEN
#define LV_TXT_LINE_BREAK_LONG_POST_MIN_LEN 1 /* Minimum number of characters of a word to put on a line after a break */
#endif
/**********************
* TYPEDEFS
**********************/
/**********************
* STATIC PROTOTYPES
**********************/
static bool is_break_char(uint32_t letter);
#if LV_TXT_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);
#else
static uint8_t lv_txt_ascii_size(const char * str);
static uint32_t lv_txt_unicode_to_ascii(uint32_t letter_uni);
static uint32_t lv_txt_ascii_conv_wc(uint32_t c);
static uint32_t lv_txt_ascii_next(const char * txt, uint32_t * i);
static uint32_t lv_txt_ascii_prev(const char * txt, uint32_t * i_start);
static uint32_t lv_txt_ascii_get_byte_id(const char * txt, uint32_t utf8_id);
static uint32_t lv_txt_ascii_get_char_id(const char * txt, uint32_t byte_id);
static uint32_t lv_txt_ascii_get_length(const char * txt);
#endif
/**********************
* STATIC VARIABLES
**********************/
/**********************
* GLOBAL VARIABLES
**********************/
#if LV_TXT_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_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;
#else
uint8_t (*lv_txt_encoded_size)(const char *) = lv_txt_ascii_size;
uint32_t (*lv_txt_unicode_to_encoded)(uint32_t) = lv_txt_unicode_to_ascii;
uint32_t (*lv_txt_encoded_conv_wc)(uint32_t) = lv_txt_ascii_conv_wc;
uint32_t (*lv_txt_encoded_next)(const char *, uint32_t *) = lv_txt_ascii_next;
uint32_t (*lv_txt_encoded_prev)(const char *, uint32_t *) = lv_txt_ascii_prev;
uint32_t (*lv_txt_encoded_get_byte_id)(const char *, uint32_t) = lv_txt_ascii_get_byte_id;
uint32_t (*lv_encoded_get_char_id)(const char *, uint32_t) = lv_txt_ascii_get_char_id;
uint32_t (*lv_txt_get_encoded_length)(const char *) = lv_txt_ascii_get_length;
#endif
/**********************
* MACROS
**********************/
/**********************
* GLOBAL FUNCTIONS
**********************/
/**
* Get size of a text
* @param size_res pointer to a 'point_t' variable to store the result
* @param text pointer to a text
* @param font pinter to font of the text
* @param letter_space letter space of the text
* @param txt.line_space line space of the text
* @param flags settings for the text from 'txt_flag_t' enum
* @param max_width max with of the text (break the lines to fit this size) Set CORD_MAX to avoid line breaks
*/
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_txt_flag_t flag)
{
size_res->x = 0;
size_res->y = 0;
if(text == NULL) return;
if(font == NULL) return;
if(flag & LV_TXT_FLAG_EXPAND) max_width = LV_COORD_MAX;
uint32_t line_start = 0;
uint32_t new_line_start = 0;
lv_coord_t act_line_length;
uint8_t letter_height = lv_font_get_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, flag);
size_res->y += letter_height ;
size_res->y += line_space;
/*Calculate the the longest line*/
act_line_length = lv_txt_get_width(&text[line_start], new_line_start - line_start,
font, letter_space, flag);
size_res->x = LV_MATH_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 line of text. Check line length and break chars too.
* @param txt a '\0' terminated string
* @param font pointer to a font
* @param letter_space letter space
* @param max_width max with of the text (break the lines to fit this size) Set CORD_MAX to avoid line breaks
* @param flags settings for the text from 'txt_flag_type' enum
* @return the index of the first char of the new line (in byte index not letter index. With UTF-8 they are different)
*/
uint16_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_txt_flag_t flag)
{
if(txt == NULL) return 0;
if(font == NULL) return 0;
if(flag & LV_TXT_FLAG_EXPAND) max_width = LV_COORD_MAX;
uint32_t i = 0;
lv_coord_t cur_w = 0;
lv_coord_t w_at_last_break = 0;
uint32_t n_char_since_last_break = 0; /* Used count word length of long words */
uint32_t last_break = NO_BREAK_FOUND;
lv_txt_cmd_state_t cmd_state = LV_TXT_CMD_STATE_WAIT;
uint32_t letter = 0;
while(txt[i] != '\0') {
lv_coord_t letter_width;
letter = lv_txt_encoded_next(txt, &i);
/*Handle the recolor command*/
if((flag & LV_TXT_FLAG_RECOLOR) != 0) {
if(lv_txt_is_cmd(&cmd_state, letter) != false) {
continue; /*Skip the letter is it is part of a command*/
}
}
/*Check for new line chars*/
if(letter == '\n' || letter == '\r') {
uint32_t i_tmp = i;
uint32_t letter_next = lv_txt_encoded_next(txt, &i_tmp);
if(letter == '\r' && letter_next == '\n') i = i_tmp;
return i; /*Return with the first letter of the next line*/
} else { /*Check the actual length*/
n_char_since_last_break++;
letter_width = lv_font_get_width(font, letter);
cur_w += letter_width;
/* Get the length of the current work and determine best place
* to break the line. */
if(cur_w > max_width) {
if( last_break != NO_BREAK_FOUND ) {
/* Continue searching for next breakable character to see if the next word will fit */
uint32_t n_char_fit = n_char_since_last_break - 1;
if( n_char_since_last_break <= LV_TXT_LINE_BREAK_LONG_PRE_MIN_LEN ) {
i = last_break;
}
else {
uint32_t i_tmp = i;
cur_w -= w_at_last_break + letter_space; /*ignore the first letter_space after the break char */
bool other = true;
while(txt[i_tmp] != '\0') {
letter = lv_txt_encoded_next(txt, &i_tmp);
/*Handle the recolor command*/
if((flag & LV_TXT_FLAG_RECOLOR) != 0) {
if(lv_txt_is_cmd(&cmd_state, letter) != false) {
continue; /*Skip the letter is it is part of a command*/
}
}
/*Check for new line chars*/
if(letter == '\n' || letter == '\r' || is_break_char(letter)) {
if(n_char_since_last_break >= LV_TXT_LINE_BREAK_LONG_LEN) {
/* Figure out the prettiest place to break */
uint32_t char_remain;
lv_txt_encoded_prev(txt, &i);
for(char_remain=n_char_since_last_break - n_char_fit;
char_remain < LV_TXT_LINE_BREAK_LONG_POST_MIN_LEN;
char_remain++) {
lv_txt_encoded_prev(txt, &i);
}
}
else{
i = last_break;
}
other = false;
break;
}
n_char_since_last_break++;
lv_coord_t letter_width2 = lv_font_get_width(font, letter);
cur_w += letter_width2;
if(cur_w > max_width) {
/* Current letter already exceeds, return previous */
lv_txt_encoded_prev(txt, &i);
other = false;
break;
}
if(letter_width2 > 0){
cur_w += letter_space;
}
}
if( other ) {
if(n_char_since_last_break >= LV_TXT_LINE_BREAK_LONG_LEN) {
/* Figure out the prettiest place to break */
uint32_t char_remain;
lv_txt_encoded_prev(txt, &i);
for(char_remain=n_char_since_last_break - n_char_fit;
char_remain < LV_TXT_LINE_BREAK_LONG_POST_MIN_LEN;
char_remain++){
lv_txt_encoded_prev(txt, &i);
}
}
else{
i = last_break;
}
}
}
} else {
/* Now this character is out of the area so it will be first character of the next line*/
/* But 'i' already points to the next character (because of lv_txt_utf8_next) step beck one*/
lv_txt_encoded_prev(txt, &i);
}
/* Do not let to return without doing nothing.
* Find at least one character (Avoid infinite loop )*/
if(i == 0) lv_txt_encoded_next(txt, &i);
return i;
}
/*If this char still can fit to this line then check if
* txt can be broken here later */
else if(is_break_char(letter)) {
last_break = i; /*Save the first char index after break*/
w_at_last_break = cur_w;
if(letter_width > 0) {
w_at_last_break += letter_space;
}
n_char_since_last_break = 0;
}
}
if(letter_width > 0) {
cur_w += letter_space;
}
}
return i;
}
/**
* Give the length of a text with a given font
* @param txt a '\0' terminate string
* @param length length of 'txt' in byte count and not characters (Á is 1 character but 2 bytes in UTF-8)
* @param font pointer to a font
* @param letter_space letter space
* @param flags settings for the text from 'txt_flag_t' enum
* @return length of a char_num long text
*/
lv_coord_t lv_txt_get_width(const char * txt, uint16_t length,
const lv_font_t * font, lv_coord_t letter_space, lv_txt_flag_t flag)
{
if(txt == NULL) return 0;
if(font == NULL) return 0;
uint32_t i = 0;
lv_coord_t width = 0;
lv_txt_cmd_state_t cmd_state = LV_TXT_CMD_STATE_WAIT;
uint32_t letter;
if(length != 0) {
while(i< length){
letter = lv_txt_encoded_next(txt, &i);
if((flag & LV_TXT_FLAG_RECOLOR) != 0) {
if(lv_txt_is_cmd(&cmd_state, letter) != false) {
continue;
}
}
lv_coord_t char_width = lv_font_get_width(font, letter);
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;
}
/**
* Check next character in a string and decide if the character is part of the command or not
* @param state pointer to a txt_cmd_state_t variable which stores the current state of command processing
* (Initied. to TXT_CMD_STATE_WAIT )
* @param c the current character
* @return true: the character is part of a command and should not be written,
* false: the character should be written
*/
bool lv_txt_is_cmd(lv_txt_cmd_state_t * state, uint32_t c)
{
bool ret = false;
if(c == (uint32_t)LV_TXT_COLOR_CMD[0]) {
if(*state == LV_TXT_CMD_STATE_WAIT) { /*Start char*/
*state = LV_TXT_CMD_STATE_PAR;
ret = true;
} else if(*state == LV_TXT_CMD_STATE_PAR) { /*Other start char in parameter is escaped cmd. char */
*state = LV_TXT_CMD_STATE_WAIT;
} else if(*state == LV_TXT_CMD_STATE_IN) { /*Command end */
*state = LV_TXT_CMD_STATE_WAIT;
ret = true;
}
}
/*Skip the color parameter and wait the space after it*/
if(*state == LV_TXT_CMD_STATE_PAR) {
if(c == ' ') {
*state = LV_TXT_CMD_STATE_IN; /*After the parameter the text is in the command*/
}
ret = true;
}
return ret;
}
/**
* Insert a string into an other
* @param txt_buf the original text (must be big enough for the result text)
* @param pos position to insert. Expressed in character index and not byte index (Different in UTF-8)
* 0: before the original text, 1: after the first char etc.
* @param ins_txt text to insert
*/
void lv_txt_ins(char * txt_buf, uint32_t pos, const char * ins_txt)
{
uint32_t old_len = strlen(txt_buf);
uint32_t ins_len = strlen(ins_txt);
uint32_t new_len = ins_len + old_len;
#if LV_TXT_UTF8 != 0
pos = lv_txt_encoded_get_byte_id(txt_buf, pos); /*Convert to byte index instead of letter index*/
#endif
/*Copy the second part into the end to make place to text to insert*/
uint32_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*/
memcpy(txt_buf + pos, ins_txt, ins_len);
}
/**
* Delete a part of a string
* @param txt string to modify
* @param pos position where to start the deleting (0: before the first char, 1: after the first char etc.)
* @param len number of characters to delete
*/
void lv_txt_cut(char * txt, uint32_t pos, uint32_t len)
{
uint32_t old_len = strlen(txt);
#if LV_TXT_UTF8 != 0
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);
#endif
/*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];
}
}
/*******************************
* UTF-8 ENCODER/DECOER
******************************/
#if LV_TXT_UTF8
/**
* 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). O on invalid code
*/
static uint8_t lv_txt_utf8_size(const char * str)
{
if((str[0] & 0x80) == 0) return 1;
else if((str[0] & 0xE0) == 0xC0) return 2;
else if((str[0] & 0xF0) == 0xE0) return 3;
else if((str[0] & 0xF8) == 0xF0) return 4;
return 0;
}
/**
* Convert an Unicode letter to UTF-8.
* @param letter_uni an 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;
}
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)
{
/*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];
memcpy(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;
}
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((txt[*i] & 0x80) == 0) {
result = txt[*i];
(*i)++;
}
/*Real UTF-8 decode*/
else {
/*2 bytes UTF-8 code*/
if((txt[*i] & 0xE0) == 0xC0) {
result = (uint32_t)(txt[*i] & 0x1F) << 6;
(*i)++;
if((txt[*i] & 0xC0) != 0x80) return 0; /*Invalid UTF-8 code*/
result += (txt[*i] & 0x3F);
(*i)++;
}
/*3 bytes UTF-8 code*/
else if((txt[*i] & 0xF0) == 0xE0) {
result = (uint32_t)(txt[*i] & 0x0F) << 12;
(*i)++;
if((txt[*i] & 0xC0) != 0x80) return 0; /*Invalid UTF-8 code*/
result += (uint32_t)(txt[*i] & 0x3F) << 6;
(*i)++;
if((txt[*i] & 0xC0) != 0x80) return 0; /*Invalid UTF-8 code*/
result += (txt[*i] & 0x3F);
(*i)++;
}
/*4 bytes UTF-8 code*/
else if((txt[*i] & 0xF8) == 0xF0) {
result = (uint32_t)(txt[*i] & 0x07) << 18;
(*i)++;
if((txt[*i] & 0xC0) != 0x80) return 0; /*Invalid UTF-8 code*/
result += (uint32_t)(txt[*i] & 0x3F) << 12;
(*i)++;
if((txt[*i] & 0xC0) != 0x80) return 0; /*Invalid UTF-8 code*/
result += (uint32_t)(txt[*i] & 0x3F) << 6;
(*i)++;
if((txt[*i] & 0xC0) != 0x80) return 0; /*Invalid UTF-8 code*/
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; i++) {
byte_cnt += lv_txt_encoded_size(&txt[byte_cnt]);
}
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)
{
#if LV_TXT_UTF8 == 0
return strlen(txt);
#else
uint32_t len = 0;
uint32_t i = 0;
while(txt[i] != '\0') {
lv_txt_encoded_next(txt, &i);
len++;
}
return len;
#endif
}
#else
/**
* 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). O on invalid code
*/
static uint8_t lv_txt_ascii_size(const char * str)
{
return 1;
}
/**
* Convert an Unicode letter to UTF-8.
* @param letter_uni an 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_ascii(uint32_t letter_uni)
{
if(letter_uni < 128) 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_ascii_conv_wc(uint32_t c)
{
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_ascii_next(const char * txt, uint32_t * i)
{
if(i == NULL) return txt[1]; /*Get the next char */
uint8_t letter = txt[*i] ;
(*i)++;
return letter;
}
/**
* 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_ascii_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 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_ascii_get_byte_id(const char * txt, uint32_t utf8_id)
{
return utf8_id; /*In Non encoded no difference*/
}
/**
* 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_ascii_get_char_id(const char * txt, uint32_t byte_id)
{
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_ascii_get_length(const char * txt)
{
return strlen(txt);
}
#endif
/**********************
* STATIC FUNCTIONS
**********************/
/**
* Test if char is break char or not (a text can broken here or not)
* @param letter a letter
* @return false: 'letter' is not break char
*/
static bool is_break_char(uint32_t letter)
{
uint8_t i;
bool ret = false;
/*Compare the letter to TXT_BREAK_CHARS*/
for(i = 0; LV_TXT_BREAK_CHARS[i] != '\0'; i++) {
if(letter == (uint32_t)LV_TXT_BREAK_CHARS[i]) {
ret = true; /*If match then it is break char*/
break;
}
}
return ret;
}
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