1 /**
2 * @file lv_bidi.h
3 *
4 */
5
6 #ifndef LV_BIDI_H
7 #define LV_BIDI_H
8
9 #ifdef __cplusplus
10 extern "C" {
11 #endif
12
13 /*********************
14 * INCLUDES
15 *********************/
16 #include "../lv_conf_internal.h"
17
18 #include <stdbool.h>
19 #include <stdint.h>
20 #include "lv_txt.h"
21
22 /*********************
23 * DEFINES
24 *********************/
25 /*Special non printable strong characters.
26 *They can be inserted to texts to affect the run's direction*/
27 #define LV_BIDI_LRO "\xE2\x80\xAD" /*U+202D*/
28 #define LV_BIDI_RLO "\xE2\x80\xAE" /*U+202E*/
29
30 /**********************
31 * TYPEDEFS
32 **********************/
33 enum {
34 LV_BASE_DIR_LTR = 0x00,
35 LV_BASE_DIR_RTL = 0x01,
36 LV_BASE_DIR_AUTO = 0x02,
37
38 LV_BASE_DIR_NEUTRAL = 0x20,
39 LV_BASE_DIR_WEAK = 0x21,
40 };
41
42 typedef uint8_t lv_base_dir_t;
43
44 /**********************
45 * GLOBAL PROTOTYPES
46 **********************/
47 #if LV_USE_BIDI
48
49 /**
50 * Convert a text to get the characters in the correct visual order according to
51 * Unicode Bidirectional Algorithm
52 * @param str_in the text to process
53 * @param str_out store the result here. Has the be `strlen(str_in)` length
54 * @param base_dir `LV_BASE_DIR_LTR` or `LV_BASE_DIR_RTL`
55 */
56 void _lv_bidi_process(const char * str_in, char * str_out, lv_base_dir_t base_dir);
57
58 /**
59 * Auto-detect the direction of a text based on the first strong character
60 * @param txt the text to process
61 * @return `LV_BASE_DIR_LTR` or `LV_BASE_DIR_RTL`
62 */
63 lv_base_dir_t _lv_bidi_detect_base_dir(const char * txt);
64
65 /**
66 * Get the logical position of a character in a line
67 * @param str_in the input string. Can be only one line.
68 * @param bidi_txt internally the text is bidi processed which buffer can be get here.
69 * If not required anymore has to freed with `lv_mem_free()`
70 * Can be `NULL` is unused
71 * @param len length of the line in character count
72 * @param base_dir base direction of the text: `LV_BASE_DIR_LTR` or `LV_BASE_DIR_RTL`
73 * @param visual_pos the visual character position which logical position should be get
74 * @param is_rtl tell the char at `visual_pos` is RTL or LTR context
75 * @return the logical character position
76 */
77 uint16_t _lv_bidi_get_logical_pos(const char * str_in, char ** bidi_txt, uint32_t len, lv_base_dir_t base_dir,
78 uint32_t visual_pos, bool * is_rtl);
79
80 /**
81 * Get the visual position of a character in a line
82 * @param str_in the input string. Can be only one line.
83 * @param bidi_txt internally the text is bidi processed which buffer can be get here.
84 * If not required anymore has to freed with `lv_mem_free()`
85 * Can be `NULL` is unused
86 * @param len length of the line in character count
87 * @param base_dir base direction of the text: `LV_BASE_DIR_LTR` or `LV_BASE_DIR_RTL`
88 * @param logical_pos the logical character position which visual position should be get
89 * @param is_rtl tell the char at `logical_pos` is RTL or LTR context
90 * @return the visual character position
91 */
92 uint16_t _lv_bidi_get_visual_pos(const char * str_in, char ** bidi_txt, uint16_t len, lv_base_dir_t base_dir,
93 uint32_t logical_pos, bool * is_rtl);
94
95 /**
96 * Bidi process a paragraph of text
97 * @param str_in the string to process
98 * @param str_out store the result here
99 * @param len length of the text
100 * @param base_dir base dir of the text
101 * @param pos_conv_out an `uint16_t` array to store the related logical position of the character.
102 * Can be `NULL` is unused
103 * @param pos_conv_len length of `pos_conv_out` in element count
104 */
105 void _lv_bidi_process_paragraph(const char * str_in, char * str_out, uint32_t len, lv_base_dir_t base_dir,
106 uint16_t * pos_conv_out, uint16_t pos_conv_len);
107
108 /**
109 * Get the real text alignment from the a text alignment, base direction and a text.
110 * @param align LV_TEXT_ALIGN_..., write back the calculated align here (LV_TEXT_ALIGN_LEFT/RIGHT/CENTER)
111 * @param base_dir LV_BASE_DIR_..., write the calculated base dir here (LV_BASE_DIR_LTR/RTL)
112 * @param txt a text, used with LV_BASE_DIR_AUTO to determine the base direction
113 */
114 void lv_bidi_calculate_align(lv_text_align_t * align, lv_base_dir_t * base_dir, const char * txt);
115
116 /**********************
117 * MACROS
118 **********************/
119
120 #else /*LV_USE_BIDI*/
121 /**
122 * For compatibility if LV_USE_BIDI = 0
123 * Get the real text alignment from the a text alignment, base direction and a text.
124 * @param align For LV_TEXT_ALIGN_AUTO give LV_TEXT_ALIGN_LEFT else leave unchanged, write back the calculated align here
125 * @param base_dir Unused
126 * @param txt Unused
127 */
lv_bidi_calculate_align(lv_text_align_t * align,lv_base_dir_t * base_dir,const char * txt)128 static inline void lv_bidi_calculate_align(lv_text_align_t * align, lv_base_dir_t * base_dir, const char * txt)
129 {
130 LV_UNUSED(txt);
131 LV_UNUSED(base_dir);
132 if(*align == LV_TEXT_ALIGN_AUTO) * align = LV_TEXT_ALIGN_LEFT;
133 }
134 #endif /*LV_USE_BIDI*/
135
136 #ifdef __cplusplus
137 } /*extern "C"*/
138 #endif
139
140 #endif /*LV_BIDI_H*/
141
