Key bindings for UTF-8 encoded characters

Internally characters (keys) have two representations: integers and key
names. Key names are characters strings, usually the name of the
character; e.g., the character A has the representations 65 and "A", and
the tab character the representations 9 and "TAB".

The function keys_int2str() turns the integer representation of a
key/character into the key name.

For display purposes the key names are usually confined to have display
width at most three. Some curses pseudo-keys have longer key names;
e.g., the back-tab character is "KEY_BTAB". A long key name makes a
character difficult to recognize in the status bar menu.

The key name of a multibyte, UTF-8 encoded character is the conventional
Unicode name of the code point; e.g., the character ü has key name
"U+00FC" because ü is the code point 0xFC. Most of these look alike in
the status bar menu.

The patch makes the key name of a multibyte character look like that of
a singlebyte character: the character itself, i.e. the key name of the
character ü is "ü".

The main tool is implementation of a utf8_encode() routine.

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>
This commit is contained in:
Lars Henriksen 2018-03-26 18:44:08 +02:00 committed by Lukas Fleischer
parent 431e4a00e7
commit 7078556f9d
4 changed files with 47 additions and 13 deletions

View File

@ -1119,6 +1119,7 @@ int utf8_decode(const char *);
int utf8_width(char *); int utf8_width(char *);
int utf8_strwidth(char *); int utf8_strwidth(char *);
int utf8_chop(char *, int); int utf8_chop(char *, int);
char *utf8_encode(int);
/* utils.c */ /* utils.c */
void exit_calcurse(int) __attribute__ ((__noreturn__)); void exit_calcurse(int) __attribute__ ((__noreturn__));

View File

@ -908,7 +908,7 @@ print_keys_bindings(WINDOW * win, int selected_row, int selected_elm,
mvwprintw(win, y, pos, mvwprintw(win, y, pos,
"%s ", key); "%s ", key);
noelm++; noelm++;
pos += strlen(key) + 1; pos += utf8_strwidth((char *)key) + 1;
} }
} else { } else {
mvwaddstr(win, y, KEYPOS, mvwaddstr(win, y, KEYPOS,

View File

@ -395,9 +395,6 @@ int keys_str2int(const char *key)
else if (strcmp(key, "KEY_END") == 0) else if (strcmp(key, "KEY_END") == 0)
return KEY_END; return KEY_END;
/* UTF-8 multibyte keys. */
if (starts_with(key, "U+"))
return strtol(&key[strlen("U+")], NULL, 16) + KEY_MAX;
/* Lookup in the keynames table. */ /* Lookup in the keynames table. */
for (int i = 1; i < 128; i++) for (int i = 1; i < 128; i++)
@ -407,8 +404,8 @@ int keys_str2int(const char *key)
if (strcmp(key, keynames[i]) == 0) if (strcmp(key, keynames[i]) == 0)
return i; return i;
/* UTF-8 multibyte keys. */
return -1; return utf8_decode(key) + KEY_MAX;
} }
char *keys_int2str(int key) char *keys_int2str(int key)
@ -421,7 +418,7 @@ char *keys_int2str(int key)
else else
return mem_strdup(keynames[key]); return mem_strdup(keynames[key]);
} else { } else {
asprintf(&res, "U+%04X", key - KEY_MAX); asprintf(&res, "%s", utf8_encode(key - KEY_MAX));
return res; return res;
} }
} }
@ -476,7 +473,7 @@ char *keys_action_allkeys(enum key action)
static char *keys_format_label(char *key, int keylen) static char *keys_format_label(char *key, int keylen)
{ {
static char fmtkey[BUFSIZ]; static char fmtkey[BUFSIZ];
const int len = strlen(key); const int len = utf8_strwidth(key);
const char dot = '.'; const char dot = '.';
int i; int i;
@ -520,7 +517,7 @@ keys_display_bindings_bar(WINDOW * win, int *bindings, int count,
const int label_pos_x = key_pos_x + KEYS_KEYLEN + 1; const int label_pos_x = key_pos_x + KEYS_KEYLEN + 1;
const int label_pos_y = key_pos_y; const int label_pos_y = key_pos_y;
char key[KEYS_KEYLEN + 1], *fmtkey; char key[UTF8_MAXLEN + 1], *fmtkey;
int binding_key; int binding_key;
@ -532,9 +529,8 @@ keys_display_bindings_bar(WINDOW * win, int *bindings, int count,
const char *label; const char *label;
if (binding_key < NBKEYS) { if (binding_key < NBKEYS) {
strncpy(key, keys_action_firstkey(binding_key), strncpy(key, keys_action_firstkey(binding_key), UTF8_MAXLEN);
KEYS_KEYLEN); key[UTF8_MAXLEN] = '\0';
key[KEYS_KEYLEN] = '\0';
label = gettext(keydef[binding_key].sb_label); label = gettext(keydef[binding_key].sb_label);
} else { } else {
switch (binding_key) { switch (binding_key) {

View File

@ -291,7 +291,44 @@ int utf8_decode(const char *s)
} }
} }
/* Get the width of a UTF-8 character. */ /*
* Encode a Unicode code point.
* Return a pointer to the resulting UTF-8 encoded character.
*/
char *utf8_encode(int u)
{
static char c[5]; /* 4 bytes + string termination */
/* 0x0000 - 0x007F: 0xxxxxxx */
if (u < 0x80) {
*(c + 1) = '\0';
*c = u;
/* 0x0080 - 0x07FF: 110xxxxx 10xxxxxx */
} else if (u < 0x800) {
*(c + 2) = '\0';
*(c + 1) = (u & 0x3F) | 0x80;
*c = (u >> 6) | 0xC0;
/* 0x0800 - 0xFFFF: 1110xxxx 10xxxxxx 10xxxxxx */
} else if (u < 0x10000) {
*(c + 3) = '\0';
*(c + 2) = (u & 0x3F) | 0x80;
*(c + 1) = (u >> 6 & 0x3F) | 0x80;
*c = (u >> 12) | 0xE0;
} else if (u < 0x110000) {
/* 0x10000 - 0x10FFFF: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
*(c + 4) = '\0';
*(c + 3) = (u & 0x3F) | 0x80;
*(c + 2) = (u >> 6 & 0x3F) | 0x80;
*(c + 1) = (u >> 12 & 0x3F) | 0x80;
*c = (u >> 18) | 0xF0;
} else {
return NULL;
}
return c;
}
/* Get the display width of a UTF-8 character. */
int utf8_width(char *s) int utf8_width(char *s)
{ {
int val, low, high, cur; int val, low, high, cur;