hermes/csedit.c

444 lines
8.6 KiB
C

//
// includes
// --------
#define _DEFAULT_SOURCE
#define _BSD_SOURCE
#define _GNU_SOURCE
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <termios.h>
#include <unistd.h>
//
// definitions
// -----------
#define CSEDIT_VERSION "0.0.1"
#define CTRL_KEY(k) ((k) & 0x1f)
enum editorMode {CommandMode, InputMode, VisualMode};
enum editorKey {
BACKSPACE = 127,
ARROW_LEFT = 1000,
ARROW_RIGHT,
ARROW_UP,
ARROW_DOWN,
PAGE_UP,
PAGE_DOWN,
DEL_KEY,
HOME_KEY,
END_KEY
};
//
// data
// ----
typedef struct erow {
int size;
char *chars;
} erow;
struct editorConfig {
enum editorMode mode;
int rowoff;
int cx, cy;
int screenRows;
int screenCols;
int numRows;
erow *row;
struct termios orig_termios;
};
struct editorConfig E;
//
// terminal
// --------
void die(const char *s) {
write(STDOUT_FILENO, "\033[2J", 4);
write(STDOUT_FILENO, "\033[H", 3);
perror(s);
write(STDOUT_FILENO, "\r", 1);
exit(1);
}
void quit() {
write(STDOUT_FILENO, "\033[2J", 4);
write(STDOUT_FILENO, "\033[H", 3);
exit(0);
}
void disableRawMode() {
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &E.orig_termios) == -1)
die("tcsetattr");
}
void enableRawMode() {
if (tcgetattr(STDIN_FILENO, &E.orig_termios) == -1) die("tcgetattr");
atexit(disableRawMode);
struct termios raw = E.orig_termios;
raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
raw.c_oflag &= ~(OPOST);
raw.c_cflag |= ~(CS8);
raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
raw.c_cc[VMIN] = 0;
raw.c_cc[VTIME] = 1;
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) die("tcsetattr");
}
int editorReadKey() {
int nread;
char c;
while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
if (nread == -1 && errno != EAGAIN) die("read");
}
if (c == '\033') {
char seq[3];
if (read(STDIN_FILENO, &seq[0], 1) != 1) return '\033';
if (read(STDIN_FILENO, &seq[1], 1) != 1) return '\033';
if (seq[0] == '[') {
if (seq[1] >= '0' && seq[1] <= '9') {
if (read(STDIN_FILENO, &seq[2], 1) != 1) return '\033';
if (seq[2] == '~') {
switch (seq[1]) {
case '1': return HOME_KEY;
case '3': return DEL_KEY;
case '4': return END_KEY;
case '5': return PAGE_UP;
case '6': return PAGE_DOWN;
case '7': return HOME_KEY;
case '8': return END_KEY;
}
}
} else {
switch (seq[1]) {
case 'A': return ARROW_UP;
case 'B': return ARROW_DOWN;
case 'C': return ARROW_RIGHT;
case 'D': return ARROW_LEFT;
case 'H': return HOME_KEY;
case 'F': return END_KEY;
}
}
} else if (seq[0] == 'O') {
switch (seq[1]) {
case 'H': return HOME_KEY;
case 'F': return END_KEY;
}
}
return '\033';
}
return c;
}
int getCursorPosition(int *rows, int *cols) {
char buf[32];
unsigned int i = 0;
if (write(STDOUT_FILENO, "\033[6n", 4) != 4) return -1;
printf("\r\n");
while (i < sizeof(buf) - 1) {
if (read(STDIN_FILENO, &buf[i], 1) != 1) break;
if (buf[i] == 'R') break;
i++;
}
buf[i] = '\0';
if (buf[0] != '\033' || buf[1] != '[') return -1;
if (scanf(&buf[2], "%d;%d", rows, cols) != 2) return -1;
return 0;
}
int getWindowSize(int *rows, int *cols) {
struct winsize ws;
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
if (write(STDOUT_FILENO, "\033[999C\033[999B", 12) != 12) return -1;
return getCursorPosition(rows, cols);
}
*cols = ws.ws_col;
*rows = ws.ws_row;
return 0;
}
//
// row ops
// -------
void editorAppendRow(char *s, size_t len) {
E.row = realloc(E.row, sizeof(erow) * (E.numRows + 1));
int at = E.numRows;
E.row[at].size = len;
E.row[at].chars = malloc(len + 1);
memcpy(E.row[at].chars, s, len);
E.row[at].chars[len] = '\0';
E.numRows++;
}
//
// file io
// -------
void editorOpen(char *filename) {
FILE *fp = fopen(filename, "r");
if (!fp) die("Open file");
char *line = NULL;
size_t linecap = 0;
ssize_t linelen;
while ((linelen = getline(&line, &linecap, fp)) != -1) {
while (linelen > 0 && (line[linelen - 1] == '\n' || line[linelen - 1] == '\r'))
linelen--;
editorAppendRow(line, linelen);
}
free(line);
fclose(fp);
}
//
// append buffer
// -------------
struct abuf {
char *b;
int len;
};
#define ABUF_INIT {NULL, 0}
void abAppend(struct abuf *ab, const char *s, int len) {
char *new = realloc(ab->b, ab->len + len);
if (new == NULL) return;
memcpy(&new[ab->len], s, len);
ab->b = new;
ab->len += len;
}
void abFree(struct abuf *ab) {
free(ab->b);
}
//
// output
// ------
void editorScroll() {
if (E.cy < E.rowoff) {
E.rowoff = E.cy;
}
if (E.cy >= E.rowoff + E.screenRows) {
E.rowoff = E.cy - E.screenRows + 1;
}
}
void editorDrawRows(struct abuf *ab) {
int y;
for (y = 0; y < E.screenRows; y++) {
int filerow = y + E.rowoff;
if (filerow >= E.numRows) {
if (E.numRows == 0 && y == E.screenRows / 3) {
char welcome[80];
int welcomelen = snprintf(welcome, sizeof(welcome), "[ cs edit ] - version %s", CSEDIT_VERSION);
if (welcomelen > E.screenCols) welcomelen = E.screenCols;
int padding = (E.screenCols - welcomelen) / 2;
if (padding) {
abAppend(ab, "~", 1);
padding--;
}
while (padding--) abAppend(ab, " ", 1);
abAppend(ab, welcome, welcomelen);
} else {
abAppend(ab, "~", 1);
}
} else {
int len = E.row[filerow].size;
if (len > E.screenCols) len = E.screenCols;
abAppend(ab, E.row[filerow].chars, len);
}
abAppend(ab, "\033[K", 3);
if (y < E.screenRows - 1) {
abAppend(ab, "\r\n", 2);
}
}
}
void editorRefreshScreen() {
editorScroll();
struct abuf ab = ABUF_INIT;
abAppend(&ab, "\033[?25l", 6);
abAppend(&ab, "\033[H", 3);
editorDrawRows(&ab);
char buf[32];
snprintf(buf, sizeof(buf), "\033[%d;%dH", (E.cy - E.rowoff) + 1, E.cx + 1);
abAppend(&ab, buf, strlen(buf));
abAppend(&ab, "\033[?25h", 6);
write(STDOUT_FILENO, ab.b, ab.len);
abFree(&ab);
}
//
// input
// -----
void editorMoveCursor(int key) {
switch (key) {
case 'j':
case ARROW_DOWN:
if (E.cy < E.numRows) {
E.cy++;
}
break;
case 'k':
case ARROW_UP:
if (E.cy != 0) {
E.cy--;
}
break;
case 'h':
case ARROW_LEFT:
if (E.cx != 0) {
E.cx--;
}
break;
case 'l':
case ARROW_RIGHT:
if (E.cx != E.screenCols - 1) {
E.cx++;
}
break;
}
}
void editorPageCursor(int key) {
if (key == PAGE_UP || key == PAGE_DOWN) {
int times = E.screenRows;
while (times--)
editorMoveCursor(key == PAGE_UP ? ARROW_UP : ARROW_DOWN);
}
}
void editorInputKp(int c) {
switch (c) {
case '\033':
E.mode = CommandMode;
default:
break;
}
}
void editorCommandKp(int c) {
switch (c) {
case 'j':
case 'k':
case 'h':
case 'l':
editorMoveCursor(c);
break;
case 'g':
E.cy = 0;
break;
case 'G':
E.cy = E.numRows - E.screenRows - 1;
editorPageCursor(PAGE_DOWN);
break;
case 'i':
E.mode = InputMode;
break;
case 'u':
editorPageCursor(PAGE_UP);
break;
case 'd':
editorPageCursor(PAGE_DOWN);
break;
case '$':
E.cx = E.screenCols - 1;
break;
case '0':
case '^':
E.cx = 0;
break;
}
}
void editorProcessKeypress() {
int c = editorReadKey();
switch (c) {
case CTRL_KEY('q'):
quit();
break;
case ARROW_DOWN:
case ARROW_UP:
case ARROW_LEFT:
case ARROW_RIGHT:
editorMoveCursor(c);
return;
case PAGE_UP:
case PAGE_DOWN:
editorPageCursor(c);
return;
case CTRL_KEY('u'):
editorPageCursor(PAGE_UP);
return;
case CTRL_KEY('d'):
editorPageCursor(PAGE_DOWN);
return;
case HOME_KEY:
E.cx = 0;
break;
case END_KEY:
E.cx = E.screenCols - 1;
}
if (E.mode == CommandMode) {
editorCommandKp(c);
} else {
editorInputKp(c);
}
}
//
// init
// ----
void initEditor() {
E.mode = CommandMode;
E.rowoff = 0;
E.numRows = 0;
E.row = NULL;
E.cx = 0;
E.cy = 0;
if (getWindowSize(&E.screenRows, &E.screenCols) == -1) die("getWindowSize");
}
int main(int argc, char *argv[]) {
enableRawMode();
initEditor();
if (argc >= 2) {
editorOpen(argv[1]);
}
while (1) {
editorRefreshScreen();
editorProcessKeypress();
}
return 0;
}