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Chapter 5: Start

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This commit is contained in:
Benjamyn Love 2024-02-08 14:46:21 +11:00
parent 035dc3dec7
commit c113787dfe
1 changed files with 121 additions and 14 deletions
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135
kilo.c
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@ -7,16 +7,19 @@
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include <termios.h>
/*** defines ***/
#define KILO_VERSION "0.0.1"
#define KILO_TAB_STOP 4
#define CTRL_KEY(k) ((k) & 0x1f)
@ -37,18 +40,24 @@ enum editorKey
typedef struct erow {
int size;
int rsize;
char *chars;
char *render;
} erow;
struct editorConfig
{
int cx, cy;
int rx;
int rowoff; // Row offset
int coloff; // Col offset
int screenrows;
int screencols;
int numrows;
erow *row;
char *filename;
char statusmsg[80];
time_t statusmsg_time;
struct termios orig_termios;
};
@ -207,6 +216,41 @@ int getWindowSize(int *rows, int *cols)
/*** row operations ***/
int editorRowCxToRx(erow *row, int cx) {
int rx = 0;
int j;
for (j = 0; j < cx; j++) {
if (row->chars[j] == '\t')
rx =+ (KILO_TAB_STOP - 1) - (rx % KILO_TAB_STOP);
rx++;
}
return rx;
}
void editorUpdateRow(erow *row) {
int tabs = 0;
int j;
for (j = 0; j < row->size; j++)
if (row->chars[j] == '\t') tabs++;
free(row->render);
row->render = malloc(row->size + tabs*(KILO_TAB_STOP - 1) + 1);
int idx = 0;
for (j = 0; j < row->size; j++) {
if (row->chars[j] == '\t') {
row->render[idx++] = ' ';
while (idx % KILO_TAB_STOP != 0) row->render[idx++] = ' ';
} else {
row->render[idx++] = row->chars[j];
}
}
row->render[idx] = '\0';
row->rsize = idx;
}
void editorAppendRow(char *s, size_t len) {
E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
@ -215,12 +259,20 @@ void editorAppendRow(char *s, size_t len) {
E.row[at].chars = malloc(len + 1);
memcpy(E.row[at].chars, s, len);
E.row[at].chars[len] = '\0';
E.row[at].rsize = 0;
E.row[at].render = NULL;
editorUpdateRow(&E.row[at]);
E.numrows++;
}
/*** file i/o ***/
void editorOpen(char *filename) {
free(E.filename);
E.filename = strdup(filename);
FILE *fp = fopen(filename, "r");
if (!fp) die("fopen");
@ -268,17 +320,24 @@ void abFree(struct abuf *ab)
/*** output ***/
void editorScroll() {
E.rx = 0;
if (E.cy < E.numrows) {
E.rx = editorRowCxToRx(&E.row[E.cy], E.cx);
}
if (E.cy < E.rowoff) {
E.rowoff = E.cy;
}
if (E.cy >= E.rowoff + E.screenrows) {
E.rowoff = E.cy - E.screenrows + 1;
}
if (E.cx < E.coloff) {
E.coloff = E.cx;
if (E.rx < E.coloff) {
E.coloff = E.rx;
}
if (E.cx >= E.coloff + E.screencols) {
E.coloff = E.cx - E.screencols + 1;
if (E.rx >= E.coloff + E.screencols) {
E.coloff = E.rx - E.screencols + 1;
}
}
@ -312,17 +371,44 @@ void editorDrawRows(struct abuf *ab)
}
} else {
int len = E.row[filerow].size - E.coloff;
int len = E.row[filerow].rsize - E.coloff;
if (len < 0) len = 0;
if (len > E.screencols) len = E.screencols;
abAppend(ab, &E.row[filerow].chars[E.coloff], len);
abAppend(ab, &E.row[filerow].render[E.coloff], len);
}
abAppend(ab, "\x1b[K", 3);
if (y < E.screenrows - 1)
{
abAppend(ab, "\r\n", 2);
abAppend(ab, "\r\n", 2);
}
}
void editorDrawStatusBar(struct abuf *ab) {
abAppend(ab, "\x1b[7m", 4);
char status[80], rstatus[80];
int len = snprintf(status, sizeof(status), "%.20s - %d lines",
E.filename ? E.filename : "[No Name]", E.numrows);
int rlen = snprintf(rstatus, sizeof(rstatus), "%d/%d",
E.cy + 1, E.numrows);
if (len > E.screencols) len = E.screencols;
abAppend(ab, status, len);
while (len < E.screencols) {
if (E.screencols - len == rlen) {
abAppend(ab, rstatus, rlen);
break;
} else {
abAppend(ab, " ", 1);
len++;
}
}
abAppend(ab, "\x1b[m", 3);
abAppend(ab, "\r\n", 2);
}
void editorDrawMessageBar(struct abuf *ab) {
abAppend(ab, "\x1b[K", 3);
int msglen = strlen(E.statusmsg);
if (msglen > E.screencols) msglen = E.screencols;
if (msglen && time(NULL) - E.statusmsg_time < 5)
abAppend(ab, E.statusmsg, msglen);
}
void editorRefreshScreen()
@ -334,9 +420,11 @@ void editorRefreshScreen()
abAppend(&ab, "\x1b[H", 3);
editorDrawRows(&ab);
editorDrawStatusBar(&ab);
editorDrawMessageBar(&ab);
char buf[32];
snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.cx - E.coloff) + 1);
snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.rx - E.coloff) + 1);
abAppend(&ab, buf, strlen(buf));
abAppend(&ab, "\x1b[?25h", 6);
@ -344,6 +432,14 @@ void editorRefreshScreen()
abFree(&ab);
}
void editorSetStatusMessage(const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
vsnprintf(E.statusmsg, sizeof(E.statusmsg), fmt, ap);
va_end(ap);
E.statusmsg_time = time(NULL);
}
/*** input ***/
void editorMoveCursor(int key)
@ -408,14 +504,18 @@ void editorProcessKeypress()
E.cx = 0;
break;
case END_KEY:
E.cx = E.screencols - 1;
if (E.cy < E.numrows)
E.cx = E.row[E.cy].size;
break;
case PAGE_UP:
case PAGE_DOWN:
{
int times = E.screenrows;
while (times--)
editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
if (c == PAGE_UP) {
E.cy = E.rowoff;
} else {
E.cy = E.rowoff + E.screenrows - 1;
if (E.cy > E.numrows) E.cy = E.numrows;
}
}
break;
@ -434,13 +534,18 @@ void initEditor()
{
E.cx = 0;
E.cy = 0;
E.rx = 0;
E.rowoff = 0;
E.coloff = 0;
E.numrows = 0;
E.row = NULL;
E.filename = NULL;
E.statusmsg[0] = '\0';
E.statusmsg_time = 0;
if (getWindowSize(&E.screenrows, &E.screencols) == -1)
die("getWindowSize");
E.screenrows -= 2;
}
int main(int argc, char *argv[])
@ -451,6 +556,8 @@ int main(int argc, char *argv[])
editorOpen(argv[1]);
}
editorSetStatusMessage("HELP Ctrl-Q = Quit");
while (1)
{
editorRefreshScreen();