Add work in progress editor frontend

1 files changed, 264 insertions, 0 deletions

diff --git a/vis.c b/vis.c
new file mode 100644
index 0000000..67483c5
--- /dev/null
+++ b/vis.c
@@ -0,0 +1,264 @@
+#define _POSIX_SOURCE
+#include <locale.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/select.h>
+#include <sys/ioctl.h>
+
+#include "editor.h"
+#include "util.h"
+
+#ifdef PDCURSES
+int ESCDELAY;
+#endif
+#ifndef NCURSES_REENTRANT
+# define set_escdelay(d) (ESCDELAY = (d))
+#endif
+
+typedef union {
+	size_t i;
+	const char *s;
+	size_t (*m)(Editor*);
+	void (*f)(Editor*);
+} Arg;
+
+typedef struct {
+	char str[6];
+	int code;
+} Key;
+
+typedef struct {
+	Key key[2];
+	void (*func)(const Arg *arg);
+	const Arg arg;
+} KeyBinding;
+
+typedef struct Mode Mode;
+struct Mode {
+	Mode *parent;
+	KeyBinding *bindings;
+	const char *name;
+	void (*enter)(void);
+	void (*leave)(void);
+	bool (*input)(const char *str, size_t len);
+};
+
+typedef struct {
+	char *name;
+	Mode *mode;
+} Config;
+
+static void cursor(const Arg *arg);
+static void call(const Arg *arg);
+static void insert(const Arg *arg);
+static void line(const Arg *arg);
+static void find_forward(const Arg *arg);
+static void find_backward(const Arg *arg);
+
+static Mode *mode;
+static Editor *editor;
+
+#include "config.h"
+
+static Config *config = &editors[0];
+
+static void cursor(const Arg *arg) {
+	arg->m(editor);
+}
+
+static void call(const Arg *arg) {
+	arg->f(editor);
+}
+
+static void line(const Arg *arg) {
+	editor_line_goto(editor, arg->i);
+}
+
+static void find_forward(const Arg *arg) {
+	editor_search(editor, arg->s, 1);
+}
+
+static void find_backward(const Arg *arg) {
+	editor_search(editor, arg->s, -1);
+}
+
+static void insert(const Arg *arg) {
+	editor_insert(editor, arg->s, strlen(arg->s));
+}
+
+typedef struct Screen Screen;
+static struct Screen {
+	int w, h;
+	bool need_resize;
+} screen = { .need_resize = true };
+
+static void sigwinch_handler(int sig) {
+	screen.need_resize = true;
+}
+
+static void resize_screen(Screen *screen) {
+	struct winsize ws;
+
+	if (ioctl(0, TIOCGWINSZ, &ws) == -1) {
+		getmaxyx(stdscr, screen->h, screen->w);
+	} else {
+		screen->w = ws.ws_col;
+		screen->h = ws.ws_row;
+	}
+
+	resizeterm(screen->h, screen->w);
+	wresize(stdscr, screen->h, screen->w);
+	screen->need_resize = false;
+}
+
+static void setup() {
+	setlocale(LC_CTYPE, "");
+	if (!getenv("ESCDELAY"))
+		set_escdelay(50);
+	initscr();
+	start_color();
+	raw();
+	noecho();
+	keypad(stdscr, TRUE);
+	meta(stdscr, TRUE);
+	resize_screen(&screen);
+	/* needed because we use getch() which implicitly calls refresh() which
+	   would clear the screen (overwrite it with an empty / unused stdscr */
+	refresh();
+
+	struct sigaction sa;
+	sa.sa_flags = 0;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_handler = sigwinch_handler;
+	sigaction(SIGWINCH, &sa, NULL);
+}
+
+static void cleanup() {
+	editor_free(editor);
+	endwin();
+}
+
+static bool keymatch(Key *key0, Key *key1) {
+	return (key0->str[0] && memcmp(key0->str, key1->str, sizeof(key1->str)) == 0) ||
+	       (key0->code && key0->code == key1->code);
+}
+
+static KeyBinding *keybinding(Mode *mode, Key *key0, Key *key1) {
+	for (; mode; mode = mode->parent) {
+		for (KeyBinding *kb = mode->bindings; kb && (kb->key[0].code || kb->key[0].str[0]); kb++) {
+			if (keymatch(key0, &kb->key[0]) && (!key1 || keymatch(key1, &kb->key[1])))
+				return kb;
+		}
+	}
+	return NULL;
+}
+
+int main(int argc, char *argv[]) {
+	/* decide which key configuration to use based on argv[0] */
+	char *arg0 = argv[0];
+	while (*arg0 && (*arg0 == '.' || *arg0 == '/'))
+		arg0++;
+	for (int i = 0; i < LENGTH(editors); i++) {
+		if (editors[i].name[0] == arg0[0]) {
+			config = &editors[i];
+			break;
+		}
+	}
+	mode = config->mode;
+
+	setup();
+	if (!(editor = editor_new(screen.w, screen.h, statusbar)))
+		return 1;
+	if (!editor_syntax_load(editor, syntaxes, colors))
+		return 1;
+	char *filename = argc > 1 ? argv[1] : NULL;
+	if (!editor_load(editor, filename))
+		return 1;
+
+	struct timeval idle = { .tv_usec = 0 }, *timeout = NULL;
+	Key key, key_prev, *key_mod = NULL;
+
+	for (;;) {
+		if (screen.need_resize) {
+			resize_screen(&screen);
+			editor_resize(editor, screen.w, screen.h);
+		}
+
+		fd_set fds;
+		FD_ZERO(&fds);
+		FD_SET(STDIN_FILENO, &fds);
+
+		editor_update(editor);
+		doupdate();
+		idle.tv_sec = 3;
+		int r = select(1, &fds, NULL, NULL, timeout);
+		if (r == -1 && errno == EINTR)
+			continue;
+
+		if (r < 0) {
+			perror("select()");
+			exit(EXIT_FAILURE);
+		}
+
+		if (!FD_ISSET(STDIN_FILENO, &fds)) {
+			editor_snapshot(editor);
+			timeout = NULL;
+			continue;
+		}
+
+		int keycode = getch();
+		if (keycode == ERR)
+			continue;
+
+		// TODO verbatim insert mode
+		int len = 0;
+		if (keycode >= KEY_MIN) {
+			key.code = keycode;
+			key.str[0] = '\0';
+		} else {
+			char keychar = keycode;
+			key.str[len++] = keychar;
+			key.code = 0;
+
+			if (!ISASCII(keychar) || keychar == '\e') {
+				nodelay(stdscr, TRUE);
+				for (int t; len < LENGTH(key.str) && (t = getch()) != ERR; len++)
+					key.str[len] = t;
+				nodelay(stdscr, FALSE);
+			}
+		}
+
+		for (size_t i = len; i < LENGTH(key.str); i++)
+			key.str[i] = '\0';
+
+		KeyBinding *action = keybinding(mode, key_mod ? key_mod : &key, key_mod ? &key : NULL);
+		if (!action && key_mod) {
+			/* second char of a combination was invalid, search again without the prefix */ 
+			action = keybinding(mode, &key, NULL);
+			key_mod = NULL;
+		}
+		if (action) {
+			/* check if it is the first part of a combination */
+			if (!key_mod && (action->key[1].code || action->key[1].str[0])) {
+				key_prev = key;
+				key_mod = &key_prev;
+				continue;
+			}
+			action->func(&action->arg);
+			key_mod = NULL;
+			continue;
+		}
+
+		if (keycode >= KEY_MIN)
+			continue;
+		
+		if (mode->input && mode->input(key.str, len))
+			timeout = &idle;
+	}
+
+	cleanup();
+	return 0;
+}