nasmfm

commit bb1400f138800794a5f2dc0e953e09098eecf2bc
parent 69eb6e669536bb7360bab5f1f99eddcfd4903438
Author: afify <hassan@afify.dev>
Date:   Wed,  9 Mar 2022 16:04:17 +0300

[feat] macros cursor

Diffstat:
M
nasmfm.c
 | 
111
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------

1 file changed, 95 insertions(+), 16 deletions(-)
diff --git a/nasmfm.c b/nasmfm.c
@@ -1,5 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 
+#include <sys/ioctl.h>
+
 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
@@ -8,32 +10,46 @@
 #include <unistd.h>
 
 /* macros */
+#define CTRL_KEY(k) ((k)&0x1f)
+#define CLEAR_SCREEN write(STDOUT_FILENO, "\x1b[2J", 4);
+#define CURSOR_TOP_LEFT write(STDOUT_FILENO, "\x1b[H", 3);
+
 /* typedef */
 /* function declarations */
 /* global variables */
 /* function implementations */
 
-struct termios orig_termios;
+typedef struct {
+	int rows;
+	int cols;
+	struct termios orig_termios;
+} Term;
+
+Term term;
+
 void
 die(const char *s)
 {
+	CLEAR_SCREEN
+	CURSOR_TOP_LEFT
 	perror(s);
 	exit(1);
 }
+
 void
 disableRawMode()
 {
-	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios) == -1)
+	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &term.orig_termios) == -1)
 		die("tcsetattr");
 }
 
 void
 enableRawMode()
 {
-	if (tcgetattr(STDIN_FILENO, &orig_termios) == -1)
+	if (tcgetattr(STDIN_FILENO, &term.orig_termios) == -1)
 		die("tcgetattr");
 	atexit(disableRawMode);
-	struct termios raw = orig_termios;
+	struct termios raw = term.orig_termios;
 
 	raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
 	raw.c_oflag &= ~(OPOST);
@@ -45,24 +61,87 @@ enableRawMode()
 	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1)
 		die("tcsetattr");
 }
+void
+editorDrawRows()
+{
+	int y;
+	for (y = 0; y < term.rows; y++) {
+		write(STDOUT_FILENO, "~", 1);
+		if (y < term.rows - 1) {
+			write(STDOUT_FILENO, "\r\n", 2);
+		}
+	}
+}
+
+void
+editorRefreshScreen()
+{
+	CLEAR_SCREEN
+	CURSOR_TOP_LEFT
+	editorDrawRows();
+	CURSOR_TOP_LEFT
+}
+
+char
+editorReadKey()
+{
+	int nread;
+	char c;
+	while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
+		if (nread == -1 && errno != EAGAIN)
+			die("read");
+	}
+	return c;
+}
+/*** input ***/
+void
+editorProcessKeypress()
+{
+	char c = editorReadKey();
+	switch (c) {
+	case CTRL_KEY('q'):
+		CLEAR_SCREEN
+		CURSOR_TOP_LEFT
+		exit(0);
+		break;
+	case 'q':
+		CLEAR_SCREEN
+		CURSOR_TOP_LEFT
+		exit(0);
+		break;
+	default:
+		printf("%d ('%c')\r\n", c, c);
+	}
+}
+
+int
+getWindowSize(int *rows, int *cols)
+{
+	struct winsize ws;
+	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
+		return -1;
+	} else {
+		*cols = ws.ws_col;
+		*rows = ws.ws_row;
+		return 0;
+	}
+}
+
+void
+initEditor()
+{
+	if (getWindowSize(&term.rows, &term.cols) == -1)
+		die("getWindowSize");
+}
 
 int
 main(int argc, char *argv[])
 {
 	enableRawMode();
+	initEditor();
 	while (1) {
-		char c = '\0';
-		if (read(STDIN_FILENO, &c, 1) == -1 && errno != EAGAIN)
-			die("read");
-		read(STDIN_FILENO, &c, 1);
-		if (iscntrl(c)) {
-			printf("%d\r\n", c);
-		} else {
-			printf("%d ('%c')\r\n", c, c);
-		}
-		if (c == 'q')
-			break;
+		editorRefreshScreen();
+		editorProcessKeypress();
 	}
-
 	return 0;
 }