stautus bars: add message bar

ConsoleApplication4/kilo.c

@@ -4,15 +4,17 @@
 #define _BSD_SOURCE
 #define _GNU_SOURCE
 
-#include<unistd.h>
-#include<termios.h>
-#include<stdlib.h>
+#include <unistd.h>
+#include <termios.h>
+#include <stdlib.h>
+#include <stdarg.h>
 #include <ctype.h>
-#include<stdio.h>
+#include <stdio.h>
 #include <errno.h>
 #include <sys/ioctl.h>
 #include <string.h>
 #include <sys/types.h>
+#include <time.h>
 
 /*** defines ***/
 #define CTRL_KEY(k) ((k) & 0x1f) //bitwise-ANDs 00011111
@@ -43,14 +45,17 @@ typedef struct erow {
 
 struct editorConfig
 {
-	int cx, cy; // cursor position
+	int cx, cy; // cursor position, current line
 	int rx;
 	int rowoff;
 	int coloff;
 	int screenrows;
 	int screencols;
 	int numrows; // 0 or 1
 	erow *row;
+	char *filename;
+	char statusmsg[80];
+	time_t statusmsg_time;
 	struct termios orig_termios;
 };
 
@@ -256,6 +261,9 @@ void editorAppendRow(char *s, size_t len) {
 /*** file i/o ***/
 
 void editorOpen(char *filename) {
+	free(E.filename);
+	E.filename = strdup(filename); //strdup: makes a copy of the given string
+
 	FILE *fp = fopen(filename, "r");
 	if (!fp) die("fopen");
 
@@ -365,13 +373,38 @@ void editorDrawRows(struct abuf *ab) {
 
 void editorDrawStatusBar(struct abuf *ab) {
 	abAppend(ab, "\x1b[7m", 4);
-	int len = 0;
+	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)
 	{
-		abAppend(ab, " ", 1);
-		len++;
+		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 meglen = strlen(E.statusmsg);
+	if (meglen > E.screencols) meglen = E.screencols;
+	if (meglen && time(NULL) - E.statusmsg_time < 5) {
+		abAppend(ab, E.statusmsg, meglen);
+	}
 }
 
 void editorRefreshScreen() {
@@ -389,6 +422,7 @@ void editorRefreshScreen() {
 
 	editorDrawRows(&ab);
 	editorDrawStatusBar(&ab);
+	editorDrawMessageBar(&ab);
 
 	char buf[32];
 	snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.rx - E.coloff) + 1);
@@ -403,6 +437,14 @@ 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) {
 	erow *row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy];
@@ -512,9 +554,10 @@ void initEditor() {
 	E.row = NULL;
 	E.rowoff = 0;
 	E.coloff = 0;
-
+	E.statusmsg[0] = '\0';
+	E.statusmsg_time = 0;
 	if (getWindowSize(&E.screenrows, &E.screencols) == -1) die("getWindowSize");
-	E.screenrows -= 1; //a line for status bar
+	E.screenrows -= 2; //2 lines for status bar
 }
 
 int main(int argc, char *argv[]) {
@@ -526,6 +569,8 @@ int main(int argc, char *argv[]) {
 		editorOpen(argv[1]);
 	}
 
+	editorSetStatusMessage("HELP: Ctrl-Q = quit");
+
 	while (1)
 	{
 		editorRefreshScreen();