add message bar

level.cpp

@@ -9,11 +9,13 @@
 #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 <termios.h>
+#include <time.h>
 #include <unistd.h>
 
 /*** defines ***/
@@ -40,19 +42,23 @@ enum editorKey {
 // erow stands for "editor row"
 typedef struct erow {
 	int size;
-	int resize;
+	int rsize;
 	char *chars;
 	char *render;
 } erow;
 
 struct editorConfig {
 	int cx, cy;
+	int rx;
 	int rowoff;
 	int coloff;
 	int screenrows;
 	int screencols;
 	int numrows;
 	erow *row;
+	char *filename;
+	char statusmsg[80];
+	time_t statusmsg_time;
 	struct termios orig_termios;
 };
 
@@ -182,6 +188,15 @@ int getWindowSize(int *rows, int *cols) {
 
 /*** row operations ***/
 
+int editorRowCxToRx(erow *row, int cx) {
+	int rx = 0;
+	for (int j = 0; j < cx; j++) {
+		if (row->chars[j] == '\t') rx += (LEVEL_TAB_STOP - 1) - (rx % LEVEL_TAB_STOP);
+		rx++;
+	}
+	return rx;
+}
+
 void editorUpdateRow(erow *row) {
 	int tabs = 0;
 	for (int j = 0; j < row->size; j++) {
@@ -189,13 +204,13 @@ void editorUpdateRow(erow *row) {
 	}
 
 	free(row->render);
-	row->render = malloc(row->size + tabs*(LEVEL_TAB_STOP - 1) + 1);
+	row->render = (char*)malloc(row->size + tabs*(LEVEL_TAB_STOP - 1) + 1);
 
 	int idx = 0;
 	for (int j = 0; j < row->size; j++) {
 		if (row->chars[j] == '\t') {
 			row->render[idx++] = ' ';
-			while (idx % LEVEL_TAB_STOP != 0) row->render(idx++) = ' ';
+			while (idx % LEVEL_TAB_STOP != 0) row->render[idx++] = ' ';
 		} else {
 			row->render[idx++] = row->chars[j];
 		}
@@ -223,6 +238,9 @@ void editorAppendRow(char *s, size_t len) {
 /*** file i/o ***/
 
 void editorOpen(char *filename) {
+	free(E.filename);
+E.filename = strdup(filename);
+
 	FILE *fp = fopen(filename, "r");
 	if (!fp) die("fopen");
 
@@ -265,10 +283,13 @@ 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.cx >= E.coloff + E.screencols) E.coloff = E.cx - E.screencols + 1;
+	if (E.cx < E.coloff) E.coloff = E.rx;
+	if (E.cx >= E.coloff + E.screencols) E.coloff = E.rx - E.screencols + 1;
 }
 
 void editorDrawRows(struct abuf *ab) {
@@ -298,24 +319,55 @@ void editorDrawRows(struct abuf *ab) {
 		}
 
 		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);
+	int len = 0;
+	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, "\x1[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() {
 	editorScroll();
 
 	struct abuf ab = ABUF_INIT;
 
 	abAppend(&ab, "\x1b[?25l", 6);
-	// abAppend(&ab, "\x1b[2J", 4);  This line clears whole screen
 	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);
+											  (E.rx - E.coloff) + 1);
 	abAppend(&ab, buf, strlen(buf));
 
 	abAppend(&ab, "\x1b[?25h", 6);
@@ -324,6 +376,14 @@ 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) {
@@ -365,12 +425,18 @@ void editorProcessKeypress() {
 			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:
 			{
+				if (c == PAGE_UP) E.cy = E.rowoff;
+				else if (c == PAGE_DOWN) {
+					E.cy = E.rowoff + E.screenrows - 1;
+					if (E.cy > E.numrows) E.cy = E.numrows;
+				}
+
 				int times = E.screenrows;
 				while (times--)
 					editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
@@ -391,12 +457,17 @@ void editorProcessKeypress() {
 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';
+	E.statusmsg_time = 0;
 
 	if (getWindowSize(&E.screenrows, &E.screencols) == -1) die("getWindowSize");
+	E.screenrows -= 2;
 }
 
 int main(int argc, char *argv[]) {
@@ -404,6 +475,8 @@ int main(int argc, char *argv[]) {
 	initEditor();
 	if (argc >= 2) editorOpen(argv[1]);
 
+	editorSetStatusMessage("HELP: Ctrl-Q = quit");
+
 	while (1) {
 		editorRefreshScreen();
 		editorProcessKeypress();