delete, enter key handling

level.cpp

@@ -8,6 +8,7 @@
 
 #include <ctype.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
@@ -22,10 +23,12 @@
 
 #define LEVEL_VERSION "0.0.1"
 #define LEVEL_TAB_STOP 8
+#define LEVEL_QUIT_TIMES 3
 
 #define CTRL_KEY(k) ((k) & 0x1f)
 
 enum editorKey {
+	BACKSPACE = 127,
 	ARROW_LEFT = 1000,
 	ARROW_RIGHT,
 	ARROW_UP,
@@ -56,6 +59,7 @@ struct editorConfig {
 	int screencols;
 	int numrows;
 	erow *row;
+	int dirty;
 	char *filename;
 	char statusmsg[80];
 	time_t statusmsg_time;
@@ -64,6 +68,10 @@ struct editorConfig {
 
 struct editorConfig E;
 
+/*** prototypes ***/
+
+void editorSetStatusMessage(const char* fmt, ...);
+
 /*** terminal ***/
 
 void die(const char *s) {
@@ -219,10 +227,12 @@ void editorUpdateRow(erow *row) {
 	row->rsize = idx;
 }
 
-void editorAppendRow(char *s, size_t len) {
+void editorInsertRow(int at, const char *s, size_t len) {
+	if (at < 0 || at > E.numrows) return;
+	
 	E.row = (erow*)realloc(E.row, sizeof(erow) * (E.numrows + 1));
+	memmove(&E.row[at + 1], &E.row[at], sizeof(erow) * (E.numrows - at));
 
-	int at = E.numrows;
 	E.row[at].size = len;
 	E.row[at].chars = (char*)malloc(len + 1);
 	memcpy(E.row[at].chars, s, len);
@@ -233,10 +243,108 @@ void editorAppendRow(char *s, size_t len) {
 	editorUpdateRow(&E.row[at]);
 
 	E.numrows++;
+	E.dirty++;
+}
+
+void editorFreeRow(erow* row) {
+	free(row->render);
+	free(row->chars);
+}
+
+void editorDelRow(int at) {
+	if (at < 0 || at >= E.numrows) return;
+	editorFreeRow(&E.row[at]);
+	memmove(&E.row[at], &E.row[at + 1], sizeof(erow) * (E.numrows - at - 1));
+	E.numrows--;
+	E.dirty++;
+}
+
+void editorRowInsertChar(erow* row, int at, int c) {
+	if (at < 0 || at > row->size) at = row->size;
+	row->chars = (char*)realloc(row->chars, row->size + 2);
+	memmove(&row->chars[at + 1], &row->chars[at], row->size - at + 1);
+	row->size++;
+	row->chars[at] = c;
+	editorUpdateRow(row);
+	E.dirty++;
+}
+
+void editorRowAppendString(erow* row, const char* s, size_t len) {
+	row->chars = (char*)realloc(row->chars, row->size + len + 1);
+	memcpy(&row->chars[row->size], s, len);
+	row->size += len;
+	row->chars[row->size] = '\0';
+	editorUpdateRow(row);
+	E.dirty++;
+}
+
+void editorRowDelChar(erow* row, int at) {
+	if (at < 0 || at >= row->size) return;
+	memmove(&row->chars[at], &row->chars[at + 1], row->size - at);
+	row->size--;
+	editorUpdateRow(row);
+	E.dirty++;
+}
+
+/*** editor operations ***/
+
+void editorInsertChar(int c) {
+	if (E.cy == E.numrows) editorInsertRow(E.numrows, "", 0);
+	editorRowInsertChar(&E.row[E.cy], E.cx, c);
+	E.cx++;
+}
+
+void editorInsertNewLine() {
+	if (E.cx == 0) {
+		editorInsertRow(E.cy, "", 0);
+	} else {
+		erow *row = &E.row[E.cy];
+		editorInsertRow(E.cy + 1, &row->chars[E.cx], row->size - E.cx);
+		row = &E.row[E.cy];
+		row->size = E.cx;
+		row->chars[row->size] = '\0';
+		editorUpdateRow(row);
+	}
+	E.cy++;
+	E.cx = 0;
+}
+
+void editorDelChar() {
+	if (E.cy == E.numrows) return;
+	if (E.cx == 0 && E.cy == 0) return;
+
+	erow* row = &E.row[E.cy];
+	if (E.cx > 0) {
+		editorRowDelChar(row, E.cx - 1);
+		E.cx--;
+	} else {
+		E.cx = E.row[E.cy - 1].size;
+		editorRowAppendString(&E.row[E.cy - 1], row->chars, row->size);
+		editorDelRow(E.cy);
+		E.cy--;
+	}
 }
 
 /*** file i/o ***/
 
+char* editorRowsToString(int* buflen) {
+	int total_len = 0;
+	for (int j = 0; j < E.numrows; j++)
+		total_len += E.row[j].size + 1;
+	*buflen = total_len;
+
+	char *buf = (char*)malloc(total_len);
+	char *p = buf;
+	for (int j = 0; j < E.numrows; j++) {
+		memcpy(p, E.row[j].chars, E.row[j].size);
+		p += E.row[j].size;
+		*p = '\n';
+		p++;
+	}
+
+	return buf;
+}
+
 void editorOpen(char *filename) {
 	free(E.filename);
 E.filename = strdup(filename);
@@ -251,11 +359,35 @@ E.filename = strdup(filename);
 		while (linelen > 0 && (line[linelen - 1] == '\n' ||
 								 line[linelen - 1] == '\r'))
 			linelen--;
-		editorAppendRow(line, linelen);
+		editorInsertRow(E.numrows, line, linelen);
 	}
 	free(line);
 	fclose(fp);
+	E.dirty = 0;
+}
 
+void editorSave() {
+	if (E.filename == NULL) return;
+
+	int len;
+	char *buf = editorRowsToString(&len);
+	
+	int fd = open(E.filename, O_RDWR | O_CREAT, 0644);
+	if (fd != -1) {
+		if (ftruncate(fd, len) != -1) {
+			if (write(fd, buf, len) == len) {
+				close(fd);
+				free(buf);
+				E.dirty = 0;
+				editorSetStatusMessage("Successfully Saved");
+				return;
+			}
+		}
+		close(fd);
+	}
+
+	free(buf);
+	editorSetStatusMessage("Can't save! I/O error: %s", strerror(errno));
 }
 
 /*** append buffer ***/
@@ -326,8 +458,9 @@ void editorDrawRows(struct abuf *ab) {
 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 len = snprintf(status, sizeof(status), "%.20s - %d lines %s",
+		E.filename ? E.filename : "[No Name]", E.numrows,
+		E.dirty ? "(modified)" : "");
 	int rlen = snprintf(rstatus, sizeof(rstatus), "%d/%d",
 		E.cy + 1, E.numrows);
 	if (len > E.screencols) len = E.screencols;
@@ -409,16 +542,32 @@ void editorMoveCursor(int key) {
 }
 
 void editorProcessKeypress() {
+	static int quit_times = LEVEL_QUIT_TIMES;
+
 	int c = editorReadKey();
 
 	switch (c) {
+		case '\r':
+			editorInsertNewLine();
+			break;
+
 		case CTRL_KEY('q'):
+			if (E.dirty && quit_times > 0) {
+				editorSetStatusMessage("WARNING! File has unsaved Changed. "
+					"Press Ctrl-Q %d more times to quit", quit_times);
+				quit_times--;
+				return;
+			}
 			write(STDOUT_FILENO, "\x1b[2J", 4);
 			write(STDOUT_FILENO, "\x1b[H", 3);
 
 			exit(0);
 			break;
 
+		case CTRL_KEY('s'):
+			editorSave();
+			break;
+
 		case HOME_KEY:
 			E.cx = 0;
 			break;
@@ -427,6 +576,13 @@ void editorProcessKeypress() {
 			if (E.cy < E.numrows) E.cx = E.row[E.cy].size;
 			break;
 
+		case BACKSPACE:
+		case CTRL_KEY('h'):
+		case DEL_KEY:
+			if (c == DEL_KEY) editorMoveCursor(ARROW_RIGHT);
+			editorDelChar();
+			break;
+
 		case PAGE_UP:
 		case PAGE_DOWN:
 			{
@@ -448,7 +604,17 @@ void editorProcessKeypress() {
 		case ARROW_RIGHT:
 			editorMoveCursor(c);
 			break;
+
+		case CTRL_KEY('l'):
+		case '\x1b':
+			break;
+
+		default:
+			editorInsertChar(c);
+			break;
 	}
+
+	quit_times = LEVEL_QUIT_TIMES;
 }
 
 /*** init ***/
@@ -461,6 +627,7 @@ void initEditor() {
 	E.coloff = 0;
 	E.numrows = 0;
 	E.row = NULL;
+	E.dirty = 0;
 	E.filename = NULL;
 	E.statusmsg[0] = '\0';
 	E.statusmsg_time = 0;
@@ -474,7 +641,7 @@ int main(int argc, char *argv[]) {
 	initEditor();
 	if (argc >= 2) editorOpen(argv[1]);
 
-	editorSetStatusMessage("HELP: Ctrl-Q = quit");
+	editorSetStatusMessage("HELP: Ctrl-S = save | Ctrl-Q = quit");
 
 	while (1) {
 		editorRefreshScreen();