Save as functionality

kilo.c

@@ -68,6 +68,8 @@ struct editorConfig E;
 /*** prototypes ***/
 
 void editorSetStatusMessage(const char *fmt, ...);
+void editorRefreshScreen();
+char *editorPrompt(char *prompt);
 
 /*** terminal ***/
 
@@ -499,8 +501,13 @@ void editorSave()
 {
 	if (E.filename == NULL)
 	{
+		E.filename = editorPrompt("Save as: %s (ESC to cancel)");
+		if (E.filename == NULL)
+		{
+			editorSetStatusMessage("Save aborted");
 			return;
 		}
+	}
 
 	int len;
 	char *buf = editorRowsToString(&len);
@@ -728,6 +735,54 @@ void editorSetStatusMessage(const char *fmt, ...)
 
 /*** input ***/
 
+char *editorPrompt(char *prompt)
+{
+	size_t bufsize = 128;
+	char *buf = malloc(bufsize);
+
+	size_t buflen = 0;
+	buf[0] = '\0';
+
+	while (1)
+	{
+		editorSetStatusMessage(prompt, buf);
+		editorRefreshScreen();
+
+		int c = editorReadKey();
+		if (c == DEL_KEY || c == CTRL_KEY('h') || c == BACKSPACE)
+		{
+			if (buflen != 0)
+			{
+				buf[buflen--] = '\0';
+			}
+		}
+		else if (c == '\x1b')
+		{
+			editorSetStatusMessage("");
+			free(buf);
+			return NULL;
+		}
+		else if (c == '\r')
+		{
+			if (buflen != 0)
+			{
+				editorSetStatusMessage("");
+				return buf;
+			}
+		}
+		else if (!iscntrl(c) && c < 128)
+		{
+			if (buflen == bufsize -1)
+			{
+				bufsize *= 2;
+				buf = realloc(buf, bufsize);
+			}
+			buf[buflen++] = c;
+			buf[buflen] = '\0';
+		}
+	}
+}
+
 void editorMoveCursor(int key)
 {
 	erow *row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy];