[mucurses] Use "<ESC>[2J" ANSI escape sequence to clear screen

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/hci/mucurses/ansi_screen.c

@@ -14,12 +14,26 @@ unsigned short _LINES = 24;
 
 static unsigned int saved_usage;
 
+static void ansiscr_attrs ( struct _curses_screen *scr, attr_t attrs ) {
+	int bold = ( attrs & A_BOLD );
+	attr_t cpair = PAIR_NUMBER ( attrs );
+	short fcol;
+	short bcol;
+
+	if ( scr->attrs != attrs ) {
+		scr->attrs = attrs;
+		pair_content ( cpair, &fcol, &bcol );
+		/* ANSI escape sequence to update character attributes */
+		printf ( "\033[0;%d;3%d;4%dm", ( bold ? 1 : 22 ), fcol, bcol );
+	}
+}
+
 static void ansiscr_reset ( struct _curses_screen *scr ) {
 	/* Reset terminal attributes and clear screen */
 	scr->attrs = 0;
 	scr->curs_x = 0;
 	scr->curs_y = 0;
-	printf ( "\033[0m" );
+	printf ( "\033[0m\033[2J" );
 }
 
 static void ansiscr_init ( struct _curses_screen *scr ) {
@@ -32,6 +46,11 @@ static void ansiscr_exit ( struct _curses_screen *scr ) {
 	console_set_usage ( saved_usage );
 }
 
+static void ansiscr_erase ( struct _curses_screen *scr, attr_t attrs ) {
+	ansiscr_attrs ( scr, attrs );
+	printf ( "\033[2J" );
+}
+
 static void ansiscr_movetoyx ( struct _curses_screen *scr,
 			       unsigned int y, unsigned int x ) {
 	if ( ( x != scr->curs_x ) || ( y != scr->curs_y ) ) {
@@ -45,18 +64,9 @@ static void ansiscr_movetoyx ( struct _curses_screen *scr,
 static void ansiscr_putc ( struct _curses_screen *scr, chtype c ) {
 	unsigned int character = ( c & A_CHARTEXT );
 	attr_t attrs = ( c & ( A_ATTRIBUTES | A_COLOR ) );
-	int bold = ( attrs & A_BOLD );
-	attr_t cpair = PAIR_NUMBER ( attrs );
-	short fcol;
-	short bcol;
 
 	/* Update attributes if changed */
-	if ( attrs != scr->attrs ) {
-		scr->attrs = attrs;
-		pair_content ( cpair, &fcol, &bcol );
-		/* ANSI escape sequence to update character attributes */
-		printf ( "\033[0;%d;3%d;4%dm", ( bold ? 1 : 22 ), fcol, bcol );
-	}
+	ansiscr_attrs ( scr, attrs );
 
 	/* Print the actual character */
 	putchar ( character );
@@ -79,6 +89,7 @@ static bool ansiscr_peek ( struct _curses_screen *scr __unused ) {
 SCREEN _ansi_screen = {
 	.init		= ansiscr_init,
 	.exit		= ansiscr_exit,
+	.erase		= ansiscr_erase,
 	.movetoyx	= ansiscr_movetoyx,
 	.putc		= ansiscr_putc,
 	.getc		= ansiscr_getc,

src/hci/mucurses/clear.c

@@ -88,3 +88,13 @@ int werase ( WINDOW *win ) {
 	wclrtobot( win );
 	return OK;
 }
+
+/**
+ * Completely clear the screen
+ *
+ * @ret rc	return status code
+ */
+int erase ( void ) {
+	stdscr->scr->erase( stdscr->scr, stdscr->attrs );
+	return OK;
+}

src/include/curses.h

@@ -37,6 +37,13 @@ typedef struct _curses_screen {
 
 	void ( *init ) ( struct _curses_screen *scr );
 	void ( *exit ) ( struct _curses_screen *scr );
+	/**
+	 * Erase screen
+	 *
+	 * @v scr	screen on which to operate
+	 * @v attrs	attributes
+	 */
+	void ( * erase ) ( struct _curses_screen *scr, attr_t attrs );
 	/**
 	 * Move cursor to position specified by x,y coords
 	 *
@@ -242,7 +249,7 @@ extern int echo ( void );
 extern int echochar ( const chtype );
 extern int endwin ( void );
 extern char erasechar ( void );
-//extern int erase ( void );
+extern int erase ( void );
 extern void filter ( void );
 extern int flash ( void );
 extern int flushinp ( void );
@@ -552,10 +559,6 @@ static inline int deleteln ( void ) {
 	return wdeleteln( stdscr );
 }
 
-static inline int erase ( void ) {
-	return werase ( stdscr );
-}
-
 static inline int getch ( void ) {
 	return wgetch ( stdscr );
 }