cgram: allow navigation with KEY_PPAGE and KEY_NPAGE

diff --git a/cgram/cgram.c b/cgram/cgram.c
index e9e5813e6e03028a2bff6f6beea2bdbb950e251c..9379dcfe2a3a343a0621acd3bfa132cdc4af1683 100644 (file)
--- a/cgram/cgram.c
+++ b/cgram/cgram.c
@@ -1,4 +1,4 @@
-/* $NetBSD: cgram.c,v 1.10 2021/02/21 20:33:42 rillig Exp $ */
+/* $NetBSD: cgram.c,v 1.11 2021/02/21 22:21:56 rillig Exp $ */
 
 /*-
  * Copyright (c) 2013, 2021 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: cgram.c,v 1.10 2021/02/21 20:33:42 rillig Exp $");
+__RCSID("$NetBSD: cgram.c,v 1.11 2021/02/21 22:21:56 rillig Exp $");
 #endif
 
 #include <assert.h>
@@ -361,8 +361,8 @@ closecurses(void)
 static void
 saturate_cursor(void)
 {
-       assert(cursor_y >= 0);
-       assert(cursor_y <= cur_max_y());
+       cursor_y = imax(cursor_y, 0);
+       cursor_y = imin(cursor_y, cur_max_y());
 
        assert(cursor_x >= 0);
        cursor_x = imin(cursor_x, cur_max_x());
@@ -445,13 +445,17 @@ handle_key(void)
                break;
        case 14:                /* ^N */
        case KEY_DOWN:
-               if (cursor_y < cur_max_y())
-                       cursor_y++;
+               cursor_y++;
                break;
        case 16:                /* ^P */
        case KEY_UP:
-               if (cursor_y > 0)
-                       cursor_y--;
+               cursor_y--;
+               break;
+       case KEY_PPAGE:
+               cursor_y -= LINES - 2;
+               break;
+       case KEY_NPAGE:
+               cursor_y += LINES - 2;
                break;
        case '*':
                hinting = !hinting;