menuconfig: Do not open code textbox scroll up/down

We don't need to explicitely use ncurses' scroll(). ncurses performs
vertical-motion optimization at wrefresh() time.

Using strace I confirmed that with the following patch curses still sends only
the new line of text to the terminal when scrolling up/down one line at a
time.

Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 11 insertions, 44 deletions

diff --git a/scripts/kconfig/lxdialog/textbox.c b/scripts/kconfig/lxdialog/textbox.c
index 506a095c387c..3b3c5c470bf8 100644
--- a/scripts/kconfig/lxdialog/textbox.c
+++ b/scripts/kconfig/lxdialog/textbox.c
@@ -166,40 +166,12 @@ do_resize:
                 case 'K':       /* Previous line */
                 case 'k':
                 case KEY_UP:
-                        if (!begin_reached) {
-                                int passed_end = 0;
-
-                                back_lines(page_length + 1);
-
-                                /* We don't call print_page() here but use
-                                 * scrolling to ensure faster screen update.
-                                 * However, 'end_reached' and 'page_length'
-                                 * should still be updated, and 'page' should
-                                 * point to start of next page. This is done
-                                 * by calling get_line() in the following
-                                 * 'for' loop. */
-                                scrollok(box, TRUE);
-                                wscrl(box, -1); /* Scroll box region down one line */
-                                scrollok(box, FALSE);
-                                page_length = 0;
-                                for (i = 0; i < boxh; i++) {
-                                        if (!i) {
-                                                /* print first line of page */
-                                                print_line(box, 0, boxw);
-                                                wnoutrefresh(box);
-                                        } else
-                                                /* Called to update 'end_reached' and 'page' */
-                                                get_line();
-                                        if (!passed_end)
-                                                page_length++;
-                                        if (end_reached && !passed_end)
-                                                passed_end = 1;
-                                }
+                        if (begin_reached)
+                                break;
 
-                                print_position(dialog);
-                                wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
-                                wrefresh(dialog);
-                        }
+                        back_lines(page_length + 1);
+                        refresh_text_box(dialog, box, boxh, boxw, cur_y,
+                                         cur_x);
                         break;
                 case 'B':       /* Previous page */
                 case 'b':
@@ -214,17 +186,12 @@ do_resize:
                 case 'J':       /* Next line */
                 case 'j':
                 case KEY_DOWN:
-                        if (!end_reached) {
-                                begin_reached = 0;
-                                scrollok(box, TRUE);
-                                scroll(box);    /* Scroll box region up one line */
-                                scrollok(box, FALSE);
-                                print_line(box, boxh - 1, boxw);
-                                wnoutrefresh(box);
-                                print_position(dialog);
-                                wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
-                                wrefresh(dialog);
-                        }
+                        if (end_reached)
+                                break;
+
+                        back_lines(page_length - 1);
+                        refresh_text_box(dialog, box, boxh, boxw, cur_y,
+                                         cur_x);
                         break;
                 case KEY_NPAGE: /* Next page */
                 case ' ':