Ticket #2453: aggressive screen repaint

... to avoid artefacts after printing of non-printable symbols.

(tty_touch_lines): new function to mark modified lines of screen.
(do_refresh): mark lines as modified before redraw of non-fullscreen dialog
and clear entire screen before redraw of fullscreen dialog.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

lib/tty/tty-ncurses.c

@@ -280,6 +280,14 @@ tty_touch_screen (void)
 
 /* --------------------------------------------------------------------------------------------- */
 
+void
+tty_touch_lines (int start, int num)
+{
+    touchline (stdscr, start, num);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 void
 tty_gotoyx (int y, int x)
 {

lib/tty/tty-slang.c

@@ -453,6 +453,14 @@ tty_touch_screen (void)
 
 /* --------------------------------------------------------------------------------------------- */
 
+void
+tty_touch_lines (int start, int num)
+{
+    SLsmg_touch_lines (start, num);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 void
 tty_gotoyx (int y, int x)
 {

lib/tty/tty.h

@@ -110,6 +110,7 @@ extern int tty_lowlevel_getch (void);
 
 extern int tty_reset_screen (void);
 extern void tty_touch_screen (void);
+extern void tty_touch_lines (int start, int num);
 
 extern void tty_gotoyx (int y, int x);
 extern void tty_getyx (int *py, int *px);

lib/widget/dialog.c

@@ -871,7 +871,12 @@ do_refresh (void)
     if (fast_refresh)
     {
         if ((d != NULL) && (d->data != NULL))
-            dlg_redraw ((Dlg_head *) d->data);
+        {
+            Dlg_head *dlg = (Dlg_head *) d->data;
+
+            tty_touch_lines (dlg->y, dlg->lines);
+            dlg_redraw (dlg);
+        }
     }
     else
     {
@@ -879,6 +884,10 @@ do_refresh (void)
         for (; d != NULL; d = g_list_next (d))
             if ((d->data != NULL) && ((Dlg_head *) d->data)->fullscreen)
                 break;
+
+        /* Clear entire screen to avoid artefacts after printing of non-printable symbols. */
+        clr_scr ();
+
         /* back to top dialog */
         for (; d != NULL; d = g_list_previous (d))
             if (d->data != NULL)