From: Thomas Roessler <roessler@does-not-exist.org>
Date: Tue, 1 Nov 2005 08:42:00 +0000 (+0000)
Subject: This should be a better patch for the menu break dance.
X-Git-Tag: mutt-1-5-12-rel~272
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ba8692c0a8fd1239bad6606ad33cbc23ba86674f;p=mutt

This should be a better patch for the menu break dance.
---

diff --git a/menu.c b/menu.c
index 2c4caada..a4bfb397 100644
--- a/menu.c
+++ b/menu.c
@@ -384,19 +384,32 @@ void menu_check_recenter (MUTTMENU *menu)
       set_option (OPTNEEDREDRAW);
     }
   }
-  else if (menu->current >= menu->top + menu->pagelen - c) /* indicator below bottom threshold */
-  {
-    if (option (OPTMENUSCROLL) || (menu->pagelen <= 0))
-      menu->top = menu->current - menu->pagelen + c;
-    else
-      menu->top += (menu->pagelen - c) * ((menu->current - menu->top) / (menu->pagelen - c)) - c;
-  }
-  else if (menu->current < menu->top + c) /* indicator above top threshold */
+  else 
   {
-    if (option (OPTMENUSCROLL) || (menu->pagelen <= 0))
-      menu->top = menu->current - c;
-    else
-      menu->top -= (menu->pagelen - c) * ((menu->top + menu->pagelen - 1 - menu->current) / (menu->pagelen - c)) - c;
+    /* 
+     * If c = menu->pagelen / 2 and menu->pagelen is even, then (obviously):
+     * 
+     *   menu->top + menu->pagelen - c == menu->top + c
+     *
+     * In that case, having an "else if" below leads to what has become known as the
+     * indicator break dance effect.  Instead of special-casing, we just forget the 
+     * "else".
+     */
+    
+    if (menu->current < menu->top + c) /* indicator above top threshold */
+    {
+      if (option (OPTMENUSCROLL) || (menu->pagelen <= 0))
+	menu->top = menu->current - c;
+      else
+	menu->top -= (menu->pagelen - c) * ((menu->top + menu->pagelen - 1 - menu->current) / (menu->pagelen - c)) - c;
+    }
+    if (menu->current >= menu->top + menu->pagelen - c) /* indicator below bottom threshold */
+    {
+      if (option (OPTMENUSCROLL) || (menu->pagelen <= 0))
+	menu->top = menu->current - menu->pagelen + c + 1;
+      else
+	menu->top += (menu->pagelen - c) * ((menu->current - menu->top) / (menu->pagelen - c)) - c;
+    }
   }
 
   if (!option (OPTMENUMOVEOFF)) /* make entries stick to bottom */