From b0095111d4816043891138c3d36568d220c2db4a Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Wed, 5 Jan 2011 06:59:02 -0700
Subject: [PATCH] restore and document scrolling behavior  Closes PR 11583, and
  everts the previous fix for PR 10853 and fixes   it in a different way

---
 collects/drracket/private/unit.rkt                | 14 ++++++--------
 collects/mred/private/wxme/editor-canvas.rkt      | 10 +++++-----
 collects/scribblings/gui/editor-admin-class.scrbl |  6 +++++-
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/collects/drracket/private/unit.rkt b/collects/drracket/private/unit.rkt
index 7720df615b..4ef50ada9a 100644
--- a/collects/drracket/private/unit.rkt
+++ b/collects/drracket/private/unit.rkt
@@ -2909,14 +2909,12 @@ module browser threading seems wrong.
           (define (set-visible-regions txt regions)
             (when regions
               (for-each (λ (canvas region) 
-                          (send canvas call-as-primary-owner
-                                (λ ()
-                                  (let ([admin (send txt get-admin)])
-                                    (send admin scroll-to 
-                                          (first region)
-                                          (second region)
-                                          (third region)
-                                          (fourth region)))))) 
+                           (set-visible-region canvas
+                                               (first region)
+                                               (second region)
+                                               (third region)
+                                               (fourth region)
+                                               #f))
                         (send txt get-canvases)
                         regions)))
           
diff --git a/collects/mred/private/wxme/editor-canvas.rkt b/collects/mred/private/wxme/editor-canvas.rkt
index e72232430b..a12cbeeba5 100644
--- a/collects/mred/private/wxme/editor-canvas.rkt
+++ b/collects/mred/private/wxme/editor-canvas.rkt
@@ -1131,17 +1131,17 @@
 
   (define/public (do-scroll-to localx localy w h refresh? bias prev? next? only-focus?)
     (and canvas
-         (or (and (or (send canvas is-focus-on?)
-                      (not only-focus?))
-                  (list (send canvas scroll-to localx localy w h refresh? bias)))
-             (and (not (send canvas is-focus-on?))
+         (or (and (not (send canvas is-focus-on?))
                   (or
                    (and prev? 
                         prevadmin
                         (send prevadmin do-scroll-to localx localy w h refresh? bias #t #f #t))
                    (and next? 
                         nextadmin
-                        (send nextadmin do-scroll-to localx localy w h refresh? bias #f #t #t)))))))
+                        (send nextadmin do-scroll-to localx localy w h refresh? bias #f #t #t))))
+             (and (or (not only-focus?)
+                      (send canvas is-focus-on?))
+                  (list (send canvas scroll-to localx localy w h refresh? bias))))))
 
   (def/override (grab-caret [(symbol-in immediate display global) dist])
     (when canvas
diff --git a/collects/scribblings/gui/editor-admin-class.scrbl b/collects/scribblings/gui/editor-admin-class.scrbl
index 6da0ea487a..2c395347fd 100644
--- a/collects/scribblings/gui/editor-admin-class.scrbl
+++ b/collects/scribblings/gui/editor-admin-class.scrbl
@@ -273,8 +273,12 @@ The @scheme[bias] argument is one of:
 The return value is @scheme[#t] if the @techlink{display} is scrolled,
  @scheme[#f] if not (either because the requested region is already
  visible, because the @techlink{display} has zero size, or because the
- editor is currently printing.)
+ editor is currently printing).
 
+If an editor has multiple @techlink{displays}, then if any display
+ currently has the keyboard focus, it is scrolled. Otherwise, the
+ ``primary owner'' of the editor (see @method[editor-canvas%
+ call-as-primary-owner]) is scrolled.
 
 }
 @methimpl{