From 93c1d1dd361f7cfe5613894e536223deaefc34e3 Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Fri, 7 Oct 2011 11:47:40 -0500
Subject: [PATCH] add a 'find longest line' menu item to the edit menu

---
 collects/drracket/private/frame.rkt           |  1 +
 collects/framework/private/frame.rkt          | 35 +++++++++++++++++++
 .../private/english-string-constants.rkt      |  3 +-
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/collects/drracket/private/frame.rkt b/collects/drracket/private/frame.rkt
index db4ee0ae44..e8b7b44c75 100644
--- a/collects/drracket/private/frame.rkt
+++ b/collects/drracket/private/frame.rkt
@@ -243,6 +243,7 @@
         (new separator-menu-item% (parent menu)))
       
       (define/override (edit-menu:between-find-and-preferences menu)
+        (super edit-menu:between-find-and-preferences menu)
         (make-object separator-menu-item% menu)
         (let ([keybindings-on-demand
                (λ (menu-item)
diff --git a/collects/framework/private/frame.rkt b/collects/framework/private/frame.rkt
index 784580895c..37928b236a 100644
--- a/collects/framework/private/frame.rkt
+++ b/collects/framework/private/frame.rkt
@@ -1507,6 +1507,41 @@
   (mixin (-editor<%>) (text<%>)
     (define/override (get-editor<%>) (class->interface text%))
     (init (filename #f) (editor% text:keymap%))
+    
+    (inherit get-editor)
+    (define/override (edit-menu:between-find-and-preferences edit-menu)
+      (when (add-find-longest-line-menu-item?)
+        (new menu-item%
+             [parent edit-menu] 
+             [label (string-constant find-longest-line)]
+             [callback 
+              (λ (x y)
+                (define ed (get-editor))
+                (define (line-len p)
+                  (define ans 
+                    (- (send ed paragraph-end-position p)
+                       (send ed paragraph-start-position p)))
+                  ans)
+                (when ed
+                  (let loop ([p (- (send ed last-paragraph) 1)]
+                             [longest-size (line-len (send ed last-paragraph))]
+                             [longest (send ed last-paragraph)])
+                    (cond
+                      [(= p -1)
+                       (send ed set-position 
+                             (send ed paragraph-start-position longest)
+                             (send ed paragraph-end-position longest))]
+                      [else
+                       (define this-size (line-len p))
+                       (cond
+                         [(<= longest-size this-size)
+                          (loop (- p 1) this-size p)]
+                         [else
+                          (loop (- p 1) longest-size longest)])]))))]))
+      (super edit-menu:between-find-and-preferences edit-menu))
+      
+    (define/public (add-find-longest-line-menu-item?) #t)
+    
     (super-new (filename filename) (editor% editor%))))
 
 (define pasteboard<%> (interface (-editor<%>)))
diff --git a/collects/string-constants/private/english-string-constants.rkt b/collects/string-constants/private/english-string-constants.rkt
index 1c8233502c..95aaf54a6b 100644
--- a/collects/string-constants/private/english-string-constants.rkt
+++ b/collects/string-constants/private/english-string-constants.rkt
@@ -929,7 +929,8 @@ please adhere to these guidelines:
  ;;; edit menu
  (split-menu-item-label "&Split")
  (collapse-menu-item-label "C&ollapse")
- 
+ (find-longest-line "Find Longest Line")
+  
  ;;; language menu
  (language-menu-name "&Language")