From 9e23d915ee00b49492c1e5fa6f0ea4f85824452e Mon Sep 17 00:00:00 2001
From: Matthias Felleisen <matthias@racket-lang.org>
Date: Mon, 24 Apr 2006 15:29:45 +0000
Subject: [PATCH] last bug fixes to hdtch/[i]draw for now

svn: r2763
---
 collects/htdch/draw/World.java  |  3 ---
 collects/htdch/draw/support.scm | 10 ++++++----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/collects/htdch/draw/World.java b/collects/htdch/draw/World.java
index f2e97ba1b4..4dd7575daf 100644
--- a/collects/htdch/draw/World.java
+++ b/collects/htdch/draw/World.java
@@ -2,9 +2,6 @@ package draw;
         
 public abstract class World {
     protected Canvas theCanvas;
-    protected void putCanvas(Canvas c) { 
-	this.theCanvas = c; 
-    };
     public boolean bigBang(int width, int height, double s) {
 	if (width <= 0)
            throw new RuntimeException(
diff --git a/collects/htdch/draw/support.scm b/collects/htdch/draw/support.scm
index 2d49103b3c..7b71d1a955 100644
--- a/collects/htdch/draw/support.scm
+++ b/collects/htdch/draw/support.scm
@@ -155,15 +155,17 @@
 
       (define (bigBangO-double-native this accs gets privates i)
         (define theCanvas ((hash-table-get accs 'theCanvas) this))
+	(define setCanvas (hash-table-get gets 'theCanvas))
         (define width (with-method ([g (theCanvas Canvas-width-get)]) (g '___)))
         (define height (with-method ([g (theCanvas Canvas-height-get)]) (g '___)))
         ;; call only *after* start 
-        (define (on-event world th)
+        (define (on-event world0 th)
           (begin-draw-sequence)
           (send theCanvas copy)
-          (send world erase)
-          (let ([world (imperative (th) world)])
-	    (send world putCanvas-draw.Canvas theCanvas)
+          (send world0 erase)
+          (let ([world (imperative (th) world0)])
+	    (unless (eq? world0 world)
+	      (setCanvas world theCanvas))
 	    (send world draw)   
 	    (end-draw-sequence)
 	    world))