From 3704e2d69fd4d91b656252d3a627e2f0816eb9f2 Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Sat, 28 Aug 2010 20:39:42 -0500
Subject: [PATCH] added a better explanation of pixels and fixed a bug in
 save-image

---
 collects/2htdp/private/img-err.rkt            |  3 +
 .../teachpack/2htdp/scribblings/image-gen.rkt |  2 +-
 .../teachpack/2htdp/scribblings/image-toc.rkt | 66 ++++++++++++++++++-
 .../2htdp/scribblings/image-util.rkt          |  4 +-
 4 files changed, 69 insertions(+), 6 deletions(-)

diff --git a/collects/2htdp/private/img-err.rkt b/collects/2htdp/private/img-err.rkt
index bbfb001c4b..3ed6288a44 100644
--- a/collects/2htdp/private/img-err.rkt
+++ b/collects/2htdp/private/img-err.rkt
@@ -239,6 +239,9 @@
      (if (string? arg)
          (string->symbol arg)
          arg)]
+    [(filename)
+     (check-arg fn-name (path-string? arg) 'path-string i arg)
+     arg]
     [else
      (error 'check "the function ~a has an argument with an unknown name: ~s"
             fn-name
diff --git a/collects/teachpack/2htdp/scribblings/image-gen.rkt b/collects/teachpack/2htdp/scribblings/image-gen.rkt
index 5bb08c5f4b..862a87fcdb 100644
--- a/collects/teachpack/2htdp/scribblings/image-gen.rkt
+++ b/collects/teachpack/2htdp/scribblings/image-gen.rkt
@@ -35,7 +35,7 @@
 (define (handle-image exp)
   (printf ".") (flush-output)
   (let ([result 
-         (with-handlers ([exn:fail?
+         (with-handlers ([(λ (x) #t)
                           (λ (x)
                             (printf "\nerror evaluating:\n")
                             (pretty-write exp)
diff --git a/collects/teachpack/2htdp/scribblings/image-toc.rkt b/collects/teachpack/2htdp/scribblings/image-toc.rkt
index 8828a85896..673eb2f71a 100644
--- a/collects/teachpack/2htdp/scribblings/image-toc.rkt
+++ b/collects/teachpack/2htdp/scribblings/image-toc.rkt
@@ -6,10 +6,40 @@
 
 (define mapping
   (list
+   (list
+    '(let* ((s
+             (crop
+              0
+              0
+              20
+              20
+              (rectangle
+               20
+               20
+               "outline"
+               (make-pen "black" 2 "solid" "round" "round"))))
+            (r (beside s s s s s s)))
+       (above r r r r r r))
+    'image
+    "5127be89b4-1.png")
+   (list
+    '(crop
+      0
+      0
+      20
+      20
+      (rectangle 20 20 "outline" (make-pen "black" 2 "solid" "round" "round")))
+    'image
+    "284a96a769b-1.png")
+   (list
+    '(let* ((s (rectangle 20 20 "outline" "black")) (r (beside s s s s s s)))
+       (above r r r r r r))
+    'image
+    "245380940d6-1.png")
    (list '(image-height (rectangle 100 100 "solid" "black")) 'val 100)
    (list '(image-baseline (rectangle 100 100 "solid" "black")) 'val 100)
-   (list '(image-height (text "Hello" 24 "black")) 'val 24)
-   (list '(image-baseline (text "Hello" 24 "black")) 'val 18)
+   (list '(image-height (text "Hello" 24 "black")) 'val 41)
+   (list '(image-baseline (text "Hello" 24 "black")) 'val 31)
    (list '(image-height (rectangle 10 0 "solid" "purple")) 'val 0)
    (list
     '(image-height
@@ -717,4 +747,34 @@
    (list '(ellipse 20 40 "solid" "blue") 'image "25451dd2997.png")
    (list '(ellipse 40 20 "outline" "black") 'image "8cb34e62d4.png")
    (list '(circle 20 "solid" "blue") 'image "54d58bf7f6.png")
-   (list '(circle 30 "outline" "red") 'image "262a4fa650a.png")))
+   (list '(circle 30 "outline" "red") 'image "262a4fa650a.png")
+   (list
+    '(let* ((s
+             (crop
+              0
+              0
+              20
+              20
+              (rectangle
+               20
+               20
+               "outline"
+               (make-pen "black" 2 "solid" "round" "round"))))
+            (r (beside s s s s s s)))
+       (above r r r r r r))
+    'image
+    "5127be89b4.png")
+   (list
+    '(crop
+      0
+      0
+      20
+      20
+      (rectangle 20 20 "outline" (make-pen "black" 2 "solid" "round" "round")))
+    'image
+    "284a96a769b.png")
+   (list
+    '(let* ((s (rectangle 20 20 "outline" "black")) (r (beside s s s s s s)))
+       (above r r r r r r))
+    'image
+    "245380940d6.png")))
diff --git a/collects/teachpack/2htdp/scribblings/image-util.rkt b/collects/teachpack/2htdp/scribblings/image-util.rkt
index 863634e199..e74e2f0a03 100644
--- a/collects/teachpack/2htdp/scribblings/image-util.rkt
+++ b/collects/teachpack/2htdp/scribblings/image-util.rkt
@@ -15,8 +15,8 @@
        (for-each (λ (exp) (printf "~s\n" (syntax->datum exp)))
                  (syntax->list #'(exp ...))))
      #'(interleave 
-         (list (racketinput exp) ...)
-         (list 'exp ...))]))
+        (list (racketinput exp) ...)
+        (list 'exp ...))]))
 
 (define (interleave expr-paras val-list+outputs)
   (make-table