From 6c26992bfc2da7d4fbdbef4f8264acf1e0fc2987 Mon Sep 17 00:00:00 2001
From: Lehi Toskin <lehi@tosk.in>
Date: Thu, 22 Dec 2016 21:25:02 -0800
Subject: [PATCH] Fix bug with (image-xmp)

---
 README.md       |  2 ++
 base.rkt        |  4 ++--
 meta-editor.rkt | 24 ++++++++++++++++--------
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index f23d09b..c828cde 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,8 @@ tracked solely by the application.
 - [png-image](https://github.com/lehitoskin/png-image)
 - [racquel](https://github.com/brown131/racquel)
 - [rsvg](https://github.com/takikawa/rsvg) (which uses librsvg)
+- [sugar](https://github.com/mbutterick/sugar)
+- [txexpr](https://github.com/mbutterick/txexpr)
 
 ### Compilation
 
diff --git a/base.rkt b/base.rkt
index 7a9ff39..8de127a 100644
--- a/base.rkt
+++ b/base.rkt
@@ -46,7 +46,7 @@
 ; pict of the currently displayed image
 (define image-pict #f)
 ; the cached XMP metadata of the image
-(define image-xmp (make-parameter ""))
+(define image-xmp (make-parameter empty))
 ; bitmap to actually display
 ; eliminate image "jaggies"
 ; reduce amount of times we use pict->bitmap, as this takes a very long time
@@ -519,7 +519,7 @@
             (unless (empty? embed-lst)
               ; the embedded tags may come back unsorted
               (incoming-tags (string-join (sort embed-lst string<?) ", ")))]
-           [else (image-xmp "")])
+           [else (image-xmp empty)])
             
      ; ...put them in the tfield
      (send tag-tfield set-value (incoming-tags))
diff --git a/meta-editor.rkt b/meta-editor.rkt
index 8acef7e..6e78ec4 100644
--- a/meta-editor.rkt
+++ b/meta-editor.rkt
@@ -120,7 +120,9 @@
          (txexpr (string->symbol type) attr-lst (list elems)))]
     ; attr stuff
     [("xmp:BaseURL" "xmp:Label" "xmp:Rating")
-     (define xexpr (string->xexpr (image-xmp)))
+     (define xexpr (string->xexpr (if (empty? (image-xmp))
+                                      ""
+                                      (first (image-xmp)))))
      ; these go inside rdf:Description as attrs
      (define rdf:desc (findf-txexpr xexpr is-rdf:Description?))
      (attr-set rdf:desc (string->symbol type) elems)]
@@ -135,14 +137,18 @@
     (case type
       [("xmp:BaseURL" "xmp:Label" "xmp:Rating")
        ((set-xmp-tag 'rdf:Description)
-        (string->xexpr (image-xmp))
+        (string->xexpr (if (empty? (image-xmp))
+                           ""
+                           (first (image-xmp))))
         (create-dc-meta type elems attrs))]
       [else
        ((set-xmp-tag (string->symbol type))
-        (string->xexpr (first (image-xmp)))
+        (string->xexpr (if (empty? (image-xmp))
+                           ""
+                           (first (image-xmp))))
         (create-dc-meta type elems attrs))]))
-  (image-xmp (xexpr->string setted))
-  (set-embed-xmp! (image-path) (image-xmp))
+  (image-xmp (list (xexpr->string setted)))
+  (set-embed-xmp! (image-path) (first (image-xmp)))
   (fields-defaults))
 
 (define (fields-defaults)
@@ -169,7 +175,7 @@
 (define dc-choice
   (new choice%
        [parent dc-hpanel]
-       [label "XMP Tags "]
+       [label "XMP Tags    "]
        [choices (append dublin-core xmp-base)]
        [selection 11]
        [stretchable-height #f]
@@ -177,7 +183,9 @@
         (λ (choice evt)
           ; when the choice is selected, fill the tfield with its contents
           (define sel (string->symbol (send choice get-string-selection)))
-          (define xexpr (string->xexpr (image-xmp)))
+          (define xexpr (string->xexpr (if (empty? (image-xmp))
+                                           ""
+                                           (first (image-xmp)))))
           (define found (findf*-txexpr xexpr (is-tag? sel)))
           (cond [found
                  (case sel
@@ -230,7 +238,7 @@
 (define attr-choice
   (new choice%
        [parent attr-hpanel]
-       [label "Attribute val   "]
+       [label "Attribute val "]
        [choices attrs]
        [selection 0]
        [stretchable-height #f]))