(describe-char): Improve description of eight-bit

char in a unibyte buffer.

2 files changed, 68 insertions, 51 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 4304949d6db..0cda430b400 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2009-01-20  Kenichi Handa  <handa@m17n.org>
+
+        * descr-text.el (describe-char): Improve description of eight-bit
+        char in a unibyte buffer.
+
 2009-01-20  Glenn Morris  <rgm@gnu.org>
 
         * emacs-lisp/authors.el (authors-aliases, authors-fixed-case):
diff --git a/lisp/descr-text.el b/lisp/descr-text.el
index 022acd67b9e..96ef2458e42 100644
--- a/lisp/descr-text.el
+++ b/lisp/descr-text.el
@@ -379,7 +379,9 @@ as well as widgets, buttons, overlays, and text properties."
   (if (>= pos (point-max))
       (error "No character follows specified position"))
   (let* ((char (char-after pos))
-         (charset (or (get-text-property pos 'charset) (char-charset char)))
+         (eight-bit-p (and (not enable-multibyte-characters) (>= char 128)))
+         (charset (if eight-bit-p 'eight-bit
+                    (or (get-text-property pos 'charset) (char-charset char))))
          (composition (find-composition pos nil nil t))
          (component-chars nil)
          (display-table (or (window-display-table)
@@ -404,9 +406,11 @@ as well as widgets, buttons, overlays, and text properties."
               (kill-buffer tmp-buf))))
          item-list max-width code)
 
-    (or (setq code (encode-char char charset))
-        (setq charset (char-charset char)
-              code (encode-char char charset)))
+    (if multibyte-p
+        (or (setq code (encode-char char charset))
+            (setq charset (char-charset char)
+                  code (encode-char char charset)))
+      (setq code char))
     (setq item-list
           `(("character"
              ,(format "%s (%d, #o%o, #x%x)"
@@ -444,34 +448,40 @@ as well as widgets, buttons, overlays, and text properties."
                   (internal-describe-syntax-value syntax)
                   (buffer-string))))
             ("category"
-             ,@(let ((category-set (char-category-set char)))
-                 (if category-set
-                     (describe-char-categories category-set)
-                   '("-- none --"))))
+             ,@(if (not eight-bit-p)
+                   (let ((category-set (char-category-set char)))
+                     (if category-set
+                         (describe-char-categories category-set)
+                       '("-- none --")))))
             ("to input"
-             ,@(let ((key-list (and (eq input-method-function
-                                        'quail-input-method)
-                                    (quail-find-key char))))
-                 (if (consp key-list)
-                     (list "type"
-                           (mapconcat #'(lambda (x) (concat "\"" x "\""))
-                                      key-list " or ")
-                           "with"
-                           `(insert-text-button
-                             ,current-input-method
-                             'type 'help-input-method
-                             'help-args '(,current-input-method))))))
+             ,@(if (not eight-bit-p)
+                   (let ((key-list (and (eq input-method-function
+                                            'quail-input-method)
+                                        (quail-find-key char))))
+                     (if (consp key-list)
+                         (list "type"
+                               (mapconcat #'(lambda (x) (concat "\"" x "\""))
+                                          key-list " or ")
+                               "with"
+                               `(insert-text-button
+                                 ,current-input-method
+                                 'type 'help-input-method
+                                 'help-args '(,current-input-method)))))))
             ("buffer code"
-             ,(encoded-string-description
-               (string-as-unibyte (char-to-string char)) nil))
+             ,(if multibyte-p
+                  (encoded-string-description
+                   (string-as-unibyte (char-to-string char)) nil)
+                (format "#x%02X" char)))
             ("file code"
-             ,@(let* ((coding buffer-file-coding-system)
-                      (encoded (encode-coding-char char coding charset)))
-                 (if encoded
-                     (list (encoded-string-description encoded coding)
-                           (format "(encoded by coding system %S)" coding))
-                   (list "not encodable by coding system"
-                         (symbol-name coding)))))
+             ,@(if multibyte-p
+                   (let* ((coding buffer-file-coding-system)
+                          (encoded (encode-coding-char char coding charset)))
+                     (if encoded
+                         (list (encoded-string-description encoded coding)
+                               (format "(encoded by coding system %S)" coding))
+                       (list "not encodable by coding system"
+                             (symbol-name coding))))
+                 (list (format "#x%02X" char))))
             ("display"
              ,(cond
                (disp-vector
@@ -529,9 +539,10 @@ as well as widgets, buttons, overlays, and text properties."
                                      `(insert-text-button
                                        ,(symbol-name face)
                                        'type 'help-face 'help-args '(,face))))))
-            ,@(let ((unicodedata (describe-char-unicode-data char)))
-                (if unicodedata
-                    (cons (list "Unicode data" " ") unicodedata)))))
+            ,@(if (not eight-bit-p)
+                  (let ((unicodedata (describe-char-unicode-data char)))
+                    (if unicodedata
+                        (cons (list "Unicode data" " ") unicodedata))))))
     (setq max-width (apply #'max (mapcar #'(lambda (x)
                                              (if (cadr x) (length (car x)) 0))
                                          item-list)))
@@ -665,25 +676,26 @@ as well as widgets, buttons, overlays, and text properties."
             (insert "\nSee the variable `reference-point-alist' for "
                     "the meaning of the rule.\n")))
 
-        (insert (if (not describe-char-unidata-list)
-                    "\nCharacter code properties are not shown: "
-                  "\nCharacter code properties: "))
-        (insert-text-button
-         "customize what to show"
-         'action (lambda (&rest ignore)
-                   (customize-variable
-                    'describe-char-unidata-list)))
-        (insert "\n")
-        (dolist (elt (if (eq describe-char-unidata-list t)
-                         (nreverse (mapcar 'car char-code-property-alist))
-                       describe-char-unidata-list))
-          (let ((val (get-char-code-property char elt))
-                description)
-            (when val
-              (setq description (char-code-property-description elt val))
-              (insert (if description
-                          (format "  %s: %s (%s)\n" elt val description)
-                        (format "  %s: %s\n" elt val))))))
+        (unless eight-bit-p
+          (insert (if (not describe-char-unidata-list)
+                      "\nCharacter code properties are not shown: "
+                    "\nCharacter code properties: "))
+          (insert-text-button
+           "customize what to show"
+           'action (lambda (&rest ignore)
+                     (customize-variable
+                      'describe-char-unidata-list)))
+          (insert "\n")
+          (dolist (elt (if (eq describe-char-unidata-list t)
+                           (nreverse (mapcar 'car char-code-property-alist))
+                         describe-char-unidata-list))
+            (let ((val (get-char-code-property char elt))
+                  description)
+              (when val
+                (setq description (char-code-property-description elt val))
+                (insert (if description
+                            (format "  %s: %s (%s)\n" elt val description)
+                          (format "  %s: %s\n" elt val)))))))
 
         (if text-props-desc (insert text-props-desc))
         (setq help-xref-stack-item (list 'help-insert-string (buffer-string)))