(Info-fontify-node): Compute header line specially

if node has no next, previous or up links.
Hide the part of the first line that is used in the header.
Use Info-next-link-keymap, etc.
(Info-next-link-keymap, Info-prev-link-keymap)
(Info-up-link-keymap): New variables.

2 files changed, 70 insertions, 24 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 4dfc1b2ab91..bd29cd50c29 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,12 @@
 2002-06-12  Richard M. Stallman  <rms@gnu.org>
 
+        * info.el (Info-fontify-node): Compute header line specially
+        if node has no next, previous or up links.
+        Hide the part of the first line that is used in the header.
+        Use Info-next-link-keymap, etc.
+        (Info-next-link-keymap, Info-prev-link-keymap) 
+        (Info-up-link-keymap): New variables.
+
         * international/mule-diag.el (describe-char-after): Doc fix.
 
         * view.el (view-mode-enter): Clarify echo area message.
diff --git a/lisp/info.el b/lisp/info.el
index 19bb7d0cf31..afc4433a253 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -2580,6 +2580,34 @@ the variable `Info-file-list-for-emacs'."
         (put-text-property (match-beginning 1) (match-end 1)
                            'font-lock-face 'info-menu-header)))))
 
+(defvar Info-next-link-keymap
+  (let ((keymap (make-sparse-keymap)))
+    (define-key keymap [header-line mouse-1] 'Info-next)
+    (define-key keymap [header-line mouse-2] 'Info-next)
+    (define-key keymap [header-line down-mouse-1] 'ignore)
+    (define-key keymap [mouse-2] 'Info-next)
+    keymap)
+  "Keymap to put on the Next link in the text or the header line.")
+
+(defvar Info-prev-link-keymap
+  (let ((keymap (make-sparse-keymap)))
+    (define-key keymap [header-line mouse-1] 'Info-prev)
+    (define-key keymap [header-line mouse-2] 'Info-prev)
+    (define-key keymap [header-line down-mouse-1] 'ignore)
+    (define-key keymap [mouse-2] 'Info-prev)
+    keymap)
+  "Keymap to put on the Prev link in the text or the header line.")
+
+
+(defvar Info-up-link-keymap
+  (let ((keymap (make-sparse-keymap)))
+    (define-key keymap [header-line mouse-1] 'Info-up)
+    (define-key keymap [header-line mouse-2] 'Info-up)
+    (define-key keymap [header-line down-mouse-1] 'ignore)
+    (define-key keymap [mouse-2] 'Info-up)
+    keymap)
+  "Keymap to put on the Up link in the text or the header line.")
+
 (defun Info-fontify-node ()
   ;; Only fontify the node if it hasn't already been done.  [We pass in
   ;; LIMIT arg to `next-property-change' because it seems to search past
@@ -2607,33 +2635,44 @@ the variable `Info-file-list-for-emacs'."
                                    (concat "Go to node "
                                            (buffer-substring nbeg nend)))
                 ;; Always set up the text property keymap.
-                ;; It will be used either in the buffer
+                ;; It will either be used in the buffer
                 ;; or copied in the header line.
-                (let ((fun (cdr (assoc tag '(("Prev" . Info-prev)
-                                             ("Next" . Info-next)
-                                             ("Up" . Info-up))))))
-                  (when fun
-                    (let ((keymap (make-sparse-keymap)))
-                      (define-key keymap [header-line mouse-1] fun)
-                      (define-key keymap [header-line mouse-2] fun)
-                      (define-key keymap [header-line down-mouse-1] 'ignore)
-                      (define-key keymap [mouse-2] fun)
-                      (put-text-property tbeg nend 'keymap keymap))))
-                  )))
+                (cond ((equal tag "Prev")
+                       (put-text-property tbeg nend 'keymap
+                                          Info-prev-link-keymap))
+                      ((equal tag "Next")
+                       (put-text-property tbeg nend 'keymap
+                                          Info-next-link-keymap))
+                      ((equal tag "Up")
+                       (put-text-property tbeg nend 'keymap
+                                          Info-up-link-keymap))))))
           (goto-char (point-min))
-          (let* ((header-end (save-excursion (end-of-line) (point)))
-                 ;; If we find neither Next: nor Prev: link, show the entire
-                 ;; node header.  Otherwise, don't show the File: and Node:
-                 ;; parts, to avoid wasting precious space on information that
-                 ;; is available in the mode line.
-                 (header-beg (if (re-search-forward
-                                  "\\(next\\|prev[ious]*\\): "
-                                  header-end t)
-                                 (match-beginning 1)
-                               (point))))
+          (let ((header-end (save-excursion (end-of-line) (point)))
+                header)
+            ;; If we find neither Next: nor Prev: link, show the entire
+            ;; node header.  Otherwise, don't show the File: and Node:
+            ;; parts, to avoid wasting precious space on information that
+            ;; is available in the mode line.
+            (if (re-search-forward
+                 "\\(next\\|up\\|prev[ious]*\\): "
+                 header-end t)
+                (progn
+                  (goto-char (match-beginning 1))
+                  (setq header (buffer-substring (point) header-end)))
+              (if (re-search-forward "node:[ \t]*[^ \t]+[ \t]*" nil t)
+                  (setq header
+                        (concat "No next, prev or up links  --  "
+                                (buffer-substring (point) header-end)))
+                (setq header (buffer-substring (point) header-end))))
+
             (put-text-property (point-min) (1+ (point-min))
-                               'header-line
-                               (buffer-substring header-beg header-end))))
+                               'header-line header)
+            ;; Hide the part of the first line
+            ;; that is in the header, if it is just part.
+            (unless (bobp)
+              ;; Hide the punctuation at the end, too.
+              (skip-chars-backward " \t,")
+              (put-text-property (point) header-end 'invisible t))))
         (goto-char (point-min))
         (while (re-search-forward "\n\\([^ \t\n].+\\)\n\\(\\*+\\|=+\\|-+\\|\\.+\\)$"
                                   nil t)