Re: Patch to bookmark.el

[Karl Fogel]

Reposting the revised patch with a log message this time, to make review
easier:

[[[
Display the bookmark list header similarly to the buffer list header
(see `list-buffers'), where the default is now an immovable/immutable
header line.

Patch by: Matthias Meulien <orontee {_AT_} gmail.com>
          Karl Fogel <kfogel {_AT_} red-bean.com>

* lisp/bookmark.el
  (bookmark-bmenu-use-header-line): New variable.
  (bookmark-bmenu-inline-header-height): New name for
    `bookmark-bmenu-header-height', to avoid confusion with the code
     for the new immovable header.  All references changed.
  (bookmark-bmenu-set-header): New function.
  (bookmark-bmenu-list, bookmark-bmenu-toggle-filenames):
    Conditionalize header construction accordingly.
  (bookmark-bmenu-ensure-position): Conditionalize the skipping of the
    inline header height.
]]]

=== modified file 'lisp/bookmark.el'
--- lisp/bookmark.el    2011-11-27 04:43:11 +0000
+++ lisp/bookmark.el    2011-12-17 21:32:01 +0000
@@ -127,9 +127,15 @@
   :type 'boolean
   :group 'bookmark)
 
+(defcustom bookmark-bmenu-use-header-line t
+  "Non-nil means to use an immovable header line, as opposed to inline
+text at the top of the buffer."
+  :type 'boolean
+  :group 'bookmark)
 
-(defconst bookmark-bmenu-header-height 2
-  "Number of lines used for the *Bookmark List* header.")
+(defconst bookmark-bmenu-inline-header-height 2
+  "Number of lines used for the *Bookmark List* header
+\(only significant when `bookmark-bmenu-use-header-line' is nil\).")
 
 (defconst bookmark-bmenu-marks-width 2
   "Number of columns (chars) used for the *Bookmark List* marks column,
@@ -1543,7 +1549,8 @@
       (set-buffer buf)))
   (let ((inhibit-read-only t))
     (erase-buffer)
-    (insert "% Bookmark\n- --------\n")
+    (if (not bookmark-bmenu-use-header-line)
+      (insert "% Bookmark\n- --------\n"))
     (add-text-properties (point-min) (point)
                         '(font-lock-face bookmark-menu-heading))
     (dolist (full-record (bookmark-maybe-sort-alist))
@@ -1568,8 +1575,10 @@
         (insert "\n")))
     (set-buffer-modified-p (not (= bookmark-alist-modification-count 0)))
     (goto-char (point-min))
-    (forward-line 2)
     (bookmark-bmenu-mode)
+    (if bookmark-bmenu-use-header-line
+       (bookmark-bmenu-set-header)
+      (forward-line bookmark-bmenu-inline-header-height))
     (if bookmark-bmenu-toggle-filenames
         (bookmark-bmenu-toggle-filenames t))))
 
@@ -1578,7 +1587,25 @@
 ;;;###autoload
 (defalias 'edit-bookmarks 'bookmark-bmenu-list)
 
-
+(defun bookmark-bmenu-set-header ()
+  "Sets the immutable header line."
+  (let ((header (concat "%% " "Bookmark")))
+    (when bookmark-bmenu-toggle-filenames 
+      (setq header (concat header 
+                          (make-string (- bookmark-bmenu-file-column 
+                                          (- (length header) 3))  ?\s)
+                          "File")))
+    (let ((pos 0))
+      (while (string-match "[ \t\n]+" header pos)
+       (setq pos (match-end 0))
+       (put-text-property (match-beginning 0) pos 'display
+                          (list 'space :align-to (- pos 1))
+                          header)))
+    (put-text-property 0 2 'face 'fixed-pitch header)
+    (setq header (concat (propertize " " 'display '(space :align-to 0))
+                        header))
+    ;; Code derived from `buff-menu.el'.
+    (setq header-line-format header)))
 
 (define-derived-mode bookmark-bmenu-mode special-mode "Bookmark Menu"
   "Major mode for editing a list of bookmarks.
@@ -1631,7 +1658,9 @@
     (setq bookmark-bmenu-toggle-filenames nil))
    (t
     (bookmark-bmenu-show-filenames)
-    (setq bookmark-bmenu-toggle-filenames t))))
+    (setq bookmark-bmenu-toggle-filenames t)))
+  (when bookmark-bmenu-use-header-line
+    (bookmark-bmenu-set-header)))
 
 
 (defun bookmark-bmenu-show-filenames (&optional force)
@@ -1696,9 +1725,11 @@
   "If point is not on a bookmark line, move it to one.
 If before the first bookmark line, move to the first; if after the
 last full line, move to the last full line.  The return value is undefined."
-  (cond ((< (count-lines (point-min) (point)) bookmark-bmenu-header-height)
+  (cond ((and (not bookmark-bmenu-use-header-line)
+             (< (count-lines (point-min) (point))
+                 bookmark-bmenu-inline-header-height))
          (goto-char (point-min))
-         (forward-line bookmark-bmenu-header-height))
+         (forward-line bookmark-bmenu-inline-header-height))
         ((and (bolp) (eobp))
          (beginning-of-line 0))))