Re: [drew.adams@oracle.com: links in Help buffer aren't alwayscorrect]

[Kevin Rodgers <ihs_4664@yahoo.com>]

Drew Adams wrote:
 > There may not be a `describe-frame-parameter' function, but the
 > `help-make-xrefs' code could use a preceding "frame parameter" to link to
 > the Info section describing the `buffer-list' parameter. Or, at the very
 > least, it could test for preceding "frame parameter" in order to do 
nothing
 > (add no link) if it is present.

Here's a start, cobbled together from describe-variable and your idea of
linking to the Info node:

(defun describe-frame-parameter (parameter &optional frame)
   "Display the full documentation of frame PARAMETER (a symbol) in FRAME.
If FRAME is nil, describe the selected frame's parameter value."
   (interactive
    (let* ((enable-recursive-minibuffers t)
           (default-param (symbol-at-point))
           (param-alist (frame-parameters nil))
           (param-name
            (completing-read (if (assq default-param param-alist)
                                 (format "Describe parameter (default %s): "
                                         default-param)
                               "Describe parameter: ")
                             obarray
                             (lambda (p) (assq p param-alist))
                             t nil nil
                             (if default-param (symbol-name 
default-param)))))
      (list (if (equal param-name "")
                default-param
              (intern param-name)))))
   (if (null frame)
       (setq frame (selected-frame)))
   (if (null parameter)
       (message "You did not specify a frame parameter")
     (with-output-to-temp-buffer "*Help*"
       (prin1 parameter)
       (princ "'s value is ")
       (terpri)
       (let ((param-value (frame-parameter frame parameter)))
         (with-current-buffer standard-output
           (let ((from (point)))
             (pp param-value)
             ;; (help-xref-on-pp from (point))
             (if (< (point) (+ from 20))
                 (save-excursion
                   (goto-char from)
                   (delete-char -1))))))
       (terpri)
       (terpri)
       (princ "Documentation (see Info node `(elisp)Window Frame 
Parameters'):")
       (terpri)
       (save-excursion
         (save-window-excursion
           (Info-goto-node "(elisp)Window Frame Parameters")
           (princ (buffer-substring
                   (re-search-forward (concat "^`" (symbol-name 
parameter) "'"))
                   (1- (or (re-search-forward "^`" nil t) 
(point-max))))))))))

-- 
Kevin Rodgers