;;; help-macro.el --- Makes command line help such as help-for-help
-;; Copyright (C) 1993 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.
;; Author: Lynn Slater <lrs@indetech.com>
;; Created: : Mon Oct 1 11:42:39 1990
;; Adapted-By: ESR
-;; Last Modified By: Lynn Slater x2048
-;; Last Modified On: Mon Sep 23 14:40:19 1991
;; This file is part of GNU Emacs.
;;; Code:
-(provide 'help-screen)
+(provide 'help-macro)
(require 'backquote)
+;;;###autoload
+(defvar three-step-help nil
+ "*Non-nil means give more info about Help command in three steps.
+The three steps are simple prompt, prompt with all options,
+and window listing and describing the options.
+A value of nil means skip the middle step, so that
+\\[help-command] \\[help-command] gives the window that lists the options.")
+
(defmacro make-help-screen (fname help-line help-text helped-map)
- "Constructs function FNAME that when invoked shows HELP-LINE and if a help
-character is requested, shows HELP-TEXT. The user is prompted for a character
-from the HELPED-MAP and the corresponding interactive function is executed."
+ "Construct help-menu function name FNAME.
+When invoked, FNAME shows HELP-LINE and reads a command using HELPED-MAP.
+If the command is the help character, FNAME displays HELP-TEXT
+and continues trying to read a command using HELPED-MAP.
+When FNAME finally does get a command, it executes that command
+and then returns."
(` (defun (, fname) ()
(, help-text)
(interactive)
(let ((line-prompt
(substitute-command-keys (, help-line))))
- (message line-prompt)
- (let ((char (read-char)))
- (if (or (= char ??) (= char help-char))
- (save-window-excursion
- (switch-to-buffer-other-window "*Help*")
- (erase-buffer)
- (insert (documentation (quote (, fname))))
- (goto-char (point-min))
- (while (memq char (cons help-char '(?? ?\C-v ?\ ?\177 ?\M-v)))
- (if (memq char '(?\C-v ?\ ))
- (scroll-up))
- (if (memq char '(?\177 ?\M-v))
- (scroll-down))
- (message "%s%s: "
- line-prompt
- (if (pos-visible-in-window-p (point-max))
- "" " or Space to scroll"))
- (let ((cursor-in-echo-area t))
- (setq char (read-char))))))
- (let ((defn (cdr (assq (downcase char) (, helped-map)))))
- (if defn
- (if (keymapp defn)
- (error "sorry, this command cannot be run from the help screen. Start over.")
- (call-interactively defn))
- (ding))))))
+ (if three-step-help
+ (message line-prompt))
+ (let* ((help-screen (documentation (quote (, fname))))
+ ;; We bind overriding-local-map for very small
+ ;; sections, *excluding* where we switch buffers
+ ;; and where we execute the chosen help command.
+ (local-map (make-sparse-keymap))
+ (minor-mode-map-alist nil)
+ (prev-frame (selected-frame))
+ config new-frame key char)
+ (unwind-protect
+ (progn
+ (setcdr local-map (, helped-map))
+ (define-key local-map [t] 'undefined)
+ (if three-step-help
+ (progn
+ (setq key (let ((overriding-local-map local-map))
+ (read-key-sequence nil)))
+ ;; Make the HELP key translate to C-h.
+ (if (lookup-key function-key-map key)
+ (setq key (lookup-key function-key-map key)))
+ (setq char (aref key 0)))
+ (setq char ??))
+ (if (or (eq char ??) (eq char help-char)
+ (memq char help-event-list))
+ (progn
+ (setq config (current-window-configuration))
+ (switch-to-buffer-other-window "*Help*")
+ (and (fboundp 'make-frame)
+ (not (eq (window-frame (selected-window))
+ prev-frame))
+ (setq new-frame (window-frame (selected-window))
+ config nil))
+ (erase-buffer)
+ (insert help-screen)
+ (help-mode)
+ (goto-char (point-min))
+ (while (or (memq char (append help-event-list
+ (cons help-char '(?? ?\C-v ?\ ?\177 delete backspace ?\M-v))))
+ (eq (car-safe char) 'switch-frame)
+ (equal key "\M-v"))
+ (condition-case nil
+ (progn
+ (if (eq (car-safe char) 'switch-frame)
+ (handle-switch-frame char))
+ (if (memq char '(?\C-v ?\ ))
+ (scroll-up))
+ (if (or (memq char '(?\177 ?\M-v
+ delete backspace))
+ (equal key "\M-v"))
+ (scroll-down)))
+ (error nil))
+ (let ((cursor-in-echo-area t)
+ (overriding-local-map local-map))
+ (setq key (read-key-sequence
+ (format "Type one of the options listed%s: "
+ (if (pos-visible-in-window-p
+ (point-max))
+ "" " or Space to scroll")))
+ char (aref key 0))))))
+ ;; Mouse clicks are not part of the help feature,
+ ;; so reexecute them in the standard environment.
+ (if (listp char)
+ (setq unread-command-events
+ (cons char unread-command-events)
+ config nil)
+ (let ((defn (lookup-key local-map key)))
+ (if defn
+ (progn
+ (if config
+ (progn
+ (set-window-configuration config)
+ (setq config nil)))
+ (if new-frame
+ (progn (iconify-frame new-frame)
+ (setq new-frame nil)))
+ (call-interactively defn))
+ (ding)))))
+ (if new-frame (iconify-frame new-frame))
+ (if config
+ (set-window-configuration config))))))
))
;;; help-macro.el