;;; help-macro.el --- Makes command line help such as help-for-help ;; Copyright (C) 1993, 1994, 1997 Free Software Foundation, Inc. ;; Author: Lynn Slater ;; Maintainer: FSF ;; Created: : Mon Oct 1 11:42:39 1990 ;; Adapted-By: ESR ;; This file is part of XEmacs. ;; XEmacs is free software; you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation; either version 2, or (at your option) ;; any later version. ;; XEmacs is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License ;; along with XEmacs; see the file COPYING. If not, write to the ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, ;; Boston, MA 02111-1307, USA. ;;; Commentary: ;;; Synched up with: FSF 20.2. ;; This file supplies the macro make-help-screen which constructs ;; single character dispatching with browsable help such as that provided ;; by help-for-help. This can be used to make many modes easier to use; for ;; example, the Gnu Emacs Empire Tool uses this for every "nested" mode map ;; called from the main mode map. ;; The name of this package was changed from help-screen.el to ;; help-macro.el in order to fit in a 14-character limit. ;;-> *********************** Example of use ********************************* ;;->(make-help-screen help-for-empire-redistribute-map ;;-> "c:civ m:mil p:population f:food ?" ;;-> "You have discovered the GEET redistribution commands ;;-> From here, you can use the following options: ;;-> ;;->c Redistribute civs from overfull sectors into connected underfull ones ;;-> The functions typically named by empire-ideal-civ-fcn control ;;-> based in part on empire-sector-civ-threshold ;;->m Redistribute military using levels given by empire-ideal-mil-fcn ;;->p Redistribute excess population to highways for max pop growth ;;-> Excess is any sector so full babies will not be born. ;;->f Even out food on highways to highway min and leave levels ;;-> This is good to pump max food to all warehouses/dist pts ;;-> ;;-> ;;->Use \\[help-for-empire-redistribute-map] for help on redistribution. ;;->Use \\[help-for-empire-extract-map] for help on data extraction. ;;->Please use \\[describe-key] to find out more about any of the other keys." ;;-> empire-shell-redistribute-map) ;;-> (define-key c-mp "\C-h" 'help-for-empire-redistribute-map) ;;-> (define-key c-mp help-character 'help-for-empire-redistribute-map) ;;; Code: (provide 'help-macro) ;;;###autoload (defcustom three-step-help t "*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." :type 'boolean :group 'help-appearance) (defmacro make-help-screen (fname help-line help-text helped-map) "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) (flet ((help-read-key (prompt) ;; This is in `flet' to avoid problems with autoloading. ;; #### The function is ill-conceived -- there should be ;; a way to do it without all the hassle! (let (events) (while (not (key-press-event-p (aref (setq events (read-key-sequence prompt)) 0))) ;; Mouse clicks are not part of the help feature, so ;; reexecute them in the standard environment. (mapc 'dispatch-event events)) (let ((key (nconc (event-modifiers (aref events 0)) (list (event-key (aref events 0)))))) ;; Make the HELP key translate to C-h. (when (lookup-key function-key-map key) (setq key (lookup-key function-key-map key))) (if (eq (length key) 1) (car key) key))))) (let ((line-prompt (substitute-command-keys ,help-line))) (when three-step-help (message "%s" line-prompt)) (let* ((help-screen (condition-case nil (documentation (quote ,fname)) (void-function "(alias for undefined function)") (error "(unexpected error from `documention')"))) ;; 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) (unwind-protect (progn (set-keymap-parents local-map (list ,helped-map)) (cond (three-step-help (let* ((overriding-local-map local-map)) (setq key (help-read-key nil)))) (t (setq key ??))) (when (or (equal key ??) (equal key (list help-char))) (setq config (current-window-configuration)) (switch-to-buffer-other-window "*Help*") (and (not (eq (window-frame (selected-window)) prev-frame)) (setq new-frame (window-frame (selected-window)) config nil)) (setq buffer-read-only nil) (erase-buffer) (insert help-screen) (help-mode) (goto-char (point-min)) (while (member key `((,help-char) ?? (control v) space ?\177 delete backspace (meta v))) (ignore-errors (cond ((member key '((control v) space)) (scroll-up)) ((member key '(?\177 delete (meta v) backspace)) (scroll-down)))) (let ((cursor-in-echo-area t) (overriding-local-map local-map)) (setq key (help-read-key (format "Type one of the options listed%s: " (if (pos-visible-in-window-p (point-max)) "" " or Space to scroll"))))))) ;; We don't need the prompt any more. (message nil) (let ((defn (lookup-key local-map key))) (cond (defn (when config (set-window-configuration config) (setq config nil)) (when new-frame (iconify-frame new-frame) (setq new-frame nil)) (call-interactively defn)) (t (ding))))) (and (get-buffer "*Help*") (bury-buffer "*Help*")) (and new-frame (iconify-frame new-frame)) (and config (set-window-configuration config)))))))) ;;; help-macro.el