1;;; help-macro.el --- makes command line help such as help-for-help 2 3;; Copyright (C) 1993, 1994, 2001, 2002, 2003, 2004, 4;; 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Lynn Slater <lrs@indetech.com> 7;; Maintainer: FSF 8;; Created: Mon Oct 1 11:42:39 1990 9;; Adapted-By: ESR 10 11;; This file is part of GNU Emacs. 12 13;; GNU Emacs is free software; you can redistribute it and/or modify 14;; it under the terms of the GNU General Public License as published by 15;; the Free Software Foundation; either version 2, or (at your option) 16;; any later version. 17 18;; GNU Emacs is distributed in the hope that it will be useful, 19;; but WITHOUT ANY WARRANTY; without even the implied warranty of 20;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21;; GNU General Public License for more details. 22 23;; You should have received a copy of the GNU General Public License 24;; along with GNU Emacs; see the file COPYING. If not, write to the 25;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 26;; Boston, MA 02110-1301, USA. 27 28;;; Commentary: 29 30;; This file supplies the macro make-help-screen which constructs 31;; single character dispatching with browsable help such as that provided 32;; by help-for-help. This can be used to make many modes easier to use; for 33;; example, the GNU Emacs Empire Tool uses this for every "nested" mode map 34;; called from the main mode map. 35 36;; The name of this package was changed from help-screen.el to 37;; help-macro.el in order to fit in a 14-character limit. 38 39;;-> *********************** Example of use ********************************* 40 41;;->(make-help-screen help-for-empire-redistribute-map 42;;-> "c:civ m:mil p:population f:food ?" 43;;-> "You have discovered the GEET redistribution commands 44;;-> From here, you can use the following options: 45;;-> 46;;->c Redistribute civs from overfull sectors into connected underfull ones 47;;-> The functions typically named by empire-ideal-civ-fcn control 48;;-> based in part on empire-sector-civ-threshold 49;;->m Redistribute military using levels given by empire-ideal-mil-fcn 50;;->p Redistribute excess population to highways for max pop growth 51;;-> Excess is any sector so full babies will not be born. 52;;->f Even out food on highways to highway min and leave levels 53;;-> This is good to pump max food to all warehouses/dist pts 54;;-> 55;;-> 56;;->Use \\[help-for-empire-redistribute-map] for help on redistribution. 57;;->Use \\[help-for-empire-extract-map] for help on data extraction. 58;;->Please use \\[describe-key] to find out more about any of the other keys." 59;;-> empire-shell-redistribute-map) 60 61;;-> (define-key c-mp "\C-h" 'help-for-empire-redistribute-map) 62;;-> (define-key c-mp help-character 'help-for-empire-redistribute-map) 63 64;;; Change Log: 65;; 66;; 22-Jan-1991 Lynn Slater x2048 67;; Last Modified: Mon Oct 1 11:43:52 1990 #3 (Lynn Slater) 68;; documented better 69 70;;; Code: 71 72(require 'backquote) 73 74;;;###autoload 75(defcustom three-step-help nil 76 "*Non-nil means give more info about Help command in three steps. 77The three steps are simple prompt, prompt with all options, 78and window listing and describing the options. 79A value of nil means skip the middle step, so that 80\\[help-command] \\[help-command] gives the window that lists the options." 81 :type 'boolean 82 :group 'help) 83 84(defmacro make-help-screen (fname help-line help-text helped-map) 85 "Construct help-menu function name FNAME. 86When invoked, FNAME shows HELP-LINE and reads a command using HELPED-MAP. 87If the command is the help character, FNAME displays HELP-TEXT 88and continues trying to read a command using HELPED-MAP. 89If HELP-TEXT contains the sequence `%THIS-KEY%', that is replaced 90with the key sequence that invoked FNAME. 91When FNAME finally does get a command, it executes that command 92and then returns." 93 (let ((doc-fn (intern (concat (symbol-name fname) "-doc")))) 94 `(progn 95 (defun ,doc-fn () ,help-text) 96 (defun ,fname () 97 "Help command." 98 (interactive) 99 (let ((line-prompt 100 (substitute-command-keys ,help-line))) 101 (if three-step-help 102 (message "%s" line-prompt)) 103 (let* ((help-screen (documentation (quote ,doc-fn))) 104 ;; We bind overriding-local-map for very small 105 ;; sections, *excluding* where we switch buffers 106 ;; and where we execute the chosen help command. 107 (local-map (make-sparse-keymap)) 108 (minor-mode-map-alist nil) 109 (prev-frame (selected-frame)) 110 config new-frame key char) 111 (if (string-match "%THIS-KEY%" help-screen) 112 (setq help-screen 113 (replace-match (key-description (substring (this-command-keys) 0 -1)) 114 t t help-screen))) 115 (unwind-protect 116 (progn 117 (setcdr local-map ,helped-map) 118 (define-key local-map [t] 'undefined) 119 ;; Make the scroll bar keep working normally. 120 (define-key local-map [vertical-scroll-bar] 121 (lookup-key global-map [vertical-scroll-bar])) 122 (if three-step-help 123 (progn 124 (setq key (let ((overriding-local-map local-map)) 125 (read-key-sequence nil))) 126 ;; Make the HELP key translate to C-h. 127 (if (lookup-key function-key-map key) 128 (setq key (lookup-key function-key-map key))) 129 (setq char (aref key 0))) 130 (setq char ??)) 131 (if (or (eq char ??) (eq char help-char) 132 (memq char help-event-list)) 133 (progn 134 (setq config (current-window-configuration)) 135 (switch-to-buffer-other-window "*Help*") 136 (and (fboundp 'make-frame) 137 (not (eq (window-frame (selected-window)) 138 prev-frame)) 139 (setq new-frame (window-frame (selected-window)) 140 config nil)) 141 (setq buffer-read-only nil) 142 (let ((inhibit-read-only t)) 143 (erase-buffer) 144 (insert help-screen)) 145 (help-mode) 146 (goto-char (point-min)) 147 (while (or (memq char (append help-event-list 148 (cons help-char '(?? ?\C-v ?\s ?\177 delete backspace vertical-scroll-bar ?\M-v)))) 149 (eq (car-safe char) 'switch-frame) 150 (equal key "\M-v")) 151 (condition-case nil 152 (progn 153 (if (eq (car-safe char) 'switch-frame) 154 (handle-switch-frame char)) 155 (if (memq char '(?\C-v ?\s)) 156 (scroll-up)) 157 (if (or (memq char '(?\177 ?\M-v 158 delete backspace)) 159 (equal key "\M-v")) 160 (scroll-down))) 161 (error nil)) 162 (let ((cursor-in-echo-area t) 163 (overriding-local-map local-map)) 164 (setq key (read-key-sequence 165 (format "Type one of the options listed%s: " 166 (if (pos-visible-in-window-p 167 (point-max)) 168 "" ", or SPACE or DEL to scroll"))) 169 char (aref key 0))) 170 171 ;; If this is a scroll bar command, just run it. 172 (when (eq char 'vertical-scroll-bar) 173 (command-execute (lookup-key local-map key) nil key))))) 174 ;; We don't need the prompt any more. 175 (message "") 176 ;; Mouse clicks are not part of the help feature, 177 ;; so reexecute them in the standard environment. 178 (if (listp char) 179 (setq unread-command-events 180 (cons char unread-command-events) 181 config nil) 182 (let ((defn (lookup-key local-map key))) 183 (if defn 184 (progn 185 (if config 186 (progn 187 (set-window-configuration config) 188 (setq config nil))) 189 (if new-frame 190 (progn (iconify-frame new-frame) 191 (setq new-frame nil))) 192 (call-interactively defn)) 193 (ding))))) 194 (if new-frame (iconify-frame new-frame)) 195 (if config 196 (set-window-configuration config)))))) 197 ))) 198 199(provide 'help-macro) 200 201;;; arch-tag: 59fee949-1686-485a-8a05-83418073e257 202;;; help-macro.el ends here 203