1
0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-11-24 07:20:37 +00:00
emacs/lisp/help-macro.el
1993-04-03 23:28:03 +00:00

109 lines
4.1 KiB
EmacsLisp

;;; help-screen.el --- Makes command line help such as help-for-help
;; Copyright (C) 1993 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.
;; GNU Emacs 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.
;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
;;; Commentary:
;;
;; 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.
;;-> *********************** 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)
;;; Change Log:
;;
;; 22-Jan-1991 Lynn Slater x2048
;; Last Modified: Mon Oct 1 11:43:52 1990 #3 (Lynn Slater)
;; documented better
;;; Code:
(provide 'help-screen)
(require 'backquote)
(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."
(` (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))))))
))
;;; help-screen.el