+++ /dev/null
-;;; helper.el --- utility help package supporting help in electric modes -*- lexical-binding: t; -*-
-
-;; Copyright (C) 1985-2024 Free Software Foundation, Inc.
-
-;; Author: K. Shane Hartman
-;; Maintainer: emacs-devel@gnu.org
-;; Keywords: help
-;; Package: emacs
-
-;; 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 3 of the License, 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. If not, see <https://www.gnu.org/licenses/>.
-
-;;; Commentary:
-
-;;; Code:
-
-;; hey, here's a helping hand.
-
-;; Bind this to a string for <blank> in "... Other keys <blank>".
-;; Helper-help uses this to construct help string when scrolling.
-;; Defaults to "return"
-(defvar Helper-return-blurb nil)
-
-;; Keymap implementation doesn't work too well for non-standard loops.
-;; But define it anyway for those who can use it. Non-standard loops
-;; will probably have to use Helper-help. You can't autoload the
-;; keymap either.
-
-
-(defvar-keymap Helper-help-map
- "m" #'Helper-describe-mode
- "b" #'Helper-describe-bindings
- "c" #'Helper-describe-key-briefly
- "k" #'Helper-describe-key
- ;;"f" #'Helper-describe-function
- ;;"v" #'Helper-describe-variable
- "?" #'Helper-help-options
- (key-description (char-to-string help-char)) #'Helper-help-options)
-(fset 'Helper-help-map Helper-help-map)
-
-(defun Helper-help-scroller ()
- (let ((blurb (or (and (boundp 'Helper-return-blurb)
- Helper-return-blurb)
- "return")))
- (save-window-excursion
- (goto-char (window-start))
- (if (get-buffer-window "*Help*")
- (pop-to-buffer "*Help*")
- (switch-to-buffer "*Help*"))
- (goto-char (point-min))
- (let ((continue t) state)
- (while continue
- (setq state (+ (* 2 (if (pos-visible-in-window-p (point-max)) 1 0))
- (if (pos-visible-in-window-p (point-min)) 1 0)))
- (message
- (nth state
- (mapcar
- #'substitute-command-keys
- '("\\`SPC' forward, \\`DEL' back. Other keys %s"
- "\\`SPC' scrolls forward. Other keys %s"
- "\\`DEL' scrolls back. Other keys %s"
- "Type anything to %s")))
- blurb)
- (setq continue (read-event))
- (cond ((and (memq continue '(?\s ?\C-v)) (< state 2))
- (scroll-up))
- ((eq continue ?\C-l)
- (recenter))
- ((and (or (eq continue 'backspace)
- (eq continue ?\177))
- (zerop (% state 2)))
- (scroll-down))
- (t (setq continue nil))))))))
-
-(defun Helper-help-options ()
- "Describe help options."
- (interactive)
- (message (substitute-command-keys
- "\\`c' (key briefly), \\`m' (mode), \\`k' (key), \\`b' (bindings)"))
- (sit-for 4))
-
-(defun Helper-describe-key-briefly (key)
- "Briefly describe binding of KEY."
- (interactive "kDescribe key briefly: ")
- (describe-key-briefly key)
- (sit-for 4))
-
-(defun Helper-describe-key (key)
- "Describe binding of KEY."
- (interactive "kDescribe key: ")
- (save-window-excursion (describe-key key))
- (Helper-help-scroller))
-
-(defun Helper-describe-function ()
- "Describe a function. Name read interactively."
- (interactive)
- (save-window-excursion (call-interactively 'describe-function))
- (Helper-help-scroller))
-
-(defun Helper-describe-variable ()
- "Describe a variable. Name read interactively."
- (interactive)
- (save-window-excursion (call-interactively 'describe-variable))
- (Helper-help-scroller))
-
-(defun Helper-describe-mode ()
- "Describe the current mode."
- (interactive)
- (let ((name (format-mode-line mode-name))
- (documentation (documentation major-mode)))
- (with-current-buffer (get-buffer-create "*Help*")
- (setq buffer-read-only nil)
- (erase-buffer)
- (insert name " Mode\n" documentation)
- (help-mode)))
- (Helper-help-scroller))
-
-;;;###autoload
-(defun Helper-describe-bindings ()
- "Describe local key bindings of current mode."
- (interactive)
- (save-window-excursion (describe-bindings))
- (Helper-help-scroller))
-
-;;;###autoload
-(defun Helper-help ()
- "Provide help for current mode."
- (interactive)
- (let ((continue t) c)
- (while continue
- (message (substitute-command-keys
- "Help (Type \\`?' for further options)"))
- (setq c (read-key-sequence nil))
- (setq c (lookup-key Helper-help-map c))
- (cond ((eq c 'Helper-help-options)
- (Helper-help-options))
- ((commandp c)
- (call-interactively c)
- (setq continue nil))
- (t
- (ding)
- (setq continue nil))))))
-
-(provide 'helper)
-
-;;; helper.el ends here