-;;; ehelp.el --- bindings for electric-help mode
+;;; ehelp.el --- bindings for electric-help mode -*- lexical-binding: t -*-
-;; Copyright (C) 1986, 1995, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-;; 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+;; Copyright (C) 1986, 1995, 2000-2016 Free Software Foundation, Inc.
;; Author: Richard Mlynarik
;; (according to ack.texi and authors.el)
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
;; Keywords: help, extensions
;; This file is part of GNU Emacs.
;;; Commentary:
;; This package provides a pre-packaged `Electric Help Mode' for
-;; browsing on-line help screens. There is one entry point,
+;; browsing Emacs help screens. There is one entry point,
;; `with-electric-help'; all you have to give it is a no-argument
;; function that generates the actual text of the help into the current
;; buffer.
(defvar electric-help-map
(let ((map (make-keymap)))
+ ;; FIXME fragile. Should derive from help-mode-map in a smarter way.
+ (set-keymap-parent map button-buffer-map)
;; allow all non-self-inserting keys - search, scroll, etc, but
;; let M-x and C-x exit ehelp mode and retain buffer:
(suppress-keymap map)
(define-key map (char-to-string help-char) 'electric-help-help)
(define-key map "?" 'electric-help-help)
(define-key map " " 'scroll-up)
+ (define-key map [?\S-\ ] 'scroll-down)
(define-key map "\^?" 'scroll-down)
(define-key map "." 'beginning-of-buffer)
(define-key map "<" 'beginning-of-buffer)
map)
"Keymap defining commands available in `electric-help-mode'.")
+(defvar electric-help-orig-major-mode nil)
+(make-variable-buffer-local 'electric-help-orig-major-mode)
+
(defun electric-help-mode ()
"`with-electric-help' temporarily places its buffer in this mode.
-\(On exit from `with-electric-help', the buffer is put in default `major-mode'.)"
+\(On exit from `with-electric-help', the original `major-mode' is restored.)"
(setq buffer-read-only t)
+ (setq electric-help-orig-major-mode major-mode)
(setq mode-name "Help")
- (setq major-mode 'help)
+ (setq major-mode 'help-mode)
(setq mode-line-buffer-identification '(" Help: %b"))
(use-local-map electric-help-map)
(add-hook 'mouse-leave-buffer-hook 'electric-help-retain)
When the user exits (with `electric-help-exit', or otherwise), the help
buffer's window disappears (i.e., we use `save-window-excursion'), and
-BUFFER is put into default `major-mode' (or `fundamental-mode')."
+BUFFER is put back into its original major mode."
(setq buffer (get-buffer-create (or buffer "*Help*")))
(let ((one (one-window-p t))
(config (current-window-configuration))
(unwind-protect
(save-excursion
(when one
- (goto-char (window-start (selected-window))))
+ (goto-char (window-start)))
(let ((pop-up-windows t))
(pop-to-buffer buffer))
(with-current-buffer buffer
(set-buffer buffer)
(setq buffer-read-only nil)
+ ;; Restore the original major mode saved by `electric-help-mode'.
;; We should really get a usable *Help* buffer when retaining
;; the electric one with `r'. The problem is that a simple
- ;; call to help-mode won't cut it; at least RET is bound wrong
- ;; afterwards. It's also not clear that `help-mode' is always
- ;; the right thing, maybe we should add an optional parameter.
+ ;; call to `help-mode' won't cut it; e.g. RET is bound wrong
+ ;; afterwards (`View-scroll-line-forward' instead of `help-follow').
+ ;; That's because Help mode should be set with `with-help-window'
+ ;; instead of the direct call to `help-mode'. But at least
+ ;; RET works correctly on links after using `help-mode'.
+ ;; This is satisfactory enough.
(condition-case ()
- (funcall (or (default-value 'major-mode) 'fundamental-mode))
+ (funcall (or electric-help-orig-major-mode 'fundamental-mode))
(error nil))
(set-window-configuration config)
(replace-buffer-in-windows buffer)
;; must do this outside of save-window-excursion
(bury-buffer buffer))
- (eval electric-help-form-to-execute))))
+ (if (functionp electric-help-form-to-execute)
+ (funcall electric-help-form-to-execute)
+ (eval electric-help-form-to-execute)))))
(defun electric-help-command-loop ()
(catch 'exit
(if (pos-visible-in-window-p (point-max))
(progn (message "%s" (substitute-command-keys "<<< Press Space to bury the help buffer, Press \\[electric-help-retain] to retain it >>>"))
- (if (equal (setq unread-command-events (list (read-event)))
- '(?\s))
- (progn (setq unread-command-events nil)
- (throw 'exit t)))))
+ (let ((ev (read-event)))
+ (if (equal ev ?\s)
+ (throw 'exit t)
+ (push ev unread-command-events)))))
(let (up down both neither
(standard (and (eq (key-binding " " nil t)
'scroll-up)
;; This is to be bound to M-x in ehelp mode. Retains ehelp buffer and then
;; continues with execute-extended-command.
-(defun electric-help-execute-extended (prefixarg)
+(defun electric-help-execute-extended (_prefixarg)
(interactive "p")
- (setq electric-help-form-to-execute '(execute-extended-command nil))
+ (setq electric-help-form-to-execute
+ (lambda () (execute-extended-command nil)))
(electric-help-retain))
;; This is to be buond to C-x in ehelp mode. Retains ehelp buffer and then
;; continues with ctrl-x prefix.
-(defun electric-help-ctrl-x-prefix (prefixarg)
+(defun electric-help-ctrl-x-prefix (_prefixarg)
(interactive "p")
- (setq electric-help-form-to-execute '(progn (message nil) (setq unread-command-char ?\C-x)))
+ (setq electric-help-form-to-execute
+ (lambda ()
+ (message nil)
+ (setq unread-command-events
+ (append unread-command-events '(?\C-x)))))
(electric-help-retain))
\f
(provide 'ehelp)
-;; arch-tag: e0e3037f-42c0-433e-ba18-322c5d951f46
;;; ehelp.el ends here