From: Tim Vaughan Date: Mon, 24 Jun 2019 21:21:07 +0000 (+0200) Subject: Merge branch 'master' into manual X-Git-Tag: v1.4.4~6 X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=elpher.git;a=commitdiff_plain;h=e709905f4a3019372b2365e97019d7fd8741b125;hp=4a7a614530e7d74318b96de4c210ea9fac9df7bc Merge branch 'master' into manual --- diff --git a/NOTES.org b/NOTES.org index a7454cd..afd3bfb 100644 --- a/NOTES.org +++ b/NOTES.org @@ -2,6 +2,29 @@ * Planned improvements +** TODO Allow multiple elpher buffers + + Shouldn't be too hard, just need elpher-current-node to be +buffer-local and allow various buffer-switching procedures to +do something sensible. + +** TODO Turn on lexical scoping + + A branch exists for this, but there are some compilation kinks +to iron out. + +** TODO Remove "redraw" command +This is only necessary for returning from displaying the raw +server response. If I can provide a better way of doing that +then we can get rid of redraw entirely. + +** TODO Replace support for user-specified starting pages +This used to be available, but was removed during a refactor. + +* Current issues + +* Completed improvements + ** DONE Implement support for telnet entries Similar to http entries, telnet entries will be handled by code @@ -33,18 +56,10 @@ functions. I always update node.parent unless parent is already an ancestor of node?) -** TODO Allow multiple elpher buffers + +** DONE Support character encoding diversity - Shouldn't be too hard, just need elpher-current-node to be -buffer-local and allow various buffer-switching procedures to -do something sensible. - -** TODO Turn on lexical scoping - - A branch exists for this, but there are some compilation kinks -to iron out. - -* Current issues +* Old issues ** DONE Org mode faces are not present in recent emacs versions Even 26.1 doesn't seem to have these. This means that, for many diff --git a/elpher.el b/elpher.el index 340f9df..5f0ef3a 100644 --- a/elpher.el +++ b/elpher.el @@ -26,10 +26,10 @@ ;;; Commentary: -;; Elpher aims to provide a practical gopher client for GNU Emacs. -;; It supports: +;; Elpher aims to provide a practical and friendly gopher client +;; for GNU Emacs. It supports: -;; - intuitive keyboard and mouse-driven interface, +;; - an intuitive keyboard and mouse-driven interface, ;; - caching of visited sites (both content and cursor position), ;; - pleasant and configurable colouring of Gopher directories, ;; - direct visualisation of image files, @@ -45,6 +45,9 @@ ;; Faces, caching and other options can be configured via ;; the Elpher customization group in Applications. +;; Elpher is under active development, and any suggestions for +;; improvements are welcome! + ;;; Code: (provide 'elpher) @@ -1071,7 +1074,7 @@ host, selector and port." (error "No link selected")))) (defun elpher-bookmarks () - "Visit bookmarks." + "Visit bookmarks page." (interactive) (switch-to-buffer "*elpher*") (elpher-visit-node @@ -1207,7 +1210,11 @@ host, selector and port." "Keymap for gopher client.") (define-derived-mode elpher-mode special-mode "elpher" - "Major mode for elpher, an elisp gopher client.") + "Major mode for elpher, an elisp gopher client. + +This mode is automatically enabled by the interactive +functions which initialize the gopher client, namely +`elpher', `elpher-go' and `elpher-bookmarks'.") (when (fboundp 'evil-set-initial-state) (evil-set-initial-state 'elpher-mode 'motion)) diff --git a/elpher.texi b/elpher.texi new file mode 100644 index 0000000..570c9fa --- /dev/null +++ b/elpher.texi @@ -0,0 +1,458 @@ +\input texinfo @c -*-texinfo-*- +@c %**start of header +@setfilename elpher.info +@settitle Elpher Manual v1.0.0 +@c %**end of header + +@copying +This manual documents Elpher, a gopher client for Emacs. + +Copyright @copyright{} 2019 Tim Vaughan + +@quotation +The source and documentation of Elpher 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, or (at your option) any later version. + +Elpher is distributed in the hope that it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNElpher FOR A PARTICULAR PURPOSE. See the GNU General Public License in +the file COPYING in the same directory as this file for more details. +@end quotation +@end copying + +@titlepage +@title Elpher Gopher Client Manual +@author Tim Vaughan + +@page +@vskip 0pt plus 1filll +@insertcopying +@end titlepage + +@contents + +@ifnottex +@node Top, Introduction, (dir), (dir) +@top Elpher + +@insertcopying +@end ifnottex + +@menu +* Introduction:: Elpher Overview: what's this all about? +* Installation:: Installing Elpher +* Quick Start:: Get up and running quickly +* Navigation:: Fundamentals of Elpher navigation +* Bookmarks:: How to record and visit bookmarks +* Character encodings:: How Elpher handles different character encodings +* Encrypted connections:: How and when TLS is enabled +* Customization:: How to customize various aspects of Elpher +* Index:: +@end menu + +@node Introduction, Installation, Top, Top +@chapter Introduction + +Elpher aims to be a capable and practical gopher client for Emacs. Its +focus is on easy keyboard-driven navigation based on sensible default +bindings (with out-of-the-box support for Evil). It is intended to be +robust and behave in non-surprising ways at all times. Additionally, +Elpher provides the following bells and whistles: + +@itemize +@item +an easily navigable history, sporting caching of visited pages (both +content and cursor position), + +@item +auto-completing menu item navigation, + +@item +followable web and gopher links in plain text, + +@item +direct visualization of image files where supported (no writing to +disk), and + +@item +a simple bookmark management system. +@end itemize + +Elpher is still under active development. Although we try very hard to +ensure that releases are bug-free, this cannot be guaranteed. However, +this also means that any usability features that you feel are missing +can likely by incoroporated quickly, so please get in touch if you +have some ideas. + +@node Installation, Quick Start, Introduction, Top +@chapter Installation + +Elpher is available from the MELPA package repository. If you have +never installed packages from this repository before, you'll need +to follow the instructions at @url{https://melpa.org/#/getting-started}. + +@noindent To install Elpher, enter the following: + +@example +@kbd{M-x package-install @key{RET} elpher @key{RET}} +@end example + +@noindent To uninstall, use + +@example +@kbd{M-x package-delete @key{RET} elpher @key{RET}}. +@end example + +While not recommended, it is also possible to install Elpher directly by +downloading the file @file{elpher.el} from +@url{https://github.com/tgvaughan/elpher}, adding it to a directory in +your @code{load-path}, and then adding + +@example +(require 'elpher) +@end example + +@noindent to your Emacs initialization file. + +@node Quick Start, Navigation, Installation, Top +@chapter Quick Start + +Before diving into the minutiae of the different commands available, +we will quickly describe how to get up and running with Elpher. + +Once installed, you can launch Elpher using + +@example +@kbd{M-x elpher @key{RET}} +@end example + +@noindent This will switch to the *Elpher* buffer and display a start +page, with information on each of the default keyboard bindings. + +From here you can move point between links (which may be menu items or +inline URLs in text files) by using @key{TAB} and @kbd{S-@key{TAB}}, +as in Info. You can also jump directly to a menu item using @key{m}, or +use the standard Emacs or Evil motion and search commands to find your +way around. To open a link, press @key{RET}. (Where a mouse is +available, Clicking on a link with the mouse cursor has the same +effect.) + +To return to the page you just followed the link from, press @key{u}. + +Elpher caches (for the duration of an Emacs session) both page contents +and the position of point on each of the pages (gopher menus, query +results, or text pages) you visit, restoring these when you next visit +the same page. Thus, pressing @key{u} displays the previous page in +exactly the same state as when you left, meaning that you can quickly +and visually explore the different documents in a menu without having to +wait for anything to reload. + +Of course, sometimes you'll @emph{want} to reload the current page +rather than stick with the cached version. To do this use @key{R}. +(This is particularly useful for search query results, where this +allows you to perform a different search.) + +That's more-or-less it. Elpher supports a number of other features, such +as bookmarking, support for different coding schemes and TLS encryption, +and a variety of customization options, all of which are explained in +the rest of this document. However the emphasis is on keeping the basic +navigation experience as intuitive and responsive as possible. + +@node Navigation, Bookmarks, Quick Start, Top +@chapter Navigation +by +Throughout this manual, we use the word ``page'' to refer to any +visualization of a response from a gopher server, be it a +menu/directory, query result, text file or image. We use + +Elpher's navigation interface is inspired by the Emacs Info mode. +Movement within a page is essentially the same as moving +around any other text file in Emacs, but with special keys +for quickly jumping between menu items and URLs in text files. +Movement between pages is facilitated by a simple linear history +coupled with caching of pages and cursor position. + +@menu +* Within-page navigation:: Moving about within a page +* Between-page navigation:: Commands for moving between pages +* History and Caching:: Explanation of how Elpher represents history +@end menu + + +@node Within-page navigation, Between-page navigation, Navigation, Navigation +@section Within-page navigation + +To move about within a page, you should be able use the same keys you usually +use to browse files in Emacs. This is even true when Evil mode is +enabled. Paragraph hopping, searching etc should work as usual. + +In addition, the following commands are provided for quickly moving between +links and menu items. + +@table @asis +@item @key{TAB} (@code{elpher-next-link}) +Move to the next link or menu item in the file. + +@item @kbd{Shift-@key{TAB}}/@key{backtab} (@code{elpher-prev-link}) +Move to the previous link or menu item in the file. + +@item @kbd{m} (@code{elpher-jump}) +Jump directly to a link within a file by specifying its display string +or link text. (Unlike the previous two commands, this immediately opens +the selected link. +@end table + +The following commands can be used to retrieve information about the +current page, or the address of the link at point: + +@table @asis +@item @kbd{i} (@code{elpher-info-link}) +Display host, port and selector information for the link at point. + +@item @kbd{I} (@code{elpher-info-current}) +Display host, port and selector information for the current page. + +@item @kbd{c} (@code{elpher-copy-link-url}) +Add URL representing address of link at point to the kill-ring and the +system clipboard (if available). + +@item @kbd{C} (@code{elpher-copy-current-url}) +Add URL representing address of the current page to the kill-ring and +the system clipboard (if available). + +@item @kbd{d} (@code{elpher-download}) +Download link at point and save the result as a file. The minibuffer +will prompt for the name of the file to write, with the default name being +the display string (if available) associated with the link. + +@item @kbd{D} (@code{elpher-download-current}) +This is similar to @code{elpher-downlowd}, but instead applies to the +current page rather than a link. + +@item @kbd{w} (@code{elpher-view-raw}) +This displays the raw server response for the current page. While not +useful for general browsing, it is useful for debugging incorrect rendering +or out-of-spec server responses. +@end table + +@node Between-page navigation, History and Caching, Within-page navigation, Navigation +@section Between-page navigation + +Moving to a different page can be accomplished in several ways, +described by the following command: + +@table @asis +@item @kbd{RET}, @kbd{mouse-1} (@code{elpher-follow-link}) +Follow the menu item or link at point (or selected with the mouse). + +Exactly what is meant by ``follow'' depends on the kind of item selected: + +@itemize +@item +For text or menu type items or links, the curent page text is replaced +by the text of this item. Unless the customization variable +@code{elpher-use-header} (@pxref{Customization}) is +@code{nil}, the display string of the link is displayed in the buffer header. +Links to images behave similarly on Emacs systems supporting the display of +bitmap graphics, however their content is not cached in memory by default. + +@item +When followed, links to search/query items (type 7) prompt for input in +the minibuffer then display the results in the same way as for text and menu +items. + +@item +Following links to binary files (and image files on unsupported systems) +causes Elpher to prompt for a filename in which to save the content. + +@item +Following links of type `h' with a selector having the `URL:' prefix, or +non-gopher URLs in text files, will result in Elpher using an external +programme to open the URL. This will be either the default system browser +or, if the @code{elpher-open-urls-with-eww} customization variable is non-nil, +Emacs' own EWW browser. (See @pxref{Customization}.) + +@end itemize + +Once a text, menu or query response page has been displayed, its contents are +cached for the duration of the Emacs session. + +@item @kbd{g} (@code{elpher-go}) +Open a particular page by specifying either its URL or directly entering +a host, port and selector. + +Note that if a non-gopher protocol is used in the URL the result will be +the same as following a URL link of the same type from a gopher menu. + +@item @kbd{O} (@code{elpher-root-dir}) +Open the root page (empty selector) on the current host. + +@item @kbd{u} (@code{elpher-back}) +Return to the previous page, where ``previous'' means the page where the +page which was displayed immediately before the current page. +@end table + + +@node History and Caching, , Between-page navigation, Navigation +@section History and Caching + +The history and caching strategy in Elpher is extremely simple, but +may be confusing without a good mental model of how it works. That +is what this section attempts to provide. + +Essentially, @strong{every} time you navigate to a new page, either +by clicking or pressing @key{RET} on a link, using @key{g} to jump +to a new page by its address, or using @key{O} to open the root selector, +the following two things occur: + +@enumerate +@item +the cursor position and content for the original page are recorded in an +in-memory cache, and + +@item +the original page is set as the ``parent'' of the new page. +@end enumerate + +The only way to return to pages in this history is by using @key{u}, +which returns to the previous of the current page. +@footnote{The addition of the new page to the history happens even if +the new page is one that has been seen before. This is mostly the +desired behaviour. However, opening an explicit ``back'' link provided +by a gopher menu will also add a new entry to the history. Unless you +haven't yet visited that menu, it's therefore better to use @key{u} to +go back in this case.} + +One aspect that may seem peculiar is that Elpher lacks a corresponding ``next'' or +``forward'' command. However, since Elpher caches the position of point, +this will be automatically positioned on the link that was most recently followed +from a given page. This means that, at least for links followed from menus +and text files, the inverse of @key{u} is actually just @key{RET}. + + +@node Bookmarks, Character encodings, Navigation, Top +@chapter Bookmarks + +Elpher has a very simple link bookmarking system involving the +following commands: + +@table @asis +@item @key{a} (@code{elpher-bookmark-link}) +Add a bookmark for the link at point. The minibuffer will prompt for +a name for the bookmark, which defaults to the display string. + +@item @key{A} (@code{elpher-bookmark-current}) +Add a bookmark for the current page. The minibuffer will prompt for +a name for the bookmark, defaulting to the display string associated +with the link that was followed to reach the current page. + +@item @key{x} (@code{elpher-unbookmark-link}) +Immediately remove the bookmark (if one exists) to the link at point. + +@item @key{X} (@code{elpher-unbookmark-current}) +Immediately remove the bookmark (if one exists) to the current page. + +@item @key{B} (@code{elpher-bookmarks}) +Open a page displaying all current bookmarks. Note that this bookmark +page is added to the history just as if you had opened it using a link. +Thus to return to the previous page, use @kbd{u}. This also means +that you can peruse the various bookmarks by visiting them in turn, +using @kbd{u} to return to the bookmark page (where the position of point +is cached), then moving to another bookmarked link and so on. +@end table + +Bookmarks are stored as a s-exp in the file @file{elpher-bookmarks} +in the user emacs directory (usually @file{~/.emacs.d/}). +Any command which modifies the list of bookmarks immediately updates +this file. + +@node Character encodings, Encrypted connections, Bookmarks, Top +@chapter Character encodings + +Responses Elpher retrieves from servers are initially read as pure +binary data. When the data is intended to be interpreted as textual (as +determined by the type parameter of the gopher menu item or the gopher +URL), this data needs to be @emph{decoded} into a sequence of +characters. To do this properly requires knowledge of the encoding +system used by whoever authored the document. + +Unfortunately gopher lacks a systematic way of acquiring this necessary +information. Thus, the details of the coding system must be either inferred from the binary data, +or must be specified by the user. + +By default, Elpher applies Emacs' built-in character encoding detection +system to the full (undecoded) response data and uses this to attempt to +convert it into a character string. +(See @pxref{Recognize coding, Recognizing coding systems, ,emacs}.) While +this approach can be okay, it is important to realise that its inference +algorithm is extremely primitive and depends heavily on assumptions based +on the language settings of your emacs system. + +The alternative is to explicitly set the coding system used for decoding +using the following command: + +@table @asis +@item @key{S} (@code{elpher-set-coding-system}) +Causes a elpher to prompt for a coding system to use for decoding +future text. The @key{TAB} key can be used at this prompt to display a +list of alternatives (which is extensive) and to autocomplete. An empty +response will cause Elpher to return to its default autodetection +behaviour. +@end table + +Note that changing the coding system only affects newly loaded text. +Thus, if text has already been decoded using an incorrect system, you +will need to select the correct coding and then reload the text using +@key{R}. + + +@node Encrypted connections, Customization, Character encodings, Top +@chapter Encrypted connections + +While RFC 1436 does not broach the topic of encryption at all, several +modern gopher servers can serve content over encrypted connections, +and a common choice for this is TLS. + +Elpher can retrieve selectors using Emacs' built-in TLS support which +uses the GnuTLS library. (It is possible to build emacs without +GnuTLS, in which case encryption is not supported.) + +To retrieve documents using TLS, Elpher's TLS mode must be enabled. +This can be directly toggled using @key{T}, but note that just as with +the character encoding, changing this mode only affects subsequent +connections. + +Alternatively, TLS mode is @emph{automatically} enabled whenever +gopher URLs starting with @code{gophers://} are followed. + +The mode is sticky, so it remains active until switched off. +It can also be automatically switched off when a TLS connection fails. +In this case Elpher will prompt for your confirmation to ensure that +you can't accidentally make a non-TLS connection. + + +@node Customization, Index, Encrypted connections, Top +@chapter Customization + + + + +@menu +* Faces:: +* Other cutomizations:: +@end menu + +@node Faces, Other cutomizations, Customization, Customization +@section Faces + +@node Other cutomizations, , Faces, Customization +@section Other customizations + +@node Index, , Customization, Top +@unnumbered Index + +@printindex cp + +@bye