1 ;;; elopher.el --- gopher client
5 ;; Simple gopher client in elisp.
12 (defconst elopher-version "1.0.0"
13 "Current version of elopher.")
15 (defconst elopher-margin-width 6
16 "Width of left-hand margin used when rendering indicies.")
18 (defconst elopher-start-page
20 (list "i\tfake\tfake\t1"
21 "i--------------------------------------------\tfake\tfake\t1"
22 "i Elopher Gopher Client \tfake\tfake\t1"
23 (format "i version %s\tfake\tfake\t1" elopher-version)
24 "i--------------------------------------------\tfake\tfake\t1"
26 "iBasic usage:\tfake\tfake\t1"
27 "i - tab/shift-tab: next/prev directory entry\tfake\tfake\t1"
28 "i - RET/mouse-1: open directory entry\tfake\tfake\t1"
29 "i - u: return to parent directory entry\tfake\tfake\t1"
30 "i - g: go to a particular site\tfake\tfake\t1"
31 "i - r: reload current page\tfake\tfake\t1"
33 "iPlaces to start exploring Gopherspace:\tfake\tfake\t1"
34 "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70"
35 "1Super-Dimensional Fortress\t\tsdf.org\t70"
37 "iTest entries:\tfake\tfake\t1"
38 "pXKCD comic image\t/fun/xkcd/comics/2130/2137/text_entry.png\tgopher.floodgap.com\t70"
39 "1Test server\t\tlocalhost\t70"
44 ;;; Customization group
48 "A simple gopher client."
51 (defcustom elopher-index-face '(foreground-color . "cyan")
52 "Face used for index records.")
53 (defcustom elopher-text-face '(foreground-color . "white")
54 "Face used for text records.")
55 (defcustom elopher-info-face '(foreground-color . "gray")
56 "Face used for info records.")
57 (defcustom elopher-image-face '(foreground-color . "green")
58 "Face used for image records.")
59 (defcustom elopher-unknown-face '(foreground-color . "red")
60 "Face used for unknown record types.")
67 (defun elopher-make-address (selector host port)
68 (list selector host port))
70 (defun elopher-address-selector (address)
73 (defun elopher-address-host (address)
76 (defun elopher-address-port (address)
81 (defun elopher-make-node (parent address getter &optional content pos)
82 (list parent address getter content pos))
84 (defun elopher-node-parent (node)
87 (defun elopher-node-address (node)
90 (defun elopher-node-getter (node)
93 (defun elopher-node-content (node)
96 (defun elopher-node-pos (node)
99 (defun elopher-set-node-content (node content)
100 (setcar (nthcdr 3 node) content))
102 (defun elopher-set-node-pos (node pos)
103 (setcar (nthcdr 4 node) pos))
105 (defun elopher-save-pos ()
106 (when elopher-current-node
107 (elopher-set-node-pos elopher-current-node (point))))
109 (defun elopher-restore-pos ()
110 (let ((pos (elopher-node-pos elopher-current-node)))
112 (goto-char (elopher-node-pos elopher-current-node))
113 (goto-char (point-min)))))
115 ;; Node graph traversal
117 (defvar elopher-start-node (elopher-make-node nil nil #'elopher-get-index-node))
118 (defvar elopher-current-node)
120 (defun elopher-visit-node (node)
122 (elopher-prepare-buffer)
123 (setq elopher-current-node node)
124 (funcall (elopher-node-getter node)))
126 (defun elopher-visit-parent-node ()
127 (let ((parent-node (elopher-node-parent elopher-current-node)))
129 (setq elopher-current-node parent-node)
130 (elopher-visit-node elopher-current-node))))
132 (defun elopher-reload-current-node ()
133 (elopher-set-node-content elopher-current-node nil)
134 (elopher-visit-node elopher-current-node))
137 ;;; Buffer preparation
140 (defun elopher-prepare-buffer ()
141 (switch-to-buffer "*elopher*")
143 (let ((inhibit-read-only t))
150 (defun elopher-insert-index (string)
151 "Inserts the index corresponding to STRING into the current buffer."
152 (dolist (line (split-string string "\r\n"))
153 (unless (string-empty-p line)
154 (elopher-insert-index-record line))))
156 (defun elopher-insert-margin (&optional type-name)
159 (insert (format (concat "%" (number-to-string (- elopher-margin-width 1)) "s")
161 (propertize "[" 'face '(foreground-color . "blue"))
162 (propertize type-name 'face '(foreground-color . "white"))
163 (propertize "]" 'face '(foreground-color . "blue")))))
165 (insert (make-string elopher-margin-width ?\s))))
167 (defun elopher-insert-index-record (line)
168 "Inserts the index record corresponding to LINE into the current buffer."
169 (let* ((type (elt line 0))
170 (fields (split-string (substring line 1) "\t"))
171 (display-string (elt fields 0))
172 (address (elopher-make-address (elt fields 1) (elt fields 2) (elt fields 3))))
174 (?i (elopher-insert-margin)
175 (insert (propertize display-string
176 'face elopher-info-face)))
177 (?0 (elopher-insert-margin "T")
178 (insert-text-button display-string
179 'face elopher-text-face
180 'elopher-node (elopher-make-node elopher-current-node
182 #'elopher-get-text-node)
183 'action #'elopher-click-link
185 (?1 (elopher-insert-margin "/")
186 (insert-text-button display-string
187 'face elopher-index-face
188 'elopher-node (elopher-make-node elopher-current-node
190 #'elopher-get-index-node)
191 'action #'elopher-click-link
193 (?.) ; Occurs at end of index, can safely ignore.
194 (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
195 (insert (propertize display-string
196 'face elopher-unknown-face))))
200 ;;; Selector retrieval (all kinds)
203 (defvar elopher-selector-string)
205 (defun elopher-get-selector (address after)
206 (setq elopher-selector-string "")
207 (let ((p (get-process "elopher-process")))
208 (if p (delete-process p)))
209 (make-network-process
210 :name "elopher-process"
211 :host (elopher-address-host address)
212 :service (elopher-address-port address)
213 :filter (lambda (proc string)
214 (setq elopher-selector-string (concat elopher-selector-string string)))
216 (process-send-string "elopher-process"
217 (concat (elopher-address-selector address) "\n")))
221 (defun elopher-get-index-node ()
222 (let ((content (elopher-node-content elopher-current-node))
223 (address (elopher-node-address elopher-current-node)))
225 (let ((inhibit-read-only t))
227 (elopher-restore-pos)
229 (elopher-get-selector address
231 (let ((inhibit-read-only t))
232 (elopher-insert-index elopher-selector-string))
233 (elopher-restore-pos)
234 (elopher-set-node-content elopher-current-node
237 (let ((inhibit-read-only t))
238 (elopher-insert-index elopher-start-page))
239 (elopher-restore-pos)
240 (elopher-set-node-content elopher-current-node
241 (buffer-string)))))))
245 (defun elopher-strip-CRs (string)
246 (replace-regexp-in-string "\r" "" string))
248 (defun elopher-get-text-node ()
249 (let ((content (elopher-node-content elopher-current-node))
250 (address (elopher-node-address elopher-current-node)))
252 (let ((inhibit-read-only t))
255 (elopher-get-selector address
257 (let ((inhibit-read-only t))
261 (elopher-strip-CRs elopher-selector-string))))
262 (elopher-set-node-content elopher-current-node
263 (buffer-string)))))))
265 ;;; Navigation methods
268 (defun elopher-next-link ()
272 (defun elopher-prev-link ()
276 (defun elopher-click-link (button)
277 (let ((node (button-get button 'elopher-node)))
278 (elopher-visit-node node)))
280 (defun elopher-follow-closest-link ()
285 "Go to a particular gopher site."
288 (hostname (read-from-minibuffer "Gopher host: "))
290 (address (list selector hostname port)))
292 (elopher-make-node elopher-current-node
294 #'elopher-get-index-node))))
296 (defun elopher-reload ()
297 "Reload current site."
299 (elopher-reload-current-node))
301 (defun elopher-back ()
302 "Go to previous site."
304 (elopher-visit-parent-node))
306 ;;; Main start procedure
309 "Start elopher with default landing page."
311 (setq elopher-current-node nil)
312 (elopher-visit-node elopher-start-node))
318 (defvar elopher-mode-map
319 (let ((map (make-sparse-keymap)))
320 (define-key map (kbd "<tab>") 'elopher-next-link)
321 (define-key map (kbd "<S-tab>") 'elopher-prev-link)
322 (define-key map (kbd "u") 'elopher-back)
323 (define-key map (kbd "g") 'elopher-go)
324 (define-key map (kbd "r") 'elopher-reload)
325 (when (require 'evil nil t)
326 (evil-define-key 'normal map
327 (kbd "C-]") 'elopher-follow-closest-link
328 (kbd "C-t") 'elopher-back
329 (kbd "u") 'elopher-back
330 (kbd "g") 'elopher-go
331 (kbd "r") 'elopher-reload))
333 "Keymap for gopher client.")
335 (define-derived-mode elopher-mode special-mode "elopher"
336 "Major mode for elopher, an elisp gopher client.")
339 ;;; elopher.el ends here