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-index
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-search-face '(foreground-color . "orange")
60 "Face used for image records.")
61 (defcustom elopher-unknown-face '(foreground-color . "red")
62 "Face used for unknown record types.")
69 (defun elopher-make-address (selector host port)
70 (list selector host port))
72 (defun elopher-address-selector (address)
75 (defun elopher-address-host (address)
78 (defun elopher-address-port (address)
83 (defun elopher-make-node (parent address getter &optional content pos)
84 (list parent address getter content pos))
86 (defun elopher-node-parent (node)
89 (defun elopher-node-address (node)
92 (defun elopher-node-getter (node)
95 (defun elopher-node-content (node)
98 (defun elopher-node-pos (node)
101 (defun elopher-set-node-content (node content)
102 (setcar (nthcdr 3 node) content))
104 (defun elopher-set-node-pos (node pos)
105 (setcar (nthcdr 4 node) pos))
107 (defun elopher-save-pos ()
108 (when elopher-current-node
109 (elopher-set-node-pos elopher-current-node (point))))
111 (defun elopher-restore-pos ()
112 (let ((pos (elopher-node-pos elopher-current-node)))
115 (goto-char (point-min)))))
117 ;; Node graph traversal
119 (defvar elopher-current-node)
121 (defun elopher-visit-node (node)
123 (elopher-prepare-buffer)
124 (setq elopher-current-node node)
125 (funcall (elopher-node-getter node)))
127 (defun elopher-visit-parent-node ()
128 (let ((parent-node (elopher-node-parent elopher-current-node)))
130 (elopher-visit-node parent-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)
157 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
160 (insert (format (concat "%" (number-to-string (- elopher-margin-width 1)) "s")
162 (propertize "[" 'face '(foreground-color . "blue"))
163 (propertize type-name 'face '(foreground-color . "white"))
164 (propertize "]" 'face '(foreground-color . "blue")))))
166 (insert (make-string elopher-margin-width ?\s))))
168 (defun elopher-insert-index-record (line)
169 "Inserts the index record corresponding to LINE into the current buffer."
170 (let* ((type (elt line 0))
171 (fields (split-string (substring line 1) "\t"))
172 (display-string (elt fields 0))
173 (address (elopher-make-address (elt fields 1) (elt fields 2) (elt fields 3)))
174 (help-string (format "mouse-1, RET: open %s on %s port %s"
175 (elopher-address-selector address)
176 (elopher-address-host address)
177 (elopher-address-port address))))
179 (?i (elopher-insert-margin)
180 (insert (propertize display-string
181 'face elopher-info-face)))
182 (?0 (elopher-insert-margin "T")
183 (insert-text-button display-string
184 'face elopher-text-face
185 'elopher-node (elopher-make-node elopher-current-node
187 #'elopher-get-text-node)
188 'action #'elopher-click-link
190 'help-echo help-string))
191 (?1 (elopher-insert-margin "/")
192 (insert-text-button display-string
193 'face elopher-index-face
194 'elopher-node (elopher-make-node elopher-current-node
196 #'elopher-get-index-node)
197 'action #'elopher-click-link
199 'help-echo help-string))
200 ((or ?g ?p ?I) (elopher-insert-margin "im")
201 (insert-text-button display-string
202 'face elopher-image-face
203 'elopher-node (elopher-make-node elopher-current-node
205 #'elopher-get-image-node)
206 'action #'elopher-click-link
208 'help-echo help-string))
209 (?7 (elopher-insert-margin "?")
210 (insert-text-button display-string
211 'face elopher-search-face
212 'elopher-node (elopher-make-node elopher-current-node
214 #'elopher-get-search-node)
215 'action #'elopher-click-link
217 'help-echo help-string))
218 (?.) ; Occurs at end of index, can safely ignore.
219 (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
220 (insert (propertize display-string
221 'face elopher-unknown-face))))
225 ;;; Selector retrieval (all kinds)
228 (defvar elopher-selector-string)
230 (defun elopher-get-selector (address after &optional binary)
231 "Retrieve selector specified by ADDRESS and store it in the
232 string elopher-selector-string, then execute AFTER as the
234 (setq elopher-selector-string "")
235 (let ((p (get-process "elopher-process")))
236 (if p (delete-process p)))
237 (make-network-process
238 :name "elopher-process"
239 :host (elopher-address-host address)
240 :service (elopher-address-port address)
241 :filter (lambda (proc string)
242 (setq elopher-selector-string (concat elopher-selector-string string)))
244 (process-send-string "elopher-process"
245 (concat (elopher-address-selector address) "\n")))
249 (defun elopher-get-index-node ()
250 (let ((content (elopher-node-content elopher-current-node))
251 (address (elopher-node-address elopher-current-node)))
254 (let ((inhibit-read-only t))
256 (elopher-restore-pos))
259 (let ((inhibit-read-only t))
260 (insert "LOADING DIRECTORY..."))
261 (elopher-get-selector address
263 (let ((inhibit-read-only t))
265 (elopher-insert-index elopher-selector-string))
266 (elopher-restore-pos)
267 (elopher-set-node-content elopher-current-node
270 (let ((inhibit-read-only t))
271 (elopher-insert-index elopher-start-index))
272 (elopher-restore-pos)
273 (elopher-set-node-content elopher-current-node
274 (buffer-string)))))))
278 (defun elopher-strip-CRs (string)
279 (replace-regexp-in-string "\r" "" string))
281 (defun elopher-get-text-node ()
282 (let ((content (elopher-node-content elopher-current-node))
283 (address (elopher-node-address elopher-current-node)))
286 (let ((inhibit-read-only t))
288 (elopher-restore-pos))
290 (let ((inhibit-read-only t))
291 (insert "LOADING TEXT..."))
292 (elopher-get-selector address
294 (let ((inhibit-read-only t))
296 (insert (elopher-strip-CRs elopher-selector-string)))
297 (elopher-restore-pos)
298 (elopher-set-node-content elopher-current-node
299 (buffer-string))))))))
303 (defun elopher-get-image-node ()
304 (let ((content (elopher-node-content elopher-current-node))
305 (address (elopher-node-address elopher-current-node)))
308 (let ((inhibit-read-only t))
309 (insert-image content))
310 (setq cursor-type nil)
311 (elopher-restore-pos))
313 (let ((inhibit-read-only t))
314 (insert "LOADING IMAGE..."))
315 (elopher-get-selector address
317 (let ((image (create-image
318 (string-as-unibyte elopher-selector-string)
320 (inhibit-read-only t))
323 (setq cursor-type nil)
324 (elopher-restore-pos)
325 (elopher-set-node-content elopher-current-node image))))))))
329 (defun elopher-get-search-node ()
330 (let* ((content (elopher-node-content elopher-current-node))
331 (address (elopher-node-address elopher-current-node))
332 (search-address (elopher-make-address (concat (elopher-address-selector address)
334 (read-from-minibuffer "Query: "))
335 (elopher-address-host address)
336 (elopher-address-port address))))
337 (let ((inhibit-read-only t))
338 (insert "LOADING RESULTS..."))
339 (elopher-get-selector search-address
341 (let ((inhibit-read-only t))
343 (elopher-insert-index elopher-selector-string))
344 (elopher-restore-pos)
345 (elopher-set-node-content elopher-current-node
349 ;;; Navigation procedures
352 (defun elopher-next-link ()
356 (defun elopher-prev-link ()
360 (defun elopher-click-link (button)
361 (let ((node (button-get button 'elopher-node)))
362 (elopher-visit-node node)))
364 (defun elopher-follow-closest-link ()
369 "Go to a particular gopher site."
372 (hostname (read-from-minibuffer "Gopher host: "))
374 (address (list selector hostname port)))
376 (elopher-make-node elopher-current-node
378 #'elopher-get-index-node))))
380 (defun elopher-reload ()
381 "Reload current site."
383 (elopher-reload-current-node))
385 (defun elopher-back ()
386 "Go to previous site."
388 (if (elopher-node-parent elopher-current-node)
389 (elopher-visit-parent-node)
390 (message "No previous site.")))
396 (defvar elopher-mode-map
397 (let ((map (make-sparse-keymap)))
398 (define-key map (kbd "<tab>") 'elopher-next-link)
399 (define-key map (kbd "<S-tab>") 'elopher-prev-link)
400 (define-key map (kbd "u") 'elopher-back)
401 (define-key map (kbd "g") 'elopher-go)
402 (define-key map (kbd "r") 'elopher-reload)
403 (when (require 'evil nil t)
404 (evil-define-key 'normal map
405 (kbd "C-]") 'elopher-follow-closest-link
406 (kbd "C-t") 'elopher-back
407 (kbd "u") 'elopher-back
408 (kbd "g") 'elopher-go
409 (kbd "r") 'elopher-reload))
411 "Keymap for gopher client.")
413 (define-derived-mode elopher-mode special-mode "elopher"
414 "Major mode for elopher, an elisp gopher client.")
417 ;;; Main start procedure
420 "Start elopher with default landing page."
422 (setq elopher-current-node nil)
423 (let ((start-node (elopher-make-node nil nil #'elopher-get-index-node)))
424 (elopher-visit-node start-node)))
426 ;;; elopher.el ends here