1 ;;; elopher.el --- gopher client
5 ;; Simple gopher client in elisp.
9 ;;; Customization group
13 "A simple gopher client."
16 (defcustom elopher-index-face '(foreground-color . "cyan")
17 "Face used for index records.")
18 (defcustom elopher-text-face '(foreground-color . "white")
19 "Face used for text records.")
20 (defcustom elopher-info-face '(foreground-color . "gray")
21 "Face used for info records.")
22 (defcustom elopher-image-face '(foreground-color . "green")
23 "Face used for image records.")
24 (defcustom elopher-unknown-face '(foreground-color . "red")
25 "Face used for unknown record types.")
30 (defun elopher-make-node (parent address &optional content)
31 (list parent address cache))
33 (defun elopher-node-parent (node)
36 (defun elopher-node-address (node)
39 (defun elopher-node-content (node)
42 (defun elopher-reload-node (node after)
48 (defconst elopher-version "1.0.0"
49 "Current version of elopher.")
51 (defconst elopher-margin-width 6
52 "Width of left-hand margin used when rendering indicies.")
54 (defconst elopher-start-page
55 (concat "i\tfake\tfake\t1\r\n"
56 "i--------------------------------------------\tfake\tfake\t1\r\n"
57 "i Elopher Gopher Client \tfake\tfake\t1\r\n"
58 (format "i version %s\tfake\tfake\t1\r\n" elopher-version)
59 "i--------------------------------------------\tfake\tfake\t1\r\n"
60 "i\tfake\tfake\t1\r\n"
61 "iBasic usage:\tfake\tfake\t1\r\n"
62 "i - tab/shift-tab: next/prev directory entry\tfake\tfake\t1\r\n"
63 "i - RET/mouse-1: open directory entry\tfake\tfake\t1\r\n"
64 "i - u: return to parent directory entry\tfake\tfake\t1\r\n"
65 "i - g: go to a particular site\tfake\tfake\t1\r\n"
66 "i\tfake\tfake\t1\r\n"
67 "iPlaces to start exploring Gopherspace:\tfake\tfake\t1\r\n"
68 "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70\r\n"
69 "1Super-Dimensional Fortress\t\tsdf.org\t70\r\n"
70 "i\tfake\tfake\t1\r\n"
71 "iTest entries:\tfake\tfake\t1\r\n"
72 "pXKCD comic image\t/fun/xkcd/comics/2130/2137/text_entry.png\tgopher.floodgap.com\t70\r\n"))
77 (setq elopher-mode-map
78 (let ((map (make-sparse-keymap)))
79 (define-key map (kbd "<tab>") 'elopher-next-link)
80 (define-key map (kbd "<S-tab>") 'elopher-prev-link)
81 (define-key map (kbd "u") 'elopher-pop-history)
82 (define-key map (kbd "g") 'elopher-go)
83 (define-key map (kbd "r") 'elopher-reload)
84 (when (require 'evil nil t)
85 (evil-define-key 'normal map
86 (kbd "C-]") 'elopher-follow-closest-link
87 (kbd "C-t") 'elopher-pop-history
88 (kbd "u") 'elopher-pop-history
90 (kbd "r") 'elopher-reload))
92 ;; "Keymap for gopher client.")
94 (define-derived-mode elopher-mode special-mode "elopher"
95 "Major mode for elopher, an elisp gopher client.")
101 (defun elopher-insert-index (string)
102 "Inserts the index corresponding to STRING into the current buffer."
103 (dolist (line (split-string string "\r\n"))
104 (elopher-insert-index-record line)))
106 (defun elopher-insert-margin (&optional type-name)
108 (insert (format (concat "%" (number-to-string elopher-margin-width) "s"
110 (propertize "[" 'face '(foreground-color . "blue"))
111 (propertize type-name 'face '(foreground-color . "white"))
112 (propertize "]" 'face '(foreground-color . "blue"))))))
113 (insert (make-string elopher-margin-width ?\s))))
115 (defun elopher-insert-index-record (line)
116 "Inserts the index record corresponding to LINE into the current buffer."
117 (let* ((type (elt line 0))
118 (fields (split-string (substring line 1) "\t"))
119 (display-string (elt fields 0))
120 (selector (elt fields 1))
121 (hostname (elt fields 2))
122 (port (elt fields 3))
123 (address (list selector hostname port)))
125 (?i (elopher-insert-margin)
126 (insert (propertize display-string
127 'face elopher-info-face)))
128 (?0 (elopher-insert-margin "T")
129 (insert-text-button display-string
130 'face elopher-text-face
131 'link-getter #'elopher-get-text
132 'link-address address
133 'action #'elopher-click-link
135 (?1 (elopher-insert-margin "/")
136 (insert-text-button display-string
137 'face elopher-index-face
138 'link-getter #'elopher-get-index
139 'link-address address
140 'action #'elopher-click-link
142 (?p (elopher-insert-margin "img")
143 (insert-text-button display-string
144 'face elopher-image-face
145 'link-getter #'elopher-get-image
146 'link-address address
147 'action #'elopher-click-link
149 (?.) ; Occurs at end of index, can safely ignore.
150 (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
151 (insert (propertize display-string
152 'face elopher-unknown-face))))
155 ;;; History management
158 (defvar elopher-history nil
159 "List of pages in elopher history.")
161 (defvar elopher-place-history nil
162 "List of objects describing how to access pages in history.")
164 (defvar elopher-current-place nil
165 "How to access current page.")
167 (defun elopher-push-history ()
168 "Add current contents of buffer, including point, to history."
169 (unless (string-empty-p (buffer-string))
171 (list (buffer-string)
175 elopher-current-place
176 elopher-place-history)))
178 (defun elopher-pop-history ()
179 "Restore most recent page from history."
181 (if (get-buffer "*elopher*")
183 (let* ((inhibit-read-only t)
184 (prev-page (pop elopher-history))
185 (page-string (car prev-page))
186 (page-point (cadr prev-page)))
187 (switch-to-buffer "*elopher*")
190 (goto-char page-point)
191 (setq elopher-current-place (pop elopher-place-history)))
192 (message "Already at start of history."))
193 (message "No elopher buffer found.")))
196 ;;; Selector retrieval (all kinds)
199 (defun elopher-get-selector (selector host port filter &optional sentinel)
200 (switch-to-buffer "*elopher*")
202 (elopher-push-history)
203 (let ((inhibit-read-only t))
205 (make-network-process
206 :name "elopher-process"
208 :service (if port port 70)
211 (process-send-string "elopher-process" (concat selector "\n")))
215 (defun elopher-index-filter (proc string)
216 (let ((marker (process-mark proc))
217 (inhibit-read-only t))
218 (if (not (marker-position marker))
219 (set-marker marker 0 (current-buffer)))
222 (elopher-render-complete-records string)
223 (set-marker marker (point)))))
225 (defun elopher-get-index (selector host port)
226 (setq elopher-incomplete-record "")
227 (elopher-get-selector selector host port
228 #'elopher-index-filter))
232 (defun elopher-text-filter (proc string)
233 (let ((marker (process-mark proc))
234 (inhibit-read-only t))
235 (if (not (marker-position marker))
236 (set-marker marker 0 (current-buffer)))
239 (dolist (line (split-string string "\r"))
241 (set-marker marker (point)))))
243 (defun elopher-get-text (selector host port)
244 (elopher-get-selector selector host port
245 #'elopher-text-filter))
249 (defvar elopher-image-buffer "")
251 (defun elopher-image-filter (proc string)
252 (setq elopher-image-buffer (concat elopher-image-buffer string)))
254 (defun elopher-image-sentinel (proc event)
255 (let ((inhibit-read-only t))
256 (insert-image (create-image elopher-image-buffer))))
258 (defun elopher-get-image (selector host port)
259 (setq elopher-image-buffer "")
260 (elopher-get-selector selector host port
261 #'elopher-image-filter
262 #'elopher-image-sentinel))
264 ;; Start page retrieval
266 (defun elopher-get-start-page (&optional selector host port)
267 "Display start page. SELECTOR, HOST and PORT are unused."
268 (let ((inhibit-read-only t))
271 (elopher-render-complete-records elopher-start-page))))
273 ;;; Navigation methods
276 (defun elopher-next-link ()
280 (defun elopher-prev-link ()
284 (defun elopher-click-link (button)
285 (apply (button-get button 'link-getter) (button-get button 'link-address))
286 (setq elopher-current-place (list link-getter link-address)))
288 (defun elopher-follow-closest-link ()
293 "Go to a particular gopher site."
296 (hostname (read-from-minibuffer "Gopher host: "))
298 (address (list selector hostname port)))
299 (elopher-get-index "" (read-from-minibuffer "Gopher host: ") 70)i
300 (setq elopher-current-place (list #'elopher-get-index address))))
302 (defun elopher-reload ()
303 "Reload current page."
305 (if elopher-current-place
306 (let ((link-getter (car elopher-current-place))
307 (address (cadr elopher-current-place)))
308 (apply link-getter address))
309 (elopher-get-start-page)))
311 ;;; Main start procedure
315 "Start elopher with default landing page."
317 (switch-to-buffer "*elopher*")
319 (setq elopher-history nil)
320 (setq elopher-place-history nil)
321 (setq elopher-current-place nil)
322 (elopher-get-start-page))
325 ;;; elopher.el ends here