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.")
26 (defcustom elopher-margin-face '(foreground-color . "orange")
27 "Face used for record margin legend.")
32 (defconst elopher-version "1.0.0"
33 "Current version of elopher.")
35 (defconst elopher-margin-width 6
36 "Width of left-hand margin used when rendering indicies.")
38 (defvar elopher-start-page
39 (concat "i\tfake\tfake\t1\r\n"
40 "i--------------------------------------------\tfake\tfake\t1\r\n"
41 "i Elopher Gopher Client \tfake\tfake\t1\r\n"
42 (format "i version %s\tfake\tfake\t1\r\n" elopher-version)
43 "i--------------------------------------------\tfake\tfake\t1\r\n"
44 "i\tfake\tfake\t1\r\n"
45 "iBasic usage:\tfake\tfake\t1\r\n"
46 "i - tab/shift-tab: next/prev directory entry\tfake\tfake\t1\r\n"
47 "i - RET/mouse-1: open directory entry\tfake\tfake\t1\r\n"
48 "i - u: return to parent directory entry\tfake\tfake\t1\r\n"
49 "i - g: go to a particular site\tfake\tfake\t1\r\n"
50 "i\tfake\tfake\t1\r\n"
51 "iPlaces to start exploring Gopherspace:\tfake\tfake\t1\r\n"
52 "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70\r\n"
53 "1Super-Dimensional Fortress\t\tsdf.org\t70\r\n"
54 "i\tfake\tfake\t1\r\n"
55 "iTest entries:\tfake\tfake\t1\r\n"
56 "pXKCD comic image\t/fun/xkcd/comics/2130/2137/text_entry.png\tgopher.floodgap.com\t70\r\n"))
62 (setq elopher-mode-map
63 (let ((map (make-sparse-keymap)))
64 (define-key map (kbd "<tab>") 'elopher-next-link)
65 (define-key map (kbd "<S-tab>") 'elopher-prev-link)
66 (define-key map (kbd "u") 'elopher-pop-history)
67 (define-key map (kbd "g") 'elopher-go)
68 (define-key map (kbd "r") 'elopher-reload)
69 (when (require 'evil nil t)
70 (evil-define-key 'normal map
71 (kbd "C-]") 'elopher-follow-closest-link
72 (kbd "C-t") 'elopher-pop-history
73 (kbd "u") 'elopher-pop-history
75 (kbd "r") 'elopher-reload))
77 ;; "Keymap for gopher client.")
79 (define-derived-mode elopher-mode special-mode "elopher"
80 "Major mode for elopher, an elisp gopher client.")
86 (defun elopher-insert-margin (&optional type-name)
89 (format (concat "%" (number-to-string elopher-margin-width) "s")
90 (concat "[" type-name "] "))
91 'face elopher-margin-face))
92 (insert (make-string elopher-margin-width ?\s))))
94 (defun elopher-render-record (line)
95 (let* ((type (elt line 0))
96 (fields (split-string (substring line 1) "\t"))
97 (display-string (elt fields 0))
98 (selector (elt fields 1))
99 (hostname (elt fields 2))
100 (port (elt fields 3))
101 (address (list selector hostname port)))
103 (?i (elopher-insert-margin)
104 (insert (propertize display-string
105 'face elopher-info-face)))
106 (?0 (elopher-insert-margin "T")
107 (insert-text-button display-string
108 'face elopher-text-face
109 'link-getter #'elopher-get-text
110 'link-address address
111 'action #'elopher-click-link
113 (?1 (elopher-insert-margin "/")
114 (insert-text-button display-string
115 'face elopher-index-face
116 'link-getter #'elopher-get-index
117 'link-address address
118 'action #'elopher-click-link
120 (?p (elopher-insert-margin "img")
121 (insert-text-button display-string
122 'face elopher-image-face
123 'link-getter #'elopher-get-image
124 'link-address address
125 'action #'elopher-click-link
127 (?.) ; Occurs at end of index, can safely ignore.
128 (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
129 (insert (propertize display-string
130 'face elopher-unknown-face))))
133 (defvar elopher-incomplete-record "")
135 (defun elopher-render-complete-records (string)
136 (let* ((til-now (string-join (list elopher-incomplete-record string)))
137 (lines (split-string til-now "\r\n")))
138 (dotimes (idx (length lines))
139 (if (< idx (- (length lines) 1))
140 (let ((line (elt lines idx)))
141 (unless (string-empty-p line)
142 (elopher-render-record line)))
143 (setq elopher-incomplete-record (elt lines idx))))))
146 ;;; History management
149 (defvar elopher-history nil
150 "List of pages in elopher history.")
152 (defvar elopher-place-history nil
153 "List of objects describing how to access pages in history.")
155 (defvar elopher-current-place nil
156 "How to access current page.")
158 (defun elopher-push-history ()
159 "Add current contents of buffer, including point, to history."
160 (unless (string-empty-p (buffer-string))
162 (list (buffer-string)
166 elopher-current-place
167 elopher-place-history)))
169 (defun elopher-pop-history ()
170 "Restore most recent page from history."
172 (if (get-buffer "*elopher*")
174 (let* ((inhibit-read-only t)
175 (prev-page (pop elopher-history))
176 (page-string (car prev-page))
177 (page-point (cadr prev-page)))
178 (switch-to-buffer "*elopher*")
181 (goto-char page-point)
182 (setq elopher-current-place (pop elopher-place-history)))
183 (message "Already at start of history."))
184 (message "No elopher buffer found.")))
187 ;;; Selector retrieval (all kinds)
190 (defun elopher-get-selector (selector host port filter &optional sentinel)
191 (switch-to-buffer "*elopher*")
193 (elopher-push-history)
194 (let ((inhibit-read-only t))
196 (make-network-process
197 :name "elopher-process"
199 :service (if port port 70)
202 (process-send-string "elopher-process" (concat selector "\n")))
206 (defun elopher-index-filter (proc string)
207 (let ((marker (process-mark proc))
208 (inhibit-read-only t))
209 (if (not (marker-position marker))
210 (set-marker marker 0 (current-buffer)))
213 (elopher-render-complete-records string)
214 (set-marker marker (point)))))
216 (defun elopher-get-index (selector host port)
217 (setq elopher-incomplete-record "")
218 (elopher-get-selector selector host port
219 #'elopher-index-filter))
223 (defun elopher-text-filter (proc string)
224 (let ((marker (process-mark proc))
225 (inhibit-read-only t))
226 (if (not (marker-position marker))
227 (set-marker marker 0 (current-buffer)))
230 (dolist (line (split-string string "\r"))
232 (set-marker marker (point)))))
234 (defun elopher-get-text (selector host port)
235 (elopher-get-selector selector host port
236 #'elopher-text-filter))
240 (defvar elopher-image-buffer "")
242 (defun elopher-image-filter (proc string)
243 (setq elopher-image-buffer (concat elopher-image-buffer string)))
245 (defun elopher-image-sentinel (proc event)
246 (let ((inhibit-read-only t))
247 (insert-image (create-image elopher-image-buffer))))
249 (defun elopher-get-image (selector host port)
250 (setq elopher-image-buffer "")
251 (elopher-get-selector selector host port
252 #'elopher-image-filter
253 #'elopher-image-sentinel))
255 ;; Start page retrieval
257 (defun elopher-get-start-page (&optional selector host port)
258 "Display start page. SELECTOR, HOST and PORT are unused."
259 (let ((inhibit-read-only t))
262 (elopher-render-complete-records elopher-start-page))))
264 ;;; Navigation methods
267 (defun elopher-next-link ()
271 (defun elopher-prev-link ()
275 (defun elopher-click-link (button)
276 (apply (button-get button 'link-getter) (button-get button 'link-address))
277 (setq elopher-current-place (list link-getter link-address)))
279 (defun elopher-follow-closest-link ()
284 "Go to a particular gopher site."
287 (hostname (read-from-minibuffer "Gopher host: "))
289 (address (list selector hostname port)))
290 (elopher-get-index "" (read-from-minibuffer "Gopher host: ") 70)i
291 (setq elopher-current-place (list #'elopher-get-index address))))
293 (defun elopher-reload ()
294 "Reload current page."
296 (if elopher-current-place
297 (let ((link-getter (car elopher-current-place))
298 (address (cadr elopher-current-place)))
299 (apply link-getter address))
300 (elopher-get-start-page)))
302 ;;; Main start procedure
306 "Start elopher with default landing page."
308 (switch-to-buffer "*elopher*")
310 (setq elopher-history nil)
311 (setq elopher-place-history nil)
312 (setq elopher-current-place nil)
313 (elopher-get-start-page))
316 ;;; elopher.el ends here