1 ;;; elopher.el --- gopher client
5 ;; Simple gopher client in elisp.
9 ;;; Customization group
13 "A simple gopher client."
17 (defcustom elopher-index-face '(foreground-color . "cyan")
18 "Face used for index records.")
19 (defcustom elopher-text-face '(foreground-color . "white")
20 "Face used for text records.")
21 (defcustom elopher-info-face '(foreground-color . "gray")
22 "Face used for info records.")
23 (defcustom elopher-image-face '(foreground-color . "green")
24 "Face used for image records.")
25 (defcustom elopher-unknown-face '(foreground-color . "red")
26 "Face used for unknown record types.")
27 (defcustom elopher-margin-face '(foreground-color . "orange")
28 "Face used for record margin legend.")
33 (defconst elopher-version "1.0.0"
34 "Current version of elopher.")
36 (defconst elopher-margin-width 6
37 "Width of left-hand margin used when rendering indicies.")
39 (defvar elopher-start-page
40 (concat "i\tfake\tfake\t1\r\n"
41 "i--------------------------------------------\tfake\tfake\t1\r\n"
42 "i Elopher Gopher Client \tfake\tfake\t1\r\n"
43 (format "i version %s\tfake\tfake\t1\r\n" elopher-version)
44 "i--------------------------------------------\tfake\tfake\t1\r\n"
45 "i\tfake\tfake\t1\r\n"
46 "iBasic usage:\tfake\tfake\t1\r\n"
47 "i - tab/shift-tab: next/prev directory entry\tfake\tfake\t1\r\n"
48 "i - RET/mouse-1: open directory entry\tfake\tfake\t1\r\n"
49 "i - u: return to parent directory entry\tfake\tfake\t1\r\n"
50 "i - g: go to a particular site\tfake\tfake\t1\r\n"
51 "i\tfake\tfake\t1\r\n"
52 "iPlaces to start exploring Gopherspace:\tfake\tfake\t1\r\n"
53 "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70\r\n"
54 "1Super-Dimensional Fortress\t\tsdf.org\t70\r\n"
55 "i\tfake\tfake\t1\r\n"
56 "iTest entries:\tfake\tfake\t1\r\n"
57 "pXKCD comic image\t/fun/xkcd/comics/2130/2137/text_entry.png\tgopher.floodgap.com\t70\r\n"))
63 (defvar elopher-mode-map
64 (let ((map (make-sparse-keymap)))
65 (define-key map (kbd "<tab>") 'elopher-next-link)
66 (define-key map (kbd "<S-tab>") 'elopher-prev-link)
67 (define-key map (kbd "u") 'elopher-history-back)
68 (define-key map (kbd "g") 'elopher-go)
69 (when (require 'evil nil t)
70 (evil-define-key 'normal map
71 (kbd "C-]") 'elopher-follow-closest-link
72 (kbd "C-t") 'elopher-history-back
73 (kbd "u") 'elopher-history-back
74 (kbd "g") 'elopher-go))
76 "Keymap for gopher client.")
78 (define-derived-mode elopher-mode special-mode "elopher"
79 "Major mode for elopher, an elisp gopher client.")
85 (defun elopher-insert-margin (&optional type-name)
88 (format (concat "%" (number-to-string elopher-margin-width) "s")
89 (concat "[" type-name "] "))
90 'face elopher-margin-face))
91 (insert (make-string elopher-margin-width ?\s))))
93 (defun elopher-render-record (line)
94 (let* ((type (elt line 0))
95 (fields (split-string (substring line 1) "\t"))
96 (display-string (elt fields 0))
97 (selector (elt fields 1))
98 (hostname (elt fields 2))
100 (address (list selector hostname port)))
102 (?i (elopher-insert-margin)
103 (insert (propertize display-string
104 'face elopher-info-face)))
105 (?0 (elopher-insert-margin "T")
106 (insert-text-button display-string
107 'face elopher-text-face
108 'link-getter #'elopher-get-text
109 'link-address address
110 'action #'elopher-click-link
112 (?1 (elopher-insert-margin "/")
113 (insert-text-button display-string
114 'face elopher-index-face
115 'link-getter #'elopher-get-index
116 'link-address address
117 'action #'elopher-click-link
119 (?p (elopher-insert-margin "img")
120 (insert-text-button display-string
121 'face elopher-image-face
122 'link-getter #'elopher-get-image
123 'link-address address
124 'action #'elopher-click-link
126 (?.) ; Occurs at end of index, can safely ignore.
127 (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
128 (insert (propertize display-string
129 'face elopher-unknown-face))))
132 (defvar elopher-incomplete-record "")
134 (defun elopher-render-complete-records (string)
135 (let* ((til-now (string-join (list elopher-incomplete-record string)))
136 (lines (split-string til-now "\r\n")))
137 (dotimes (idx (length lines))
138 (if (< idx (- (length lines) 1))
139 (let ((line (elt lines idx)))
140 (unless (string-empty-p line)
141 (elopher-render-record line)))
142 (setq elopher-incomplete-record (elt lines idx))))))
145 ;;; History management
148 (defvar elopher-history nil
149 "List of pages in elopher history.")
151 (defun elopher-push-history ()
152 "Add current contents of buffer, including point, to history."
153 (unless (string-empty-p (buffer-string))
155 (list (buffer-string)
159 (defun elopher-pop-history ()
160 "Restore most recent page from history."
162 (if (get-buffer "*elopher*")
164 (let* ((inhibit-read-only t)
165 (prev-page (pop elopher-history))
166 (page-string (car prev-page))
167 (page-point (cadr prev-page)))
168 (switch-to-buffer "*elopher*")
171 (goto-char page-point))
172 (message "Already at start of history."))
173 (message "No elopher buffer found.")))
176 ;;; Selector retrieval (all kinds)
180 (defun elopher-get-selector (selector host port filter &optional sentinel)
181 (switch-to-buffer "*elopher*")
183 (elopher-push-history)
184 (let ((inhibit-read-only t))
186 (make-network-process
187 :name "elopher-process"
189 :service (if port port 70)
192 (process-send-string "elopher-process" (concat selector "\n")))
196 (defun elopher-index-filter (proc string)
197 (let ((marker (process-mark proc))
198 (inhibit-read-only t))
199 (if (not (marker-position marker))
200 (set-marker marker 0 (current-buffer)))
203 (elopher-render-complete-records string)
204 (set-marker marker (point)))))
206 (defun elopher-get-index (selector host port)
207 (setq elopher-incomplete-record "")
208 (elopher-get-selector selector host port
209 #'elopher-index-filter))
213 (defun elopher-text-filter (proc string)
214 (let ((marker (process-mark proc))
215 (inhibit-read-only t))
216 (if (not (marker-position marker))
217 (set-marker marker 0 (current-buffer)))
220 (dolist (line (split-string string "\r"))
222 (set-marker marker (point)))))
224 (defun elopher-get-text (selector host port)
225 (elopher-get-selector selector host port
226 #'elopher-text-filter))
230 (defvar elopher-image-buffer "")
232 (defun elopher-image-filter (proc string)
233 (setq elopher-image-buffer (concat elopher-image-buffer string)))
235 (defun elopher-image-sentinel (proc event)
236 (let ((inhibit-read-only t))
237 (insert-image (create-image elopher-image-buffer))))
239 (defun elopher-get-image (selector host port)
240 (setq elopher-image-buffer "")
241 (elopher-get-selector selector host port
242 #'elopher-image-filter
243 #'elopher-image-sentinel))
246 ;;; Navigation methods
249 (defun elopher-next-link ()
253 (defun elopher-prev-link ()
257 (defun elopher-click-link (button)
258 (apply (button-get button 'link-getter) (button-get button 'link-address)))
260 (defun elopher-follow-closest-link ()
265 "Go to a particular gopher site."
267 (elopher-get-index "" (read-from-minibuffer "Gopher host: ") 70))
270 ;;; Main start procedure
274 "Start elopher with default landing page."
276 (switch-to-buffer "*elopher*")
278 (setq elopher-history nil)
279 (let ((inhibit-read-only t))
282 (elopher-render-complete-records elopher-start-page))))
285 ;;; elopher.el ends here