;;; Code:
-;; (defvar elopher-mode-map nil "Keymap for gopher client.")
-;; (define-key elopher-mode-map (kbd "p") 'elopher-quit)
+;;; Global constants
+;;
-;; (define-derived-mode elopher-mode special-mode "elopher"
-;; "Major mode for elopher, an elisp gopher client.")
+(defconst elopher-version "1.0.0"
+ "Current version of elopher.")
-;; (global-set-key (kbd "C-c C-b") 'eval-buffer)
+(defconst elopher-margin-width 6
+ "Width of left-hand margin used when rendering indicies.")
-(defvar elopher-type-margin-width 5)
+(defconst elopher-start-index
+ (string-join
+ (list "i\tfake\tfake\t1"
+ "i--------------------------------------------\tfake\tfake\t1"
+ "i Elopher Gopher Client \tfake\tfake\t1"
+ (format "i version %s\tfake\tfake\t1" elopher-version)
+ "i--------------------------------------------\tfake\tfake\t1"
+ "i\tfake\tfake\t1"
+ "iBasic usage:\tfake\tfake\t1"
+ "i - tab/shift-tab: next/prev directory entry\tfake\tfake\t1"
+ "i - RET/mouse-1: open directory entry\tfake\tfake\t1"
+ "i - u: return to parent directory entry\tfake\tfake\t1"
+ "i - g: go to a particular site\tfake\tfake\t1"
+ "i - r: reload current page\tfake\tfake\t1"
+ "i\tfake\tfake\t1"
+ "iPlaces to start exploring Gopherspace:\tfake\tfake\t1"
+ "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70"
+ "1Super-Dimensional Fortress\t\tsdf.org\t70"
+ "i\tfake\tfake\t1"
+ "iTest entries:\tfake\tfake\t1"
+ "pXKCD comic image\t/fun/xkcd/comics/2130/2137/text_entry.png\tgopher.floodgap.com\t70"
+ "1Test server\t\tlocalhost\t70"
+ ".")
+ "\r\n"))
-(defun elopher-type-margin (&optional type-name)
+
+;;; Customization group
+;;
+
+(defgroup elopher nil
+ "A simple gopher client."
+ :group 'applications)
+
+(defcustom elopher-index-face '(foreground-color . "cyan")
+ "Face used for index records.")
+(defcustom elopher-text-face '(foreground-color . "white")
+ "Face used for text records.")
+(defcustom elopher-info-face '(foreground-color . "gray")
+ "Face used for info records.")
+(defcustom elopher-image-face '(foreground-color . "green")
+ "Face used for image records.")
+(defcustom elopher-unknown-face '(foreground-color . "red")
+ "Face used for unknown record types.")
+
+;;; Model
+;;
+
+;; Address
+
+(defun elopher-make-address (selector host port)
+ (list selector host port))
+
+(defun elopher-address-selector (address)
+ (car address))
+
+(defun elopher-address-host (address)
+ (cadr address))
+
+(defun elopher-address-port (address)
+ (caddr address))
+
+;; Node
+
+(defun elopher-make-node (parent address getter &optional content pos)
+ (list parent address getter content pos))
+
+(defun elopher-node-parent (node)
+ (elt node 0))
+
+(defun elopher-node-address (node)
+ (elt node 1))
+
+(defun elopher-node-getter (node)
+ (elt node 2))
+
+(defun elopher-node-content (node)
+ (elt node 3))
+
+(defun elopher-node-pos (node)
+ (elt node 4))
+
+(defun elopher-set-node-content (node content)
+ (setcar (nthcdr 3 node) content))
+
+(defun elopher-set-node-pos (node pos)
+ (setcar (nthcdr 4 node) pos))
+
+(defun elopher-save-pos ()
+ (when elopher-current-node
+ (elopher-set-node-pos elopher-current-node (point))))
+
+(defun elopher-restore-pos ()
+ (let ((pos (elopher-node-pos elopher-current-node)))
+ (if pos
+ (goto-char pos)
+ (goto-char (point-min)))))
+
+;; Node graph traversal
+
+(defvar elopher-current-node)
+
+(defun elopher-visit-node (node)
+ (elopher-save-pos)
+ (elopher-prepare-buffer)
+ (setq elopher-current-node node)
+ (funcall (elopher-node-getter node)))
+
+(defun elopher-visit-parent-node ()
+ (let ((parent-node (elopher-node-parent elopher-current-node)))
+ (when parent-node
+ (elopher-visit-node parent-node))))
+
+(defun elopher-reload-current-node ()
+ (elopher-set-node-content elopher-current-node nil)
+ (elopher-visit-node elopher-current-node))
+
+
+;;; Buffer preparation
+;;
+
+(defun elopher-prepare-buffer ()
+ (switch-to-buffer "*elopher*")
+ (elopher-mode)
+ (let ((inhibit-read-only t))
+ (erase-buffer)))
+
+
+;;; Index rendering
+;;
+
+(defun elopher-insert-index (string)
+ "Inserts the index corresponding to STRING into the current buffer."
+ (dolist (line (split-string string "\r\n"))
+ (unless (string-empty-p line)
+ (elopher-insert-index-record line))))
+
+(defun elopher-insert-margin (&optional type-name)
+ "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
(if type-name
- (insert (propertize
- (format (concat "%" (number-to-string elopher-type-margin-width) "s")
- (concat "[" type-name "] "))
- 'face '(foreground-color . "yellow")))
- (insert (make-string elopher-type-margin-width ?\s))))
-
-(defun elopher-format-i (display-string)
- (elopher-type-margin)
- (insert (propertize display-string 'face '(foreground-color . "white")))
- (insert "\n"))
-
-(defun elopher-format-0 (display-string selector hostname port)
- (elopher-type-margin "T")
- (insert (propertize display-string 'face '(foreground-color . "gray")))
- (insert "\n"))
-
-(defun elopher-format-1 (display-string selector hostname port)
- (elopher-type-margin "/")
- (let ((map (make-sparse-keymap)))
- (define-key map [mouse-1]
- (eval `(lambda () (interactive) (elopher-get-index ,hostname ,port ,selector))))
- (insert (propertize display-string
- 'face '(foreground-color . "cyan")
- 'mouse-face 'highlight
- 'help-echo "mouse-1: follow link"
- 'keymap map))
- (insert "\n")))
+ (progn
+ (insert (format (concat "%" (number-to-string (- elopher-margin-width 1)) "s")
+ (concat
+ (propertize "[" 'face '(foreground-color . "blue"))
+ (propertize type-name 'face '(foreground-color . "white"))
+ (propertize "]" 'face '(foreground-color . "blue")))))
+ (insert " "))
+ (insert (make-string elopher-margin-width ?\s))))
-(defun elopher-process-record (line)
+(defun elopher-insert-index-record (line)
+ "Inserts the index record corresponding to LINE into the current buffer."
(let* ((type (elt line 0))
(fields (split-string (substring line 1) "\t"))
- (g-display-string (elt fields 0))
- (g-selector (elt fields 1))
- (g-hostname (elt fields 2))
- (g-port (elt fields 3)))
+ (display-string (elt fields 0))
+ (address (elopher-make-address (elt fields 1) (elt fields 2) (elt fields 3)))
+ (help-string (format "mouse-1, RET: open %s on %s port %s"
+ (elopher-address-selector address)
+ (elopher-address-host address)
+ (elopher-address-port address))))
(pcase type
- (?i (elopher-format-i g-display-string))
- (?0 (elopher-format-0 g-display-string g-selector g-hostname g-port))
- (?1 (elopher-format-1 g-display-string g-selector g-hostname g-port)))))
-
-(defvar elopher-incomplete-record "")
-
-(defun elopher-process-complete-records (string)
- (let* ((til-now (string-join (list elopher-incomplete-record string)))
- (lines (split-string til-now "\r\n")))
- (dotimes (idx (length lines))
- (if (< idx (- (length lines) 1))
- (elopher-process-record (elt lines idx))
- (setq elopher-incomplete-record (elt lines idx))))))
-
-(defun elopher-filter (proc string)
- (with-current-buffer (get-buffer "*elopher*")
- (let ((marker (process-mark proc)))
- (if (not (marker-position marker))
- (set-marker marker 0 (current-buffer)))
- (save-excursion
- (goto-char marker)
- (elopher-process-complete-records string)
- (set-marker marker (point))))))
-
-(defun elopher-get-index (host &optional port path)
- (switch-to-buffer "*elopher*")
- (erase-buffer)
+ (?i (elopher-insert-margin)
+ (insert (propertize display-string
+ 'face elopher-info-face)))
+ (?0 (elopher-insert-margin "T")
+ (insert-text-button display-string
+ 'face elopher-text-face
+ 'elopher-node (elopher-make-node elopher-current-node
+ address
+ #'elopher-get-text-node)
+ 'action #'elopher-click-link
+ 'follow-link t
+ 'help-echo help-string))
+ (?1 (elopher-insert-margin "/")
+ (insert-text-button display-string
+ 'face elopher-index-face
+ 'elopher-node (elopher-make-node elopher-current-node
+ address
+ #'elopher-get-index-node)
+ 'action #'elopher-click-link
+ 'follow-link t
+ 'help-echo help-string))
+ ((or ?g ?p ?I) (elopher-insert-margin "im")
+ (insert-text-button display-string
+ 'face elopher-image-face
+ 'elopher-node (elopher-make-node elopher-current-node
+ address
+ #'elopher-get-image-node)
+ 'action #'elopher-click-link
+ 'follow-link t
+ 'help-echo help-string))
+ (?.) ; Occurs at end of index, can safely ignore.
+ (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
+ (insert (propertize display-string
+ 'face elopher-unknown-face))))
+ (insert "\n")))
+
+
+;;; Selector retrieval (all kinds)
+;;
+
+(defvar elopher-selector-string)
+
+(defun elopher-get-selector (address after &optional binary)
+ "Retrieve selector specified by ADDRESS and store it in the
+string elopher-selector-string, then execute AFTER as the
+sentinal function."
+ (setq elopher-selector-string "")
+ (let ((p (get-process "elopher-process")))
+ (if p (delete-process p)))
(make-network-process
:name "elopher-process"
- :host host
- :service (if port port 70)
- :filter #'elopher-filter)
- (process-send-string "elopher-process" (concat path "\n")))
+ :host (elopher-address-host address)
+ :service (elopher-address-port address)
+ :filter (lambda (proc string)
+ (setq elopher-selector-string (concat elopher-selector-string string)))
+ :sentinel after)
+ (process-send-string "elopher-process"
+ (concat (elopher-address-selector address) "\n")))
-(defun elopher ()
- "Start gopher client."
+;; Index retrieval
+
+(defun elopher-get-index-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (let ((inhibit-read-only t))
+ (insert content))
+ (elopher-restore-pos))
+ (if address
+ (elopher-get-selector address
+ (lambda (proc event)
+ (let ((inhibit-read-only t))
+ (elopher-insert-index elopher-selector-string))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string))))
+ (progn
+ (let ((inhibit-read-only t))
+ (elopher-insert-index elopher-start-index))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string)))))))
+
+;; Text retrieval
+
+(defun elopher-strip-CRs (string)
+ (replace-regexp-in-string "\r" "" string))
+
+(defun elopher-get-text-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (let ((inhibit-read-only t))
+ (insert content))
+ (elopher-restore-pos))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (let ((inhibit-read-only t))
+ (insert (elopher-strip-CRs elopher-selector-string)))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string)))))))
+
+;; Image retrieval
+
+(defun elopher-get-image-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (let ((inhibit-read-only t))
+ (insert-image content))
+ (elopher-restore-pos))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (let ((image (create-image
+ (string-as-unibyte elopher-selector-string)
+ nil t))
+ (inhibit-read-only t))
+ (insert-image image)
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node image)))))))
+
+
+
+;;; Navigation procedures
+;;
+
+(defun elopher-next-link ()
(interactive)
- (elopher-get-index (read-from-minibuffer "Gopher host: ") 70))
+ (forward-button 1))
-;; (elopher-get-index "cosmic.voyage")
-(elopher-get-index "gopher.floodgap.com")
-;; (elopher-get-index "maurits.id.au")
+(defun elopher-prev-link ()
+ (interactive)
+ (backward-button 1))
-(defun elopher-quit ()
+(defun elopher-click-link (button)
+ (let ((node (button-get button 'elopher-node)))
+ (elopher-visit-node node)))
+
+(defun elopher-follow-closest-link ()
+ (interactive)
+ (push-button))
+
+(defun elopher-go ()
+ "Go to a particular gopher site."
+ (interactive)
+ (let* ((selector "")
+ (hostname (read-from-minibuffer "Gopher host: "))
+ (port 70)
+ (address (list selector hostname port)))
+ (elopher-visit-node
+ (elopher-make-node elopher-current-node
+ address
+ #'elopher-get-index-node))))
+
+(defun elopher-reload ()
+ "Reload current site."
+ (interactive)
+ (elopher-reload-current-node))
+
+(defun elopher-back ()
+ "Go to previous site."
+ (interactive)
+ (if (elopher-node-parent elopher-current-node)
+ (elopher-visit-parent-node)
+ (message "No previous site.")))
+
+
+;;; Mode and keymap
+;;
+
+(defvar elopher-mode-map
+ (let ((map (make-sparse-keymap)))
+ (define-key map (kbd "<tab>") 'elopher-next-link)
+ (define-key map (kbd "<S-tab>") 'elopher-prev-link)
+ (define-key map (kbd "u") 'elopher-back)
+ (define-key map (kbd "g") 'elopher-go)
+ (define-key map (kbd "r") 'elopher-reload)
+ (when (require 'evil nil t)
+ (evil-define-key 'normal map
+ (kbd "C-]") 'elopher-follow-closest-link
+ (kbd "C-t") 'elopher-back
+ (kbd "u") 'elopher-back
+ (kbd "g") 'elopher-go
+ (kbd "r") 'elopher-reload))
+ map)
+ "Keymap for gopher client.")
+
+(define-derived-mode elopher-mode special-mode "elopher"
+ "Major mode for elopher, an elisp gopher client.")
+
+
+;;; Main start procedure
+;;
+(defun elopher ()
+ "Start elopher with default landing page."
(interactive)
- (kill-buffer "*elopher*"))
+ (setq elopher-current-node nil)
+ (let ((start-node (elopher-make-node nil nil #'elopher-get-index-node)))
+ (elopher-visit-node start-node)))
;;; elopher.el ends here