;;; 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.")
-(defvar my-marker nil)
+(defconst elopher-margin-width 6
+ "Width of left-hand margin used when rendering indicies.")
-(defun my-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)
- (insert (propertize string 'face '(foreground-color . "yellow")))
- (set-marker marker (point))))))
-
+(defconst elopher-start-index
+ (mapconcat 'identity
+ (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\tfake\tfake\t1"
+ "i - tab/shift-tab: next/prev directory entry on current page\tfake\tfake\t1"
+ "i - RET/mouse-1: open directory entry under cursor\tfake\tfake\t1"
+ "i - u: return to parent directory entry\tfake\tfake\t1"
+ "i - g: go to a particular page\tfake\tfake\t1"
+ "i - r: reload current page\tfake\tfake\t1"
+ "i - t: display the current page as text (i.e. \"source\")\tfake\tfake\t1"
+ "i\tfake\tfake\t1"
+ "iPlaces to start exploring Gopherspace:\tfake\tfake\t1"
+ "i\tfake\tfake\t1"
+ "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70"
+ "i\tfake\tfake\t1"
+ "iAlternatively, select the following item and enter some\tfake\tfake\t1"
+ "isearch terms:\tfake\tfake\t1"
+ "i\tfake\tfake\t1"
+ "7Veronica-2 Gopher Search Engine\t/v2/vs\tgopher.floodgap.com\t70"
+ ".")
+ "\r\n"))
-(defun elopher ()
- "Start gopher client."
+
+;;; Customization group
+;;
+
+(defgroup elopher nil
+ "A simple gopher client."
+ :group 'applications)
+
+(defcustom elopher-index-face '(foreground-color . "cyan")
+ "Face used for index records."
+ :type '(face))
+
+(defcustom elopher-text-face '(foreground-color . "white")
+ "Face used for text records."
+ :type '(face))
+
+(defcustom elopher-info-face '(foreground-color . "gray")
+ "Face used for info records."
+ :type '(face))
+
+(defcustom elopher-image-face '(foreground-color . "green")
+ "Face used for image records."
+ :type '(face))
+
+(defcustom elopher-search-face '(foreground-color . "orange")
+ "Face used for image records."
+ :type '(face))
+
+(defcustom elopher-http-face '(foreground-color . "yellow")
+ "Face used for image records."
+ :type '(face))
+
+(defcustom elopher-unknown-face '(foreground-color . "red")
+ "Face used for unknown record types."
+ :type '(face))
+
+(defcustom elopher-open-urls-with-eww nil
+ "If non-nil, open URL selectors using eww.
+Otherwise, use the system browser via the BROWSE-URL function."
+ :type '(boolean))
+
+;;; 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 &optional raw)
+ (elopher-save-pos)
+ (setq elopher-current-node node)
+ (if raw
+ (elopher-get-node-raw)
+ (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
+;;
+
+(defmacro elopher-with-clean-buffer (&rest args)
+ (list 'progn
+ '(switch-to-buffer "*elopher*")
+ '(elopher-mode)
+ (append (list 'let '((inhibit-read-only t))
+ '(erase-buffer))
+ args)))
+
+;;; Index rendering
+;;
+
+(defun elopher-insert-index (string)
+ "Insert the index corresponding to STRING into the current buffer."
+ (dolist (line (split-string string "\r\n"))
+ (unless (= (length line) 0)
+ (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
+ (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-insert-index-record (line)
+ "Insert the index record corresponding to LINE into the current buffer."
+ (let* ((type (elt line 0))
+ (fields (split-string (substring line 1) "\t"))
+ (display-string (elt fields 0))
+ (selector (elt fields 1))
+ (host (elt fields 2))
+ (port (elt fields 3))
+ (address (elopher-make-address selector host port))
+ (help-string (format "mouse-1, RET: open %s on %s port %s"
+ selector host port)))
+ (pcase type
+ (?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))
+ (?7 (elopher-insert-margin "S")
+ (insert-text-button display-string
+ 'face elopher-search-face
+ 'elopher-node (elopher-make-node elopher-current-node
+ address
+ #'elopher-get-search-node)
+ 'action #'elopher-click-link
+ 'follow-link t
+ 'help-echo help-string))
+ (?h (elopher-insert-margin "W")
+ (let ((url (elt (split-string selector "URL:") 1)))
+ (insert-text-button display-string
+ 'face elopher-http-face
+ 'elopher-url url
+ 'action #'elopher-click-url
+ 'follow-link t
+ 'help-echo (format "mouse-1, RET: open url %s" url))))
+ (?.) ; 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)
+ "Retrieve selector specified by ADDRESS, then execute AFTER.
+The result is stored as a string in the variable elopher-selector-string."
+ (setq elopher-selector-string "")
+ (let ((p (get-process "elopher-process")))
+ (if p (delete-process p)))
+ (make-network-process
+ :name "elopher-process"
+ :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")))
+
+;; 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
+ (elopher-with-clean-buffer
+ (insert content))
+ (elopher-restore-pos))
+ (if address
+ (progn
+ (elopher-with-clean-buffer
+ (insert "LOADING DIRECTORY..."))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-selector-string))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string)))))
+ (progn
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-start-index))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string)))))))
+
+;; Text retrieval
+
+(defun elopher-process-text (string)
+ (let ((chopped-str (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string)))
+ (replace-regexp-in-string "\r" "" chopped-str)))
+
+(defun elopher-get-text-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (elopher-with-clean-buffer
+ (insert content))
+ (elopher-restore-pos))
+ (progn
+ (elopher-with-clean-buffer
+ (insert "LOADING TEXT..."))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (elopher-with-clean-buffer
+ (insert (elopher-process-text 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
+ (elopher-with-clean-buffer
+ (insert-image content))
+ (setq cursor-type nil)
+ (elopher-restore-pos))
+ (progn
+ (elopher-with-clean-buffer
+ (insert "LOADING IMAGE..."))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (let ((image (create-image
+ (string-as-unibyte elopher-selector-string)
+ nil t)))
+ (elopher-with-clean-buffer
+ (insert-image image))
+ (setq cursor-type nil)
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node image))))))))
+
+;; Search retrieval
+
+(defun elopher-get-search-node ()
+ (let* ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (elopher-with-clean-buffer
+ (insert content))
+ (elopher-restore-pos)
+ (message "Displaying cached search results. Reload to perform a new search."))
+ (let* ((query-string (read-string "Query: "))
+ (query-selector (concat (elopher-address-selector address) "\t" query-string))
+ (search-address (elopher-make-address query-selector
+ (elopher-address-host address)
+ (elopher-address-port address))))
+ (elopher-with-clean-buffer
+ (insert "LOADING RESULTS..."))
+ (elopher-get-selector search-address
+ (lambda (proc event)
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-selector-string))
+ (goto-char (point-min))
+ (elopher-set-node-content elopher-current-node
+ (buffer-string))))))))
+
+(defun elopher-get-node-raw ()
+ (let* ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (elopher-with-clean-buffer
+ (insert "LOADING RAW SERVER RESPONSE..."))
+ (if address
+ (elopher-get-selector address
+ (lambda (proc event)
+ (elopher-with-clean-buffer
+ (insert elopher-selector-string))
+ (goto-char (point-min))))
+ (progn
+ (elopher-with-clean-buffer
+ (insert elopher-start-index))
+ (goto-char (point-min)))))
+ (message "Displaying raw server response. Reload to return to standard view."))
+
+
+;;; Navigation procedures
+;;
+
+(defun elopher-next-link ()
(interactive)
- (switch-to-buffer-other-window "*elopher*")
- (setq my-marker (make-marker))
- (erase-buffer)
- (make-process
- :name "date"
- :command (list "/bin/ls" "-l" "/")
- :filter #'my-filter))
+ (forward-button 1))
-(elopher)
-
- ;; (address (read-from-minibuffer "Address of gopher server: ")))
- ;; (message "Connecting to '%s' ..." address)
- ;; (erase-buffer)
- ;; (insert (propertize "Hello, world." 'face '(foreground-color . "red")))
- ;; (newline)
- ;; (insert (propertize "Hello, Tim." 'face '(foreground-color . "yellow"))))
+(defun elopher-prev-link ()
+ (interactive)
+ (backward-button 1))
+
+(defun elopher-click-link (button)
+ (let ((node (button-get button 'elopher-node)))
+ (elopher-visit-node node)))
+
+(defun elopher-click-url (button)
+ (let ((url (button-get button 'elopher-url)))
+ (if elopher-open-urls-with-eww
+ (browse-web url)
+ (browse-url url))))
+
+(defun elopher-follow-closest-link ()
+ (interactive)
+ (push-button))
+
+(defun elopher-go ()
+ "Go to a particular gopher site."
+ (interactive)
+ (let* (
+ (hostname (read-string "Gopher host: "))
+ (selector (read-string "Selector (default none): " nil nil ""))
+ (port (read-string "Port (default 70): " nil nil 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 page."
+ (interactive)
+ (elopher-reload-current-node))
-(defun elopher-quit ()
+(defun elopher-view-raw ()
+ "View current page as plain text."
(interactive)
- (kill-buffer "*elopher*"))
+ (elopher-visit-node elopher-current-node t))
-(start-process "ls" "*elopher*" "/bin/date")
+(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)
+ (define-key map (kbd "w") 'elopher-view-raw)
+ (when (fboundp 'evil-define-key)
+ (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
+ (kbd "w") 'elopher-view-raw))
+ 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)
+ (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
-(list-processes)