X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=elopher.el;h=2d97313d7271fe4b52fcb8534bb9510fffbdb923;hb=9d519f3e22fb7678d31f2b71c165c2c5cf3a8ed4;hp=fd0e91029ff9c6a9110a3f97de39e4b8d4f896b8;hpb=4e8af883d7ef57fad6fbfa8b26ba20d42f4ff343;p=elpher.git

diff --git a/elopher.el b/elopher.el
index fd0e910..2d97313 100644
--- a/elopher.el
+++ b/elopher.el
@@ -1,56 +1,633 @@
-;;; elopher.el --- gopher client
+;;; elopher.el --- elisp gopher client
 
 ;;; Commentary:
 
-;; Simple gopher client in elisp.
+;; An elisp gopher client.
 
 ;;; 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: redraw current page (using cached contents if available)\tfake\tfake\t1"
+         "i - R: reload current page (regenerates cache)\tfake\tfake\t1"
+         "i - d: download directory entry under cursor\tfake\tfake\t1"
+         "i - w: display the raw server response for the current page\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")
+  "Source for elopher start page.")
 
-(defun elopher ()
-  "Start gopher client."
+
+;;; Customization group
+;;
+
+(defgroup elopher nil
+  "A gopher client."
+  :group 'applications)
+
+(defface elopher-index
+  '((((background dark)) :foreground "deep sky blue")
+    (((background light)) :foreground "blue"))
+  "Face used for index records.")
+
+(defface elopher-text
+  '((((background dark)) :foreground "white")
+    (((background light)) :weight bold))
+  "Face used for text records.")
+
+(defface elopher-info '()
+  "Face used for info records.")
+
+(defface elopher-image
+  '((((background dark)) :foreground "green")
+    (t :foreground "dark green"))
+  "Face used for image records.")
+
+(defface elopher-search
+  '((((background light)) :foreground "orange")
+    (((background dark)) :foreground "dark orange"))
+  "Face used for search records.")
+
+(defface elopher-url
+  '((((background dark)) :foreground "yellow")
+    (((background light)) :foreground "dark red"))
+  "Face used for url records.")
+
+(defface elopher-binary
+  '((t :foreground "magenta"))
+  "Face used for binary records.")
+
+(defface elopher-unknown
+  '((t :foreground "red"))
+  "Face used for unknown record types.")
+
+(defface elopher-margin-key
+  '((((background dark)) :foreground "white"))
+  "Face used for margin key.")
+
+(defface elopher-margin-brackets
+  '((t :foreground "blue"))
+  "Face used for brackets around margin key.")
+
+(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)
+  "Create an address of a gopher object with SELECTOR, HOST and PORT."
+  (list selector host port))
+
+(defun elopher-address-selector (address)
+  "Retrieve selector from ADDRESS."
+  (car address))
+
+(defun elopher-address-host (address)
+  "Retrieve host from ADDRESS."
+  (cadr address))
+
+(defun elopher-address-port (address)
+  "Retrieve port from ADDRESS."
+  (caddr address))
+
+;; Node
+
+(defun elopher-make-node (parent address getter &optional content pos)
+  "Create a node in the gopher page hierarchy.
+
+PARENT specifies the parent of the node, ADDRESS specifies the address of
+the gopher page, GETTER provides the getter function used to obtain this
+page.
+
+The optional arguments CONTENT and POS can be used to fill the cached
+content and cursor position fields of the node."
+  (list parent address getter content pos))
+
+(defun elopher-node-parent (node)
+  "Retrieve the parent node of NODE."
+  (elt node 0))
+
+(defun elopher-node-address (node)
+  "Retrieve the address of NODE."
+  (elt node 1))
+
+(defun elopher-node-getter (node)
+  "Retrieve the preferred getter function of NODE."
+  (elt node 2))
+
+(defun elopher-node-content (node)
+  "Retrieve the cached content of NODE, or nil if none exists."
+  (elt node 3))
+
+(defun elopher-node-pos (node)
+  "Retrieve the cached cursor position for NODE, or nil if none exists."
+  (elt node 4))
+
+(defun elopher-set-node-content (node content)
+  "Set the content cache of NODE to CONTENT."
+  (setcar (nthcdr 3 node) content))
+
+(defun elopher-set-node-pos (node pos)
+  "Set the cursor position cache of NODE to POS."
+  (setcar (nthcdr 4 node) pos))
+
+(defun elopher-save-pos ()
+  "Save the current position of point to the current node."
+  (when elopher-current-node
+    (elopher-set-node-pos elopher-current-node (point))))
+
+(defun elopher-restore-pos ()
+  "Restore the position of point to that cached in the current node."
+  (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 getter)
+  "Visit NODE using its own getter or GETTER, if non-nil."
+  (elopher-save-pos)
+  (elopher-process-cleanup)
+  (setq elopher-current-node node)
+  (if getter
+      (funcall getter)
+    (funcall (elopher-node-getter node))))
+
+(defun elopher-visit-parent-node ()
+  "Visit the parent of the current node."
+  (let ((parent-node (elopher-node-parent elopher-current-node)))
+    (when parent-node
+      (elopher-visit-node parent-node))))
+      
+(defun elopher-reload-current-node ()
+  "Reload the current node, discarding any existing cached content."
+  (elopher-set-node-content elopher-current-node nil)
+  (elopher-visit-node elopher-current-node))
+
+;;; Buffer preparation
+;;
+
+(defmacro elopher-with-clean-buffer (&rest args)
+  "Evaluate ARGS with a clean *elopher* buffer as current."
+  (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 'elopher-margin-brackets)
+                         (propertize type-name 'face 'elopher-margin-key)
+                         (propertize "]" 'face 'elopher-margin-brackets))))
+        (insert " "))
+    (insert (make-string elopher-margin-width ?\s))))
+
+(defvar elopher-type-map
+  '((?0 elopher-get-text-node "T" elopher-text)
+    (?1 elopher-get-index-node "/" elopher-index)
+    (?g elopher-get-image-node "im" elopher-image)
+    (?p elopher-get-image-node "im" elopher-image)
+    (?I elopher-get-image-node "im" elopher-image)
+    (?4 elopher-get-node-download "B" elopher-binary)
+    (?5 elopher-get-node-download "B" elopher-binary)
+    (?9 elopher-get-node-download "B" elopher-binary)
+    (?7 elopher-get-search-node "?" elopher-search))
+  "Association list from types to getters, margin codes and index faces.")
+
+(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))
+         (type-map-entry (alist-get type elopher-type-map)))
+    (if type-map-entry
+        (let ((getter (car type-map-entry))
+              (margin-code (cadr type-map-entry))
+              (face (caddr type-map-entry)))
+          (elopher-insert-margin margin-code)
+          (insert-text-button display-string
+                              'face face
+                              'elopher-node (elopher-make-node elopher-current-node
+                                                               address
+                                                               getter)
+                              'action #'elopher-click-link
+                              'follow-link t
+                              'help-echo (format "mouse-1, RET: open %s on %s port %s"
+                                                 selector host port)))
+      (pcase type
+        (?i (elopher-insert-margin) ; Information
+            (insert (propertize display-string
+                                'face 'elopher-info)))
+        (?h (elopher-insert-margin "W") ; Web link
+            (let ((url (elt (split-string selector "URL:") 1)))
+              (insert-text-button display-string
+                                  'face 'elopher-url
+                                  '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)
+;;
+
+(defun elopher-process-cleanup ()
+  "Immediately shut down any extant elopher process."
+  (let ((p (get-process "elopher-process")))
+    (if p (delete-process p))))
+
+(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 "")
+  (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)
+                                    (unless (string-prefix-p "deleted" 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
+
+(defconst elopher-url-regex "\\(https?\\|gopher\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
+  "Regexp used to locate and buttinofy URLs in text files loaded by elopher.")
+
+(defun elopher-buttonify-urls (string)
+  "Turn substrings which look like urls in STRING into clickable buttons."
+  (with-temp-buffer
+    (insert string)
+    (goto-char (point-min))
+    (while (re-search-forward elopher-url-regex nil t)
+      (let ((url (match-string 0))
+            (protocol (downcase (match-string 1))))
+        (if (string= protocol "gopher")
+            (let* ((host (match-string 2))
+                   (port 70)
+                   (type-and-selector (match-string 4))
+                   (type (if (> (length type-and-selector) 1)
+                             (elt type-and-selector 1)
+                           ?1))
+                   (selector (if (> (length type-and-selector) 1)
+                                 (substring type-and-selector 2)
+                               ""))
+                   (address (elopher-make-address selector host port))
+                   (getter (car (alist-get type elopher-type-map))))
+              (make-text-button (match-beginning 0)
+                                (match-end 0)
+                                'elopher-node (elopher-make-node elopher-current-node
+                                                                 address
+                                                                 getter)
+                                'action #'elopher-click-link
+                                'follow-link t
+                                'help-echo (format "mouse-1, RET: open %s on %s port %s"
+                                                   selector host port)))
+          (make-text-button (match-beginning 0)
+                            (match-end 0)
+                            'elopher-url url
+                            'action #'elopher-click-url
+                            'follow-link t
+                            'help-echo (format "mouse-1, RET: open url %s" url)))))
+    (buffer-string)))
+
+(defun elopher-process-text (string)
+  (let* ((chopped-str (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string))
+         (cleaned-str (replace-regexp-in-string "\r" "" chopped-str)))
+    (elopher-buttonify-urls cleaned-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)
+                                (unless (string-prefix-p "deleted" 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)
+                                (unless (string-prefix-p "deleted" 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))
+        (aborted t))
+    (if content
+        (progn
+          (elopher-with-clean-buffer
+           (insert content))
+          (elopher-restore-pos)
+          (message "Displaying cached search results.  Reload to perform a new search."))
+      (unwind-protect
+          (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))))
+            (setq aborted nil)
+            (elopher-with-clean-buffer
+             (insert "LOADING RESULTS..."))
+            (elopher-get-selector search-address
+                                  (lambda (proc event)
+                                    (unless (string-prefix-p "deleted" event)
+                                      (elopher-with-clean-buffer
+                                       (elopher-insert-index elopher-selector-string))
+                                      (goto-char (point-min))
+                                      (elopher-set-node-content elopher-current-node
+                                                                (buffer-string))))))
+        (if aborted
+            (elopher-visit-parent-node))))))
+
+;; Raw server response retrieval
+
+(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)
+                                (unless (string-prefix-p "deleted" 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 or redraw to return to standard view."))
+ 
+;; File export retrieval
+
+(defvar elopher-download-filename)
+
+(defun elopher-get-node-download ()
+  (let* ((address (elopher-node-address elopher-current-node))
+         (selector (elopher-address-selector address)))
+    (elopher-visit-parent-node) ; Do first in case of non-local exits.
+    (let* ((filename-proposal (file-name-nondirectory selector))
+           (filename (read-file-name "Save file as: "
+                                     nil nil nil
+                                     (if (> (length filename-proposal) 0)
+                                         filename-proposal
+                                       "gopher.file"))))
+      (message "Downloading...")
+      (setq elopher-download-filename filename)
+      (elopher-get-selector address
+                            (lambda (proc event)
+                              (let ((coding-system-for-write 'binary))
+                                (with-temp-file elopher-download-filename
+                                  (insert elopher-selector-string)
+                                  (message (format "Download complate, saved to file %s."
+                                                   elopher-download-filename)))))))))
+
+
+;;; 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-quit ()
+(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-current-link ()
+  "Open the link or url at point."
+  (interactive)
+  (push-button))
+
+(defun elopher-go ()
+  "Go to a particular gopher site."
   (interactive)
-  (kill-buffer "*elopher*"))
+  (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))))
 
-(start-process "ls" "*elopher*" "/bin/date")
+(defun  elopher-redraw ()
+  "Redraw current page."
+  (interactive)
+  (elopher-visit-node elopher-current-node))
 
-;;; elopher.el ends here
+(defun  elopher-reload ()
+  "Reload current page."
+  (interactive)
+  (elopher-reload-current-node))
+
+(defun elopher-view-raw ()
+  "View current page as plain text."
+  (interactive)
+  (elopher-visit-node elopher-current-node
+                      #'elopher-get-node-raw))
+
+(defun elopher-back ()
+  "Go to previous site."
+  (interactive)
+  (if (elopher-node-parent elopher-current-node)
+      (elopher-visit-parent-node)
+    (message "No previous site.")))
 
-(list-processes)
+(defun elopher-download ()
+  "Download the link at point."
+  (interactive)
+  (let ((button (button-at (point))))
+    (if button
+        (let ((node (button-get button 'elopher-node)))
+          (if node
+              (elopher-visit-node (button-get button 'elopher-node)
+                                  #'elopher-get-node-download)
+            (message "Can only download gopher links, not general URLs.")))
+      (message "No link selected."))))
+
+;;; Mode and keymap
+;;
+
+(defvar elopher-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map (kbd "TAB") 'elopher-next-link)
+    (define-key map (kbd "<backtab>") 'elopher-prev-link)
+    (define-key map (kbd "u") 'elopher-back)
+    (define-key map (kbd "g") 'elopher-go)
+    (define-key map (kbd "r") 'elopher-redraw)
+    (define-key map (kbd "R") 'elopher-reload)
+    (define-key map (kbd "w") 'elopher-view-raw)
+    (define-key map (kbd "d") 'elopher-download)
+    (when (fboundp 'evil-define-key)
+      (evil-define-key 'normal map
+        (kbd "TAB") 'elopher-next-link
+        (kbd "C-]") 'elopher-follow-current-link
+        (kbd "C-t") 'elopher-back
+        (kbd "u") 'elopher-back
+        (kbd "g") 'elopher-go
+        (kbd "r") 'elopher-redraw
+        (kbd "R") 'elopher-reload
+        (kbd "w") 'elopher-view-raw
+        (kbd "d") 'elopher-download))
+    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))
+  "Started Elopher.") ; Otherwise (elopher) evaluates to start page string.
+
+;;; elopher.el ends here