elpher-go now trims surrounding whitespace from input string.
[elpher.git] / elpher.el
index e508c61..1ea9e71 100644 (file)
--- a/elpher.el
+++ b/elpher.el
@@ -4,7 +4,7 @@
 
 ;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
 ;; Created: 11 April 2019
-;; Version: 2.7.5
+;; Version: 2.7.9
 ;; Keywords: comm gopher
 ;; Homepage: http://thelambdalab.xyz/elpher
 ;; Package-Requires: ((emacs "26"))
@@ -70,7 +70,7 @@
 ;;; Global constants
 ;;
 
-(defconst elpher-version "2.7.5"
+(defconst elpher-version "2.7.9"
   "Current version of elpher.")
 
 (defconst elpher-margin-width 6
@@ -148,10 +148,25 @@ The actual width used is the minimum of this value and the window width at
 the time when the text is rendered."
   :type '(integer))
 
+(defcustom elpher-gemini-link-string "→ "
+  "Specify the string used to indicate links when rendering gemini maps.
+May be empty."
+  :type '(string))
+
+(defcustom elpher-gemini-bullet-string "•"
+  "Specify the string used for bullets when rendering gemini maps."
+  :type '(string))
+
 (defcustom elpher-bookmarks-file (locate-user-emacs-file "elpher-bookmarks")
   "Specify the name of the file where elpher bookmarks will be saved."
   :type '(file))
 
+(defcustom elpher-ipv4-always nil
+  "If non-nil, elpher will always use IPv4 to establish network connections.
+This can be useful when browsing from a computer that supports IPv6, because
+some servers which do not support IPv6 can take a long time to time-out."
+  :type '(boolean))
+
 ;; Face customizations
 
 (defgroup elpher-faces nil
@@ -222,6 +237,10 @@ the time when the text is rendered."
   '((t :inherit bold :height 1.2))
   "Face used for gemini heading level 3.")
 
+(defface elpher-gemini-preformatted
+  '((t :inherit fixed-pitch))
+  "Face used for pre-formatted gemini text blocks.")
+
 ;;; Model
 ;;
 
@@ -288,9 +307,25 @@ requiring gopher-over-TLS."
 
 (defun elpher-address-to-url (address)
   "Get string representation of ADDRESS, or nil if ADDRESS is special."
-  (if (not (elpher-address-special-p address))
-      (url-encode-url (url-recreate-url address))
-    nil))
+  (if (elpher-address-special-p address)
+      nil
+    (let* ((port (url-port address))
+           (address-to-convert
+            (if (= port 0)
+                address
+              (let ((address-copy (seq-copy address))
+                    (protocol (url-type address)))
+                (if (or (and (equal protocol "gopher")
+                             (= port 70))
+                        (and (equal protocol "gemini")
+                             (= port 1965))
+                        (and (equal protocol "http")
+                             (= port 80))
+                        (and (equal protocol "finger")
+                             (= port 79)))
+                    (setf (url-port address-copy) 0))
+                address-copy))))
+      (url-encode-url (url-recreate-url address-to-convert)))))
 
 (defun elpher-address-type (address)
   "Retrieve type of ADDRESS object.
@@ -354,7 +389,7 @@ If no address is defined, returns 0.  (This is for compatibility with the URL li
   "Retrieve gopher selector from ADDRESS object."
   (if (member (url-filename address) '("" "/"))
       ""
-    (substring (url-filename address) 2)))
+    (url-unhex-string (substring (url-filename address) 2))))
 
 
 ;; Cache
@@ -545,6 +580,7 @@ to ADDRESS."
       (error "Cannot retrieve TLS gopher selector: GnuTLS not available")))
   (unless (< (elpher-address-port address) 65536)
     (error "Cannot retrieve gopher selector: port number > 65536"))
+  (defvar gnutls-verify-error)
   (condition-case nil
       (let* ((kill-buffer-query-functions nil)
              (gnutls-verify-error nil) ; We use the NSM for verification
@@ -555,7 +591,9 @@ to ADDRESS."
              (hkbytes-received 0)
              (proc (open-network-stream "elpher-process"
                                         nil
-                                        (if force-ipv4 (dns-query host) host)
+                                        (if (or elpher-ipv4-always force-ipv4)
+                                            (dns-query host)
+                                          host)
                                         (if (> port 0) port 70)
                                         :type (if elpher-use-tls 'tls 'plain)
                                         :nowait t))
@@ -576,7 +614,7 @@ to ADDRESS."
                                         (elpher-network-error address "Could not establish encrypted connection")))
                                      ('connect
                                       (elpher-process-cleanup)
-                                      (unless force-ipv4
+                                      (unless (or elpher-ipv4-always force-ipv4)
                                         (message "Connection timed out. Retrying with IPv4 address.")
                                         (elpher-get-selector address renderer t))))))))
         (setq elpher-network-timer timer)
@@ -673,12 +711,19 @@ once they are retrieved from the gopher server."
         (insert " "))
     (insert (make-string elpher-margin-width ?\s))))
 
-(defun elpher-page-button-help (page)
-  "Return a string containing the help text for a button corresponding to PAGE."
-  (let ((address (elpher-page-address page)))
-    (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
-                                          address
-                                        (elpher-address-to-url address)))))
+(defun elpher--page-button-help (_window buffer pos)
+  "Function called by Emacs to generate mouse-over text.
+The arguments specify the BUFFER and the POS within the buffer of the item
+for which help is required.  The function returns the help to be
+displayed.  The _WINDOW argument is currently unused."
+  (with-current-buffer buffer
+    (let ((button (button-at pos)))
+      (when button
+        (let* ((page (button-get button 'elpher-page))
+               (address (elpher-page-address page)))
+          (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
+                                                address
+                                              (url-recreate-url address))))))))
 
 (defun elpher-insert-index-record (display-string &optional address)
   "Function to insert an index record into the current buffer.
@@ -698,7 +743,7 @@ If ADDRESS is not supplied or nil the record is rendered as an
                               'elpher-page page
                               'action #'elpher-click-link
                               'follow-link t
-                              'help-echo (elpher-page-button-help page)))
+                              'help-echo #'elpher--page-button-help))
       (pcase type
         ('nil ;; Information
          (elpher-insert-margin)
@@ -744,7 +789,7 @@ If ADDRESS is not supplied or nil the record is rendered as an
                             'elpher-page  page
                             'action #'elpher-click-link
                             'follow-link t
-                            'help-echo (elpher-page-button-help page)
+                            'help-echo #'elpher--page-button-help
                             'face 'button)))
     (buffer-string)))
 
@@ -874,6 +919,7 @@ to ADDRESS."
       (error "Cannot establish gemini connection: GnuTLS not available")
     (unless (< (elpher-address-port address) 65536)
       (error "Cannot establish gemini connection: port number > 65536"))
+    (defvar gnutls-verify-error)
     (condition-case nil
         (let* ((kill-buffer-query-functions nil)
                (gnutls-verify-error nil) ; We use the NSM for verification
@@ -884,14 +930,16 @@ to ADDRESS."
                (hkbytes-received 0)
                (proc (open-network-stream "elpher-process"
                                           nil
-                                          (if force-ipv4 (dns-query host) host)
+                                          (if (or elpher-ipv4-always force-ipv4)
+                                              (dns-query host)
+                                            host)
                                           (if (> port 0) port 1965)
                                           :type 'tls
                                           :nowait t))
                (timer (run-at-time elpher-connection-timeout nil
                                    (lambda ()
                                      (elpher-process-cleanup)
-                                     (unless force-ipv4
+                                     (unless (or elpher-ipv4-always force-ipv4)
                                         ; Try again with IPv4
                                        (message "Connection timed out.  Retrying with IPv4.")
                                        (elpher-get-gemini-response address renderer t))))))
@@ -928,7 +976,7 @@ to ADDRESS."
                                                    "\r\n"))))
                                        ((string-prefix-p "deleted" event)) ; do nothing
                                        ((and (not response-string-parts)
-                                             (not force-ipv4))
+                                             (not (or elpher-ipv4-always force-ipv4)))
                                         ; Try again with IPv4
                                         (message "Connection failed. Retrying with IPv4.")
                                         (cancel-timer timer)
@@ -1084,17 +1132,18 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
 
 (defun elpher-address-from-gemini-url (url)
   "Extract address from URL with defaults as per gemini map files."
-  (let ((address (url-generic-parse-url url)))
+  (let ((address (url-generic-parse-url url))
+        (current-address (elpher-page-address elpher-current-page)))
     (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
       (setf (url-fullness address) t)
       (if (url-host address) ;if there is an explicit host, filenames are absolute
           (if (string-empty-p (url-filename address))
               (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
-        (setf (url-host address) (url-host (elpher-page-address elpher-current-page)))
+        (setf (url-host address) (url-host current-address))
+        (setf (url-port address) (url-port current-address))
         (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
           (setf (url-filename address)
-                (concat (file-name-directory
-                         (url-filename (elpher-page-address elpher-current-page)))
+                (concat (file-name-directory (url-filename current-address))
                         (url-filename address)))))
       (unless (url-type address)
         (setf (url-type address) "gemini"))
@@ -1111,7 +1160,7 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
          (type (if address (elpher-address-type address) nil))
          (type-map-entry (cdr (assoc type elpher-type-map))))
     (when display-string
-      (insert "→ ")
+      (insert elpher-gemini-link-string)
       (if type-map-entry
           (let* ((face (elt type-map-entry 3))
                  (filtered-display-string (ansi-color-filter-apply display-string))
@@ -1121,7 +1170,7 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
                                 'elpher-page page
                                 'action #'elpher-click-link
                                 'follow-link t
-                                'help-echo (elpher-page-button-help page)))
+                                'help-echo #'elpher--page-button-help))
         (insert (propertize display-string 'face 'elpher-unknown)))
       (insert "\n"))))
   
@@ -1142,6 +1191,24 @@ by HEADER-LINE."
                             (_ 'default)))
               "\n"))))
 
+(defun elpher-gemini-insert-text (text-line)
+  "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
+This function uses Emacs' auto-fill to wrap text sensibly to a maximum
+width defined by elpher-gemini-max-fill-width."
+  (string-match "\\(^[ \t]*\\)\\(\*[ \t]\\)?" text-line)
+  (let* ((processed-text-line (if (match-string 2 text-line)
+                                  (concat
+                                   (replace-regexp-in-string "\*"
+                                                             elpher-gemini-bullet-string
+                                                             (match-string 0 text-line))
+                                   (substring text-line (match-end 0)))
+                                text-line))
+         (fill-prefix (if (match-string 1 text-line)
+                          (replace-regexp-in-string "\*" " " (match-string 0 text-line))
+                        nil)))
+    (insert (elpher-process-text-for-display processed-text-line))
+    (newline)))
+
 (defun elpher-render-gemini-map (data _parameters)
   "Render DATA as a gemini map file, PARAMETERS is currently unused."
   (elpher-with-clean-buffer
@@ -1151,10 +1218,12 @@ by HEADER-LINE."
      (dolist (line (split-string data "\n"))
        (cond
         ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
-        (preformatted (insert (elpher-process-text-for-display line) "\n"))
+        (preformatted (insert (elpher-process-text-for-display
+                               (propertize line 'face 'elpher-gemini-preformatted))
+                              "\n"))
         ((string-prefix-p "=>" line) (elpher-gemini-insert-link line))
         ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
-        (t (insert (elpher-process-text-for-display line)) (newline)))))
+        (t (elpher-gemini-insert-text line)))))
    (elpher-cache-content
     (elpher-page-address elpher-current-page)
     (buffer-string))))
@@ -1170,7 +1239,11 @@ by HEADER-LINE."
 ;; Finger page connection
 
 (defun elpher-get-finger-page (renderer &optional force-ipv4)
-  "Opens a finger connection to the current page address and renders it using RENDERER."
+  "Opens a finger connection to the current page address.
+The result is rendered using RENDERER.  When the optional argument
+FORCE-IPV4 or the variable `elpher-ipv4-always' are non-nil, the
+IPv4 address returned by a DNS lookup will be used explicitly in
+making the connection."
   (let* ((address (elpher-page-address elpher-current-page))
          (content (elpher-get-cached-content address)))
     (if (and content (funcall renderer nil))
@@ -1191,7 +1264,9 @@ by HEADER-LINE."
                  (selector-string-parts nil)
                  (proc (open-network-stream "elpher-process"
                                             nil
-                                            (if force-ipv4 (dns-query host) host)
+                                            (if (or elpher-ipv4-always force-ipv4)
+                                                (dns-query host)
+                                              host)
                                             port
                                             :type 'plain
                                             :nowait t))
@@ -1201,7 +1276,7 @@ by HEADER-LINE."
                                        (pcase (process-status proc)
                                          ('connect
                                           (elpher-process-cleanup)
-                                          (unless force-ipv4
+                                          (unless (or elpher-ipv4-always force-ipv4)
                                             (message "Connection timed out. Retrying with IPv4 address.")
                                             (elpher-get-finger-page renderer t))))))))
             (setq elpher-network-timer timer)
@@ -1215,7 +1290,7 @@ by HEADER-LINE."
                                         (cons string selector-string-parts))))
             (set-process-sentinel proc
                                   (lambda (_proc event)
-                                    (condition-case the-error
+                                    (condition-case _the-error
                                         (cond
                                          ((string-prefix-p "deleted" event))
                                          ((string-prefix-p "open" event)
@@ -1283,7 +1358,7 @@ by HEADER-LINE."
            " - TAB/Shift-TAB: next/prev item on current page\n"
            " - RET/mouse-1: open item under cursor\n"
            " - m: select an item on current page by name (autocompletes)\n"
-           " - u/mouse-3: return to previous page\n"
+           " - u/mouse-3/U: return to previous page or to the start page\n"
            " - o/O: visit different selector or the root menu of the current server\n"
            " - g: go to a particular address (gopher, gemini, finger)\n"
            " - d/D: download item under cursor or current page\n"
@@ -1463,11 +1538,12 @@ If ADDRESS is already bookmarked, update the label only."
   "Go to a particular gopher site HOST-OR-URL.
 When run interactively HOST-OR-URL is read from the minibuffer."
   (interactive "sGopher or Gemini URL: ")
-  (let ((page (elpher-make-page host-or-url
-                                (elpher-address-from-url host-or-url))))
+  (let* ((cleaned-host-or-url (string-trim host-or-url))
+         (address (elpher-address-from-url cleaned-host-or-url))
+         (page (elpher-make-page cleaned-host-or-url address))) 
     (switch-to-buffer "*elpher*")
     (elpher-visit-page page)
-    '()))
+    nil))
 
 (defun elpher-go-current ()
   "Go to a particular site read from the minibuffer, initialized with the current URL."
@@ -1512,6 +1588,15 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   (interactive)
   (elpher-visit-previous-page))
 
+(defun elpher-back-to-start ()
+  "Go all the way back to the start page."
+  (interactive)
+  (setq elpher-current-page nil)
+  (setq elpher-history nil)
+  (let ((start-page (elpher-make-page "Elpher Start Page"
+                                      (elpher-make-special-address 'start))))
+    (elpher-visit-page start-page)))
+
 (defun elpher-download ()
   "Download the link at point."
   (interactive)
@@ -1617,7 +1702,8 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   "Remove bookmark for the current page."
   (interactive)
   (let ((address (elpher-page-address elpher-current-page)))
-    (unless (elpher-address-special-p address)
+    (when (and (not (elpher-address-special-p address))
+               (y-or-n-p "Really remove bookmark for the current page? "))
       (elpher-remove-address-bookmark address)
       (message "Bookmark removed."))))
 
@@ -1626,10 +1712,11 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   (interactive)
   (let ((button (button-at (point))))
     (if button
-        (let ((page (button-get button 'elpher-page)))
-          (elpher-remove-address-bookmark (elpher-page-address page))
-          (elpher-reload-bookmarks)
-          (message "Bookmark removed."))
+        (when (y-or-n-p "Really remove bookmark for this link? ")
+          (let ((page (button-get button 'elpher-page)))
+            (elpher-remove-address-bookmark (elpher-page-address page))
+            (elpher-reload-bookmarks)
+            (message "Bookmark removed.")))
       (error "No link selected"))))
 
 (defun elpher-bookmarks ()
@@ -1701,6 +1788,7 @@ When run interactively HOST-OR-URL is read from the minibuffer."
     (define-key map (kbd "<backtab>") 'elpher-prev-link)
     (define-key map (kbd "C-M-i") 'elpher-prev-link)
     (define-key map (kbd "u") 'elpher-back)
+    (define-key map (kbd "U") 'elpher-back-to-start)
     (define-key map [mouse-3] 'elpher-back)
     (define-key map (kbd "O") 'elpher-root-dir)
     (define-key map (kbd "g") 'elpher-go)
@@ -1728,6 +1816,7 @@ When run interactively HOST-OR-URL is read from the minibuffer."
         (kbd "C-") 'elpher-follow-current-link
         (kbd "C-t") 'elpher-back
         (kbd "u") 'elpher-back
+        (kbd "U") 'elpher-back-to-start
         [mouse-3] 'elpher-back
         (kbd "g") 'elpher-go
         (kbd "o") 'elpher-go-current
@@ -1773,6 +1862,7 @@ functions which initialize the gopher client, namely
       (switch-to-buffer "*elpher*")
     (switch-to-buffer "*elpher*")
     (setq elpher-current-page nil)
+    (setq elpher-history nil)
     (let ((start-page (elpher-make-page "Elpher Start Page"
                                         (elpher-make-special-address 'start))))
       (elpher-visit-page start-page)))