Clarified commentary.

[elpher.git] / elpher.el

diff --git a/elpher.el b/elpher.el
index 7c1b9d0..d4c582a 100644 (file)
--- a/elpher.el
+++ b/elpher.el
@@ -36,9 +36,8 @@
 ;; - (m)enu key support, similar to Emacs' info browser,
 ;; - clickable web and gopher links in plain text.
 
-;; The caching mechanism works by maintaining a hierarchy of visited
-;; pages rather than a linear history, meaning that it is quick and
-;; easy to navigate this history.
+;; Visited pages are stored as a hierarchy rather than a linear history,
+;; meaning that navigation between these pages is quick and easy.
 
 ;; To launch Elpher, simply use 'M-x elpher'.  This will open a start
 ;; page containing information on key bindings and suggested starting
@@ -54,7 +53,7 @@
 ;;; Global constants
 ;;
 
-(defconst elpher-version "1.0.0"
+(defconst elpher-version "1.1.0"
   "Current version of elpher.")
 
 (defconst elpher-margin-width 6
@@ -64,10 +63,10 @@
   (mapconcat
    'identity
    (list "i\tfake\tfake\t1"
-         "i--------------------------------------------\tfake\tfake\t1"
-         "i           Elpher Gopher Client             \tfake\tfake\t1"
-         (format "i              version %s\tfake\tfake\t1" elpher-version)
-         "i--------------------------------------------\tfake\tfake\t1"
+         "i     --------------------------------------------\tfake\tfake\t1"
+         "i                Elpher Gopher Client             \tfake\tfake\t1"
+         (format "i                   version %s\tfake\tfake\t1" elpher-version)
+         "i     --------------------------------------------\tfake\tfake\t1"
          "i\tfake\tfake\t1"
          "iUsage:\tfake\tfake\t1"
          "i\tfake\tfake\t1"
@@ -163,6 +162,10 @@
 Otherwise, use the system browser via the BROWSE-URL function."
   :type '(boolean))
 
+(defcustom elpher-buttonify-urls-in-directories nil
+  "If non-nil, turns URLs matched in directories into clickable buttons."
+  :type '(boolean))
+
 (defcustom elpher-cache-images nil
   "If non-nil, cache images in memory in the same way as other content."
   :type '(boolean))
@@ -173,7 +176,6 @@ Otherwise, a list containing the selector, host and port of a directory to
 use as the start page."
   :type '(list string string integer))
 
-
 ;;; Model
 ;;
 
@@ -197,6 +199,9 @@ use as the start page."
 
 ;; Node
 
+(defvar elpher-seen-nodes (make-hash-table :test 'equal)
+  "Table mapping addresses to existing (seen) node objects.")
+
 (defun elpher-make-node (parent address getter &optional content pos)
   "Create a node in the gopher page hierarchy.
 
@@ -205,8 +210,16 @@ 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))
+content and cursor position fields of the node.
+
+If the hash table `elpher-seen-nodes' contains a key equal to ADDRESS,
+the node contained as its value will be returned instead."
+  (let ((existing-node (gethash address elpher-seen-nodes)))
+    (if existing-node
+        existing-node
+      (let ((new-node (list parent address getter content pos)))
+        (puthash address new-node elpher-seen-nodes)
+        new-node))))
 
 (defun elpher-node-parent (node)
   "Retrieve the parent node of NODE."
@@ -238,7 +251,7 @@ content and cursor position fields of the node."
 
 ;; Node graph traversal
 
-(defvar elpher-current-node)
+(defvar elpher-current-node nil)
 
 (defun elpher-visit-node (node &optional getter)
   "Visit NODE using its own getter or GETTER, if non-nil."
@@ -334,8 +347,11 @@ content and cursor position fields of the node."
                                                  selector host port)))
       (pcase type
         (?i (elpher-insert-margin) ;; Information
-            (insert (propertize display-string
-                                'face 'elpher-info)))
+            (insert (propertize
+                     (if elpher-buttonify-urls-in-directories
+                         (elpher-buttonify-urls display-string)
+                       display-string)
+                     'face 'elpher-info)))
         (?h (elpher-insert-margin "W") ;; Web link
             (let ((url (elt (split-string selector "URL:") 1)))
               (insert-text-button display-string
@@ -631,18 +647,24 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
 (defun  elpher-redraw ()
   "Redraw current page."
   (interactive)
-  (elpher-visit-node elpher-current-node))
+  (if elpher-current-node
+      (elpher-visit-node elpher-current-node)
+    (message "No current site.")))
 
 (defun  elpher-reload ()
   "Reload current page."
   (interactive)
-  (elpher-reload-current-node))
+  (if elpher-current-node
+      (elpher-reload-current-node)
+    (message "No current site.")))
 
 (defun elpher-view-raw ()
   "View current page as plain text."
   (interactive)
-  (elpher-visit-node elpher-current-node
-                      #'elpher-get-node-raw))
+  (if elpher-current-node
+      (elpher-visit-node elpher-current-node
+                         #'elpher-get-node-raw)
+    (message "No current site.")))
 
 (defun elpher-back ()
   "Go to previous site."