Handling of non-local exits and load aborting.

[elpher.git] / elopher.el

diff --git a/elopher.el b/elopher.el
index b8170c5..fe30d93 100644 (file)
--- a/elopher.el
+++ b/elopher.el
@@ -143,11 +143,12 @@ Otherwise, use the system browser via the BROWSE-URL function."
 
 (defvar elopher-current-node)
 
-(defun elopher-visit-node (node &optional raw)
+(defun elopher-visit-node (node &optional getter)
   (elopher-save-pos)
+  (elopher-process-cleanup)
   (setq elopher-current-node node)
-  (if raw
-      (elopher-get-node-raw)
+  (if getter
+      (funcall getter)
     (funcall (elopher-node-getter node))))
 
 (defun elopher-visit-parent-node ()
@@ -163,6 +164,7 @@ Otherwise, use the system browser via the BROWSE-URL function."
 ;;
 
 (defmacro elopher-with-clean-buffer (&rest args)
+  "Evaluate ARGS with a clean *elopher* buffer as current."
   (list 'progn
         '(switch-to-buffer "*elopher*")
         '(elopher-mode)
@@ -260,14 +262,17 @@ Otherwise, use the system browser via the BROWSE-URL function."
 ;;; 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 "")
-  (let ((p (get-process "elopher-process")))
-    (if p (delete-process p)))
   (make-network-process
    :name "elopher-process"
    :host (elopher-address-host address)
@@ -286,7 +291,7 @@ The result is stored as a string in the variable elopher-selector-string."
     (if content
         (progn
           (elopher-with-clean-buffer
-            (insert content))
+           (insert content))
           (elopher-restore-pos))
       (if address
           (progn
@@ -294,14 +299,16 @@ The result is stored as a string in the variable elopher-selector-string."
              (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)))))
+                                    (unless (string-prefix-p "deleted" event)
+                                      (message 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-insert-index elopher-start-index))
           (elopher-restore-pos)
           (elopher-set-node-content elopher-current-node
                                     (buffer-string)))))))
@@ -318,18 +325,19 @@ The result is stored as a string in the variable elopher-selector-string."
     (if content
         (progn
           (elopher-with-clean-buffer
-            (insert content))
+           (insert content))
           (elopher-restore-pos))
       (progn
         (elopher-with-clean-buffer
-          (insert "LOADING TEXT..."))
+         (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))))))))
+                                (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
 
@@ -339,22 +347,24 @@ The result is stored as a string in the variable elopher-selector-string."
     (if content
         (progn
           (elopher-with-clean-buffer
-            (insert-image content))
+           (insert-image content))
           (setq cursor-type nil)
           (elopher-restore-pos))
       (progn
         (elopher-with-clean-buffer
-          (insert "LOADING IMAGE..."))
+         (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))))))))
+                                (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
 
@@ -376,11 +386,12 @@ The result is stored as a string in the variable elopher-selector-string."
          (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))))))))
+                                (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)))))))))
 
 ;; Raw server response retrieval
 
@@ -392,9 +403,10 @@ The result is stored as a string in the variable elopher-selector-string."
     (if address
         (elopher-get-selector address
                               (lambda (proc event)
-                                (elopher-with-clean-buffer
-                                 (insert elopher-selector-string))
-                                (goto-char (point-min))))
+                                (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))
@@ -406,17 +418,27 @@ The result is stored as a string in the variable elopher-selector-string."
 
 (defvar elopher-download-filename)
 
-(defun elopher-download-node (node filename)
-  (let* ((address (elopher-node-address node)))
-    (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))))))
+(defun elopher-get-node-download ()
+  (let* ((address (elopher-node-address elopher-current-node))
+         (selector (elopher-address-selector address)))
+    (unwind-protect
+        (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)))))
+      (elopher-visit-parent-node))))
+        
 
 ;;; Navigation procedures
 ;;
@@ -464,7 +486,8 @@ The result is stored as a string in the variable elopher-selector-string."
 (defun elopher-view-raw ()
   "View current page as plain text."
   (interactive)
-  (elopher-visit-node elopher-current-node t))
+  (elopher-visit-node elopher-current-node
+                      #'elopher-get-node-raw))
 
 (defun elopher-back ()
   "Go to previous site."
@@ -478,18 +501,11 @@ The result is stored as a string in the variable elopher-selector-string."
   (interactive)
   (let ((button (button-at (point))))
     (if button
-        (let* ((node (button-get button 'elopher-node))
-               (address (elopher-node-address node))
-               (selector (elopher-address-selector address))
-               (filename-proposal (file-name-nondirectory selector))
-               (filename (read-file-name "Name of file to write: "
-                                         nil nil nil
-                                         (if (> (length filename-proposal) 0)
-                                             filename-proposal
-                                           "gopher.file"))))
-          (elopher-download-node node filename))
+        (elopher-visit-node (button-get button 'elopher-node)
+                            #'elopher-get-node-download)
       (message "No link selected."))))
 
+
 ;;; Mode and keymap
 ;;
 
@@ -520,12 +536,14 @@ The result is stored as a string in the variable elopher-selector-string."
 
 ;;; 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-visit-node start-node))
+  "Started Elopher.") ; Otherwise (elopher) evaluates to start page string.
 
 ;;; elopher.el ends here