Implement navigation abstraction to allow the summary buffer to

properly share commands with the folder buffer.

diff --git a/v7/src/imail/imail-top.scm b/v7/src/imail/imail-top.scm
index 4c272d8fbdd5febad85ae48c93be1b1a6969c29e..6cec94efab687c1b2434e8b10cbfcacbe38c1b84 100644 (file)
--- a/v7/src/imail/imail-top.scm
+++ b/v7/src/imail/imail-top.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: imail-top.scm,v 1.71 2000/05/19 18:06:18 cph Exp $
+;;; $Id: imail-top.scm,v 1.72 2000/05/19 18:21:01 cph Exp $
 ;;;
 ;;; Copyright (c) 1999-2000 Massachusetts Institute of Technology
 ;;;
@@ -123,7 +123,7 @@ May be called with an IMAIL folder URL as argument;
                    (associate-imail-with-buffer buffer folder #f)
                    buffer))))
         (select-message folder
-                        (or (first-unseen-message folder)
+                        (or (navigator/first-unseen-message folder)
                             (selected-message #f buffer))
                         #t)
         buffer)))))
@@ -319,7 +319,7 @@ DEL Scroll to previous screen of this message.
          (select-message
           folder
           (or (selected-message #f buffer)
-              (first-unseen-message folder))
+              (navigator/first-unseen-message folder))
           #t)))))
 
 (define (imail-kill-buffer buffer)
@@ -345,7 +345,7 @@ DEL Scroll to previous screen of this message.
   ()
   (lambda ()
     (let ((folder (selected-folder)))
-      (select-message folder (last-message folder)))))
+      (select-message folder (navigator/last-message folder)))))
 
 (define-command imail-next-message
   "Show following message whether deleted or not.
@@ -433,8 +433,8 @@ With prefix argument N moves backward N messages with these flags."
       (call-with-values
          (lambda ()
            (if (< delta 0)
-               (values (- delta) previous-message "previous")
-               (values delta next-message "next")))
+               (values (- delta) navigator/previous-message "previous")
+               (values delta navigator/next-message "next")))
        (lambda (n step direction)
          (let ((folder (selected-folder))
                (msg (selected-message)))
@@ -460,7 +460,7 @@ With prefix argument N moves backward N messages with these flags."
                       selector
                       (loop (message-index selector))))
                 ((not selector)
-                 (last-message folder))
+                 (navigator/last-message folder))
                 ((and (exact-integer? selector)
                       (<= 0 selector)
                       (< selector (folder-length folder)))
@@ -577,7 +577,7 @@ With prefix argument N moves backward N messages with these flags."
             (if (or (default-object? buffer) (not buffer))
                 (selected-buffer)
                 buffer)))
-       (let ((method (buffer-get buffer 'IMAIL-MESSAGE-METHOD #f)))
+       (let ((method (navigator/selected-message)))
          (if method
              (method buffer)
              (let ((buffer (chase-imail-buffer buffer)))
@@ -658,6 +658,54 @@ With prefix argument N moves backward N messages with these flags."
                          headers)))
        headers)))
 \f
+;;;; Navigation hooks
+
+(define (navigator/first-unseen-message folder)
+  ((or (imail-navigator imail-navigators/first-unseen-message)
+       first-unseen-message)
+   folder))
+
+(define (navigator/first-message folder)
+  ((or (imail-navigator imail-navigators/first-message)
+       first-message)
+   folder))
+
+(define (navigator/last-message folder)
+  ((or (imail-navigator imail-navigators/last-message)
+       last-message)
+   folder))
+
+(define (navigator/next-message message #!optional predicate)
+  ((or (imail-navigator imail-navigators/next-message)
+       next-message)
+   message
+   (if (default-object? predicate) #f predicate)))
+
+(define (navigator/previous-message message)
+  ((or (imail-navigator imail-navigators/previous-message)
+       previous-message)
+   message
+   (if (default-object? predicate) #f predicate)))
+
+(define (imail-navigator accessor)
+  (let ((navigators (buffer-get (selected-buffer) 'IMAIL-NAVIGATORS #f)))
+    (and navigators
+        (accessor navigators))))
+
+(define (navigator/selected-message)
+  (let ((navigators (buffer-get (selected-buffer) 'IMAIL-NAVIGATORS #f)))
+    (and navigators
+        (imail-navigators/selected-message navigators))))
+
+(define-structure (imail-navigators safe-accessors
+                                   (conc-name imail-navigators/))
+  (first-unseen-message #f read-only #t)
+  (first-message #f read-only #t)
+  (last-message #f read-only #t)
+  (next-message #f read-only #t)
+  (previous-message #f read-only #t)
+  (selected-message #f read-only #t))
+\f
 ;;;; Message deletion
 
 (define-command imail-delete-message
@@ -687,7 +735,8 @@ Deleted messages stay in the file until the \\[imail-expunge] command is given."
     (let ((message (selected-message)))
       (if (message-deleted? message)
          (undelete-message message)
-         (let ((message (previous-message message message-deleted?)))
+         (let ((message
+                (navigator/previous-message message message-deleted?)))
            (if (not message)
                (editor-error "No previous deleted message."))
            (undelete-message message)
@@ -701,10 +750,10 @@ Deleted messages stay in the file until the \\[imail-expunge] command is given."
          (message
           (let ((message (selected-message)))
             (if (message-deleted? message)
-                (or (next-message message message-undeleted?)
-                    (previous-message message message-undeleted?)
-                    (next-message message)
-                    (previous-message message))
+                (or (navigator/next-message message message-undeleted?)
+                    (navigator/previous-message message message-undeleted?)
+                    (navigator/next-message message)
+                    (navigator/previous-message message))
                 message))))
       (expunge-deleted-messages folder)
       (select-message folder message))))
@@ -755,7 +804,7 @@ Completion is performed over known flags when reading."
        (close-folder folder*))
       (select-message folder
                      (or (selected-message #f)
-                         (first-unseen-message folder))))))
+                         (navigator/first-unseen-message folder))))))
 
 (define-command imail-output
   "Append this message to a specified folder."
@@ -974,22 +1023,22 @@ Currently useful only for IMAP folders."
   (lambda ()
     (let ((folder (selected-folder)))
       (let ((count (folder-modification-count folder))
-           (last (last-message folder)))
+           (last (navigator/last-message folder)))
        (probe-folder folder)
        (if (> (folder-modification-count folder) count)
            (select-message
             folder
             (or (cond ((not last)
-                       (first-message folder))
+                       (navigator/first-message folder))
                       ((message-attached? last folder)
-                       (next-message last))
+                       (navigator/next-message last))
                       ((message-index last)
                        => (lambda (index)
                             (let ((index (+ index 1)))
                               (if (< index (folder-length folder))
                                   (get-message folder index)
-                                  (first-unseen-message folder)))))
-                      (else (first-unseen-message folder)))
+                                  (navigator/first-unseen-message folder)))))
+                      (else (navigator/first-unseen-message folder)))
                 (selected-message #f)))
            (message "(No changes to mail folder)"))))))