emacs: show: mark tags changed since buffer loaded

This allows (and requires) the original-tags to be passed along with
the current-tags to be passed to notmuch-tag-format-tags. This allows
the tag formatting to show added and deleted tags.By default a removed
tag is displayed with strike-through in red (if strike-through is not
available, eg on a terminal, inverse video is used instead) and an
added tag is displayed underlined in green.

If the caller does not wish to use the new feature it can pass
current-tags for both arguments and, at this point, we do exactly that
in the three callers of this function.

Note, we cannot tidily allow original-tags to be optional because we would
need to distinguish nil meaning "we are not specifying original-tags"
from nil meaning there were no original-tags (an empty list).

We use this in subsequent patches to make it clear when a message was
unread when you first loaded a show buffer (previously the unread tag
could be removed before a user realised that it had been unread).

The code adds into the existing tag formatting code. The user can
specify exactly how a tag should be displayed normally, when deleted,
or when added.

Since the formatting code matches regexps a user can match all deleted
tags with a ".*" in notmuch-tag-deleted-formats.  For example setting
notmuch-tag-deleted-formats to '((".*" nil)) tells notmuch not to show
deleted tags at all.

All the variables are customizable; however, more complicated cases
like changing the face depending on the type of display will require
custom lisp.

Currently this overrides notmuch-tag-deleted-formats for the tests
setting it to '((".*" nil)) so that they get removed from the display
and, thus, all tests still pass.

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 019f51d71a678ece8a83b0adc39a295173f9983e..5492be426d731b081f955f4174e25a412efb8985 100644 (file)
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -344,7 +344,7 @@ operation on the contents of the current buffer."
     (if (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
        (let ((inhibit-read-only t))
          (replace-match (concat "("
-                                (notmuch-tag-format-tags tags)
+                                (notmuch-tag-format-tags tags tags)
                                 ")"))))))
 
 (defun notmuch-clean-address (address)
@@ -423,7 +423,7 @@ message at DEPTH in the current thread."
            " ("
            date
            ") ("
-           (notmuch-tag-format-tags tags)
+           (notmuch-tag-format-tags tags tags)
            ")\n")
     (overlay-put (make-overlay start (point)) 'face 'notmuch-message-summary-face)))
 

diff --git a/emacs/notmuch-tag.el b/emacs/notmuch-tag.el
index 3ae5e62ffa106ef57c038a95550ecd4cc4ce581a..07c260ebbd07e13e23ce6524d1a5fdc9368ca481 100644 (file)
--- a/emacs/notmuch-tag.el
+++ b/emacs/notmuch-tag.el
@@ -193,45 +193,71 @@ This can be used with `notmuch-tag-format-image-data'."
   "Clear the internal cache of tag formats."
   (clrhash notmuch-tag--format-cache))
 
-(defun notmuch-tag-format-tag (tag)
-  "Format TAG by according to `notmuch-tag-formats'.
-
-Callers must ensure that the tag format cache has been recently cleared
-via `notmuch-tag-clear-cache' before using this function.  For example,
-it would be appropriate to clear the cache just prior to filling a
-buffer that uses formatted tags."
-
-  (let ((formatted (gethash tag notmuch-tag--format-cache 'missing)))
-    (when (eq formatted 'missing)
-      (let* ((formats
-             (save-match-data
-               ;; Don't use assoc-default since there's no way to
-               ;; distinguish a missing key from a present key with a
-               ;; null cdr:.
-               (assoc* tag notmuch-tag-formats
-                       :test (lambda (tag key)
-                               (and (eq (string-match key tag) 0)
-                                    (= (match-end 0) (length tag))))))))
-       (setq formatted
-             (cond
-              ((null formats)          ;; - Tag not in `notmuch-tag-formats',
-               tag)                    ;;   the format is the tag itself.
-              ((null (cdr formats))    ;; - Tag was deliberately hidden,
-               nil)                    ;;   no format must be returned
-              (t                       ;; - Tag was found and has formats,
-               (let ((tag tag))        ;;   we must apply all the formats.
-                 (dolist (format (cdr formats) tag)
-                   (setq tag (eval format)))))))
-       (puthash tag formatted notmuch-tag--format-cache)))
-    formatted))
-
-(defun notmuch-tag-format-tags (tags &optional face)
+(defun notmuch-tag--get-formats (tag format-alist)
+  "Find the first item whose car regexp-matches TAG."
+  (save-match-data
+    ;; Don't use assoc-default since there's no way to distinguish a
+    ;; missing key from a present key with a null cdr.
+    (assoc* tag format-alist
+           :test (lambda (tag key)
+                   (and (eq (string-match key tag) 0)
+                        (= (match-end 0) (length tag)))))))
+
+(defun notmuch-tag--do-format (tag formatted-tag formats)
+  "Apply a tag-formats entry to TAG."
+  (cond ((null formats)                ;; - Tag not in `formats',
+        formatted-tag)         ;;   the format is the tag itself.
+       ((null (cdr formats))   ;; - Tag was deliberately hidden,
+        nil)                   ;;   no format must be returned
+       (t
+        ;; Tag was found and has formats, we must apply all the
+        ;; formats.  TAG may be null so treat that as a special case.
+        (let ((bare-tag tag)
+              (tag (copy-sequence (or formatted-tag ""))))
+          (dolist (format (cdr formats))
+            (setq tag (eval format)))
+          (if (and (null formatted-tag) (equal tag ""))
+              nil
+            tag)))))
+
+(defun notmuch-tag-format-tag (tags orig-tags tag)
+  "Format TAG according to `notmuch-tag-formats'.
+
+TAGS and ORIG-TAGS are lists of the current tags and the original
+tags; tags which have been deleted (i.e., are in ORIG-TAGS but
+are not in TAGS) are shown using formats from
+`notmuch-tag-deleted-formats'; tags which have been added (i.e.,
+are in TAGS but are not in ORIG-TAGS) are shown using formats
+from `notmuch-tag-added-formats' and tags which have not been
+changed (the normal case) are shown using formats from
+`notmuch-tag-formats'"
+  (let* ((tag-state (cond ((not (member tag tags)) 'deleted)
+                         ((not (member tag orig-tags)) 'added)))
+        (formatted-tag (gethash (cons tag tag-state) notmuch-tag--format-cache 'missing)))
+    (when (eq formatted-tag 'missing)
+      (let ((base (notmuch-tag--get-formats tag notmuch-tag-formats))
+           (over (case tag-state
+                   (deleted (notmuch-tag--get-formats
+                             tag notmuch-tag-deleted-formats))
+                   (added (notmuch-tag--get-formats
+                           tag notmuch-tag-added-formats))
+                   (otherwise nil))))
+       (setq formatted-tag (notmuch-tag--do-format tag tag base))
+       (setq formatted-tag (notmuch-tag--do-format tag formatted-tag over))
+
+       (puthash (cons tag tag-state) formatted-tag notmuch-tag--format-cache)))
+    formatted-tag))
+
+(defun notmuch-tag-format-tags (tags orig-tags &optional face)
   "Return a string representing formatted TAGS."
-  (let ((face (or face 'notmuch-tag-face)))
+  (let ((face (or face 'notmuch-tag-face))
+       (all-tags (sort (delete-dups (append tags orig-tags nil)) #'string<)))
     (notmuch-apply-face
      (mapconcat #'identity
                ;; nil indicated that the tag was deliberately hidden
-               (delq nil (mapcar #'notmuch-tag-format-tag tags))
+               (delq nil (mapcar
+                          (apply-partially #'notmuch-tag-format-tag tags orig-tags)
+                          all-tags))
                " ")
      face
      t)))

diff --git a/emacs/notmuch-tree.el b/emacs/notmuch-tree.el
index c78d9de5114c90eed69bc1eac168b6ad85cc7d9e..8bf2fbc5c78c2cb9f6a61cc4cc68a75229bb53d2 100644 (file)
--- a/emacs/notmuch-tree.el
+++ b/emacs/notmuch-tree.el
@@ -704,7 +704,7 @@ unchanged ADDRESS if parsing fails."
            (face (if match
                      'notmuch-tree-match-tag-face
                    'notmuch-tree-no-match-tag-face)))
-       (format format-string (notmuch-tag-format-tags tags face)))))))
+       (format format-string (notmuch-tag-format-tags tags tags face)))))))
 
 (defun notmuch-tree-format-field-list (field-list msg)
   "Format fields of MSG according to FIELD-LIST and return string"

diff --git a/emacs/notmuch.el b/emacs/notmuch.el
index 2e0b20eb937095825f442d662e4b8f6a6e038a66..59ad541eb10d444888b9f85a1666af555a2deedc 100644 (file)
--- a/emacs/notmuch.el
+++ b/emacs/notmuch.el
@@ -754,7 +754,7 @@ non-authors is found, assume that all of the authors match."
 
    ((string-equal field "tags")
     (let ((tags (plist-get result :tags)))
-      (insert (format format-string (notmuch-tag-format-tags tags)))))))
+      (insert (format format-string (notmuch-tag-format-tags tags tags)))))))
 
 (defun notmuch-search-show-result (result &optional pos)
   "Insert RESULT at POS or the end of the buffer if POS is null."

diff --git a/test/test-lib.el b/test/test-lib.el
index 37fcb3d0e19dd845fa5cbf202fce63cf2df60811..437f83f44d08e8224465181a08a0f17e748a0413 100644 (file)
--- a/test/test-lib.el
+++ b/test/test-lib.el
@@ -165,3 +165,8 @@ nothing."
 
      (t
       (notmuch-test-report-unexpected output expected)))))
+
+;; For historical reasons, we hide deleted tags by default in the test
+;; suite
+(setq notmuch-tag-deleted-formats
+      '((".*" nil)))