X-Git-Url: https://git.notmuchmail.org/git?p=notmuch;a=blobdiff_plain;f=emacs%2Fnotmuch-tree.el;h=b3c2c992486fd9e5ccd7f7510c138728f72f7c37;hp=57843e256f437d5f6206ef31e5aab9915d10e49a;hb=HEAD;hpb=adfded9ed0a5a4b06886f462314cd4511cb72d47

diff --git a/emacs/notmuch-tree.el b/emacs/notmuch-tree.el
index 57843e25..faec89c4 100644
--- a/emacs/notmuch-tree.el
+++ b/emacs/notmuch-tree.el
@@ -1,4 +1,4 @@
-;;; notmuch-tree.el --- displaying notmuch forests
+;;; notmuch-tree.el --- displaying notmuch forests  -*- lexical-binding: t -*-
 ;;
 ;; Copyright © Carl Worth
 ;; Copyright © David Edmondson
@@ -24,20 +24,18 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'mail-parse)
 
 (require 'notmuch-lib)
-(require 'notmuch-query)
 (require 'notmuch-show)
 (require 'notmuch-tag)
 (require 'notmuch-parser)
 (require 'notmuch-jump)
 
 (declare-function notmuch-search "notmuch"
-		  (&optional query oldest-first target-thread target-line))
-(declare-function notmuch-call-notmuch-process "notmuch" (&rest args))
+		  (&optional query oldest-first target-thread target-line
+			     no-display))
+(declare-function notmuch-call-notmuch-process "notmuch-lib" (&rest args))
 (declare-function notmuch-read-query "notmuch" (prompt))
 (declare-function notmuch-search-find-thread-id "notmuch" (&optional bare))
 (declare-function notmuch-search-find-subject "notmuch" ())
@@ -47,13 +45,12 @@
 (declare-function notmuch-search-previous-thread "notmuch" ())
 (declare-function notmuch-tree-from-search-thread "notmuch" ())
 
-;; the following variable is defined in notmuch.el
-(defvar notmuch-search-query-string)
-
 ;; this variable distinguishes the unthreaded display from the normal tree display
 (defvar-local notmuch-tree-unthreaded nil
   "A buffer local copy of argument unthreaded to the function notmuch-tree.")
 
+;;; Options
+
 (defgroup notmuch-tree nil
   "Showing message and thread structure."
   :group 'notmuch)
@@ -73,24 +70,66 @@
       notmuch-unthreaded-show-out
     notmuch-tree-show-out))
 
+(defcustom notmuch-tree-thread-symbols
+  '((prefix . " ")
+    (top . "─")
+    (top-tee . "┬")
+    (vertical . "│")
+    (vertical-tee . "├")
+    (bottom . "╰")
+    (arrow . "►"))
+  "Strings used to draw trees in notmuch tree results.
+Symbol keys denote where the corresponding string value is used:
+`prefix' is used at the top of the tree, followed by `top' if it
+has no children or `top-tee' if it does; `vertical' is a bar
+connecting with a response down the list skipping the current
+one, while `vertical-tee' marks the current message as a reply to
+the previous one; `bottom' is used at the bottom of threads.
+Finally, the `arrrow' string in the list is used as a pointer to
+every message.
+
+Common customizations include setting `prefix' to \"-\", to see
+equal-length prefixes, and `arrow' to an empty string or to a
+different kind of arrow point."
+  :type '(alist :key-type symbol :value-type string)
+  :group 'notmuch-tree)
+
+(defconst notmuch-tree--field-names
+  '(choice :tag "Field"
+	   (const :tag "Date" "date")
+	   (const :tag "Authors" "authors")
+	   (const :tag "Subject" "subject")
+	   (const :tag "Tree" "tree")
+	   (const :tag "Tags" "tags")
+	   (function)))
+
 (defcustom notmuch-tree-result-format
   `(("date" . "%12s  ")
     ("authors" . "%-20s")
-    ((("tree" . "%s")("subject" . "%s")) ." %-54s ")
+    ((("tree" . "%s")
+      ("subject" . "%s"))
+     . " %-54s ")
     ("tags" . "(%s)"))
-  "Result formatting for tree view. Supported fields are: date,
-authors, subject, tree, tags.  Tree means the thread tree
-box graphics. The field may also be a list in which case
-the formatting rules are applied recursively and then the
-output of all the fields in the list is inserted
-according to format-string.
-
-Note the author string should not contain
-whitespace (put it in the neighbouring fields instead).
-For example:
-        (setq notmuch-tree-result-format \(\(\"authors\" . \"%-40s\"\)
-                                          \(\"subject\" . \"%s\"\)\)\)"
-  :type '(alist :key-type (string) :value-type (string))
+  "Result formatting for tree view.
+
+List of pairs of (field . format-string).  Supported field
+strings are: \"date\", \"authors\", \"subject\", \"tree\",
+\"tags\".  It is also supported to pass a function in place of a
+field-name. In this case the function is passed the thread
+object (plist) and format string.
+
+Tree means the thread tree box graphics. The field may
+also be a list in which case the formatting rules are
+applied recursively and then the output of all the fields
+in the list is inserted according to format-string.
+
+Note that the author string should not contain whitespace
+\(put it in the neighbouring fields instead)."
+
+  :type `(alist :key-type (choice ,notmuch-tree--field-names
+				  (alist :key-type ,notmuch-tree--field-names
+					 :value-type (string :tag "Format")))
+		:value-type (string :tag "Format"))
   :group 'notmuch-tree)
 
 (defcustom notmuch-unthreaded-result-format
@@ -98,19 +137,26 @@ For example:
     ("authors" . "%-20s")
     ((("subject" . "%s")) ." %-54s ")
     ("tags" . "(%s)"))
-  "Result formatting for unthreaded tree view. Supported fields are: date,
-authors, subject, tree, tags.  Tree means the thread tree
-box graphics. The field may also be a list in which case
-the formatting rules are applied recursively and then the
-output of all the fields in the list is inserted
-according to format-string.
-
-Note the author string should not contain
-whitespace (put it in the neighbouring fields instead).
-For example:
-        (setq notmuch-tree-result-format \(\(\"authors\" . \"%-40s\"\)
-                                          \(\"subject\" . \"%s\"\)\)\)"
-  :type '(alist :key-type (string) :value-type (string))
+  "Result formatting for unthreaded tree view.
+
+List of pairs of (field . format-string).  Supported field
+strings are: \"date\", \"authors\", \"subject\", \"tree\",
+\"tags\".  It is also supported to pass a function in place of a
+field-name. In this case the function is passed the thread
+object (plist) and format string.
+
+Tree means the thread tree box graphics. The field may
+also be a list in which case the formatting rules are
+applied recursively and then the output of all the fields
+in the list is inserted according to format-string.
+
+Note that the author string should not contain whitespace
+\(put it in the neighbouring fields instead)."
+
+  :type `(alist :key-type (choice ,notmuch-tree--field-names
+				  (alist :key-type ,notmuch-tree--field-names
+					 :value-type (string :tag "Format")))
+		:value-type (string :tag "Format"))
   :group 'notmuch-tree)
 
 (defun notmuch-tree-result-format ()
@@ -118,7 +164,9 @@ For example:
       notmuch-unthreaded-result-format
     notmuch-tree-result-format))
 
-;; Faces for messages that match the query.
+;;; Faces
+;;;; Faces for messages that match the query
+
 (defface notmuch-tree-match-face
   '((t :inherit default))
   "Default face used in tree mode face for matching messages"
@@ -140,7 +188,7 @@ For example:
      (:foreground "dark blue"))
     (t
      (:bold t)))
-  "Face used in tree mode for the date in messages matching the query."
+  "Face used in tree mode for the author in messages matching the query."
   :group 'notmuch-tree
   :group 'notmuch-faces)
 
@@ -152,7 +200,8 @@ For example:
 
 (defface notmuch-tree-match-tree-face
   nil
-  "Face used in tree mode for the thread tree block graphics in messages matching the query."
+  "Face used in tree mode for the thread tree block graphics in
+messages matching the query."
   :group 'notmuch-tree
   :group 'notmuch-faces)
 
@@ -169,7 +218,8 @@ For example:
   :group 'notmuch-tree
   :group 'notmuch-faces)
 
-;; Faces for messages that do not match the query.
+;;;; Faces for messages that do not match the query
+
 (defface notmuch-tree-no-match-face
   '((t (:foreground "gray")))
   "Default face used in tree mode face for non-matching messages."
@@ -190,13 +240,14 @@ For example:
 
 (defface notmuch-tree-no-match-tree-face
   nil
-  "Face used in tree mode for the thread tree block graphics in messages matching the query."
+  "Face used in tree mode for the thread tree block graphics in
+messages matching the query."
   :group 'notmuch-tree
   :group 'notmuch-faces)
 
 (defface notmuch-tree-no-match-author-face
   nil
-  "Face used in tree mode for the date in messages matching the query."
+  "Face used in tree mode for non-matching authors."
   :group 'notmuch-tree
   :group 'notmuch-faces)
 
@@ -206,6 +257,8 @@ For example:
   :group 'notmuch-tree
   :group 'notmuch-faces)
 
+;;; Variables
+
 (defvar-local notmuch-tree-previous-subject
   "The subject of the most recent result shown during the async display.")
 
@@ -238,6 +291,8 @@ This is used to try and make sure we don't close the message pane
 if the user has loaded a different buffer in that window.")
 (put 'notmuch-tree-message-buffer 'permanent-local t)
 
+;;; Tree wrapper commands
+
 (defmacro notmuch-tree--define-do-in-message-window (name cmd)
   "Define NAME as a command that calls CMD interactively in the message window.
 If the message pane is closed then this command does nothing.
@@ -305,17 +360,21 @@ then NAME behaves like CMD."
  notmuch-tree-view-raw-message
  notmuch-show-view-raw-message)
 
+;;; Keymap
+
 (defvar notmuch-tree-mode-map
   (let ((map (make-sparse-keymap)))
     (set-keymap-parent map notmuch-common-keymap)
     ;; These bindings shadow common bindings with variants
     ;; that additionally close the message window.
     (define-key map [remap notmuch-bury-or-kill-this-buffer] 'notmuch-tree-quit)
-    (define-key map [remap notmuch-search]       'notmuch-tree-to-search)
-    (define-key map [remap notmuch-help]         'notmuch-tree-help)
-    (define-key map [remap notmuch-mua-new-mail] 'notmuch-tree-new-mail)
-    (define-key map [remap notmuch-jump-search]  'notmuch-tree-jump-search)
+    (define-key map [remap notmuch-search]        'notmuch-tree-to-search)
+    (define-key map [remap notmuch-help]          'notmuch-tree-help)
+    (define-key map [remap notmuch-mua-new-mail]  'notmuch-tree-new-mail)
+    (define-key map [remap notmuch-jump-search]   'notmuch-tree-jump-search)
 
+    (define-key map "o" 'notmuch-tree-toggle-order)
+    (define-key map "i" 'notmuch-tree-toggle-hide-excluded)
     (define-key map "S" 'notmuch-search-from-tree-current-query)
     (define-key map "U" 'notmuch-unthreaded-from-tree-current-query)
     (define-key map "Z" 'notmuch-tree-from-unthreaded-current-query)
@@ -338,6 +397,9 @@ then NAME behaves like CMD."
     (define-key map "r" 'notmuch-tree-reply-sender)
     (define-key map "R" 'notmuch-tree-reply)
     (define-key map "V" 'notmuch-tree-view-raw-message)
+    (define-key map "l" 'notmuch-tree-filter)
+    (define-key map "t" 'notmuch-tree-filter-by-tag)
+    (define-key map "E" 'notmuch-tree-edit-search)
 
     ;; The main tree view bindings
     (define-key map (kbd "RET") 'notmuch-tree-show-message)
@@ -363,6 +425,8 @@ then NAME behaves like CMD."
     map)
   "Keymap for \"notmuch tree\" buffers.")
 
+;;; Message properties
+
 (defun notmuch-tree-get-message-properties ()
   "Return the properties of the current message as a plist.
 
@@ -388,9 +452,8 @@ Some useful entries are:
     (notmuch-tree-set-message-properties props)))
 
 (defun notmuch-tree-get-prop (prop &optional props)
-  (let ((props (or props
-		   (notmuch-tree-get-message-properties))))
-    (plist-get props prop)))
+  (plist-get (or props (notmuch-tree-get-message-properties))
+	     prop))
 
 (defun notmuch-tree-set-tags (tags)
   "Set the tags of the current message."
@@ -411,9 +474,10 @@ Some useful entries are:
 
 (defun notmuch-tree-get-match ()
   "Return whether the current message is a match."
-  (interactive)
   (notmuch-tree-get-prop :match))
 
+;;; Update display
+
 (defun notmuch-tree-refresh-result ()
   "Redisplay the current message line.
 
@@ -456,6 +520,8 @@ NOT change the database."
 	  (when (string= tree-msg-id (notmuch-show-get-message-id))
 	    (notmuch-show-update-tags new-tags)))))))
 
+;;; Commands (and some helper functions used by them)
+
 (defun notmuch-tree-tag (tag-changes)
   "Change tags for the current message."
   (interactive
@@ -525,7 +591,9 @@ NOT change the database."
   "Call notmuch search with the current query."
   (interactive)
   (notmuch-tree-close-message-window)
-  (notmuch-search (notmuch-tree-get-query)))
+  (notmuch-search (notmuch-tree-get-query)
+		  notmuch-search-oldest-first
+		  notmuch-search-hide-excluded))
 
 (defun notmuch-tree-message-window-kill-hook ()
   "Close the message pane when exiting the show buffer."
@@ -561,7 +629,7 @@ NOT change the database."
       (with-selected-window notmuch-tree-message-window
 	(let (;; Since we are only displaying one message do not indent.
 	      (notmuch-show-indent-messages-width 0)
-	      (notmuch-show-only-matching-messages t)
+	      (notmuch-show-single-message t)
 	      ;; Ensure that `pop-to-buffer-same-window' uses the
 	      ;; window we want it to use.
 	      (display-buffer-overriding-action
@@ -581,12 +649,13 @@ NOT change the database."
   "Show the current message (in whole window)."
   (interactive)
   (let ((id (notmuch-tree-get-message-id))
-	(inhibit-read-only t)
-	buffer)
+	(inhibit-read-only t))
     (when id
       ;; We close the window to kill off un-needed buffers.
       (notmuch-tree-close-message-window)
-      (notmuch-show id))))
+      ;; n-s-s-m is buffer local, so use inner let.
+      (let ((notmuch-show-single-message t))
+	(notmuch-show id)))))
 
 (defun notmuch-tree-show-message (arg)
   "Show the current message.
@@ -736,7 +805,9 @@ nil otherwise."
 			 query-context
 			 target
 			 nil
-			 unthreaded)))
+			 unthreaded
+			 notmuch-search-oldest-first
+			 notmuch-search-hide-excluded)))
 
 (defun notmuch-tree-thread-top ()
   (when (notmuch-tree-get-message-properties)
@@ -775,8 +846,7 @@ search results instead."
       (notmuch-tree-from-search-thread))))
 
 (defun notmuch-tree-next-thread (&optional previous)
-  "Move to the next thread in the current tree or parent search
-results
+  "Move to the next thread in the current tree or parent search results.
 
 If PREVIOUS is non-nil, move to the previous thread in the tree or
 search results instead."
@@ -786,14 +856,13 @@ search results instead."
     (notmuch-tree-next-thread-from-search previous)))
 
 (defun notmuch-tree-prev-thread ()
-  "Move to the previous thread in the current tree or parent search
-results"
+  "Move to the previous thread in the current tree or parent search results."
   (interactive)
   (notmuch-tree-next-thread t))
 
 (defun notmuch-tree-thread-mapcar (function)
-  "Iterate through all messages in the current thread
- and call FUNCTION for side effects."
+  "Call FUNCTION for each message in the current thread.
+FUNCTION is called for side effects only."
   (save-excursion
     (notmuch-tree-thread-top)
     (cl-loop collect (funcall function)
@@ -835,7 +904,7 @@ buffer."
     (notmuch-tree-tag-thread
      (notmuch-tag-change-list notmuch-archive-tags unarchive))))
 
-;; Functions below here display the tree buffer itself.
+;;; Functions for displaying the tree buffer itself
 
 (defun notmuch-tree-clean-address (address)
   "Try to clean a single email ADDRESS for display. Return
@@ -856,6 +925,9 @@ unchanged ADDRESS if parsing fails."
      ((listp field)
       (format format-string (notmuch-tree-format-field-list field msg)))
 
+     ((functionp field)
+      (funcall field format-string msg))
+
      ((string-equal field "date")
       (let ((face (if match
 		      'notmuch-tree-match-date-face
@@ -939,7 +1011,8 @@ unchanged ADDRESS if parsing fails."
       (goto-char (point-max))
       (forward-line -1)
       (when notmuch-tree-open-target
-	(notmuch-tree-show-message-in)))))
+	(notmuch-tree-show-message-in)
+	(notmuch-tree-command-hook)))))
 
 (defun notmuch-tree-insert-tree (tree depth tree-status first last)
   "Insert the message tree TREE at depth DEPTH in the current thread.
@@ -947,36 +1020,41 @@ unchanged ADDRESS if parsing fails."
 A message tree is another name for a single sub-thread: i.e., a
 message together with all its descendents."
   (let ((msg (car tree))
-	(replies (cadr tree)))
+	(replies (cadr tree))
+	;; outline level, computed from the message's depth and
+	;; whether or not it's the first message in the tree.
+	(level (1+ (if (and (eq 0 depth) (not first)) 1 depth))))
     (cond
      ((and (< 0 depth) (not last))
-      (push "├" tree-status))
+      (push (alist-get 'vertical-tee  notmuch-tree-thread-symbols) tree-status))
      ((and (< 0 depth) last)
-      (push "╰" tree-status))
+      (push (alist-get 'bottom notmuch-tree-thread-symbols) tree-status))
      ((and (eq 0 depth) first last)
-      ;; Choice between these two variants is a matter of taste.
-      ;; (push "─" tree-status))
-      (push " " tree-status))
+      (push (alist-get 'prefix notmuch-tree-thread-symbols) tree-status))
      ((and (eq 0 depth) first (not last))
-      (push "┬" tree-status))
+      (push (alist-get 'top-tee notmuch-tree-thread-symbols) tree-status))
      ((and (eq 0 depth) (not first) last)
-      (push "╰" tree-status))
+      (push (alist-get 'bottom notmuch-tree-thread-symbols) tree-status))
      ((and (eq 0 depth) (not first) (not last))
-      (push "├" tree-status)))
-    (push (concat (if replies "┬" "─") "►") tree-status)
+      (push (alist-get 'vertical-tee notmuch-tree-thread-symbols) tree-status)))
+    (push (concat (alist-get (if replies 'top-tee 'top) notmuch-tree-thread-symbols)
+		  (alist-get 'arrow notmuch-tree-thread-symbols))
+	  tree-status)
     (setq msg (plist-put msg :first (and first (eq 0 depth))))
     (setq msg (plist-put msg :tree-status tree-status))
     (setq msg (plist-put msg :orig-tags (plist-get msg :tags)))
+    (setq msg (plist-put msg :level level))
     (notmuch-tree-goto-and-insert-msg msg)
     (pop tree-status)
     (pop tree-status)
     (if last
 	(push " " tree-status)
-      (push "│" tree-status))
+      (push (alist-get 'vertical notmuch-tree-thread-symbols) tree-status))
     (notmuch-tree-insert-thread replies (1+ depth) tree-status)))
 
 (defun notmuch-tree-insert-thread (thread depth tree-status)
-  "Insert the collection of sibling sub-threads THREAD at depth DEPTH in the current forest."
+  "Insert the collection of sibling sub-threads THREAD at depth
+DEPTH in the current forest."
   (let ((n (length thread)))
     (cl-loop for tree in thread
 	     for count from 1 to n
@@ -986,10 +1064,9 @@ message together with all its descendents."
 
 (defun notmuch-tree-insert-forest-thread (forest-thread)
   "Insert a single complete thread."
-  (let (tree-status)
-    ;; Reset at the start of each main thread.
-    (setq notmuch-tree-previous-subject nil)
-    (notmuch-tree-insert-thread forest-thread 0 tree-status)))
+  ;; Reset at the start of each main thread.
+  (setq notmuch-tree-previous-subject nil)
+  (notmuch-tree-insert-thread forest-thread 0 nil))
 
 (defun notmuch-tree-insert-forest (forest)
   "Insert a forest of threads.
@@ -1014,21 +1091,26 @@ Complete list of currently available key bindings:
   (setq notmuch-buffer-refresh-function #'notmuch-tree-refresh-view)
   (hl-line-mode 1)
   (setq buffer-read-only t)
-  (setq truncate-lines t))
+  (setq truncate-lines t)
+  (when notmuch-tree-outline-enabled (notmuch-tree-outline-mode 1)))
+
+(defvar notmuch-tree-process-exit-functions nil
+  "Functions called when the process inserting a tree of results finishes.
+
+Functions in this list are called with one argument, the process
+object, and with the tree results buffer as the current buffer.")
 
-(defun notmuch-tree-process-sentinel (proc msg)
+(defun notmuch-tree-process-sentinel (proc _msg)
   "Add a message to let user know when \"notmuch tree\" exits."
   (let ((buffer (process-buffer proc))
 	(status (process-status proc))
-	(exit-status (process-exit-status proc))
-	(never-found-target-thread nil))
+	(exit-status (process-exit-status proc)))
     (when (memq status '(exit signal))
       (kill-buffer (process-get proc 'parse-buf))
       (when (buffer-live-p buffer)
 	(with-current-buffer buffer
 	  (save-excursion
-	    (let ((inhibit-read-only t)
-		  (atbob (bobp)))
+	    (let ((inhibit-read-only t))
 	      (goto-char (point-max))
 	      (when (eq status 'signal)
 		(insert "Incomplete search results (tree view process was killed).\n"))
@@ -1036,14 +1118,14 @@ Complete list of currently available key bindings:
 		(insert "End of search results.")
 		(unless (= exit-status 0)
 		  (insert (format " (process returned %d)" exit-status)))
-		(insert "\n")))))))))
+		(insert "\n"))))
+	  (run-hook-with-args 'notmuch-tree-process-exit-functions proc))))))
 
 (defun notmuch-tree-process-filter (proc string)
   "Process and filter the output of \"notmuch show\" for tree view."
   (let ((results-buf (process-buffer proc))
 	(parse-buf (process-get proc 'parse-buf))
-	(inhibit-read-only t)
-	done)
+	(inhibit-read-only t))
     (if (not (buffer-live-p results-buf))
 	(delete-process proc)
       (with-current-buffer parse-buf
@@ -1054,7 +1136,9 @@ Complete list of currently available key bindings:
 	(notmuch-sexp-parse-partial-list 'notmuch-tree-insert-forest-thread
 					 results-buf)))))
 
-(defun notmuch-tree-worker (basic-query &optional query-context target open-target unthreaded)
+(defun notmuch-tree-worker (basic-query &optional query-context target
+					open-target unthreaded oldest-first
+					exclude)
   "Insert the tree view of the search in the current buffer.
 
 This is is a helper function for notmuch-tree. The arguments are
@@ -1062,6 +1146,8 @@ the same as for the function notmuch-tree."
   (interactive)
   (notmuch-tree-mode)
   (add-hook 'post-command-hook #'notmuch-tree-command-hook t t)
+  (setq notmuch-search-oldest-first oldest-first)
+  (setq notmuch-search-hide-excluded exclude)
   (setq notmuch-tree-unthreaded unthreaded)
   (setq notmuch-tree-basic-query basic-query)
   (setq notmuch-tree-query-context (if (or (string= query-context "")
@@ -1080,14 +1166,16 @@ the same as for the function notmuch-tree."
   (let* ((search-args (concat basic-query
 			      (and query-context
 				   (concat " and (" query-context ")"))))
-	 (message-arg (if unthreaded "--unthreaded" "--entire-thread")))
-    (when (equal (car (process-lines notmuch-command "count" search-args)) "0")
+	 (sort-arg (if oldest-first "--sort=oldest-first" "--sort=newest-first"))
+	 (message-arg (if unthreaded "--unthreaded" "--entire-thread"))
+	 (exclude-arg (if exclude "--exclude=true" "--exclude=false")))
+    (when (equal (car (notmuch--process-lines notmuch-command "count" search-args)) "0")
       (setq search-args basic-query))
     (notmuch-tag-clear-cache)
     (let ((proc (notmuch-start-notmuch
 		 "notmuch-tree" (current-buffer) #'notmuch-tree-process-sentinel
-		 "show" "--body=false" "--format=sexp" "--format-version=4"
-		 message-arg search-args))
+		 "show" "--body=false" "--format=sexp" "--format-version=5"
+		 sort-arg message-arg exclude-arg search-args))
 	  ;; Use a scratch buffer to accumulate partial output.
 	  ;; This buffer will be killed by the sentinel, which
 	  ;; should be called no matter how the process dies.
@@ -1105,7 +1193,28 @@ the same as for the function notmuch-tree."
 	      ")")
     notmuch-tree-basic-query))
 
-(defun notmuch-tree (&optional query query-context target buffer-name open-target unthreaded parent-buffer)
+(defun notmuch-tree-toggle-order ()
+  "Toggle the current search order.
+
+This command toggles the sort order for the current search. The
+default sort order is defined by `notmuch-search-oldest-first'."
+  (interactive)
+  (setq notmuch-search-oldest-first (not notmuch-search-oldest-first))
+  (notmuch-tree-refresh-view))
+
+(defun notmuch-tree-toggle-hide-excluded ()
+  "Toggle whether to hide excluded messages.
+
+This command toggles whether to hide excluded messages for the current
+search. The default value for this is defined by `notmuch-search-hide-excluded'."
+  (interactive)
+  (setq notmuch-search-hide-excluded (not notmuch-search-hide-excluded))
+  (notmuch-tree-refresh-view))
+
+;;;###autoload
+(defun notmuch-tree (&optional query query-context target buffer-name
+			       open-target unthreaded parent-buffer
+			       oldest-first hide-excluded)
   "Display threads matching QUERY in tree view.
 
 The arguments are:
@@ -1120,29 +1229,275 @@ The arguments are:
       it is nil \"*notmuch-tree\" followed by QUERY is used.
   OPEN-TARGET: If TRUE open the target message in the message pane.
   UNTHREADED: If TRUE only show matching messages in an unthreaded view."
-  (interactive)
+  (interactive
+   (list
+    ;; Prompt for a query
+    nil
+    ;; Fill other args with nil.
+    nil nil nil nil nil nil
+    ;; Populate these from the default value of these options.
+    (default-value 'notmuch-search-oldest-first)
+    (default-value 'notmuch-search-hide-excluded)))
   (unless query
     (setq query (notmuch-read-query (concat "Notmuch "
 					    (if unthreaded "unthreaded " "tree ")
 					    "view search: "))))
-  (let ((buffer (get-buffer-create (generate-new-buffer-name
-				    (or buffer-name
-					(concat "*notmuch-"
-						(if unthreaded "unthreaded-" "tree-")
-						query "*")))))
+  (let* ((name
+	  (or buffer-name
+	      (notmuch-search-buffer-title query
+					   (if unthreaded "unthreaded" "tree"))))
+	 (buffer (get-buffer-create (generate-new-buffer-name name)))
 	(inhibit-read-only t))
     (pop-to-buffer-same-window buffer))
   ;; Don't track undo information for this buffer
-  (set 'buffer-undo-list t)
-  (notmuch-tree-worker query query-context target open-target unthreaded)
+  (setq buffer-undo-list t)
+  (notmuch-tree-worker query query-context target open-target
+		       unthreaded oldest-first hide-excluded)
   (setq notmuch-tree-parent-buffer parent-buffer)
   (setq truncate-lines t))
 
-(defun notmuch-unthreaded (&optional query query-context target buffer-name open-target)
+(defun notmuch-unthreaded (&optional query query-context target buffer-name
+				     open-target oldest-first hide-excluded)
+  "Display threads matching QUERY in unthreaded view.
+
+See function NOTMUCH-TREE for documentation of the arguments"
+  (interactive
+   (list
+    ;; Prompt for a query
+    nil
+    ;; Fill other args with nil.
+    nil nil nil nil
+    ;; Populate these from the default value of these options.
+    (default-value 'notmuch-search-oldest-first)
+    (default-value 'notmuch-search-hide-excluded)))
+  (notmuch-tree query query-context target buffer-name open-target
+		t nil oldest-first hide-excluded))
+
+(defun notmuch-tree-filter (query)
+  "Filter or LIMIT the current search results based on an additional query string.
+
+Runs a new tree search matching only messages that match both the
+current search results AND the additional query string provided."
+  (interactive (list (notmuch-read-query "Filter search: ")))
+  (let ((notmuch-show-process-crypto (notmuch-tree--message-process-crypto))
+	(grouped-query (notmuch-group-disjunctive-query-string query))
+	(grouped-original-query (notmuch-group-disjunctive-query-string
+				 (notmuch-tree-get-query))))
+    (notmuch-tree-close-message-window)
+    (notmuch-tree (if (string= grouped-original-query "*")
+		      grouped-query
+		    (concat grouped-original-query " and " grouped-query)))))
+
+(defun notmuch-tree-filter-by-tag (tag)
+  "Filter the current search results based on a single TAG.
+
+Run a new search matching only messages that match the current
+search results and that are also tagged with the given TAG."
+  (interactive
+   (list (notmuch-select-tag-with-completion "Filter by tag: "
+					     notmuch-tree-basic-query)))
+  (let ((notmuch-show-process-crypto (notmuch-tree--message-process-crypto)))
+    (notmuch-tree-close-message-window)
+    (notmuch-tree (concat notmuch-tree-basic-query " and tag:" tag)
+		  notmuch-tree-query-context
+		  nil
+		  nil
+		  nil
+		  notmuch-tree-unthreaded
+		  nil
+		  notmuch-search-oldest-first
+		  notmuch-search-hide-excluded)))
+
+(defun notmuch-tree-edit-search (query)
+  "Edit the current search"
+  (interactive (list (read-from-minibuffer "Edit search: "
+					   notmuch-tree-basic-query)))
+  (let ((notmuch-show-process-crypto (notmuch-tree--message-process-crypto)))
+    (notmuch-tree-close-message-window)
+    (notmuch-tree query
+		  notmuch-tree-query-context
+		  nil
+		  nil
+		  nil
+		  notmuch-tree-unthreaded
+		  nil
+		  notmuch-search-oldest-first)))
+
+;;; Tree outline mode
+;;;; Custom variables
+(defcustom notmuch-tree-outline-enabled nil
+  "Whether to automatically activate `notmuch-tree-outline-mode' in tree views."
+  :type 'boolean)
+
+(defcustom notmuch-tree-outline-visibility 'hide-others
+  "Default state of the forest outline for `notmuch-tree-outline-mode'.
+
+This variable controls the state of a forest initially and after
+a movement command.  If set to nil, all trees are displayed while
+the symbol hide-all indicates that all trees in the forest should
+be folded and hide-other that only the first one should be
+unfolded."
+  :type '(choice (const :tag "Show all" nil)
+		 (const :tag "Hide others" hide-others)
+		 (const :tag "Hide all" hide-all)))
+
+(defcustom notmuch-tree-outline-auto-close nil
+  "Close message and tree windows when moving past the last message."
+  :type 'boolean)
+
+(defcustom notmuch-tree-outline-open-on-next nil
+  "Open new messages under point if they are closed when moving to next one.
+
+When this flag is set, using the command
+`notmuch-tree-outline-next' with point on a header for a new
+message that is not shown will open its `notmuch-show' buffer
+instead of moving point to next matching message."
+  :type 'boolean)
+
+;;;; Helper functions
+(defsubst notmuch-tree-outline--pop-at-end (pop-at-end)
+  (if notmuch-tree-outline-auto-close (not pop-at-end) pop-at-end))
+
+(defun notmuch-tree-outline--set-visibility ()
+  (when (and notmuch-tree-outline-mode (> (point-max) (point-min)))
+    (cl-case notmuch-tree-outline-visibility
+      (hide-others (notmuch-tree-outline-hide-others))
+      (hide-all (outline-hide-body)))))
+
+(defun notmuch-tree-outline--on-exit (proc)
+  (when (eq (process-status proc) 'exit)
+    (notmuch-tree-outline--set-visibility)))
+
+(add-hook 'notmuch-tree-process-exit-functions #'notmuch-tree-outline--on-exit)
+
+(defsubst notmuch-tree-outline--level (&optional props)
+  (or (plist-get (or props (notmuch-tree-get-message-properties)) :level) 0))
+
+(defsubst notmuch-tree-outline--message-open-p ()
+  (and (buffer-live-p notmuch-tree-message-buffer)
+       (get-buffer-window notmuch-tree-message-buffer)
+       (let ((id (notmuch-tree-get-message-id)))
+	 (and id
+	      (with-current-buffer notmuch-tree-message-buffer
+		(string= (notmuch-show-get-message-id) id))))))
+
+(defsubst notmuch-tree-outline--at-original-match-p ()
+  (and (notmuch-tree-get-prop :match)
+       (equal (notmuch-tree-get-prop :orig-tags)
+              (notmuch-tree-get-prop :tags))))
+
+(defun notmuch-tree-outline--next (prev thread pop-at-end &optional open-new)
+  (cond (thread
+	 (notmuch-tree-thread-top)
+	 (if prev
+	     (outline-backward-same-level 1)
+	   (outline-forward-same-level 1))
+	 (when (> (notmuch-tree-outline--level) 0) (outline-show-branches))
+	 (notmuch-tree-outline--next nil nil pop-at-end t))
+	((and (or open-new notmuch-tree-outline-open-on-next)
+	      (notmuch-tree-outline--at-original-match-p)
+	      (not (notmuch-tree-outline--message-open-p)))
+	 (notmuch-tree-outline-hide-others t))
+	(t (outline-next-visible-heading (if prev -1 1))
+	   (unless (notmuch-tree-get-prop :match)
+	     (notmuch-tree-matching-message prev pop-at-end))
+	   (notmuch-tree-outline-hide-others t))))
+
+;;;; User commands
+(defun notmuch-tree-outline-hide-others (&optional and-show)
+  "Fold all threads except the one around point.
+If AND-SHOW is t, make the current message visible if it's not."
+  (interactive)
+  (save-excursion
+    (while (and (not (bobp)) (> (notmuch-tree-outline--level) 1))
+      (outline-previous-heading))
+    (outline-hide-sublevels 1))
+  (when (> (notmuch-tree-outline--level) 0)
+    (outline-show-subtree)
+    (when and-show (notmuch-tree-show-message nil))))
+
+(defun notmuch-tree-outline-next (&optional pop-at-end)
+  "Next matching message in a forest, taking care of thread visibility.
+A prefix argument reverses the meaning of `notmuch-tree-outline-auto-close'."
+  (interactive "P")
+  (let ((pop (notmuch-tree-outline--pop-at-end pop-at-end)))
+    (if (null notmuch-tree-outline-visibility)
+	(notmuch-tree-matching-message nil pop)
+      (notmuch-tree-outline--next nil nil pop))))
+
+(defun notmuch-tree-outline-previous (&optional pop-at-end)
+  "Previous matching message in forest, taking care of thread visibility.
+With prefix, quit the tree view if there is no previous message."
+  (interactive "P")
+  (if (null notmuch-tree-outline-visibility)
+      (notmuch-tree-prev-matching-message pop-at-end)
+    (notmuch-tree-outline--next t nil pop-at-end)))
+
+(defun notmuch-tree-outline-next-thread ()
+  "Next matching thread in forest, taking care of thread visibility."
   (interactive)
-  (notmuch-tree query query-context target buffer-name open-target t))
+  (if (null notmuch-tree-outline-visibility)
+      (notmuch-tree-next-thread)
+    (notmuch-tree-outline--next nil t nil)))
 
-;;
+(defun notmuch-tree-outline-previous-thread ()
+  "Previous matching thread in forest, taking care of thread visibility."
+  (interactive)
+  (if (null notmuch-tree-outline-visibility)
+      (notmuch-tree-prev-thread)
+    (notmuch-tree-outline--next t t nil)))
+
+;;;; Mode definition
+(defvar notmuch-tree-outline-mode-lighter nil
+  "The lighter mark for notmuch-tree-outline mode.
+Usually empty since outline-minor-mode's lighter will be active.")
+
+(define-minor-mode notmuch-tree-outline-mode
+  "Minor mode allowing message trees to be folded as outlines.
+
+When this mode is set, each thread and subthread in the results
+list is treated as a foldable section, with its first message as
+its header.
+
+The mode just makes available in the tree buffer all the
+keybindings in `outline-minor-mode', and binds the following
+additional keys:
+
+\\{notmuch-tree-outline-mode-map}
+
+The customizable variable `notmuch-tree-outline-visibility'
+controls how navigation in the buffer is affected by this mode:
+
+  - If it is set to nil, `notmuch-tree-outline-previous',
+    `notmuch-tree-outline-next', and their thread counterparts
+    behave just as the corresponding notmuch-tree navigation keys
+    when this mode is not enabled.
+
+  - If, on the other hand, `notmuch-tree-outline-visibility' is
+    set to a non-nil value, these commands hiding the outlines of
+    the trees you are not reading as you move to new messages.
+
+To enable notmuch-tree-outline-mode by default in all
+notmuch-tree buffers, just set
+`notmuch-tree-outline-mode-enabled' to t."
+  :lighter notmuch-tree-outline-mode-lighter
+  :keymap `((,(kbd "TAB") . outline-cycle)
+	    (,(kbd "M-TAB") . outline-cycle-buffer)
+	    ("n" . notmuch-tree-outline-next)
+	    ("p" . notmuch-tree-outline-previous)
+	    (,(kbd "M-n") . notmuch-tree-outline-next-thread)
+	    (,(kbd "M-p") . notmuch-tree-outline-previous-thread))
+  (outline-minor-mode notmuch-tree-outline-mode)
+  (unless (derived-mode-p 'notmuch-tree-mode)
+    (user-error "notmuch-tree-outline-mode is only meaningful for notmuch trees!"))
+  (if notmuch-tree-outline-mode
+      (progn (setq-local outline-regexp "^[^\n]+")
+	     (setq-local outline-level #'notmuch-tree-outline--level)
+	     (notmuch-tree-outline--set-visibility))
+    (setq-local outline-regexp (default-value 'outline-regexp))
+    (setq-local	outline-level (default-value 'outline-level))))
+
+;;; _
 
 (provide 'notmuch-tree)