bug#68765: 30.0.50; Adding window-tool-bar package.

[Jared Finder via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

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This is a follow-up from bug#68334 where there was interest in adding 
support into Emacs core for tool bars in windows. 
(https://debbugs.gnu.org/cgi/bugreport.cgi?bug=68334#52)  I have 
attached three changes I authored to accomplish this, two small changes 
to tool-bar and tab-line, and then a code drop of my window-tool-bar.el 
package.  I have not yet put in documentation in NEWS or the manual 
about window-tool-bar and was hoping to get a code review done first.

I think it would be good to have window-tool-bar.el also be a package so 
that I can keep supporting Emacs 29 as well.  I am happy to have this 
put on GNU ELPA and would appreciate help in getting that completed.

I am open to renaming the package and public functions if that's 
desired.  I like the name "window-tool-bar-mode" as it clearly relates 
to tool-bar-mode.

After these patches are accepted, I'd also like to clean up the existing 
tool bar maps for built in minor modes.  This would allow me to address 
Eli's request to have a usable tool bar for M-x gdb 
(https://debbugs.gnu.org/cgi/bugreport.cgi?bug=68334#23).

For tracking purposes, I signed copyright paperwork back in 2020, so 
that shouldn't be an issue.  Thanks.

   -- MJF

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From 7f344ed1590b81323e24cdedf77477ae57cb49f9 Mon Sep 17 00:00:00 2001
From: Jared Finder <jared@finder.org>
Date: Fri, 26 Jan 2024 09:49:03 -0800
Subject: [PATCH 1/3] Enable multiple modes to appear in tab line

This adds space for window-tool-bar-mode, which will be added in an
upcoming commit.

* lisp/tab-line.el (tab-line-format-template): Add separator space.
(tab-line-display-order): New user variable to control display order.
(tab-line--runtime-display-order, tab-line--cookie): New internal
variables.
(tab-line-set-display): New function for modes to call to enable only
their content.
(tab-line-mode): Call `tab-line-set-display'.
---
 lisp/tab-line.el | 89 +++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 80 insertions(+), 9 deletions(-)

diff --git a/lisp/tab-line.el b/lisp/tab-line.el
index cc60f94c9c5..c7283641cbd 100644
--- a/lisp/tab-line.el
+++ b/lisp/tab-line.el
@@ -573,7 +573,8 @@ tab-line-format-template
      (when (and (eq tab-line-tabs-function #'tab-line-tabs-window-buffers)
                 tab-line-new-button-show
                 tab-line-new-button)
-       (list tab-line-new-button)))))
+       (list tab-line-new-button))
+     (list " "))))
 
 (defun tab-line-tab-face-inactive-alternating (tab tabs face _buffer-p selected-p)
   "Return FACE for TAB in TABS with alternation.
@@ -997,18 +998,88 @@ tab-line-event-start
       (event-start event)))
 
 \f
+;;; Tab line display ordering
+(defcustom tab-line-display-order
+  (copy-tree '(tab-line-mode window-tool-bar-mode))
+  "The order to display content in the tab-line.
+
+This is a list of symbols.  By convention, the symbols correspond
+to the mode name that enables / disables content.  Any symbol not
+listed here will automatically be put at the end of the tab line.
+
+See `tab-line-set-display' for the Lisp interface to add and
+remove content."
+  :type '(repeat symbol)
+  :group 'tab-line
+  :version "30.1")
+
+(defvar tab-line--runtime-display-order
+  nil
+  "Symbols that contain content but are not in `tab-line-display-order'.
+This list ensures that content stays in a stable position in the
+tab line.")
+
+(defconst tab-line--cookie
+  '(tab-line-set-display nil)
+  "Cookie used by `tab-line-set-display'.
+This is used to tell if the tab line is being set based on
+`tab-line-display-order' or was overridden by the user.")
+
+(defun tab-line-set-display (sym value)
+  "Lisp interface to add or remove content from the tab line.
+
+After calling this, if there is no content in the tab line, it
+will be automatically hidden.
+
+SYM is a symbol, usually the symbol corresponding to the mode
+showing content such as `tab-line-mode'.
+
+VALUE is the content to display and will be added to
+`tab-line-format' at an appropriate index based on
+`tab-line-display-order'.  If you want to remove content because
+the mode is being disabled, set this to nil."
+  ;; Preserve tab-line-format if altered outside of this function.
+  (when (or (null tab-line-format)
+            ;; Assume that user modifications will not use this
+            ;; cookie.
+            (equal (car tab-line-format) tab-line--cookie))
+    (let (pos)
+      (setf pos (seq-position tab-line-display-order sym))
+      (unless pos
+        (when-let ((append-pos (seq-position tab-line--runtime-display-order sym)))
+          (setf pos (+ (length tab-line-display-order)
+                       append-pos))))
+      (unless pos
+        (warn "Symbol %S not found in `tab-line-display-order'.  Putting at end."
+              sym)
+        (setf pos (+ (length tab-line-display-order)
+                     (length tab-line--runtime-display-order))
+              tab-line--runtime-display-order
+              (append tab-line--runtime-display-order
+                      (list sym))))
+
+      (let ((desired-length (+ pos 2))  ;Plus 1 additional for the cookie,
+            (current-length (length tab-line-format)))
+        (when (> desired-length current-length)
+          (setf tab-line-format
+                (append tab-line-format
+                        (make-list (- desired-length current-length) nil))
+                ;; If tab-line-format was nil, then the cookie needs to be set.
+                (car tab-line-format) tab-line--cookie)))
+
+      (setf (nth (1+ pos) tab-line-format) value))
+
+    ;; If the entire display has been disabled, tab line would display
+    ;; as empty.  Explicitly hide the tab line in this case.
+    (when (seq-every-p #'null (cdr tab-line-format))
+      (setf tab-line-format nil))))
+\f
 ;;;###autoload
 (define-minor-mode tab-line-mode
   "Toggle display of tab line in the windows displaying the current buffer."
   :lighter nil
-  (let ((default-value '(:eval (tab-line-format))))
-    (if tab-line-mode
-        ;; Preserve the existing tab-line set outside of this mode
-        (unless tab-line-format
-          (setq tab-line-format default-value))
-      ;; Reset only values set by this mode
-      (when (equal tab-line-format default-value)
-        (setq tab-line-format nil)))))
+  (tab-line-set-display 'tab-line-mode
+                        (if tab-line-mode '(:eval (tab-line-format)) nil)))
 
 (defcustom tab-line-exclude-modes
   '(completion-list-mode)
-- 
2.39.2


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From ba90ed7f057ea627bd2168d47223396a7bc36c20 Mon Sep 17 00:00:00 2001
From: Jared Finder <jared@finder.org>
Date: Fri, 26 Jan 2024 10:08:30 -0800
Subject: [PATCH 2/3] Add user option to only display default tool bar

This works well with `window-tool-bar-mode', to be added in upcoming
commit.  Then the default tool bar is displayed frame-wide and
mode-specific tool bars are displayed in the window that mode is
active in.

* lisp/tool-bar.el (tool-bar-always-show-default): New user option.
(tool-bar--cache-key, tool-bar-make-keymap-1): Return default tool bar
when option is set.
---
 lisp/tool-bar.el | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/lisp/tool-bar.el b/lisp/tool-bar.el
index 96b61c7b229..685e4dfbb86 100644
--- a/lisp/tool-bar.el
+++ b/lisp/tool-bar.el
@@ -100,7 +100,9 @@ secondary-tool-bar-map
 (defconst tool-bar-keymap-cache (make-hash-table :test #'equal))
 
 (defsubst tool-bar--cache-key ()
-  (cons (frame-terminal) (sxhash-eq tool-bar-map)))
+  (cons (frame-terminal)
+        (sxhash-eq (if tool-bar-always-show-default (default-value 'tool-bar-map)
+                     tool-bar-map))))
 
 (defsubst tool-bar--secondary-cache-key ()
   (cons (frame-terminal) (sxhash-eq secondary-tool-bar-map)))
@@ -191,7 +193,9 @@ tool-bar-make-keymap-1
 				      bind))
 		  (plist-put plist :image image)))
 	      bind))
-	  (or map tool-bar-map)))
+	  (or map
+              (if tool-bar-always-show-default (default-value 'tool-bar-map)
+                tool-bar-map))))
 
 ;;;###autoload
 (defun tool-bar-add-item (icon def key &rest props)
@@ -377,6 +381,15 @@ tool-bar-setup
 	     (modify-all-frames-parameters
 	      (list (cons 'tool-bar-position val))))))
 
+(defcustom tool-bar-always-show-default nil
+  "If non-nil, do not show mode-specific tool bars.
+This works well when using `global-window-tool-bar-mode' to
+display the mode-specific tool bars attached to each window."
+  :type 'boolean
+  :group 'frames
+  :group 'mouse
+  :version "30.1")
+
 \f
 
 ;; Modifier bar mode.
-- 
2.39.2


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From 24ed752ec0bfdded24cba4892426c2c9710126cf Mon Sep 17 00:00:00 2001
From: Jared Finder <jared@finder.org>
Date: Fri, 26 Jan 2024 15:44:12 -0800
Subject: [PATCH 3/3] Adding window-tool-bar package

---
 lisp/window-tool-bar.el | 488 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 488 insertions(+)
 create mode 100644 lisp/window-tool-bar.el

diff --git a/lisp/window-tool-bar.el b/lisp/window-tool-bar.el
new file mode 100644
index 00000000000..3950fe12f1a
--- /dev/null
+++ b/lisp/window-tool-bar.el
@@ -0,0 +1,488 @@
+;;; window-tool-bar.el --- Add tool bars inside windows -*- lexical-binding: t -*-
+
+;; Copyright (C) 2023-2024 Free Software Foundation, Inc.
+;; Author: Jared Finder <jared@finder.org>
+;; Created: Nov 21, 2023
+;; Version: 0.2
+;; Keywords: mouse
+;; URL: http://github.com/chaosemer/window-tool-bar
+;; Package-Requires: ((emacs "29.1"))
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; This package puts a tool bar in each window.  This allows you to see
+;; multiple tool bars simultaneously directly next to the buffer it
+;; acts on which feels much more intuitive.  Emacs "browsing" modes
+;; generally have sensible tool bars, for example: *info*, *help*, and
+;; *eww* have them.
+;;
+;; It does this while being mindful of screen real estate.  Most modes
+;; do not provide a custom tool bar, and this package does not show the
+;; default tool bar.  This means that for most buffers there will be no
+;; space taken up.  Furthermore, you can put this tool bar in the mode
+;; line or tab line if you want to share it with existing content.
+;;
+;; To get the default behavior, run (global-window-tool-bar-mode 1) or
+;; enable via M-x customize-group RET window-tool-bar RET.  This uses
+;; the per-window tab line to show the tool bar.
+;;
+;; If you want to share space with an existing tab line, mode line, or
+;; header line, add (:eval (window-tool-bar-string)) to
+;; `tab-line-format', `mode-line-format', or `header-line-format'.
+
+;;; Known issues:
+;;
+;; On GNU Emacs 29.1, terminals dragging to resize windows will error
+;; with message "<tab-line> <mouse-movement> is undefined".  This is a
+;; bug in GNU Emacs,
+;; <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=67457>.
+;;
+;; On GNU Emacs 29, performance in terminals is lower than on
+;; graphical frames.  This is due to a workaround, see "Workaround for
+;; https://debbugs.gnu.org/cgi/bugreport.cgi?bug=68334", below.
+
+;;; Todo:
+;;
+;; Not all features planned are implemented yet.  Eventually I would
+;; like to also generally make tool bars better.
+;;
+;; Targeting 0.3:
+;; * Properly support reamining less frequently used tool bar item specs.  From
+;;   `parse_tool_bar_item':
+;;     * :visible
+;;     * :filter
+;;     * :button
+;;     * :wrap
+;; * Add display customization similar to `tool-bar-style'.
+;;
+;; Targeting 1.0:
+;;
+;; * Clean up Emacs tool bars
+;;     * Default: Remove default tool-bar entirely
+;;     * grep, vc: Remove default tool-bar inherited
+;;     * info: Remove Next / Prev / Up, which is already in the header
+;;     * smerge: Add tool bar for next/prev
+;;
+;; Post 1.0 work:
+;;
+;; * Show keyboard shortcut on help text.
+;;
+;; * Add a bit more documentation.
+;; * Add customization option: ignore-default-tool-bar-map
+;; * Make tab-line dragging resize the window
+
+;;; Code:
+
+(require 'mwheel)
+(require 'tab-line)
+(require 'tool-bar)
+\f
+;;; Benchmarking code
+;;
+;; Refreshing the tool bar is computationally simple, but generates a
+;; lot of garbage.  So this benchmarking focuses on garbage
+;; generation.  Since it has to run after most commands, generating
+;; significantly more garbage will cause noticeable performance
+;; degration.
+;;
+;; The refresh has two steps:
+;;
+;; Step 1: Look up the <tool-bar> map.
+;; Step 2: Generate a Lisp string using text properties for the tool
+;; bar string.
+;;
+;; Additionally, we keep track of the percentage of commands that
+;; acutally created a refresh.
+(defvar window-tool-bar--memory-use-delta-step1 (make-list 7 0)
+  "Absolute delta of memory use counters during step 1.
+This is a list in the same structure as `memory-use-counts'.")
+(defvar window-tool-bar--memory-use-delta-step2 (make-list 7 0)
+  "Absolute delta of memory use counters during step 2.
+This is a list in the same structure as `memory-use-counts'.")
+(defvar window-tool-bar--refresh-done-count 0
+  "Number of tool bar string refreshes run.
+The total number of requests is the sum of this and
+`window-tool-bar--refresh-skipped-count'.")
+(defvar window-tool-bar--refresh-skipped-count 0
+  "Number of tool bar string refreshes that were skipped.
+The total number of requests is the sum of this and
+`window-tool-bar--refresh-done-count'.")
+
+(defun window-tool-bar--memory-use-avg-step1 ()
+  "Return average memory use delta during step 1."
+  (mapcar (lambda (elt) (/ elt window-tool-bar--refresh-done-count 1.0))
+          window-tool-bar--memory-use-delta-step1))
+
+(defun window-tool-bar--memory-use-avg-step2 ()
+  "Return average memory use delta during step 2."
+  (mapcar (lambda (elt) (/ elt window-tool-bar--refresh-done-count 1.0))
+          window-tool-bar--memory-use-delta-step2))
+
+(declare-function time-stamp-string "time-stamp")
+
+(defun window-tool-bar-show-memory-use ()
+  "Pop up a window showing the memory use metrics."
+  (interactive)
+  (require 'time-stamp)
+  (save-selected-window
+    (pop-to-buffer "*WTB Memory Report*")
+    (unless (eq major-mode 'special-mode)
+      (special-mode))
+
+    (goto-char (point-max))
+    (let ((inhibit-read-only t))
+      (insert (propertize (concat "Function: window-tool-bar-string "
+                                  (time-stamp-string))
+                          'face 'underline 'font-lock-face 'underline)
+              "\n\n")
+      (window-tool-bar--insert-memory-use
+       "Step 1" (window-tool-bar--memory-use-avg-step1))
+      (window-tool-bar--insert-memory-use
+       "Step 2" (window-tool-bar--memory-use-avg-step2))
+      (insert (format "Refresh count  %d\n" window-tool-bar--refresh-done-count)
+              (format "Refresh executed percent %.2f\n"
+                      (/ window-tool-bar--refresh-done-count
+                         (+ window-tool-bar--refresh-done-count
+                            window-tool-bar--refresh-skipped-count)
+                         1.0))
+              "\n"))))
+
+(defun window-tool-bar--insert-memory-use (label avg-memory-use)
+  "Insert memory use into current buffer.
+
+LABEL: A prefix string to be in front of the data.
+AVG-MEMORY-USE: A list of averages, with the same meaning as
+  `memory-use-counts'."
+  (let* ((label-len (length label))
+         (padding (make-string label-len ?\s)))
+    (insert (format "%s  %8.2f Conses\n" label (elt avg-memory-use 0)))
+    (insert (format "%s  %8.2f Floats\n" padding (elt avg-memory-use 1)))
+    (insert (format "%s  %8.2f Vector cells\n" padding (elt avg-memory-use 2)))
+    (insert (format "%s  %8.2f Symbols\n" padding (elt avg-memory-use 3)))
+    (insert (format "%s  %8.2f String chars\n" padding (elt avg-memory-use 4)))
+    (insert (format "%s  %8.2f Intervals\n" padding (elt avg-memory-use 5)))
+    (insert (format "%s  %8.2f Strings\n" padding (elt avg-memory-use 6)))))
+\f
+(defgroup window-tool-bar nil
+  "Tool bars per-window."
+  :group 'convenience
+  :prefix "window-tool-bar-")
+
+(defvar-keymap window-tool-bar--button-keymap
+  :doc "Keymap used by `window-tool-bar--keymap-entry-to-string'."
+  "<follow-link>" 'mouse-face
+  ;; Follow link on all clicks of mouse-1 and mouse-2 since the tool
+  ;; bar is not a place the point can travel to.
+  "<tab-line> <mouse-1>" #'window-tool-bar--call-button
+  "<tab-line> <double-mouse-1>" #'window-tool-bar--call-button
+  "<tab-line> <triple-mouse-1>" #'window-tool-bar--call-button
+  "<tab-line> <mouse-2>" #'window-tool-bar--call-button
+  "<tab-line> <double-mouse-2>" #'window-tool-bar--call-button
+  "<tab-line> <triple-mouse-2>" #'window-tool-bar--call-button
+
+  ;; Mouse down events do nothing.  A binding is needed so isearch
+  ;; does not exit when the tab bar is clicked.
+  "<tab-line> <down-mouse-1>" #'window-tool-bar--ignore
+  "<tab-line> <double-down-mouse-1>" #'window-tool-bar--ignore
+  "<tab-line> <triple-down-mouse-1>" #'window-tool-bar--ignore
+  "<tab-line> <down-mouse-2>" #'window-tool-bar--ignore
+  "<tab-line> <double-down-mouse-2>" #'window-tool-bar--ignore
+  "<tab-line> <triple-down-mouse-2>" #'window-tool-bar--ignore)
+(fset 'window-tool-bar--button-keymap window-tool-bar--button-keymap) ; So it can be a keymap property
+
+;; Register bindings that stay in isearch.  Technically, these
+;; commands don't pop up a menu but they act very similar in that they
+;; end up calling an actual command via `call-interactively'.
+(push 'window-tool-bar--call-button isearch-menu-bar-commands)
+(push 'window-tool-bar--ignore isearch-menu-bar-commands)
+
+(defvar-local window-tool-bar-string--cache nil
+  "Cache for previous result of `window-tool-bar-string'.")
+
+;;;###autoload
+(defun window-tool-bar-string ()
+  "Return a (propertized) string for the tool bar.
+
+This is for when you want more customizations than
+`window-tool-bar-mode' provides.  Commonly added to the variable
+`tab-line-format', `header-line-format', or `mode-line-format'"
+  (if (or (null window-tool-bar-string--cache)
+          (window-tool-bar--last-command-triggers-refresh-p))
+      (let* ((mem0 (memory-use-counts))
+             (toolbar-menu (window-tool-bar--get-keymap))
+             (mem1 (memory-use-counts))
+             (result (mapconcat #'window-tool-bar--keymap-entry-to-string
+                                (cdr toolbar-menu) ;Skip 'keymap
+                                ;; Without spaces between the text, hovering
+                                ;; highlights all adjacent buttons.
+                                (if (window-tool-bar--use-images)
+                                    (propertize " " 'invisible t)
+                                  " ")))
+             (mem2 (memory-use-counts)))
+        (cl-mapl (lambda (l-init l0 l1)
+                   (cl-incf (car l-init) (- (car l1) (car l0))))
+                 window-tool-bar--memory-use-delta-step1 mem0 mem1)
+        (cl-mapl (lambda (l-init l1 l2)
+                   (cl-incf (car l-init) (- (car l2) (car l1))))
+                 window-tool-bar--memory-use-delta-step2 mem1 mem2)
+
+        (setf window-tool-bar-string--cache
+              (concat
+               ;; The tool bar face by default puts boxes around the
+               ;; buttons.  However, this box is not displayed if the
+               ;; box starts at the leftmost pixel of the tab-line.
+               ;; Add a single space in this case so the box displays
+               ;; correctly.
+               (when (display-supports-face-attributes-p
+                      '(:box (line-width 1)))
+                 (propertize " " 'display '(space :width (1))))
+               result))
+        (cl-incf window-tool-bar--refresh-done-count))
+    (cl-incf window-tool-bar--refresh-skipped-count))
+
+  window-tool-bar-string--cache)
+
+(defconst window-tool-bar--graphical-separator
+  (let ((str (make-string 3 ?\s)))
+    (set-text-properties 0 1 '(display (space :width (4))) str)
+    (set-text-properties 1 2
+                         '(display (space :width (1))
+                           face (:inverse-video t))
+                         str)
+    (set-text-properties 2 3 '(display (space :width (4))) str)
+    str))
+
+(defun window-tool-bar--keymap-entry-to-string (menu-item)
+  "Convert MENU-ITEM into a (propertized) string representation.
+
+MENU-ITEM: Menu item to convert.  See info node (elisp)Tool Bar."
+  (pcase menu-item
+    ;; Separators
+    ((or `(,_ "--")
+         `(,_ menu-item ,(and (pred stringp)
+                              (pred (string-prefix-p "--")))))
+     (if (window-tool-bar--use-images)
+         window-tool-bar--graphical-separator
+       "|"))
+
+    ;; Menu item, turn into propertized string button
+    (`(,key menu-item ,name-expr ,binding . ,plist)
+     (when binding      ; If no binding exists, then button is hidden.
+       (let* ((name (eval name-expr))
+              (str (upcase-initials (or (plist-get plist :label)
+                                        (string-trim-right name "\\.+"))))
+              (len (length str))
+              (enable-form (plist-get plist :enable))
+              (enabled (or (not enable-form)
+                           (eval enable-form))))
+         (if enabled
+             (add-text-properties 0 len
+                                  '(mouse-face window-tool-bar-button-hover
+                                    keymap window-tool-bar--button-keymap
+				    face window-tool-bar-button)
+                                  str)
+           (put-text-property 0 len
+                              'face
+                              'window-tool-bar-button-disabled
+                              str))
+         (when-let ((spec (and (window-tool-bar--use-images)
+                               (plist-get menu-item :image))))
+           (put-text-property 0 len
+                              'display
+                              (append spec
+                                      (if enabled '(:margin 2 :ascent center)
+                                        '(:margin 2 :ascent center
+                                          :conversion disabled)))
+                              str))
+         (put-text-property 0 len
+                            'help-echo
+                            (or (plist-get plist :help) name)
+                            str)
+         (put-text-property 0 len 'tool-bar-key key str)
+         str)))))
+
+(defun window-tool-bar--call-button ()
+  "Call the button that was clicked on in the tab line."
+  (interactive)
+  (when (mouse-event-p last-command-event)
+    (let ((posn (event-start last-command-event)))
+      ;; Commands need to execute with the right buffer and window
+      ;; selected.  The selection needs to be permanent for isearch.
+      (select-window (posn-window posn))
+      (let* ((str (posn-string posn))
+             (key (get-text-property (cdr str) 'tool-bar-key (car str)))
+             (cmd (lookup-key (window-tool-bar--get-keymap) (vector key))))
+        (call-interactively cmd)))))
+
+(defun window-tool-bar--ignore ()
+  "Do nothing.  This command exists for isearch."
+  (interactive)
+  nil)
+
+(defvar window-tool-bar--ignored-event-types
+  (let ((list (list 'mouse-movement 'pinch
+                    'wheel-down 'wheel-up 'wheel-left 'wheel-right
+                    mouse-wheel-down-event mouse-wheel-up-event
+                    mouse-wheel-left-event mouse-wheel-right-event
+                    (bound-and-true-p mouse-wheel-down-alternate-event)
+                    (bound-and-true-p mouse-wheel-up-alternate-event)
+                    (bound-and-true-p mouse-wheel-left-alternate-event)
+                    (bound-and-true-p mouse-wheel-right-alternate-event))))
+    (delete-dups (delete nil list)))
+  "Cache for `window-tool-bar--last-command-triggers-refresh-p'.")
+
+(defun window-tool-bar--last-command-triggers-refresh-p ()
+  "Test if the recent command or event should trigger a tool bar refresh."
+  (let ((type (event-basic-type last-command-event)))
+    (and
+     ;; Assume that key presses and button presses are the only user
+     ;; interactions that can alter the tool bar.  Specifically, this
+     ;; excludes mouse movement, mouse wheel scroll, and pinch.
+     (not (member type window-tool-bar--ignored-event-types))
+     ;; Assume that any command that triggers shift select can't alter
+     ;; the tool bar.  This excludes pure navigation commands.
+     (not (window-tool-bar--command-triggers-shift-select-p last-command))
+     ;; Assume that self-insert-command won't alter the tool bar.
+     ;; This is the most commonly executed command.
+     (not (eq last-command 'self-insert-command)))))
+
+(defun window-tool-bar--command-triggers-shift-select-p (command)
+  "Test if COMMAND would trigger shift select."
+  (let* ((form (interactive-form command))
+         (spec (car-safe (cdr-safe form))))
+    (and (eq (car-safe form) 'interactive)
+         (stringp spec)
+         (seq-position spec ?^))))
+
+;;;###autoload
+(define-minor-mode window-tool-bar-mode
+  "Toggle display of the tool bar in the tab line of the current buffer."
+  :lighter nil
+  (let ((should-display (and window-tool-bar-mode
+                             (not (eq tool-bar-map
+                                      (default-value 'tool-bar-map))))))
+    (if (fboundp 'tab-line-set-display)
+        ;; Newly added function for Emacs 30.
+        (tab-line-set-display 'window-tool-bar-mode
+			      (and should-display
+				   '(:eval (window-tool-bar-string))))
+      ;; Legacy path for Emacs 29.
+      (setq tab-line-format
+            (and should-display
+                 '(:eval (window-tool-bar-string)))))))
+
+;;;###autoload
+(define-globalized-minor-mode global-window-tool-bar-mode
+  window-tool-bar-mode window-tool-bar--turn-on
+  :group 'window-tool-bar
+  (add-hook 'isearch-mode-hook #'window-tool-bar--turn-on)
+  (add-hook 'isearch-mode-end-hook #'window-tool-bar--turn-on))
+
+(defvar window-tool-bar--allow-images t
+  "Internal debug flag to force text mode.")
+
+(defun window-tool-bar--use-images ()
+  "Internal function.
+Respects `window-tool-bar--allow-images' as well as frame
+capabilities."
+  (and window-tool-bar--allow-images
+       (display-images-p)))
+\f
+;;; Display styling:
+(defface window-tool-bar-button
+  '((default
+     :inherit tab-line)
+    (((class color) (min-colors 88) (supports :box t))
+     :box (:line-width -1 :style released-button)
+     :background "grey85")
+    ;; If the box is not supported, dim the button background a bit.
+    (((class color) (min-colors 88))
+     :background "grey70")
+    (t
+     :inverse-video t))
+  "Face used for buttons when the mouse is not hovering over the button."
+  :group 'window-tool-bar)
+
+(defface window-tool-bar-button-hover
+  '((default
+     :inherit tab-line)
+    (((class color) (min-colors 88))
+     :box (:line-width -1 :style released-button)
+     :background "grey95")
+    (t
+     :inverse-video t))
+  "Face used for buttons when the mouse is hovering over the button."
+  :group 'window-tool-bar)
+
+(defface window-tool-bar-button-disabled
+  '((default
+     :inherit tab-line)
+    (((class color) (min-colors 88))
+     :box (:line-width -1 :style released-button)
+     :background "grey50"
+     :foreground "grey70")
+    (t
+     :inverse-video t
+     :background "brightblack"))
+  "Face used for buttons when the button is disabled."
+  :group 'window-tool-bar)
+\f
+;;; Workaround for https://debbugs.gnu.org/cgi/bugreport.cgi?bug=68334.
+(defun window-tool-bar--get-keymap ()
+  "Return the tool bar keymap."
+  (let ((tool-bar-always-show-default nil))
+    (if (and (version< emacs-version "30")
+             (not (window-tool-bar--use-images)))
+        ;; This code path is a less efficient workaround.
+        (window-tool-bar--make-keymap-1)
+      (keymap-global-lookup "<tool-bar>"))))
+
+(declare-function image-mask-p "image.c" (spec &optional frame))
+
+(defun window-tool-bar--make-keymap-1 ()
+  "Patched copy of `tool-bar-make-keymap-1'."
+  (mapcar (lambda (bind)
+            (let (image-exp plist)
+              (when (and (eq (car-safe (cdr-safe bind)) 'menu-item)
+			 ;; For the format of menu-items, see node
+			 ;; `Extended Menu Items' in the Elisp manual.
+			 (setq plist (nthcdr (if (consp (nth 4 bind)) 5 4)
+					     bind))
+			 (setq image-exp (plist-get plist :image))
+			 (consp image-exp)
+			 (not (eq (car image-exp) 'image))
+			 (fboundp (car image-exp)))
+		(let ((image (and (display-images-p)
+                                  (eval image-exp))))
+		  (unless (and image (image-mask-p image))
+		    (setq image (append image '(:mask heuristic))))
+		  (setq bind (copy-sequence bind)
+			plist (nthcdr (if (consp (nth 4 bind)) 5 4)
+				      bind))
+		  (plist-put plist :image image)))
+	      bind))
+          tool-bar-map))
+
+(defun window-tool-bar--turn-on ()
+  "Internal function called by `global-window-tool-bar-mode'."
+  (when global-window-tool-bar-mode
+    (window-tool-bar-mode 1)))
+
+(provide 'window-tool-bar)
+
+;;; window-tool-bar.el ends here
-- 
2.39.2