The key prefix 'C-x t t' displays next command buffer in a new tab (bug#41691)

* lisp/tab-bar.el (other-tab-prefix): New command.
(tab-prefix-map): Bind key 'C-x t t' to other-tab-prefix.

* lisp/windmove.el (windmove-display-in-direction):
Use display-buffer-override-next-command.

* lisp/window.el (display-buffer-override-next-command):
New function refactored from windmove-display-in-direction.

etc/NEWS

@@ -109,6 +109,10 @@ setting the variable 'auto-save-visited-mode' buffer-locally to nil.
 
 * Changes in Specialized Modes and Packages in Emacs 28.1
 
+** Tab Bars
+
+*** The key prefix 'C-x t t' displays next command buffer in a new tab.
+
 ** New bindings in occur-mode, 'next-error-no-select' bound to 'n' and
 'previous-error-no-select' bound to 'p'.
 

lisp/tab-bar.el

@@ -1575,6 +1575,25 @@ Like \\[find-file-other-frame] (which see), but creates a new tab."
           value)
       (switch-to-buffer-other-tab value))))
 
+(defun other-tab-prefix ()
+  "Display the buffer of the next command in a new tab.
+The next buffer is the buffer displayed by the next command invoked
+immediately after this command (ignoring reading from the minibuffer).
+Creates a new tab before displaying the buffer, or switches to the tab
+that already contains that buffer.
+When `switch-to-buffer-obey-display-actions' is non-nil,
+`switch-to-buffer' commands are also supported."
+  (interactive)
+  (display-buffer-override-next-command
+   (lambda (buffer alist)
+     (cons (progn
+             (display-buffer-in-tab
+              buffer (append alist '((inhibit-same-window . nil)
+                                     (reusable-frames . t))))
+             (selected-window))
+           'tab)))
+  (message "Display next command buffer in a new tab..."))
+
 (define-key tab-prefix-map "2" 'tab-new)
 (define-key tab-prefix-map "1" 'tab-close-other)
 (define-key tab-prefix-map "0" 'tab-close)
@@ -1585,6 +1604,7 @@ Like \\[find-file-other-frame] (which see), but creates a new tab."
 (define-key tab-prefix-map "b" 'switch-to-buffer-other-tab)
 (define-key tab-prefix-map "f" 'find-file-other-tab)
 (define-key tab-prefix-map "\C-f" 'find-file-other-tab)
+(define-key tab-prefix-map "t" 'other-tab-prefix)
 
 
 (provide 'tab-bar)

lisp/windmove.el

@@ -461,60 +461,38 @@ select the window with a displayed buffer, and the meaning of
 the prefix argument is reversed.
 When `switch-to-buffer-obey-display-actions' is non-nil,
 `switch-to-buffer' commands are also supported."
-  (let* ((no-select (xor (consp arg) windmove-display-no-select))
+  (let ((no-select (xor (consp arg) windmove-display-no-select)))
-         (old-window (or (minibuffer-selected-window) (selected-window)))
+    (display-buffer-override-next-command
-         (new-window)
+     (lambda (_buffer alist)
-         (minibuffer-depth (minibuffer-depth))
+       (let* ((type 'reuse)
-         (action (lambda (buffer alist)
+              (window (cond
-                   (unless (> (minibuffer-depth) minibuffer-depth)
+                       ((eq dir 'new-tab)
-                     (let* ((type 'reuse)
+                        (let ((tab-bar-new-tab-choice t))
-                            (window (cond
+                          (tab-bar-new-tab))
-                                     ((eq dir 'new-tab)
+                        (setq type 'tab)
-                                      (let ((tab-bar-new-tab-choice t))
+                        (selected-window))
-                                        (tab-bar-new-tab))
+                       ((eq dir 'new-frame)
-                                      (setq type 'tab)
+                        (let* ((params (cdr (assq 'pop-up-frame-parameters alist)))
-                                      (selected-window))
+                               (pop-up-frame-alist (append params pop-up-frame-alist))
-                                     ((eq dir 'new-frame)
+                               (frame (make-frame-on-current-monitor
-                                      (let* ((params (cdr (assq 'pop-up-frame-parameters alist)))
+                                       pop-up-frame-alist)))
-                                             (pop-up-frame-alist (append params pop-up-frame-alist))
+                          (unless (cdr (assq 'inhibit-switch-frame alist))
-                                             (frame (make-frame-on-current-monitor
+	                    (window--maybe-raise-frame frame))
-                                                     pop-up-frame-alist)))
+                          (setq type 'frame)
-                                        (unless (cdr (assq 'inhibit-switch-frame alist))
+                          (frame-selected-window frame)))
-	                                  (window--maybe-raise-frame frame))
+                       ((eq dir 'same-window)
-                                        (setq type 'frame)
+                        (selected-window))
-                                        (frame-selected-window frame)))
+                       (t (window-in-direction
-                                     ((eq dir 'same-window)
+                           dir nil nil
-                                      (selected-window))
+                           (and arg (prefix-numeric-value arg))
-                                     (t (window-in-direction
+                           windmove-wrap-around)))))
-                                         dir nil nil
+         (unless window
-                                         (and arg (prefix-numeric-value arg))
+           (setq window (split-window nil nil dir) type 'window))
-                                         windmove-wrap-around)))))
+         (cons window type)))
-                       (unless window
+     (lambda (old-window new-window)
-                         (setq window (split-window nil nil dir) type 'window))
+       (when (window-live-p (if no-select old-window new-window))
-                       (setq new-window (window--display-buffer buffer window
+         (select-window (if no-select old-window new-window))))))
-                                                                type alist))))))
+  (message "[display-%s]" dir))
-         (command this-command)
-         (clearfun (make-symbol "clear-display-buffer-overriding-action"))
-         (exitfun
-          (lambda ()
-            (setq display-buffer-overriding-action
-                  (delq action display-buffer-overriding-action))
-            (when (window-live-p (if no-select old-window new-window))
-              (select-window (if no-select old-window new-window)))
-            (remove-hook 'post-command-hook clearfun))))
-    (fset clearfun
-          (lambda ()
-            (unless (or
-		     ;; Remove the hook immediately
-		     ;; after exiting the minibuffer.
-		     (> (minibuffer-depth) minibuffer-depth)
-		     ;; But don't remove immediately after
-		     ;; adding the hook by the same command below.
-		     (eq this-command command))
-              (funcall exitfun))))
-    (add-hook 'post-command-hook clearfun)
-    (push action display-buffer-overriding-action)
-    (message "[display-%s]" dir)))
 
 ;;;###autoload
 (defun windmove-display-left (&optional arg)

lisp/window.el

@@ -8578,6 +8578,47 @@ documentation for additional customization information."
   (interactive
    (list (read-buffer-to-switch "Switch to buffer in other frame: ")))
   (pop-to-buffer buffer-or-name display-buffer--other-frame-action norecord))
+
+(defun display-buffer-override-next-command (pre-function &optional post-function)
+  "Set `display-buffer-overriding-action' for the next command.
+`pre-function' is called to prepare the window where the buffer should be
+displayed.  This function takes two arguments `buffer' and `alist', and
+should return a cons with the displayed window and its type.  See the
+meaning of these values in `window--display-buffer'.
+Optional `post-function' is called after the buffer is displayed in the
+window; the function takes two arguments: an old and new window."
+  (let* ((old-window (or (minibuffer-selected-window) (selected-window)))
+         (new-window nil)
+         (minibuffer-depth (minibuffer-depth))
+         (action (lambda (buffer alist)
+                   (unless (> (minibuffer-depth) minibuffer-depth)
+                     (let* ((ret (funcall pre-function buffer alist))
+                            (window (car ret))
+                            (type (cdr ret)))
+                       (setq new-window (window--display-buffer buffer window
+                                                                type alist))))))
+         (command this-command)
+         (clearfun (make-symbol "clear-display-buffer-overriding-action"))
+         (exitfun
+          (lambda ()
+            (setq display-buffer-overriding-action
+                  (delq action display-buffer-overriding-action))
+            (remove-hook 'post-command-hook clearfun)
+            (when (functionp post-function)
+              (funcall post-function old-window new-window)))))
+    (fset clearfun
+          (lambda ()
+            (unless (or
+		     ;; Remove the hook immediately
+		     ;; after exiting the minibuffer.
+		     (> (minibuffer-depth) minibuffer-depth)
+		     ;; But don't remove immediately after
+		     ;; adding the hook by the same command below.
+		     (eq this-command command))
+              (funcall exitfun))))
+    (add-hook 'post-command-hook clearfun)
+    (push action display-buffer-overriding-action)))
+
 
 (defun set-window-text-height (window height)
   "Set the height in lines of the text display area of WINDOW to HEIGHT.