Dired+. Mouse click - open folder in the same window

Question

When I open a folder by pressing "Enter" it will open in the same window:

This behavior is OK and basically what I expect.

But when I try to open a folder by clicking with the left mouse button the folder will open in another window:

I would like to open the folder in the same window no matter if I use the keyboard or click with the mouse.

How I can do this with Emacs 25.1, and Dired+, in Windows 10?

Answer 1

If you're using Emacs 26 or later (unlike what is specified in the question...), you can just use:

(define-key dired-mode-map [mouse-2] 'dired-mouse-find-file)

(The default binding is dired-mouse-find-file-other-window.)

If you're using Emacs 24 or 25, you'll need to copy the definition of the function, from the Emacs sources (or from this answer — I've copied the definition below, for completeness) into you init.el. I've tested with Emacs 24.5, and it works.

Definition of dired-mouse-find-file

I've taken the function from here and wrapped it in a check for the version of Emacs, so that if you upgrade to a later Emacs and the definition of the function changes, the stale definition doesn't override the new one.

(when (< emacs-major-version 26)
  (defun dired-mouse-find-file (event &optional find-file-func find-dir-func)
    "In Dired, visit the file or directory name you click on.
The optional arguments FIND-FILE-FUNC and FIND-DIR-FUNC specify
functions to visit the file and directory, respectively.  If
omitted or nil, these arguments default to `find-file' and `dired',
respectively."
    (interactive "e")
    (or find-file-func (setq find-file-func 'find-file))
    (or find-dir-func (setq find-dir-func 'dired))
    (let (window pos file)
      (save-excursion
        (setq window (posn-window (event-end event))
              pos (posn-point (event-end event)))
        (if (not (windowp window))
            (error "No file chosen"))
        (set-buffer (window-buffer window))
        (goto-char pos)
        (setq file (dired-get-file-for-visit)))
      (if (file-directory-p file)
          (or (and (cdr dired-subdir-alist)
                   (dired-goto-subdir file))
              (progn
                (select-window window)
                (funcall find-dir-func file)))
        (select-window window)
        (funcall find-file-func (file-name-sans-versions file t))))))

(For license purposes, the code is under GPLv3+, not under CC BY-SA!)

Explanation

The reason why we're binding mouse-2 rather than mouse-1, even to specify the action taken when you click on the link with the left mouse button (mouse-1) is slightly complicated.

Dired specifies (via dired-insert-set-properties) that in the dired buffer, the name of the file or folder (as opposed to the displayed permissions, name of the owner and other metadata) is a link. In the dired-mode-map, the "key sequence" [follow-link] is bound to mouse-face. This means that when you left-click on the link (but not elsewhere), emacs "translates" your left-click to a middle-click (mouse-2). (For more details, see the manual.)

Consequently, if you want to specify what happens when you left-click on the link, but not elsewhere, you slightly perversely have to change the binding of mouse-2. You could directly bind to mouse-1 with (define-key dired-mode-map [mouse-1] 'dired-mouse-find-file), but that would mean that left-clicking anywhere in the buffer (including in the metadata columns) would cause the corresponding file or directory to be opened.