Reputation: 309

emacs: How to display a buffer without switching window and without raising frames?

I want to display something in a specific emacs buffer. If the buffer is not already displayed in some window, I want to display it in a new window in the current frame. If it is already displayed somewhere, I do not want to bring this window or frame up or to focus. Things I have tried: (pop-to-buffer buf nil 'norecord) This does not work, since when I am in a different frame to the one that displays "buf", it will open a new window. (display-buffer buf nil t) This almost works, but it raises the frame showing the buffer. I wish the frame to remain in the background.

How to proceed? Maybe there is a function to check whether a buffer is already displayed in some frame in some window?

Upvotes: 5

Answers (3)

user2053036

Reputation:

If I understood you question correctly the following function will do what you want

(defun my-switch-to-buffer (buffer)
  (interactive
   (list (ido-read-buffer "Switch to buffer: ")))
  ;; get-buffer-window (with second argument t) will return
  ;; nil if the buffer is not open in any window across any
  ;; frame
  (unless (get-buffer-window buffer 0)
    (pop-to-buffer buffer nil t)))

Upvotes: 4

Drew

Reputation: 30701

What Emacs version are you using? display-buffer was changed quite a bit in Emacs 24, offering an almost limitless number of display possibilities. But as a result the behavior is in general non-trivial, as is also the doc.

(And pop-to-buffer always selects the buffer, which you say you do not want.)

Here is the doc for display-buffer from a recent Emacs build. Consult the Elisp manual for even more info. Regardless of whether someone gives you a short answer here that is sufficient, you might well want to learn how to tame the display-buffer beast. (Good luck.)

,----
| display-buffer is an interactive compiled Lisp function in
| `window.el'.
| 
| It is bound to C-x 4 C-o.
| 
| (display-buffer BUFFER-OR-NAME &optional ACTION FRAME)
| 
| Display BUFFER-OR-NAME in some window, without selecting it.
| BUFFER-OR-NAME must be a buffer or the name of an existing
| buffer.  Return the window chosen for displaying BUFFER-OR-NAME,
| or nil if no such window is found.
| 
| Optional argument ACTION, if non-nil, should specify a display
| action.  Its form is described below.
| 
| Optional argument FRAME, if non-nil, acts like an additional
| ALIST entry (reusable-frames . FRAME) to the action list of ACTION,
| specifying the frame(s) to search for a window that is already
| displaying the buffer.  See `display-buffer-reuse-window'
| 
| If ACTION is non-nil, it should have the form (FUNCTION . ALIST),
| where FUNCTION is either a function or a list of functions, and
| ALIST is an arbitrary association list (alist).
| 
| Each such FUNCTION should accept two arguments: the buffer to
| display and an alist.  Based on those arguments, it should
| display the buffer and return the window.  If the caller is
| prepared to handle the case of not displaying the buffer
| and returning nil from `display-buffer' it should pass
| (allow-no-window . t) as an element of the ALIST.
| 
| The `display-buffer' function builds a function list and an alist
| by combining the functions and alists specified in
| `display-buffer-overriding-action', `display-buffer-alist', the
| ACTION argument, `display-buffer-base-action', and
| `display-buffer-fallback-action' (in order).  Then it calls each
| function in the combined function list in turn, passing the
| buffer as the first argument and the combined alist as the second
| argument, until one of the functions returns non-nil.
| 
| If ACTION is nil, the function list and the alist are built using
| only the other variables mentioned above.
| 
| Available action functions include:
|  `display-buffer-same-window'
|  `display-buffer-reuse-window'
|  `display-buffer-pop-up-frame'
|  `display-buffer-pop-up-window'
|  `display-buffer-in-previous-window'
|  `display-buffer-use-some-window'
| 
| Recognized alist entries include:
| 
|  `inhibit-same-window' -- A non-nil value prevents the same
|                           window from being used for display.
| 
|  `inhibit-switch-frame' -- A non-nil value prevents any other
|                            frame from being raised or selected,
|                            even if the window is displayed there.
| 
|  `reusable-frames' -- Value specifies frame(s) to search for a
|                       window that already displays the buffer.
|                       See `display-buffer-reuse-window'.
| 
|  `pop-up-frame-parameters' -- Value specifies an alist of frame
|                               parameters to give a new frame, if
|                               one is created.
| 
|  `window-height' -- Value specifies either an integer (the number
|     of lines of a new window), a floating point number (the
|     fraction of a new window with respect to the height of the
|     frame's root window) or a function to be called with one
|     argument - a new window.  The function is supposed to adjust
|     the height of the window; its return value is ignored.
|     Suitable functions are `shrink-window-if-larger-than-buffer'
|     and `fit-window-to-buffer'.
| 
|  `window-width' -- Value specifies either an integer (the number
|     of columns of a new window), a floating point number (the
|     fraction of a new window with respect to the width of the
|     frame's root window) or a function to be called with one
|     argument - a new window.  The function is supposed to adjust
|     the width of the window; its return value is ignored.
| 
|  `allow-no-window' -- A non-nil value indicates readiness for the case
|     of not displaying the buffer and FUNCTION can safely return
|     a non-window value to suppress displaying.
| 
| The ACTION argument to `display-buffer' can also have a non-nil
| and non-list value.  This means to display the buffer in a window
| other than the selected one, even if it is already displayed in
| the selected window.  If called interactively with a prefix
| argument, ACTION is t.
`----

Upvotes: 2