windows are dedicated to other buffers (@pxref{Dedicated Windows}).
@end defun
+@defun display-buffer-in-direction buffer alist
+This function tries to display @var{buffer} at a location specified by
+@var{alist}. For this purpose, @var{alist} should contain a
+@code{direction} entry whose value is one of @code{left}, @code{above}
+(or @code{up}), @code{right} and @code{below} (or @code{down}). Other
+values are usually interpreted as @code{below}.
+
+If @var{alist} also contains a @code{window} entry, its value
+specifies a reference window. That value can be a special symbol like
+@code{main} which stands for the selected frame's main window
+(@pxref{Side Window Options and Functions}) or @code{root} standing
+for the selected frame's root window (@pxref{Windows and Frames}). It
+can also specify an arbitrary valid window. Any other value (or
+omitting the @code{window} entry entirely) means to use the selected
+window as reference window.
+
+This function first tries to reuse a window in the specified direction
+that already shows @var{buffer}. If no such window exists, it tries
+to split the reference window in order to produce a new window in the
+specified direction. If this fails as well, it will try to display
+@var{buffer} in an existing window in the specified direction. In
+either case, the window chosen will appear on the side of the
+reference window specified by the @code{direction} entry, sharing at
+least one edge with the reference window.
+
+If the reference window is live, the edge the chosen window will share
+with it is always the opposite of the one specified by the
+@code{direction} entry. For example, if the value of the
+@code{direction} entry is @code{left}, the chosen window's right edge
+coordinate (@pxref{Coordinates and Windows}) will equal the reference
+window's left edge coordinate.
+
+If the reference window is internal, a reused window must share with
+it the edge specified by the @code{direction} entry. Hence if, for
+example, the reference window is the frame's root window and the value
+of the @code{direction} entry is @code{left}, a reused window must be
+on the left of the frame. This means that the left edge coordinate of
+the chosen window and that of the reference window are the same.
+
+A new window, however, will be created by splitting the reference
+window such that the chosen window will share the opposite edge with
+the reference window. In our example, a new root window would be
+created with a new live window and the reference window as its
+children. The chosen window's right edge coordinate would then equal
+the left edge coordinate of the reference window. Its left edge
+coordinate would equal the left edge coordinate of the frame's new
+root window.
+
+Four special values for @code{direction} entries allow to implicitly
+specify the selected frame's main window as the reference window:
+@code{leftmost}, @code{top}, @code{rightmost} and @code{bottom}. This
+means that instead of, for example, @w{@code{(direction . left)
+(window . main)}} one can just specify @w{@code{(direction
+. leftmost)}}. An existing @code{window} @var{alist} entry is ignored
+in such cases.
+@end defun
+
@defun display-buffer-below-selected buffer alist
This function tries to display @var{buffer} in a window below the
selected window. If there is a window below the selected one and that
supposed to display the buffer. This entry is used only by
@code{display-buffer-in-side-window}.
+@vindex direction@r{, a buffer display action alist entry}
+@item direction
+The value specifies a direction which, together with a @code{window}
+entry, allows @code{display-buffer-in-direction} to determine the
+location of the window to display the buffer.
+
@vindex window@r{, a buffer display action alist entry}
@item window
The value specifies a window that is in some way related to the window
chosen by @code{display-buffer}. This entry is currently used by
@code{display-buffer-in-atom-window} to indicate the window on whose
-side the new window shall be created.
+side the new window shall be created. It is also used by
+@code{display-buffer-in-direction} to specify the reference window on
+whose side the resulting window shall appear.
@vindex allow-no-window@r{, a buffer display action alist entry}
@item allow-no-window
(unless (cdr (assq 'inhibit-switch-frame alist))
(window--maybe-raise-frame frame)))))
+(defun windows-sharing-edge (&optional window edge within)
+ "Return list of live windows sharing the same edge with WINDOW.
+WINDOW must be a valid window and defaults to the selected one.
+EDGE stands for the edge to share and must be either 'left',
+'above', 'right' or 'below'. Omitted or nil, EDGE defaults to
+'left'.
+
+WITHIN nil means to find a live window that shares the opposite
+EDGE with WINDOW. For example, if EDGE equals 'left', WINDOW has
+to share (part of) the right edge of any window returned. WITHIN
+non-nil means to find all live windows that share the same EDGE
+with WINDOW (Window must be internal in this case). So if EDGE
+equals 'left', WINDOW's left edge has to fully encompass the left
+edge of any window returned."
+ (setq window (window-normalize-window window))
+ (setq edge (or edge 'left))
+ (when (and within (window-live-p window))
+ (error "Cannot share edge from within live window %s" window))
+ (let ((window-edges (window-edges window nil nil t))
+ (horizontal (memq edge '(left right)))
+ (n (pcase edge
+ ('left 0) ('above 1) ('right 2) ('below 3))))
+ (unless (numberp n)
+ (error "Invalid EDGE %s" edge))
+ (let ((o (mod (+ 2 n) 4))
+ (p (if horizontal 1 0))
+ (q (if horizontal 3 2))
+ windows)
+ (walk-window-tree
+ (lambda (other)
+ (let ((other-edges (window-edges other nil nil t)))
+ (when (and (not (eq window other))
+ (= (nth n window-edges)
+ (nth (if within n o) other-edges))
+ (cond
+ ((= (nth p window-edges) (nth p other-edges)))
+ ((< (nth p window-edges) (nth p other-edges))
+ (< (nth p other-edges) (nth q window-edges)))
+ (t
+ (< (nth p window-edges) (nth q other-edges)))))
+ (setq windows (cons other windows)))))
+ (window-frame window) nil 'nomini)
+ (reverse windows))))
+
+(defun window--try-to-split-window-in-direction (window direction alist)
+ "Try to split WINDOW in DIRECTION.
+DIRECTION is passed as SIDE argument to `split-window-no-error'.
+ALIST is a buffer display alist."
+ (and (not (frame-parameter (window-frame window) 'unsplittable))
+ (let* ((window-combination-limit
+ ;; When `window-combination-limit' equals
+ ;; `display-buffer' or equals `resize-window' and a
+ ;; `window-height' or `window-width' alist entry are
+ ;; present, bind it to t so resizing steals space
+ ;; preferably from the window that was split.
+ (if (or (eq window-combination-limit 'display-buffer)
+ (and (eq window-combination-limit 'window-size)
+ (or (cdr (assq 'window-height alist))
+ (cdr (assq 'window-width alist)))))
+ t
+ window-combination-limit))
+ (new-window (split-window-no-error window nil direction)))
+ (and (window-live-p new-window) new-window))))
+
+(defun display-buffer-in-direction (buffer alist)
+ "Try to display BUFFER in a direction specified by ALIST.
+ALIST has to contain a 'direction' entry whose value should be
+one of 'left', 'above' (or 'up'), 'right', and 'below' (or
+'down'). Other values are usually interpreted as 'below'.
+
+If ALIST also contains a 'window' entry, its value specifies a
+reference window. That value can be a special symbol like
+'main' (which stands for the selected frame's main window) or
+'root' (standings for the selected frame's root window) or an
+arbitrary valid window. Any other value (or omitting the
+'window' entry) means to use the selected window as reference
+window.
+
+This function tries to reuse or split a window such that the
+window produced this way is on the side of the reference window
+specified by the 'direction' entry.
+
+Four special values for 'direction' entries allow to implicitly
+specify the selected frame's main window as reference window:
+'leftmost', 'top', 'rightmost' and 'bottom'. Hence, instead of
+'(direction . left) (window . main)' one can simply write
+'(direction . leftmost)'."
+ (let ((direction (cdr (assq 'direction alist))))
+ (when direction
+ (let ((window (cdr (assq 'window alist)))
+ within windows other-window-shows-buffer other-window)
+ ;; Sanitize WINDOW.
+ (cond
+ ((or (eq window 'main)
+ (memq direction '(top bottom leftmost rightmost)))
+ (setq window (window-main-window)))
+ ((eq window 'root)
+ (setq window (frame-root-window)))
+ ((window-valid-p window))
+ (t
+ (setq window (selected-window))))
+ (setq within (not (window-live-p window)))
+ ;; Sanitize DIRECTION
+ (cond
+ ((memq direction '(left above right below)))
+ ((eq direction 'leftmost)
+ (setq direction 'left))
+ ((memq direction '(top up))
+ (setq direction 'above))
+ ((eq direction 'rightmost)
+ (setq direction 'right))
+ ((memq direction '(bottom down))
+ (setq direction 'below))
+ (t
+ (setq direction 'below)))
+
+ (setq alist
+ (append alist
+ `(,(if temp-buffer-resize-mode
+ '(window-height . resize-temp-buffer-window)
+ '(window-height . fit-window-to-buffer))
+ ,(when temp-buffer-resize-mode
+ '(preserve-size . (nil . t))))))
+
+ (setq windows (windows-sharing-edge window direction within))
+ (dolist (other windows)
+ (cond
+ ((and (not other-window-shows-buffer)
+ (eq buffer (window-buffer other)))
+ (setq other-window-shows-buffer t)
+ (setq other-window other))
+ ((not other-window)
+ (setq other-window other))))
+ (or (and other-window-shows-buffer
+ (window--display-buffer buffer other-window 'reuse alist))
+ (and (setq other-window
+ (window--try-to-split-window-in-direction
+ window direction alist))
+ (window--display-buffer buffer other-window 'window alist))
+ (and (setq window other-window)
+ (not (window-dedicated-p other-window))
+ (not (window-minibuffer-p other-window))
+ (window--display-buffer buffer other-window 'reuse alist)))))))
+
+;; This should be rewritten as
+;; (display-buffer-in-direction buffer (cons '(direction . below) alist))
(defun display-buffer-below-selected (buffer alist)
"Try displaying BUFFER in a window below the selected window.
If there is a window below the selected one and that window
(display-buffer--maybe-pop-up-frame buffer alist)
(display-buffer-at-bottom buffer alist))))
+;; This should be rewritten as
+;; (display-buffer-in-direction buffer (cons '(direction . bottom) alist))
(defun display-buffer-at-bottom (buffer alist)
"Try displaying BUFFER in a window at the bottom of the selected frame.
This either reuses such a window provided it shows BUFFER
projects / emacs.git / commitdiff