From: Martin Rudalics Date: Sat, 8 Dec 2018 08:37:40 +0000 (+0100) Subject: New buffer display action alist entry 'window-min-height' (Bug#32825) X-Git-Tag: emacs-27.0.90~4027^2 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=d2b3a37886d97abdc10e16f6389200e8ad45dd7a;p=emacs.git New buffer display action alist entry 'window-min-height' (Bug#32825) * lisp/window.el (display-buffer-below-selected): Handle 'window-min-height' action alist entry (Bug#32825). * doc/lispref/windows.texi (Buffer Display Action Functions) (Buffer Display Action Alists): Add documentation for 'window-min-height' action alist entries. * etc/NEWS: Mention 'window-min-height' action alist entry. --- diff --git a/doc/lispref/windows.texi b/doc/lispref/windows.texi index b86bccab202..eb057662112 100644 --- a/doc/lispref/windows.texi +++ b/doc/lispref/windows.texi @@ -2607,6 +2607,12 @@ suitable @code{window-height} or @code{window-width} entry, see above. If splitting the selected window fails and there is a non-dedicated window below the selected one showing some other buffer, this function tries to use that window for showing @var{buffer}. + +If @var{alist} contains a @code{window-min-height} entry, this +function ensures that the window used is or can become at least as +high as specified by that entry's value. Note that this is only a +guarantee. In order to actually resize the window used, @var{alist} +must also provide an appropriate @code{window-height} entry. @end defun @defun display-buffer-at-bottom buffer alist @@ -2790,6 +2796,22 @@ The value specifies an alist of window parameters to give the chosen window. All action functions that choose a window should process this entry. +@vindex window-min-height@r{, a buffer display action alist entry} +@item window-min-height +The value specifies a minimum height of the window used, in lines. If +a window is not or cannot be made as high as specified by this entry, +the window is not considered for use. The only client of this entry +is presently @code{display-buffer-below-selected}. + +Note that providing such an entry alone does not necessarily make the +window as tall as specified by its value. To actually resize an +existing window or make a new window as tall as specified by that +value, a @code{window-height} entry specifying that value should be +provided as well. Such a @code{window-height} entry can, however, +specify a completely different value or ask the window height to be +fit to that of its buffer in which case the @code{window-min-height} +entry provides the guaranteed minimum height of the window used. + @vindex window-height@r{, a buffer display action alist entry} @item window-height The value specifies whether and how to adjust the height of the chosen diff --git a/etc/NEWS b/etc/NEWS index cad44f92338..7a0db872653 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -1227,6 +1227,12 @@ of the Emacs Lisp Reference manual for more detail. A buffer-local value of this hook is now run only if at least one window showing the buffer has changed its size. ++++ +** New buffer display action alist entry 'window-min-height'. +Such an entry allows to specify a minimum height of the window used +for displaying a buffer. 'display-buffer-below-selected' is the only +action function to respect it at the moment. + +++ ** The function 'assoc-delete-all' now takes an optional predicate argument. diff --git a/lisp/window.el b/lisp/window.el index a16ceb4eb99..25a599f91d2 100644 --- a/lisp/window.el +++ b/lisp/window.el @@ -7465,22 +7465,45 @@ If there is a window below the selected one and that window already displays BUFFER, use that window. Otherwise, try to create a new window below the selected one and show BUFFER there. If that attempt fails as well and there is a non-dedicated window -below the selected one, use that window." - (let (window) +below the selected one, use that window. + +If ALIST contains a 'window-min-height' entry, this function +ensures that the window used is or can become at least as high as +specified by that entry's value. Note that such an entry alone +will not resize the window per se. In order to do that, ALIST +must also contain a 'window-height' entry with the same value." + (let ((min-height (cdr (assq 'window-min-height alist))) + window) (or (and (setq window (window-in-direction 'below)) - (eq buffer (window-buffer window)) + (eq buffer (window-buffer window)) + (or (not (numberp min-height)) + (>= (window-height window) min-height) + ;; 'window--display-buffer' can resize this window if + ;; and only if it has a 'quit-restore' parameter + ;; certifying that it always showed BUFFER before. + (let ((height (window-height window)) + (quit-restore (window-parameter window 'quit-restore))) + (and quit-restore + (eq (nth 1 quit-restore) 'window) + (window-resizable-p window (- min-height height))))) (window--display-buffer buffer window 'reuse alist)) (and (not (frame-parameter nil 'unsplittable)) - (let ((split-height-threshold 0) + (or (not (numberp min-height)) + (window-sizable-p nil (- min-height))) + (let ((split-height-threshold 0) split-width-threshold) - (setq window (window--try-to-split-window + (setq window (window--try-to-split-window (selected-window) alist))) - (window--display-buffer - buffer window 'window alist display-buffer-mark-dedicated)) + (window--display-buffer + buffer window 'window alist display-buffer-mark-dedicated)) (and (setq window (window-in-direction 'below)) - (not (window-dedicated-p window)) + (not (window-dedicated-p window)) + (or (not (numberp min-height)) + ;; A window that showed another buffer before cannot + ;; be resized. + (>= (window-height window) min-height)) (window--display-buffer - buffer window 'reuse alist display-buffer-mark-dedicated))))) + buffer window 'reuse alist display-buffer-mark-dedicated))))) (defun display-buffer--maybe-at-bottom (buffer alist) (let ((alist (append alist `(,(if temp-buffer-resize-mode