[Emacs-diffs] Changes to emacs/lisp/window.el,v

[Martin Rudalics]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Martin Rudalics <m061211>       08/06/08 12:59:39

Index: window.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/window.el,v
retrieving revision 1.139
retrieving revision 1.140
diff -u -b -r1.139 -r1.140
--- window.el   8 Jun 2008 07:54:25 -0000       1.139
+++ window.el   8 Jun 2008 12:59:39 -0000       1.140
@@ -742,32 +742,37 @@
   :type 'boolean
   :group 'windows)
 
-(defcustom split-window-preferred-function nil
-  "How `display-buffer' shall split windows.
-Choices are `Vertically', `Horizontally', and `Sensibly' where
-the latter attempts to split wide windows horizontally, narrow
-ones vertically.  Alternatively, you can set this to a function
-called with a window as single argument to split that window in
-two and return the new window."
-  :type '(choice
-         (const :tag "Vertically" nil)
-         (const :tag "Horizontally" horizontally)
-         (const :tag "Sensibly" sensibly)
-         (function :tag "Function"))
-  :version "23.1"
-  :group 'windows)
-
 (defcustom split-height-threshold 80
-  "Minimum height of window to be split vertically by `display-buffer'.
-If there is only one window, it can be split regardless of this."
+  "Minimum height of window to be split vertically.
+If the value is a number, `display-buffer' can split a window
+only if it has at least as many lines.  If the value is nil,
+`display-buffer' cannot split a window vertically.
+
+If the window is the only window on its frame, `display-buffer'
+can split it regardless of this value."
+  :type '(choice (const nil) (number :tag "lines"))
   :type 'number
   :version "23.1"
   :group 'windows)
 
 (defcustom split-width-threshold 160
-  "Minimum width of window to be split horizontally by `display-buffer'.
-If there is only one window, it can be split regardless of this."
-  :type 'number
+  "Minimum width of window to be split horizontally.
+If the value is a number, `display-buffer' can split a window
+only if it has at least as many columns.  If the value is nil,
+`display-buffer' cannot split a window horizontally."
+  :type '(choice (const nil) (number :tag "columns"))
+  :version "23.1"
+  :group 'windows)
+
+(defcustom split-window-preferred-function nil
+  "Function used by `display-buffer' to split windows.
+If non-nil, a function called with a window as single argument
+supposed to split that window and return the new window.  If the
+function returns nil the window is not split.
+
+If nil, `display-buffer' will split the window respecting the
+values of `split-height-threshold' and `split-width-threshold'."
+  :type '(choice (const nil) (function :tag "Function"))
   :version "23.1"
   :group 'windows)
 
@@ -779,11 +784,11 @@
 WINDOW can be split vertically when the following conditions
 hold:
 
-- `window-size-fixed' is either nil or equals `width' for the buffer of
-  WINDOW.
+- `window-size-fixed' is either nil or equals `width' for the
+  buffer of WINDOW.
 
-- WINDOW is at least as high as `split-height-threshold' or it is
-  the only window on its frame.
+- `split-height-threshold' is a number and WINDOW is at least as
+  high as `split-height-threshold'.
 
 - When WINDOW is split evenly, the emanating windows are at least
   `window-min-height' lines tall and can accomodate at least one
@@ -795,7 +800,8 @@
 - `window-size-fixed' is either nil or equals `height' for the
   buffer of WINDOW.
 
-- WINDOW is at least as wide as `split-width-threshold'.
+- `split-width-threshold' is a number and WINDOW is at least as
+  wide as `split-width-threshold'.
 
 - When WINDOW is split evenly, the emanating windows are at least
   `window-min-width' or two (whichever is larger) columns wide."
@@ -807,49 +813,52 @@
          ;; and at least twice as wide as `window-min-width' and 2 (the
          ;; latter value is hardcoded).
          (and (memq window-size-fixed '(nil height))
+              ;; Testing `window-full-width-p' here hardly makes any
+              ;; sense nowadays.  This can be done more intuitively by
+              ;; setting up `split-width-threshold' appropriately.
+              (numberp split-width-threshold)
               (>= (window-width window)
                   (max split-width-threshold
                        (* 2 (max window-min-width 2)))))
        ;; A window can be split vertically when its height is not
-       ;; fixed, it is at least `split-height-threshold' lines high or
-       ;; the only window on its frame, and it is at least twice as
-       ;; high as `window-min-height' and 2 if it has a modeline or 1.
+       ;; fixed, it is at least `split-height-threshold' lines high,
+       ;; and it is at least twice as high as `window-min-height' and 2
+       ;; if it has a modeline or 1.
        (and (memq window-size-fixed '(nil width))
+            (numberp split-height-threshold)
             (>= (window-height window)
-                (max (if (one-window-p 'nomini) 0 split-height-threshold)
+                (max split-height-threshold
                      (* 2 (max window-min-height
                                (if mode-line-format 2 1))))))))))
 
 (defun window--try-to-split-window (window)
   "Split window WINDOW if it is splittable.
-See `split-window-preferred-function' for how WINDOW shall be
-split.  See `window--splittable-p' for how to determine whether a
-window is splittable.  If WINDOW can be split, return the value
-returned by `split-window' or `split-window-preferred-function'."
+See `window--splittable-p' for how to determine whether a window
+is splittable.  If WINDOW can be split, return the value returned
+by `split-window' or `split-window-preferred-function'."
   (when (and (window-live-p window)
-            ;; Testing `window-full-width-p' here hardly makes any
-            ;; sense nowadays.  This can be done more intuitively by
-            ;; setting up `split-width-threshold' appropriately.
             (not (frame-parameter (window-frame window) 'unsplittable)))
-    (or (and (not split-window-preferred-function)
-            (window--splittable-p window)
+    (if (functionp split-window-preferred-function)
+       ;; `split-window-preferred-function' is specified, so use it.
+       (funcall split-window-preferred-function window)
+      (or (and (window--splittable-p window)
+              ;; Split window vertically.
             (split-window window))
-       (and (eq split-window-preferred-function 'horizontally)
-            (window--splittable-p window t)
+         (and (window--splittable-p window t)
+              ;; Split window horizontally.
             (split-window window nil t))
-       (and (eq split-window-preferred-function 'sensibly)
-            ;; The following naive aspect-ratio test should become
-            ;; more sensible.
-            (or (and (> (window-width window) (window-height window))
-                     (window--splittable-p window t)
-                     (split-window window nil t))
-                (and (window--splittable-p window)
-                     (split-window window))))
-       (and (functionp split-window-preferred-function)
-            (funcall split-window-preferred-function window)))))
+         (and (with-selected-window window
+                (one-window-p 'nomini))
+              ;; If WINDOW is the only window on its frame, attempt to
+              ;; split it vertically disregarding the current value of
+              ;; `split-height-threshold'.
+              (let ((split-height-threshold 0))
+                (window--splittable-p window)
+                (split-window window)))))))
 
 (defun window--frame-usable-p (frame)
   "Return frame FRAME if it can be used to display another buffer."
+  (when (framep frame)
   (let ((window (frame-root-window frame)))
     ;; `frame-root-window' may be an internal window which is considered
     ;; "dead" by `window-live-p'.  Hence if `window' is not live we
@@ -857,7 +866,7 @@
     (when (or (not (window-live-p window))
              (and (not (window-minibuffer-p window))
                   (not (window-dedicated-p window))))
-      frame)))
+       frame))))
 
 (defcustom even-window-heights t
   "If non-nil `display-buffer' will try to even window heights.
@@ -1009,12 +1018,12 @@
                 (or (window--try-to-split-window
                      (get-largest-window frame-to-use t))
                     (window--try-to-split-window
-                     (get-lru-window frame-to-use t))
-                    (get-lru-window frame-to-use nil)))
+                     (get-lru-window frame-to-use t))))
           (window--display-buffer-2 buffer window-to-use)))
      ((setq window-to-use
            ;; Reuse an existing window.
-           (or (get-buffer-window buffer 'visible)
+           (or (get-lru-window frame-to-use)
+               (get-buffer-window buffer 'visible)
                (get-largest-window 'visible nil)
                (get-buffer-window buffer 0)
                (get-largest-window 0 nil)