X-Git-Url: https://git.distorted.org.uk/~mdw/profile/blobdiff_plain/6ada84f4e0acb4149b95b02ab35ec7a3f73ac1c8..183e55e2d8a6203d14cefbe6b55ee4bc66628525:/el/dot-emacs.el

diff --git a/el/dot-emacs.el b/el/dot-emacs.el
index bc512b4..8b4f8f8 100644
--- a/el/dot-emacs.el
+++ b/el/dot-emacs.el
@@ -287,6 +287,59 @@ This is sadly necessary because Emacs 26 is broken in this regard."
   (set-frame-parameter frame 'background-color (car colour))
   (set-frame-parameter frame 'foreground-color (cdr colour)))
 
+;; Window configuration switching.
+
+(defvar mdw-current-window-configuration nil
+  "The current window configuration register name, or `nil'.")
+
+(defun mdw-switch-window-configuration (register &optional no-save)
+  "Switch make REGISTER be the new current window configuration.
+If a current window configuration register is established, and
+NO-SAVE is nil, then save the current window configuration to
+that register first.
+
+Signal an error if the new register contains something other than
+a window configuration.  If the register is unset then save the
+current window configuration to it immediately.
+
+With one or three C-u, or an odd numeric prefix argument, set
+NO-SAVE, so the previous window configuration register is left
+unchanged.
+
+With two or three C-u, or a prefix argument which is an odd
+multiple of 2, just clear the record of the current window
+configuration register, so that the next switch doesn't save the
+prevailing configuration."
+  (interactive
+   (let ((arg current-prefix-arg))
+     (list (if (or (and (consp arg) (= (car arg) 16) (= (car arg) 64))
+		   (and (integerp arg) (not (zerop (logand arg 2)))))
+	       nil
+	     (register-read-with-preview "Switch to window configuration: "))
+	   (or (and (consp arg) (= (car arg) 4) (= (car arg) 64))
+	       (and (integerp arg) (not (zerop (logand arg 1))))))))
+
+  (let ((current-windows (list (current-window-configuration)
+			       (point-marker)))
+	(register-value (and register (get-register register))))
+    (when (and mdw-current-window-configuration (not no-save))
+      (set-register mdw-current-window-configuration current-windows))
+    (cond ((null register)
+	   (setq mdw-current-window-configuration nil))
+	  ((not (or (null register-value)
+		    (and (consp register-value)
+			 (window-configuration-p (car register-value))
+			 (integer-or-marker-p (cadr register-value))
+			 (null (caddr register-value)))))
+	   (error "Register `%c' is not a window configuration" register))
+	  (t
+	   (cond ((null register-value)
+		  (set-register register current-windows))
+		 (t
+		  (set-window-configuration (car register-value))
+		  (goto-char (cadr register-value))))
+	   (setq mdw-current-window-configuration register)))))
+
 ;; Don't raise windows unless I say so.
 
 (defcustom mdw-inhibit-raise-frame nil