anchor.diff:                            *clip-rect-height* (mezzano.supervisor:framebuffer-height *main-screen*)
                             *clip-rect-x* 0
                             *clip-rect-y* 0)))
  +                 ((and (member :meta *keyboard-modifier-state*)
  +                       (eql translated #\Tab))
  +                  (when (not (key-releasep event))
  +                    (when (not *m-tab-active*)
  +                      (setf *m-tab-active* t
  +                            *m-tab-list* (remove-if-not #'allow-m-tab (copy-list *window-list*))))
  +                    (let* ((p (position *active-window* *m-tab-list*))
  +                           (n-windows (length *m-tab-list*))
  +                           (next (if p
  +                                     (elt *m-tab-list* (rem (+ p
  +                                                               (if (member :shift *keyboard-modifier-state*)
  +                                                                   -1
  +                                                                   +1))
  +                                                            n-windows))
  +                                     (first *m-tab-list*))))
  +                      (activate-window next))))
                    ;; Otherwise, dispatch to active window.
                    (*active-window*
                     (send-event *active-window*
  
positive.code:       (send-event *active-window* (make-instance 'window-activation-event
                                                   :window *active-window*
                                                   :state t))))
    (setf *clip-rect-width* (mezzano.supervisor:framebuffer-width *main-screen*)
          *clip-rect-height* (mezzano.supervisor:framebuffer-height *main-screen*)
          *clip-rect-x* 0
  
negative.code:   "Set to true when the drag was compositor-initiated.
  A passive drag sends no drag events to the window.")
  (defvar *resize-origin* nil)
  
  (defvar *m-tab-active* nil)
  (defvar *m-tab-list* nil)
  
  (defun allow-m-tab (window)
    (not (and (zerop (width window))
              (zerop (height window)))))
  
  (defun activate-window (window)
    "Make WINDOW the active window."
  