anchor.diff:  
   (defpackage :mezzano.gui.desktop
     (:use :cl)
  -  (:export #:spawn))
  +  (:export #:spawn)
  +  (:local-nicknames (:gui :mezzano.gui)
  +                    (:comp :mezzano.gui.compositor)
  +                    (:font :mezzano.gui.font)))
   
   (in-package :mezzano.gui.desktop)
   
  
positive.code: 
  (defun redraw-desktop-window (desktop)
    (let* ((window (window desktop))
           (desktop-width (mezzano.gui.compositor:width window))
           (desktop-height (mezzano.gui.compositor:height window))
           (framebuffer (mezzano.gui.compositor:window-buffer window))
           (font (font desktop)))
      (mezzano.gui:bitset :set
                          desktop-width desktop-height
                          (colour desktop)
                          framebuffer 0 0)
      (when (image desktop)
        (let* ((image (image desktop))
               (image-width (mezzano.gui:surface-width image))
               (image-height (mezzano.gui:surface-height image)))
          (mezzano.gui:bitblt :blend
                              image-width image-height
                              image 0 0
                              framebuffer
  
negative.code:      do (progn ;ignore-errors
            (incf icon-pen 20)
            (let* ((image (load-image icon))
                   (width (gui:surface-width image))
                   (height (gui:surface-height image)))
              (when (and (<= 20 x (1- (+ 20 width)))
                         (<= icon-pen y (1- (+ icon-pen height))))
                (return icon-repr))
              (incf icon-pen (gui:surface-height image))))))
  
  (defmethod dispatch-event (desktop (event comp:mouse-event))
    (when (logbitp 0 (comp:mouse-button-change event))
      (let ((x (comp:mouse-x-position event))
            (y (comp:mouse-y-position event)))
        (cond ((logbitp 0 (comp:mouse-button-state event))
               ;; Mouse down, begin click. Highlight the clicked thing.
               (setf (clicked-icon desktop) (get-icon-at-point desktop x y))
               (when (clicked-icon desktop)
  