1 (in-package :lisp-on-lines
)
7 (define-layered-function display-using-description
(description display object
&rest args
)
9 "Displays OBJECT via description using/in/with/on display"))
13 (defun modify-layer-context (context &key activate deactivate
)
14 (dolist (d deactivate
)
15 (setf context
(remove-layer (find-description d
)
17 (dolist (d activate context
)
18 (setf context
(adjoin-layer (find-description d
)
24 (defun display (display object
&rest args
&key deactivate activate
&allow-other-keys
)
25 (funcall-with-layer-context
26 (modify-layer-context (current-layer-context)
28 :deactivate deactivate
)
30 (apply #'display-using-description
(description-of object
) display object args
))))
32 (define-layered-method display-using-description
33 :around
(description display object
&rest args
)
34 (declare (ignorable args
))
35 (let ((*display
* display
))
36 (apply #'funcall-with-described-object
39 object description args
)))
45 (defun display/d
(&rest args
)
46 (apply #'display-using-description args
))
48 (define-layered-method display-using-description
(description display object
&rest args
)
49 (error "No DISPLAY-USING-DESCRIPTION methods are specified for: ~% DESCRIPTION: ~A ~% DISPLAY: ~A ~% OBJECT: ~A ~% ARGS: ~S
51 OMGWTF! If you didn't do this, it's a bug!" description display object args
))
53 (defmacro define-display
(&body body
)
54 (loop with in-descriptionp
= (eq (car body
) :in-description
)
55 with description
= (if in-descriptionp
(cadr body
) 't
)
56 for tail on
(if in-descriptionp
(cddr body
) body
)
57 until
(listp (car tail
))
58 collect
(car tail
) into qualifiers
60 (when (member :in-description qualifiers
)
61 (error "Incorrect occurrence of :in-description in defdisplay. Must occur before qualifiers."))
63 (destructuring-bind (description-spec &optional
(display-spec (gensym)) (object-spec (gensym)))
65 `(define-layered-method
66 display-using-description
67 :in-layer
,(if (eq t description
)
69 (defining-description description
))
71 (,(if (listp description-spec
)
72 (list (first description-spec
)
73 (if (eq 'description
(second description-spec
))
75 (defining-description (second description-spec
)))))
77 ,object-spec
&rest args
)
78 (declare (ignorable args
))