(in-package :lisp-on-lines)
-(defvar *description*)
+
(defvar *display*)
-(defvar *object*)
-(deflayer display-layer)
(define-layered-function display-using-description (description display object &rest args)
(:documentation
"Displays OBJECT via description using/in/with/on display"))
-(defun display (display object &rest args)
- (display-using-description (description-of object) display object args))
+
+
+(defun modify-layer-context (context &key activate deactivate)
+ (dolist (d deactivate)
+ (setf context (remove-layer (find-description d)
+ context)))
+ (dolist (d activate context)
+ (setf context (adjoin-layer (find-description d)
+ context))))
+
+
+
+
+(defun display (display object &rest args &key deactivate activate &allow-other-keys)
+ (funcall-with-layer-context
+ (modify-layer-context (current-layer-context)
+ :activate activate
+ :deactivate deactivate)
+ (lambda ()
+ (apply #'display-using-description (description-of object) display object args))))
(define-layered-method display-using-description
:around (description display object &rest args)
(declare (ignorable args))
- (let ((*description* description)
- (*display* display)
- (*object* object))
-
- (call-next-method)))
+ (let ((*display* display))
+ (apply #'funcall-with-described-object
+ (lambda ()
+ (call-next-method))
+ object description args)))
+
+
+(defun display/d (&rest args)
+ (apply #'display-using-description args))
+
(define-layered-method display-using-description (description display object &rest args)
(error "No DISPLAY-USING-DESCRIPTION methods are specified for: ~% DESCRIPTION: ~A ~% DISPLAY: ~A ~% OBJECT: ~A ~% ARGS: ~S
OMGWTF! If you didn't do this, it's a bug!" description display object args))
-
-
(defmacro define-display (&body body)
(loop with in-descriptionp = (eq (car body) :in-description)
with description = (if in-descriptionp (cadr body) 't)
(return
(destructuring-bind (description-spec &optional (display-spec (gensym)) (object-spec (gensym)))
(car tail)
- `(define-layered-method
+ `(define-layered-method
display-using-description
:in-layer ,(if (eq t description)
t