Moved description details out of display.

[clinton/lisp-on-lines.git] / src / display.lisp

diff --git a/src/display.lisp b/src/display.lisp
index 862cf98..a0be611 100644 (file)
--- a/src/display.lisp
+++ b/src/display.lisp
@@ -1,36 +1,55 @@
 (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)
@@ -43,7 +62,7 @@ OMGWTF! If you didn't do this, it's a bug!" description display object args))
        (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