API CHANGE: Removed the OBJECT arg from attribute-value

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

diff --git a/src/display.lisp b/src/display.lisp
index 91cbd06..f9998a7 100644 (file)
--- a/src/display.lisp
+++ b/src/display.lisp
@@ -1,44 +1,73 @@
 (in-package :lisp-on-lines)
 
-(defvar *object*)
+(defvar *description*)
 (defvar *display*)
+(defvar *object* nil)
+
+
+(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 display (display object &rest args &key attributes )
+  (let ((*display-attributes* attributes))
+    (apply #'display-using-description (description-of object) display object args)))
 
 (define-layered-method display-using-description 
   :around (description display object &rest args)
-  (let ((*display* display)
+  (declare (ignorable args))
+  (let ((*description* description)
+       (*display* display)
        (*object*  object))
-    (call-next-method)))
+    (dletf (((described-object description) object))
+    (contextl::funcall-with-special-initargs  
+      (loop 
+        :for (key val) :on args :by #'cddr
+        :collect (list (find key (description-attributes description) 
+                             :key #'attribute-keyword)
+                       :value val))
+      (lambda ()
+       (contextl::funcall-with-special-initargs  
+        (let ((attribute (find-attribute description 'active-attributes)))     
+          (when attribute
+            (loop for spec in (attribute-value attribute)
+                 if (listp spec)
+                 collect (cons (or 
+                                (find-attribute description (car spec))
+                                                (error "No attribute matching ~A" (car spec)))
+                                (cdr spec)))))
+     (lambda ()
+       (call-next-method))))))))
+                             
+
+
+(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))
 
-(defun display-attribute (attribute)
-  (display-using-description attribute *display* *object*))
-
 (defmacro define-display (&body body)
-  (loop with in-layerp = (eq (car body) :in-layer)
-       with layer = (if in-layerp (cadr body) 't)
-       for tail on (if in-layerp (cddr body) body)
+  (loop with in-descriptionp = (eq (car body) :in-description)
+       with description = (if in-descriptionp (cadr body) 't)
+       for tail on (if in-descriptionp (cddr body) body)
        until (listp (car tail))
        collect (car tail) into qualifiers
        finally
-       (when (member :in-layer qualifiers)
-         (error "Incorrect occurrence of :in-layer in defdisplay. Must occur before qualifiers."))
+       (when (member :in-description qualifiers)
+         (error "Incorrect occurrence of :in-description in defdisplay. Must occur before qualifiers."))
        (return
          (destructuring-bind (description-spec &optional  (display-spec (gensym)) (object-spec (gensym))) 
              (car tail) 
                `(define-layered-method
                  display-using-description
-                  :in-layer ,layer
+                  :in-layer ,(if (eq t description) 
+                                 t
+                                 (defining-description description))
                   ,@qualifiers
                   (,(if (listp description-spec)
                        (list (first description-spec)