+(in-package :lisp-on-lines)
+
+(define-layered-function display-using-description (description object component)
+; (:argument-precedence-order )
+ (:method-combination wrapping-standard)
+ (:documentation
+ "Render the object in component,
+ using DESCRIPTION, which is an occurence, an attribute, or something else entirely."))
+
+(define-layered-method
+ display-using-description (d o c)
+ (<:as-html "default :" o))
+
+(defmethod find-layer-for-type (type)
+ type)
+
+
+(define-layered-function display (component object &rest args)
+ (:documentation
+ "Displays OBJECT in COMPONENT."))
+
+(define-layered-method display ((component t) (object t)
+ &rest properties
+ &key type (line #'line-in)
+ &allow-other-keys)
+ " The default display dispatch method
+
+ DISPLAY takes two required arguments,
+ COMPONENT : The component to display FROM (not neccesarily 'in')
+ OBJECT : The 'thing' we want to display... in this case it's the component
+
+ DISPLAY also takes keywords arguments which modify the DESCRIPTION,
+ that is to say the parameters that come together to create the output.
+
+The default display calls out via FUNCALL-WITH-LAYERS to tche DISPLAY-USING-DESCRIPTION method."
+
+ (let* ((description (find-occurence object)))
+
+ (if description
+ (dletf (((description.type description) type)
+ ((attributes description) (or
+ (attributes description)
+ (list-slots object))))
+ ;; apply the default line to the description
+ (funcall-with-description
+ description
+ (funcall line object)
+ ;; apply the passed in arguments and call display-using-description
+ #'(lambda ()
+ (funcall-with-description
+ description
+ properties
+ #'display-using-description description object component))))
+ (error "no description for ~A" object))))
+
+;;;;; Macros
+
+
+(defun funcall-with-description (description properties function &rest args)
+
+ (if description
+ (dletf* (((description.type description) (or
+ (getf properties :type)
+ (description.type description)))
+
+ ((description.layers description) (append
+ (description.layers description)
+ (getf properties :layers)))
+ ((description.properties description) (append (description.properties description) properties)))
+ (funcall-with-layers
+ (description.layers description)
+ #'(lambda ()
+ (contextl::funcall-with-special-initargs
+ (list (cons description properties))
+ #'(lambda ()
+ (apply function args))))))
+ (apply function args)))
+
+
+
+(defmacro with-description ((description &rest properties) &body body)
+ `(funcall-with-description ,description (if ',(cdr properties)
+ (list ,@properties)
+ ,(car properties))
+ #'(lambda ()
+ ,@body)))
+
+(define-layered-function find-do-attributes (desc))
+
+(define-layered-method find-do-attributes ((description description))
+
+ (loop
+ :for att
+ :in (attributes description)
+ :collect (let ((default (find (car (ensure-list att))
+ (default-attributes description)
+ :key #'car)))
+ (or default att))))
+
+(defmacro do-attributes ((var description &optional (attributes `(find-do-attributes ,description))) &body body)
+ (with-unique-names (att properties type)
+ `(dolist* (,att ,attributes)
+ (let* ((,att (ensure-list ,att))
+ (,properties (rest ,att))
+ (,type (getf ,properties :type))
+ (,var (let ((a (find-attribute ,description (first ,att))))
+ (if ,type
+ (apply #'make-attribute :name (first ,att) :type ,type ,properties)
+ (if a a (make-attribute :name (first ,att) :slot-name (first ,att)))))))
+ (funcall-with-description ,var ,properties
+ #'(lambda ()
+ ,@body))))))
+
+(defmacro with-component ((component) &body body)
+ `(let ((self ,component))
+ (declare (ignorable self))
+ (flet ((display* (thing &rest args)
+ (apply #'display ,component thing args))
+ (display-attribute (attribute obj &optional props)
+ (if props
+ (funcall-with-description
+ attribute props
+ #'display-using-description attribute obj ,component)
+ (display-using-description attribute obj ,component))))
+ (declare (ignorable #'display* #'display-attribute))
+ ,@body)))
+
+(defmacro defdisplay (&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)
+ 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."))
+ (return
+ (destructuring-bind (description &optional object component) (car tail)
+ (with-unique-names (d c)
+ (let (standard-description-p)
+ `(define-layered-method
+ display-using-description
+ :in-layer ,layer
+ ,@qualifiers
+
+ ,@(unless object
+ (setf object description)
+ (setf description d)
+ nil)
+ (,(cond
+ ((listp description)
+ (setf d (car description))
+ description)
+ (t
+ (setf d description)
+ (setf standard-description-p t)
+ `(,d description)))
+ ,object
+ ,(cond
+ ((null component)
+ `(,c component))
+ ((listp component)
+ (setf c (car component))
+ component)
+ (t
+ (setf c component)
+ `(,c component))))
+ (with-component (,c)
+ ,@(cdr tail)))))))))
+
+
HCoop / clinton / lisp-on-lines.git / blobdiff