X-Git-Url: https://git.hcoop.net/clinton/lisp-on-lines.git/blobdiff_plain/a310ff0da8c12588814d39348481309d30eca0e6..e9c163726f466dee83a8dbe7d952f6aaff4345b6:/src/defdisplay.lisp

diff --git a/src/defdisplay.lisp b/src/defdisplay.lisp
index e69de29..cb50cf5 100644
--- a/src/defdisplay.lisp
+++ b/src/defdisplay.lisp
@@ -0,0 +1,193 @@
+(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))
+
+(defun make-display-function (component object
+			      &rest properties
+			      &key type (line #'line-in)
+			      &allow-other-keys)
+  "returns a function that expects a 3 argument function as its argument
+
+The function (which is usually display-using-description) will be called with the proper environment for display all set up nice n pretty like."
+
+  (lambda (function)
+    (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
+		  function description object component))))
+	  (error "no description for ~A" object)))))
+
+(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)))))))))
+
+