src/display.lisp

   1 (in-package :lisp-on-lines)
   2
   3
   4 (defvar *display*)
   5
   6
   7 (define-layered-function display-using-description (description display object &rest args)
   8   (:documentation
   9    "Displays OBJECT via description using/in/with/on display"))
  10
  11
  12
  13 (defun modify-layer-context (context &key activate deactivate)
  14   (dolist (d deactivate)
  15     (setf context (remove-layer (find-description d)
  16                                 context)))
  17   (dolist (d activate context)
  18     (setf context (adjoin-layer (find-description (if (consp d) (car d) d))
  19                                 context))))
  20
  21 (defun funcall-with-attribute-context (attribute thunk)
  22   (funcall-with-layer-context
  23    (modify-layer-context (current-layer-context)
  24                          :activate (attribute-active-descriptions attribute)
  25                          :deactivate (attribute-inactive-descriptions attribute))
  26    (lambda ()
  27      (with-special-symbol-access
  28        (contextl::funcall-with-special-initargs
  29         (mappend (lambda (desc)
  30                    (when (consp desc)
  31                      (let ((description (find-description (car desc))))
  32                        (loop
  33                           :for (key val) :on (cdr desc) :by #'cddr
  34                           :collect (list (find key (description-attributes description)
  35                                                :key #'attribute-keyword)
  36                                   :value val)))))
  37                  (attribute-active-descriptions attribute))
  38         (lambda ()
  39           (without-special-symbol-access
  40             (funcall thunk))))))))
  41
  42 (defmacro with-attribute-context ((attribute) &body body)
  43   `(funcall-with-attribute-context ,attribute (lambda () ,@body)))
  44
  45
  46 (defun display (display object &rest args &key deactivate activate &allow-other-keys)
  47   (funcall-with-layer-context
  48    (modify-layer-context (current-layer-context)
  49                          :activate activate
  50                          :deactivate deactivate)
  51    (lambda ()
  52      (apply #'display-using-description (description-of object) display object args))))
  53
  54 (define-layered-method display-using-description
  55   :around ((description standard-description-object) display object &rest args)
  56   (declare (ignorable args))
  57 #+nil  (break "Entering DISPLAY for ~A on ~A using ~A" object display description)
  58   (let ((*display* display))
  59     (apply #'funcall-with-described-object
  60      (lambda ()
  61        (call-next-method))
  62      object description args)))
  63
  64
  65
  66
  67 (defun display/d (&rest args)
  68   (apply #'display-using-description args))
  69
  70 (define-layered-method display-using-description (description display object &rest args)
  71  (error "No DISPLAY-USING-DESCRIPTION methods are specified for: ~%  DESCRIPTION: ~A ~%  DISPLAY: ~A ~%  OBJECT: ~A ~%  ARGS: ~S
  72
  73 OMGWTF! If you didn't do this, it's a bug!" description display object args))
  74
  75 (defmacro define-display (&body body)
  76   (loop with in-descriptionp = (eq (car body) :in-description)
  77         with description = (if in-descriptionp (cadr body) 't)
  78         for tail on (if in-descriptionp (cddr body) body)
  79         until (listp (car tail))
  80         collect (car tail) into qualifiers
  81         finally
  82         (when (member :in-description qualifiers)
  83           (error "Incorrect occurrence of :in-description in defdisplay. Must occur before qualifiers."))
  84         (return
  85           (destructuring-bind (description-spec &optional  (display-spec (gensym)) (object-spec (gensym)))
  86               (car tail)
  87             `(define-layered-method
  88                   display-using-description
  89                    :in-layer ,(if (eq t description)
  90                                   t
  91                                   (defining-description description))
  92                    ,@qualifiers
  93                    (,(if (listp description-spec)
  94                         (list (first description-spec)
  95                              (if (eq 'description (second description-spec))
  96                                      'description
  97                                      (contextl::defining-layer (defining-description (second description-spec))))))
  98                    ,display-spec
  99                    ,object-spec &rest args)
 100                    (declare (ignorable args))
 101                    ,@(cdr tail))))))
 102
 103
 104
 105