capi:draw-pinboard-object with nil x, y, &c., or masking with highlights...

Hi all, (I think is aimed mainly at the LW folks, but maybe others
know what's happening here…)

I'm trying to use capi:highlight-pinboard-object with some
pinboard-object that I've defined.  I'd also like to use a
gp:with-graphics-mask in the capi:draw-pinboard-object method for my
objects, to avoid drawing more than I need to.  I started getting some
errors about NILs in arithmetic operations though.  Here's the first
stab at a minimal reproducible error.  The methods for my-item and
my-masked-item should achieve the same results, except that the method
for my-masked-item makes a mask with the x, y, width, and height
values from capi:highlight-pinboard-object.  To figure out whether the
problem is, the example function is parameterized by the
:highlight-style, and whether the masked item will be highlighted.


(defclass my-item (capi:pinboard-object) ())

(defmethod capi:draw-pinboard-object (pinboard
                                      (mi my-item)
                                      &key x y width height
                                      &allow-other-keys)
  (capi:with-geometry mi
    (gp:draw-rectangle pinboard
                       capi:%x%
                       capi:%y%
                       (1- capi:%height%)
                       (1- capi:%width%))))

(defclass my-masked-item (my-item) ())

(defmethod capi:draw-pinboard-object :around (pinboard
                                              (mmi my-masked-item)
                                              &key x y width height
                                              &allow-other-keys)
  (gp:with-graphics-mask (pinboard (list x y width height))
    (call-next-method)))
(defun example (&key (level 1) (highlight :invert))
  (let ((p (make-instance 'capi:pinboard-layout
                          :highlight-style highlight
                          :visible-min-width 200
                          :visible-min-height 200))
        (mi (make-instance 'my-item
                           :width 50 :height 50
                           :x 25 :y 25))
        (mmi (make-instance 'my-masked-item
                            :width 50 :height 50
                            :x 100 :y 100)))
    (capi:contain p)
    (capi:manipulate-pinboard p (list mi mmi) :add-many)
    (when (>= level 1)
      (capi:highlight-pinboard-object p mi :redisplay t))
    (when (>= level 2)
      (capi:highlight-pinboard-object p mmi :redisplay t))))


Here are the situations that do and don't cause errors:


;; (example :level 1 :highlight :default) ; no error (but no highlighting)
;; (example :level 2 :highlight :default) ; no error (but no highlighting)

;; (example :level 1 :highlight :standard) ; no error
;; (example :level 2 :highlight :standard) ; (+ NIL NIL) error

;; (example :level 1 :highlight :invert) ; no error
;; (example :level 2 :highlight :invert) ; (+ NIL NIL) error


I get an arithmetic error when I try to highlight a masked item and
the highlight style is :standard or :invert.  I don't get any
highlighting with the :standard method (that uses
draw-pinboard-object-highlighted), but I'm not sure whether I should
expect anything there.

If I add some poor-man's tracing to the draw-pinboard-object methods
with the following, I can see some interesting things happening.

(defmethod capi:draw-pinboard-object (pinboard
                                      (mi my-item)
                                      &key x y width height
                                      &allow-other-keys)
  (print (list 'dpo-mi pinboard mi x y width height)) ;
draw-...-object for my-item
  (capi:with-geometry mi
    (gp:draw-rectangle pinboard
                       capi:%x%
                       capi:%y%
                       (1- capi:%height%)
                       (1- capi:%width%))))

(defmethod capi:draw-pinboard-object :around (pinboard
                                              (mmi my-masked-item)
                                              &key x y width height
                                              &allow-other-keys)
  (print (list 'dpo-mmi pinboard mmi x y width height)) ;
draw-...-object for my-masked-item
  (gp:with-graphics-mask (pinboard (list x y width height))
    (call-next-method)))


For (example :level n :highlight :default) for n=1 and n=2, I see what
I'd expect, but in some of the other combination, there are NILs in
places where I'd expect numbers.  Finally, if define the
draw-pinboard-object method for the masked-item to set x, y, width,
and height to values that I'm sure aren't NIL, I get all the drawing
behaviors that I expect:

(defmethod capi:draw-pinboard-object :around (pinboard
                                              (mmi my-masked-item)
                                              &key x y width height
                                              &allow-other-keys)
  (print (list 'dpo-mmi pinboard mmi x y width height))
  (capi:with-geometry mmi
    (setf x (or x capi:%x%)
          y (or y capi:%y%)
          width (or width capi:%width%)
          height (or height capi:%height%)))
  (gp:with-graphics-mask (pinboard (list x y width height))
    (call-next-method)))


Now none of the examples causes an error, but of course I'm not
getting the masking that I'd been aiming for at the start.  What's
also strange is that the output still has NILs in it.  Sorry for the
very long email, but I a guess there are few particular questions
aside from the general "what am I doing wrong?":

1) Should draw-pinboard-object always be getting numeric values for
its x, y, width, and height?
1a) If so, what's happening here?
2) What is the intended interaction between masking and highlighting?

Thanks in advance,
//JT


-- 
=====================
Joshua Taylor
tayloj@cs.rpi.edu, jtaylor@alum.rpi.edu

"A lot of good things went down one time,
  back in the goodle days."
    John Hartford