foo.lisp

#|
    Here's the problem:
    When the panel is initially created, all graphics are drawn correctly. In this simplified example
    this means that there are two lines being drawn.

    Next, I type a command in the interactor, which results in the REPAINT-ALL function being called again.

    On the screen, only one of the lines is now drawn. The second one (the one inside the inner output record)
    is inivisible, but I can make it appear by calling CLIM:REPAINT-SHEET.
|#

;;; The main panel is created like this
(defun create-panel ()
  (clim:make-clim-stream-pane :type 'canvas-pane
                                  :name name
                                  :default-view +canvas-view+
                                  :display-function 'repaint-all
                                  :incremental-redisplay nil
                                  :display-time t
                                  :borders t))

;;; This is the relevant part of the redraw function
(defun repaint-all ()
  (let ((obj ...)) ;; An object that should be drawn on the pane
    (clim:with-output-as-presentation (pane obj (clim:presentation-type-of obj)
                                               :view (clim:stream-default-view pane)
                                               :allow-sensitive-inferiors t
                                               :single-box t
                                               :record-type 'canvas-object-record)
         (let ((rec (clim:with-output-to-output-record (pane 'canvas-object-record-inner)
                      ;; This is where all the real drawing takes place. I've replaced it with a
                      ;; single call to DRAW-LINE for simplicity
                      ;; This line becomes invisible
                      (clim:draw-line* pane 10 10 20 20)))
           ;; This line is still visible
           (clim:draw-line* pane 0 0 100 50)
           (clim:stream-add-output-record pane rec)))))