Re: capi scrolling & scroll-bars

Hi,

Give your interface a bit of a width to display scrollbar. Change :visible-min-width to
:visible-min-width 810 for example.

(interface
(make-instance 'capi:interface
:title "Albums"
:layout (list layout)
:x 960
:visible-min-width 810
:visible-min-height 800
)))

BR,
/Alexey

On Tuesday, January 6th, 2026 at 20:39, Paul Werkowski (as pw at snoopy dot qozzy dot com) <[email protected]> wrote:

> On 1/6/2026 2:34 PM, David McClain wrote:
>
>> Hi Paul,
>>
>> None of your code examples made it through…
>
> ;;;; forgot to include them :(
>
> (in-package ::user)
>
> (defun run-test ()
> ;; where is scroll-bar?
> (flet ((draw-thing (pane x y w h)
> (declare (ignorable x y w h))
> (gp:draw-rectangle pane 10 100 144 144 :foreground :red)
> (gp:draw-rectangle pane 100 750 144 144 :foreground :blue)))
> (let* ((max-h 6336)
> (layout (make-instance
> 'capi:tracking-pinboard-layout
> ;; :description nil ; list of 151 drawn images
> :scroll-height max-h
> :vertical-scroll t
> :visible-min-width 800
> :visible-min-height (min 800 max-h)
> :display-callback #'draw-thing ; this example only
> ))
> (interface
> (make-instance 'capi:interface
> :title "Albums"
> :layout (list layout)
> :x 960
> :visible-min-width 750
> :visible-min-height 800
> )))
> (capi:display interface)
> )))
>
> ;;; from LW UG&RM 12.4.1 Ordinary Scrolling
>
> (defun run-example ()
> (flet ((my-display-callback (pane x y width height)
> (declare (ignore x width))
> (format t " y = ~d, height = ~d~%" y height)
> (gp:draw-rectangle pane 0 100 10 10
> :foreground :green :filled t)
> (gp:draw-rectangle pane 0 400 10 10
> :foreground :blue :filled t)))
> (let* ((output-pane
> (make-instance
> ;;'capi:output-pane
> 'capi:tracking-pinboard-layout
> :vertical-scroll t
> :scroll-height 600
> :visible-min-height 300
> :display-callback #'my-display-callback)))
> (capi:contain output-pane))))