[REBOL] Re: Capturing transparent faces.
From: petr:krenzelok:trz:cz at: 25-Jun-2005 22:09
Carl Read wrote:
>Hi all,
>
>If you have a transparent face in View, it can be used to grab an image of the faces
under it. However, I can only get this to work on a layout in an open window - when
I attempt it on layout, all I get is a black image.
>
>Here's an example of this: Just run it, click on the "Grab Area" button and you'll
see what I mean...
>
>rebol []
>lo: layout [
> title "Grab area test."
> at 30x20
> b: box 80x30 with [color: none] ; Transparent box.
> button "Grab Area" [
> window-grab: to-image b
> unview/all
> ]
>]
>lo-grab: to-image b
>
Look, I am no guru at View, but imo following happens. Feel free to
correct me eventually:
you create snapshot of 'b (lo-grab), even before it is being shown for
the first time. Imo layout just defines structures, but does not apply
effect, until the face is actually shown. But - even if you first apply
view lo
and then "lo-grab: to-image b", you apply 'unview after the
button press. 'lo object still remains in memory, but who knows what
'unview causes internally.
Better ask some guru ...
-pekr-
