[REBOL] Styles, 'with, shared stuff & confusion ...
From: petr::krenzelok::trz::cz at: 13-Nov-2000 15:06
Hi,
last two or three weeks I try to use /View for various purposes, and am
struggling with strange /View behavior and in my opinion the rebol
object architecture is the reason for unwanted behavior ....
As we know: once you create clone of object, you will receive separate
context, except the subobjects - they are shared. I am not sure what it
is good for (memory saving?), but I remember Carl's message to one of
the latest /View releases, stating "more stuff is copied now" or
something similar.
1) -----------
First I met the problem when I tried to put several progress bars into
one window, and tried to change it's bar property - the change was
reflected thru ALL progress bars in the view, and you will surely agree
that's something I didn't want to do. So I had to save the bar first to
solve my problem:
saved-bar: make system/view/vid/vid-styles/progress/bar []
styly: stylize [
txt: text bold font [shadow: none]
progr1: progress with [
color: none
bar: make saved-bar []
; and here we make the copy of our saved-bar ...
bar/color: none
bar/effect: [gradmul 0x1 255.100.100]
]
]
Now the question - wouldn't we expect such behavior by default?
----------------
2) the 'stylize or 'with is buggy in a similar way, or so it seems so
....
scenario: I have panel and large bitmap inside of it. I want to put
another face in the view, which I want to be transparent ....
--------
observations:
-------------
- once I created 'imagemap style, each new 'image was affected. Just
touch the zooming face and try to move mouse. Because of reverse-confine
function it jumps at the corner ... No matter if you use 'image, 'box,
etc, they will all share 'engage method, while they shouldn't imho ...
note - reverse confine is reverse behavior of confine function - very
good aproach to keep larger bitmap on-bonds ...
- second observation is speed. Try to uncomment second line and comment
out first line:
at 100x100 b: box 100x100 "Zoom" effect [crop 0x0 50x50 fit]
edge [size: 2x2]
; at 100x100 b: box 100x100 "Zoom" effect [crop 0x0 50x50 fit]
with [edge/size: 2x2]
you will see so drastical speed difference you will not believe it even
on your pentium 600 box ;-) So - is 'with flawed? Shouldn't it produce
the same result?
note1 - once setting 2x2 edge - EACH 'image, 'box, etc. in view will
have the same edge - shared stuff in action once again ...
note2 - try to comment out second line, and uncoment first one, and you
will receive still the same results ... I tried, unviewing, unsetting,
recycling, but the result is still very low speed. The only one thing
which seems to help is restarting rebol ...
3) Now comment out following line from stylize block:
face/offset: reverse-confine face/offset face/size 0x0
face/parent-face/size
After restarting the script you will be able to move your Zoom face, and
you can also move your imagemap out of boundaries of panel (black
background will appear).
-Move Zoom face to the left side of the panel - can you see the
reflection? A bug? It should be clipped by pane boundaries imho ...
- Move corner of imagemap over the Zoom face .... part of "Zoom" text
appears on the Zoom face once again ...
- try to move the background - ugh ... even backtile is reflected ...
- btw: don't try to "print mold p", as panel doesn't seem to use it's
pane - instead of that it uses parent-face field, and its pane. You will
end up printing all rebol/view styles in endless "?" loop (well, after 2
megs of data I stopped echoing to file)
4) delete 'black from panel definition and move the imagemap - you will
notice the slowdown, as we don't cache the background. So let's do it
all by following code:
p: panel 500x400 [
at 0x0 img: imagemap mapa
at 100x100 b: box 100x100 "Zoom" effect [crop 0x0 50x50 fit]
edge [size: 2x2]
; at 100x100 b: box 100x100 "Zoom" effect [crop 0x0 50x50 fit]
with [edge/size: 2x2]
] with [saved-area: true]
- move imagemap away and you will see another one under it - rebol saves
it's face backrounds together with already displayed stuff upon it ...
it's a bug in layout imho ....
OK, here's the all script ...
I hope some of you will find my observations informative to avoid
struggling with similar behavior once coding in /View ...
PS: sent to feedback ...
Cheers,
-pekr-
-----------------
REBOL [
Title: "Cyklotrasy ..."
Author: "Petr Krenželok"
Email: [pekr--rebol--cz]
Date: 12-Nov-2000
]
reverse-confine: func [
{Return the correct offset to keep rectangular area on-bounds.}
offset [pair!] "Initial offset"
size [pair!] "Size of area"
origin [pair!] "Lower bound (upper left)"
margin [pair!] "Upper bound (lower right)"
][
if offset/x > origin/x [offset/x: origin/x]
if offset/y > origin/y [offset/y: origin/y]
margin: margin - size
if offset/x < margin/x [offset/x: margin/x]
if offset/y < margin/y [offset/y: margin/y]
offset
]
cyklo-styles: stylize [
imagemap: image with [
feel/engage: func [face action event][
if action = 'down [face/data: event/offset]
if event/type = 'move [
face/offset: face/offset + event/offset - face/data
face/offset: reverse-confine face/offset face/size
0x0 face/parent-face/size
]
show face
]
]
]
print "Downloading images .... Wait please."
titl: load-thru http://www.rebol.cz/~kondik/cyklo/grafika/00cyklo.GIF
mapa: load-thru http://www.rebol.cz/~kondik/cyklo/grafika/4mapa.jpg
main: center-face layout/size [
styles cyklo-styles
bckgr: backtile %carlwaves.jpg effect [tile gradcol 0x1 0.0.100
0.0.250]
nadpis: image titl
across
p: panel black 500x400 [
at 0x0 img: imagemap mapa
at 100x100 b: box 100x100 "Zoom" effect [crop 0x0 50x50 fit]
edge [size: 2x2]
; at 100x100 b: box 100x100 "Zoom" effect [crop 0x0 50x50 fit]
with [edge/size: 2x2]
]
sly: slider 16x400 [
img/offset/y: negate to-integer ((img/size/y - p/size/y)
* sly/data)
show img
] below
slx: slider 500x16 [
img/offset/x: negate to-integer ((img/size/x - p/size/x)
* slx/data)
show img
]
] 640x490 none
view main
