[REBOL] AW: frustrating pairs...
From: Christian:Ensel:GMX at: 8-May-2004 3:12
Dear Alain,
> either d = 'x [bx/pane/offset/x: - tmp * sf/data ] [ ; how to improve that
?
> bx/pane/offset/y: - tmp * sf/data ]
The function MIX-PAIRS as defined below takes two PAIR!s and a word of value
X or Y. Depending on the latter MIX-PAIRS returns a new PAIR! which is
composed by A's axis as supplied in the 'D argument and B's opposite axis.
This lets you 'simulate' touching only one axis easily.
Sounds very confusing, I know, but look at the following code snippet, you
will get the idea:
;------------ cut'n'paste -- (beware of
line-breaks) -------------------------
REBOL []
mix-pairs: func [a [pair!] b [pair!] 'd [word!] /local way] [
(a * way: pick [1x0 0x1] :d = 'x) + (b * reverse way)
]
scroll: func [bx sf 'd] [
bx/pane/offset: mix-pairs bx/size - bx/pane/size * sf/data bx/pane/offset
:d
;^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
;-- bx/pane/offset is modified only for the direction supplied in :d
; by setting the opposite axis back to the value before the
modification
;
show bx
]
d: 'x
view layout [
across bx: box 200x100 white with [
pane: make-face/spec 'box [size: 40x40 color: red]
]
sf: slider 20x100 [scroll bx sf :d] return
tg: btn "toggle" [d: select [x y x] :d
sf/data: bx/pane/offset/:d / (bx/size/:d - bx/pane/size/:d)
show [tg sf]
] ]
;------------ cut'n'paste -- (beware of
line-breaks) -------------------------
regards,
Christian
