[REBOL] /view slider data (size - 4) ? Re:
From: jkinraid:clear at: 2-Aug-2000 14:57
[RChristiansen--pop--isdfa--sei-it--com] wrote:
> When I make a slider, how come the slider /data value reaches a maximum
> of four integers less than the size of the slider?
>
> For example, to return a maximum /data value of 255, use the following...
>
> REBOL []
>
> face-one: layout [
> s: slider 10x259 [s/color: 0.0.0 + s/data show s print s/data]
> ]
>
> view/title face-one "face one"
The problem is because of the edges on the slider. Because they use up
4 pixels of space, you end up with a maximum value of the slider width -
4. So if you did this -
face-one: layout [
s: slider 10x259 with [edge/size: 4x4]
[s/color: 0.0.0 + s/data show s print s/data]
]
view/title face-one "face one"
You can use these functions to get/set the position of a slider -
get-slider-position: func [
"Returns the sliders position, a value between 0.0 and 1.0"
slider [object!]
/scale amount [number!]
"Scales the position by amount, and converts to an integer"
/local result way
] [
way: not zero? slider/pane/way/1
result: (slider/data - 1) / pick
(slider/size - (2 * slider/edge/size) - slider/pane/way) way
if scale [result: to-integer result * amount]
result
]
set-slider-position: func [
slider [object!]
position [number!]
/scale amount [number!]
"Scale the position down to a number between 0.0 and 1.0"
/local way offset
] [
if scale [position: position / amount]
way: not zero? slider/pane/way/1
offset: to-integer (position * pick
(slider/size - (2 * slider/edge/size) - slider/pane/way) way) + 1
slider/data: offset
slider/pane/offset: slider/pane/way * (to-integer position * pick
(slider/size - slider/pane/size - (2 * slider/edge/size)) way)
]
So now the code becomes -
face-one: layout [
s: slider 10x300 [
s/color: 0.0.0 + get-slider-position/scale s 255
show s
print s/color
]
]
view/title face-one "face one"
Julian Kinraid
