[REBOL] Re: Skinz 0.2 Volume Control (The follow along tutorial :)

From: greggirwin:mindspring at: 26-Feb-2002 9:39

Hi Terry,

<< Ok, need a slider that provides a value of 0 on the bottom, to 255 on the
top.  Once the slider stops moving, must fill in n below and make this
call...

send-message winamp-hwnd WM_USER n 122 >>

    map-slider-to-value: func [
        "Converts a slider value between 0 and 1 to a value within a range."
        value   [number!] "A value between 0 and 1."
        min-val [number!] "The minimum range value (if value = 0)."
        max-val [number!] "The maximum range value (if value = 1)."
    ][
        max-val - min-val * value + min-val
    ]

    map-value-to-slider: func [
        "Converts a value within a range to a slider value between 0 and 1."
        value   [number!] "A value between min-val and max-val."
        min-val [number!] "The minimum range value. Equals a slider value of
0."
        max-val [number!] "The maximum range value. Equals a slider value of
1."
    ][
        value - min-val / (max-val - min-val)
    ]

view layout [
    sld-vol: slider [
        vol-val: to-integer map-slider-to-value sld-vol/data 255 1
        print vol-val
    ]
]

You can use map-value-to-slider to preset the slider to the correct position
if you can read the current volume setting from WinAmp.

        sld-vol/data: map-value-to-slider vol-current-value 255 1

--Gregg

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