Rebol Programming/scroll-para

= USAGE: = SCROLL-PARA tf sf

= DESCRIPTION: = Scroll a text face, given a scroller/slider face.

SCROLL-PARA is a function value. = ARGUMENTS =
 * tf -- Text face to scroll (Type: any)
 * sf -- Scroller face (Type: any)

= SOURCE CODE = scroll-para: func [ "Scroll a text face, given a scroller/slider face." tf "Text face to scroll" sf "Scroller face" /local tmp ][   if none? tf/para [exit] tmp: tf/para/margin + tf/para/origin + size-text tf    tmp: min 0x0 tf/size - tmp - either tf/edge [2 * tf/edge/size] [0x0] either sf/size/x > sf/size/y [tf/para/scroll/x: sf/data * first tmp] [ tf/para/scroll/y: sf/data * second tmp ]    show tf ]