factor/basis/math/rectangles/positioning/positioning.factor

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Factor

! Copyright (C) 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: sequences kernel accessors math math.vectors
math.rectangles math.order arrays locals fry
combinators.short-circuit ;
IN: math.rectangles.positioning
! Some geometry code for positioning popups and menus
! in a semi-intelligent manner
<PRIVATE
: adjust-visible-rect ( visible-rect popup-dim screen-dim -- visible-rect' )
[ drop clone ] dip '[ _ vmin ] change-loc ;
: popup-x ( visible-rect popup-dim screen-dim -- x )
[ loc>> first ] 2dip swap [ first ] bi@ - min 0 max ;
: preferred-y ( visible-rect -- y )
[ loc>> ] [ dim>> ] bi [ second ] bi@ + ;
: alternate-y ( visible-rect popup-dim -- y )
[ loc>> ] dip [ second ] bi@ - ;
: preferred-fit? ( visible-rect popup-dim screen-dim -- ? )
[ [ preferred-y ] [ second ] bi* + ] dip second < ;
: alternate-fit? ( visible-rect popup-dim -- ? )
alternate-y 0 >= ;
: popup-y ( visible-rect popup-dim screen-dim -- y )
3dup { [ preferred-fit? not ] [ drop alternate-fit? ] } 3&&
[ drop alternate-y ] [ 2drop preferred-y ] if ;
: popup-loc ( visible-rect popup-dim screen-dim -- loc )
[ popup-x ] [ popup-y ] 3bi 2array ;
:: popup-dim ( loc popup-dim screen-dim -- dim )
screen-dim loc v- popup-dim vmin ;
PRIVATE>
: popup-rect ( visible-rect popup-dim screen-dim -- rect )
[ adjust-visible-rect ] 2keep
[ popup-loc dup ] 2keep popup-dim <rect> ;