     gadget grid>> [| row j |
         row [| cell i |
             cell [
-                i j [ size * ] bi@ 2array { size size } gl-fill-rect
+                i j [ size * ] bi@ 2array
+                { size size } gl-fill-rect
             ] when
         ] each-index
     ] each-index ;

    gadget hand-rel first2 [ size /i ] bi@ :> ( i j )
    i 0 cols 1 - between?
    j 0 rows 1 - between? and [
        t i j gadget grid>> nth set-nth
    ] when gadget relayout-1 ;

: on-scroll ( gadget -- )

    grid count-neighbors :> neighbors
    grid [| row j |
        row [| cell i |
            i j neighbors nth nth
            cell [
                2 3 between? i j grid nth set-nth
            ] [
                3 = [ t i j grid nth set-nth ] when
            ] if
        ] each-index
    ] each-index ;
