factor/library/ui/paragraphs.factor

57 lines
1.4 KiB
Factor

IN: gadgets-layouts
USING: arrays gadgets gadgets-labels generic kernel math
namespaces sequences ;
! A word break gadget
TUPLE: word-break-gadget ;
C: word-break-gadget ( gadget -- gadget )
[ set-delegate ] keep ;
! A gadget that arranges its children in a word-wrap style.
TUPLE: paragraph margin ;
C: paragraph ( margin -- gadget )
[ set-paragraph-margin ] keep dup delegate>gadget ;
SYMBOL: x SYMBOL: max-x
SYMBOL: y SYMBOL: max-y
SYMBOL: margin
: overrun? ( width -- ? ) x get + margin get >= ;
: wrap-line ( height -- ) 0 x set y [ + ] change ;
: wrap-pos ( -- pos ) x get y get 0 3array ;
: advance-x ( x -- ) x [ + dup ] change max-x [ max ] change ;
: advance-y ( y -- ) y get + max-y [ max ] change ;
: wrap-step ( quot child -- | quot: pos child -- )
dup pref-dim [
over word-break-gadget? [
dup first overrun? [ dup second wrap-line ] when
] unless drop wrap-pos rot call
] keep first2 advance-y advance-x ; inline
: wrap-dim ( -- dim ) max-x get max-y get 0 3array ;
: init-wrap ( paragraph -- )
paragraph-margin margin set
0 { x max-x y max-y } [ set ] each-with ;
: do-wrap ( paragraph quot -- dim | quot: pos child -- )
[
swap dup init-wrap
[ wrap-step ] each-child-with wrap-dim
] with-scope ; inline
M: paragraph pref-dim* ( paragraph -- dim )
[ 2drop ] do-wrap ;
M: paragraph layout* ( paragraph -- )
[ swap dup prefer set-rect-loc ] do-wrap drop ;