1 ! Copyright (C) 2009 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: arrays kernel locals math math.functions math.order math.vectors
4 sequences ui.gadgets accessors combinators ;
5 IN: ui.baseline-alignment
10 TUPLE: aligned-gadget < gadget baseline cap-height ;
12 GENERIC: baseline* ( gadget -- y )
14 GENERIC: baseline ( gadget -- y )
16 M: gadget baseline drop f ;
18 M: aligned-gadget baseline
21 [ baseline* ] [ ] [ layout-state>> ] tri
22 [ drop ] [ dupd baseline<< ] if
25 GENERIC: cap-height* ( gadget -- y )
27 GENERIC: cap-height ( gadget -- y )
29 M: gadget cap-height drop f ;
31 M: aligned-gadget cap-height
34 [ cap-height* ] [ ] [ layout-state>> ] tri
35 [ drop ] [ dupd cap-height<< ] if
40 ! Text has ascent/descent/cap-height slots, graphics does not.
41 TUPLE: gadget-metrics height ascent descent cap-height ;
43 : <gadget-metrics> ( gadget dim -- metrics )
44 second swap [ baseline ] [ cap-height ] bi
45 [ dup [ 2dup - ] [ f ] if ] dip
46 gadget-metrics boa ; inline
48 : ?supremum ( seq -- n/f )
49 sift [ f ] [ supremum ] if-empty ;
51 : max-ascent ( seq -- n )
52 [ ascent>> ] map ?supremum ;
54 : max-cap-height ( seq -- n )
55 [ cap-height>> ] map ?supremum ;
57 : max-descent ( seq -- n )
58 [ descent>> ] map ?supremum ;
60 : max-graphics-height ( seq -- y )
61 [ ascent>> not ] filter [ height>> ] map ?supremum 0 or ;
63 :: combine-metrics ( graphics-height ascent descent cap-height -- ascent' descent' )
65 cap-height 2 / :> mid-line
67 [ ascent mid-line - max mid-line + floor >integer ]
68 [ descent mid-line + max mid-line - ceiling >integer ] bi
71 : (measure-metrics) ( children sizes -- graphics-height ascent descent cap-height )
72 [ <gadget-metrics> ] 2map
74 [ max-graphics-height ]
82 :: align-baselines ( gadgets -- ys )
83 gadgets [ dup pref-dim <gadget-metrics> ] map
84 dup max-ascent 0 or :> max-ascent
85 dup max-cap-height 0 or :> max-cap-height
86 dup max-graphics-height :> max-graphics-height
88 max-cap-height max-graphics-height + 2 /i :> critical-line
89 critical-line max-ascent [-] :> text-leading
90 max-ascent critical-line [-] :> graphics-leading
94 [ ascent>> max-ascent swap - text-leading ]
95 [ height>> max-graphics-height swap - 2 /i graphics-leading ] if +
98 : measure-metrics ( children sizes -- ascent descent )
99 (measure-metrics) combine-metrics ;
101 : measure-height ( children sizes -- height )
102 (measure-metrics) dup [ combine-metrics + ] [ 3drop ] if ;