ふりがな Deep Dive try! Swift Tokyo 2026

ふりがな Deep Dive
try! Swift Tokyo 2026
https://www.youtube.com/watch?v=ND5V4nl9-nI

Apr 13 2026

Transcript

1. watura ( Wataru Nishimoto )
 note Inc
 https://wtr.io Furigana Deep Dive try! Swift Tokyo
2. Furigana? ;Γ͕ͳ? Base Character Furigana
3. Ruby is a small-sized, supplementary text attached to a character or a group of characters in the main text. A run of ruby text, usually attached to the right of the characters in vertical writing mode or immediately above them in horizontal writing mode, indicates the reading or the meaning of those characters (see Figure 105). The characters in the main text that are annotated by ruby are called "base characters". Mainly Hiragana (cl-15) characters are often used for ruby to indicate how to read ideographic characters (cl-19); this is known as ruby annotation or as "furigana".
4. Requirements for Japanese Text Layout ೔ຊޠ૊൛ॲཧͷཁ݅ʢ೔ ຊޠ൛ʣ8$ https://www.w3.org/TR/jlreq/#ruby_and_emphasis_dots
6. ੈքத ͔Β։ൃऀ͕ू͍·͢ɻ All over the world developers ͭͲ
8. UIKit
9. UIKit CoreText!!
10. f u n c C TR u byAnn o ta tionCr ea t eW ithAt tr ibu t es ( _ a l ign m en t : C TR u by Align m ent , // De f au l t A l ig n m e nt _ o v e r h an g : C TR u b y O ve r h an g , / / A lig n m e nt f o r lo ng e r f u r ig an a _ p o si t i on : C TR u byPo si t i on , / / Furi g an a P o s i t ion _ s t r ing : C F S t r ing , _ a t tr ib u t es : C F Di c tio n a ry ) -> C TR u byAnn o ta tion There are options that meets the Furigana requirements.
11. let pairs: [(String, String)] = [ ("ੈքத", "All over the world"), ("͔Β", ""), ("։ൃऀ", "developers"), ("͕", ""), ("ू", "ͭͲ"), ("͍·͢ɻ", "") ] func ruby(_ base: String, _ ruby: String) -> NSAttributedString { let annotation = CTRubyAnnotationCreateWithAttributes( .auto, .auto, .before, ruby as CFString, [kCTRubyAnnotationSizeFactorAttributeName: 0.5] as CFDictionary ) return NSAttributedString( string: base, attributes: [ kCTRubyAnnotationAttributeName as NSAttributedString.Key: annotation ] ) }
12. SwiftUI
13. NO CTRubyAnnotation
14. Text("ੈքத") Text("͔Β") Text("։ൃऀ") Text("͕") Text("ू") Text("͍·͢ɻ") FuriganaText("All over the world") FuriganaText("developers") FuriganaText("ͭͲ")
15. Text("ੈքத") Text("͔Β") Text("։ൃऀ") Text("͕") Text("ू") Text("͍·͢ɻ") FuriganaText("All over the world") FuriganaText("͔͍͸ͭ͠Ό") FuriganaText("ͭͲ") 🤮
16. TextRenderer + TextAttribute
17. https://youtu.be/zbnYo_46kS8?si=KVbhqTkoTuXKcGfS
18. s tr uct Ru by A t tr ibu te: T e x tA t tr ib u te { l e t f u llR e a d i ng : S t r ing } s tr uct Ru byTe xtRe nd e re r : T e xt Re nd e re r { f u n c dr aw ( la yo ut : T e x t . La yo ut , i n ctx: in o ut G ra p h i cs C o n t e xt ) { f o r l i ne i n la yo u t { ctx.dr aw (l ine ) } } } l e t text = T e xt ("ੈքத") . c u s t o m At tr i bu te( Ru by At tr i bu te( f u llRe a d i ng : "A l l o v e r t he wo rl d") ) + T e xt ("͔Β") + T e xt ("։ൃऀ") . c u s t o m At tr i bu te( Ru by At tr i bu te( f u llRe a d i ng : " d ev e l o p er ") ) + T e xt ("͕") + T e xt ("ू") . c u s t o m At tr i bu te( Ru by At tr i bu te( f u llRe a d i ng : "ͭͲ") ) + T e xt ("͍·͢ɻʣ tex t . text Re nd e re r ( Ru byTe xtRe nd e re r ())
19. ੈքத ͔Β ͍·͢ɻ ։ൃऀ ͕ू developer All over the world ͭͲ
20. ੈքத ͔Β ͍·͢ɻ ։ൃऀ ͕ू developer All over the world ͭͲ
21. ू ͭͲ Small Text above base characters ։ൃऀ developer Center alignment (Furigana < Base) All over the world Center alignment (Furigana > Base) ͔Β ੈքதO O
22. ू ͭͲ Small Text above base characters ։ൃऀ developer Center alignment (Furigana < Base) fu n c dr aw ( la yo ut : T e xt . La yo ut , i n c o n t e xt : i n o u t G ra p h i cs C on t ex t ) { }
23. ू ͭͲ Small Text above base characters ։ൃऀ developer Center alignment (Furigana < Base) fu n c dr aw ( la yo ut : T e xt . La yo ut , i n c o n t e xt : i n o u t G ra p h i cs C on t ex t ) { // 1. Mo v e c o n t ext f o r bi g g e r l in e H e i g ht var s hi f ted = c o n t e xt shi f t ed .t ra n s lat e B y (x: 0, y: l ine H e i gh t ) }
24. ू ͭͲ Small Text above base characters ։ൃऀ developer Center alignment (Furigana < Base) fu n c dr aw ( la yo ut : T e xt . La yo ut , i n c o n t e xt : i n o u t G ra p h i cs C on t ex t ) { // 1. Mo v e c o n t ext f o r bi g g e r l in e H e i g ht var s hi f ted = c o n t e xt shi f t ed .t ra n s lat e B y (x: 0, y: l ine H e i gh t ) f o r l ine i n la yo ut { f o r r un i n l ine { / / 2. Ca l c u late f u rig an a p o si t i on l e t b ound s = l i ne . ty po g r a p h i c B o und s l e t x = b ound s . rect .m idX / / C en te r A lig n m ent l e t y = b ound s . rect .m inY } } }
25. ू ͭͲ Small Text above base characters ։ൃऀ developer Center alignment (Furigana < Base) fu n c dr aw ( la yo ut : T e xt . La yo ut , i n c o n t e xt : i n o u t G ra p h i cs C on t ex t ) { // 1. Mo v e c o n t ext f o r bi g g e r l in e H e i g ht var s hi f ted = c o n t e xt shi f t ed .t ra n s lat e B y (x: 0, y: l ine H e i gh t ) f o r l ine i n la yo ut { f o r r un i n l ine { / / 2. Ca l c u late f u rig an a p o si t i on l e t b ound s = l i ne . ty po g r a p h i c B o und s l e t x = b ound s . rect .m idX / / C en te r A lig n m ent l e t y = b ound s . rect .m inY / / 3. D raw Furi g an a A n d Ba s e Ch a r a c te r l e t ru b y R e s o l v e d = sh i f t ed . re s o l ve ( T e xt ( T EXT ) . font (. c a p tion )) s hi f ted .dr aw ( ru b y R e s o l v e d , a t : . i n i t(x: x, y: y), a nch o r : . b ottom ) s hi f ted .dr aw ( ru n ) // D ra w Ba s e Cha r a c te r } } }
26. All over the world Center alignment (Furigana > Base) // W i dth ca l cu la ti on l e t b as eW i dth = ru n . ty po g r a p h i c B o und s .w i dth l e t ru b y R e s o l v e d = shi f ted . re s o l ve ( T e xt ( ru b y C ha rs). f ont (. c a ptio n )) l e t ru b yW i dth = ru b y R e s o l v e d . me as u re( i n: m e as u r eS ize ).w i dth l e t extra Wi dth = m ax (0, ru b yW i dth - b as eWi dth) l e t p ad d i ng = extr aWi dth / 2 // D raw b as e text var s = s hi f ted s.t ra n s lat e B y (x: p ad d i n g , y: 0 ) s.dr aw ( ru n ) // D raw F uri g an a l e t x = r un . ty po g r a p h i c B o und s . re ct .m i dX + p ad d i ng l e t y = r un . ty po g r a p h i c B o und s . re ct .m i nY shi f ted .dr aw ( ru b y R e s o l v e d , a t : . i n i t(x: x, y: y), a nch or : . bott om ) // A dvanc e f o r n e x t run c o n t ext .t ra n s lat e B y (x: extraW i dth, y: 0 ) ͔Β ੈքதO O
27. ੈքத ੈքத ͔Β All over the world ੈքத ͔Β All over the world ↓Move Context c o n t ext .t ra n s lat e B y (x: extraW i dth, y: 0 )
28. There are more requirements to use TextRenderer Furigana in production.
29. Want a real code? ask Claude code to make it.
30. watura ( Wataru Nishimoto )
 note Inc
 https://wtr.io Furigana Deep Dive try! Swift Tokyo