20b07ed2a0
Add named Chinese punctuation presets and a Korean keep-words mode for horizontal and vertical layout. Preserve the saved spaces-only mode and keep source offsets stable through safe emergency wrapping. Apply bounded CJK spacing and justification, expose the new choices in the sidebar, and document preset bounds and remaining release checks. Verify renderer, frontend, common and exporter tests, both WASM builds, and sample save/reload plus PNG, PDF and SVG exports. Existing CI failures remain documented in the layout notes. AI-assisted-by: GPT-6
4.2 KiB
Chinese and Korean core layout
Paragraph text-language selects a layout policy. Writing mode remains a
whole-shape value. UI availability never changes either attribute.
Named Chinese presets
| Tags | Preset |
|---|---|
zh, zh-Hans, zh-Hant, unknown regions |
Original basic punctuation policy |
zh-Hans-CN, zh-Hant-CN, zh-CN, zh-SG |
Mainland: adjacent punctuation compression; quarter-em Han/Latin gaps |
zh-Hant-TW, zh-TW |
Taiwan: solid punctuation; quarter-em Han/Latin gaps |
zh-Hant-HK, zh-HK, zh-MO |
Hong Kong: centered punctuation spacing; quarter-em Han/Latin gaps |
Script does not imply region. Changing a profile does not convert characters. These presets select a limited set of styles; they do not claim that every publication in a region uses the same settings.
Compression applies to eligible adjacent full-width punctuation. Vertical colon, semicolon, question and exclamation marks keep their full frame. Proportional horizontal punctuation is not compressed again. Vertical cells retain at least a half-em frame. The Taiwan and Hong Kong presets allow a single comma or full stop to hang by at most half an em vertically; adjacent punctuation and horizontal text do not hang.
Chinese justification expands eligible character gaps by at most half an em. The final line/column remains unexpanded. These bounds are explicit POC choices, not numeric requirements imposed by a regional standard.
Korean modes
- Missing
korean-wrap, orsyllable: syllable wrapping with punctuation rules. keep-words: keep adjoining letters and digits together across scripts and style runs. Punctuation keeps its own opportunities and restrictions.spaces-only: preserve the earlier experiment. It remains readable in the UI for saved text but is not offered for new selections by default.
Fitting words move whole. Overlong words may use safe grapheme boundaries. Nonbreaking spaces/joiners, numeric prefixes/suffixes, paired dashes/ellipses, annotations and punctuation restrictions remain separate from letter ties. Korean justification first expands spaces, at most half an em per gap. Syllable mode may then expand eligible character gaps by at most one eighth of an em. Word mode never expands inside a word. Original spaces remain in source text; no Japanese word-space substitution applies.
Horizontal emergency wrapping and offsets
SkParagraph can ignore word joins during emergency wrapping. The horizontal plan measures candidate units and replaces joins with zero-width break opportunities only inside overlong units, at safe grapheme boundaries. Both marker characters occupy three UTF-8 bytes and one UTF-16 code unit. Their offset maps therefore stay identical for drawing, hit testing, carets, selection, text paths and export. Width participates in the plan cache key; resizing a box restores whole-word joins when the word fits again.
A horizontal indivisible unit wider than the entire box remains subject to
SkParagraph's last-resort fallback. Very narrow boxes containing punctuation
or annotation units need further work; this implementation does not claim
complete CSS keep-all conformance.
Evidence and release checks
Renderer tests cover regional geometry, horizontal/vertical wrapping, style boundaries, decomposed Jamo, punctuation, justification, stable offsets and distinct wrap protocol bytes. Editor splits preserve the complete wrap mode. Both WASM consumers use the same writer and byte values: 0 syllable, 1 experiment, 2 keep-words; unknown values fall back to syllable wrapping.
Real Pinyin, Zhuyin and Korean IME checks and native-reader review remain release checks. Font glyph coverage and localized forms still depend on the chosen fonts. Pinyin/Zhuyin annotation tools belong to Stage 4.
References checked on 2026-10-19:
- CLREQ draft, 2026-10-07, sections 6.1 and 6.3.2: punctuation boundaries, compression and hanging.
- KLREQ draft, 2026-03-21, sections 7.1 and 7.2: syllable/word wrapping and justification restrictions.
- CSS Text 3: letter-breaking policy is distinct from punctuation and overflow handling.