gridcraft/docs/localization-parity.md

Localization parity

Last reviewed: 2026-10-10 · Last updated: 2026-10-21 · Change: minor (the Japanese catalog covers the dialogs, messages and menus; Dutch interface language; Romanian interface catalog) · Target: Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4

Per-language status against Excel, which ships its UI in dozens of languages (Windows language packs cover 100+), with localized function names, argument separators, number and date formats, right-to-left sheets and full complex-script support. Part of target-app-parity.md. Localization: ~10% ready, 100–165 h (estimated).

Where we are (measured from source on main, after the 2026-10-10 merges)

• A first catalog exists. crates/ui-egui/src/i18n.rs (merged 10-10 in #31, #104, #82; German added 10-11) adds an interface-language preference that defaults to the system language (closes #20) and a View-tab switcher, with English-keyed lookup tables: Simplified Chinese, Korean, Russian, German and Czech 266–518 labels each, Brazilian Portuguese and Japanese 943 each. The tables are used by the ribbon, sheet tabs and widgets (ribbon.rs, tabs.rs, widgets.rs), the Format Cells dialog, every dialog title and the shared OK/Cancel buttons; Japanese and Portuguese also cover the other dialog labels, message boxes, Backstage/File-view items, template names and native menus (Japanese, 10-17: i18n/ja.rs keeps the shared 398-label core and adds 545 of those strings). The remaining menus, context menus, task panes, status messages, command labels and function descriptions are still English literals. Untranslated labels fall back to English.
• About 2,200 user-visible strings in all (heuristic source scan: ~1,700 UI and command strings plus ~500 function descriptions), so the ribbon-only languages cover ~12% and Japanese and Portuguese ~43% (measured count / estimated total).
• en-US only formulas and formats. Function names, , argument separator, . decimal separator, en-US number and date formats (crates/numfmt says "en-US only"). Users ask for localized function names and ; separators (#45). German with localized numbers and formulas is in PR #163 (open).
• Script support. System-font fallback for CJK, Thai and Hebrew landed in #38 (closes #32; #142 is still open pending confirmation). There is no complex-text shaping: Arabic and Devanagari don't join or reorder, and there is no bidirectional layout. Sheet Right-to-Left (view.rightToLeft, Page Layout › Sheet Options, XLSX rightToLeft, .xls WINDOW2 fRightToLeft) mirrors the grid (#146): column A and the row headers on the right, the vertical scrollbar on the left; hit-testing, arrow keys, editor, popups and floating objects follow; text stays left-to-right inside its box (no bidi), and the sheet tabs, horizontal scrollbar and printing/PDF are not mirrored yet. Text boxes and shapes keep their paragraphs' right-to-left direction (a:pPr rtl) through XLSX save, though GridCraft still draws that text left to right. IME input goes through egui/winit and is unverified for Chinese, Japanese and Korean.
• Names in any script. Defined names (Define Name, Create from Selection) are limited to 255 characters, counted as characters rather than UTF-8 bytes, so a 255-letter Arabic name is accepted as in Excel. Sheet names already counted characters (31).
• PDF export uses only the 14 standard PDF fonts: non-Latin text cannot export.

Languages

UI strings translated are measured counts against the ~2,200 estimate. Estimates to full include the rest of the catalog work below (10–20 h, counted once), localized function names, separators, number/date formats, machine translation with agent review, and script work.

Language	Code	UI strings translated	Dialogs / tooltips / help	Script support	Native review	Status	Estimate to full
English	en	~2,200 / ~2,200 (100%, source)	yes	Latin: yes	yes	full	—
Simplified Chinese (Mandarin)	zh-Hans	266 (~12%)	no	CJK system-font fallback (#38); IME unverified; PDF can't export	no	menus only	8–13 h
Spanish	es	0 (0%)	no	Latin: yes	no	none	6–10 h
Hindi	hi	0 (0%)	no	Devanagari: no shaping	no	none	12–18 h
Arabic	ar	0 (0%)	no	no shaping, no RTL UI; Sheet Right-to-Left mirrors the grid (#146)	no	none	25–35 h
French	fr	0 (0%)	no	Latin: yes	no	none	6–10 h
Portuguese	pt-BR	943 (~43%)	dialogs and tooltips (dialogs take effect with #669)	Latin: yes	no	menus, File view, dialogs	2–4 h
Indonesian	id	0 (0%)	no	Latin: yes	no	none	5–8 h
Japanese	ja	943 (~43%)	dialogs and messages	CJK system-font fallback; IME unverified; no furigana display	no	menus, File view, dialogs, messages	3–5 h
German	de	266 (~12%)	no	Latin: yes	no	menus only	4–8 h
Italian	it	971 (~44%)	dialogs, tooltips, pivot pane	Latin: yes	no	menus, File view, dialogs, pivot pane	3–5 h
Korean	ko	266 (~12%)	no	Hangul via the CJK fallback; IME unverified	no	menus only	6–10 h
Vietnamese	vi	398 (~18%)	no	Latin with stacked diacritics: unverified	no	menus, File view	5–9 h

Other shipped languages: Russian (ru) and German (de), 266 labels each (~12%), menus only; Dutch (nl), 518 labels (~24%): ribbon, context menus, File view, dialog titles and the Options page.

Total: catalog work 10–20 h + languages 92–144 h ≈ 100–165 h. Parallelizes almost fully once the catalog covers dialogs and commands. Needs a human: native-speaker review of every language (none so far) and of localized function names.

Infrastructure (do first)

1. Extend the catalog from the ribbon to every user-visible string (dialogs, menus, task panes, status and error messages, command labels, function descriptions), with a missing-key check in cargo xtask ci. Language switching and the system-language default already exist (#31).
2. Locale-aware formulas: localized function-name tables and separators at the formula-bar boundary only (files keep en-US invariant names), locale number and date formats, list separators in CSV.
3. Text shaping and fallback: a shaping engine for grid, editor and PDF text (Arabic, Devanagari, Thai), system font fallback for CJK, bidirectional runs, right-to-left sheet tabs and printing; embedded subset fonts in PDF.

Revision history

Date	Change	Summary
2026-10-21	minor	Romanian interface (ro, Română): 970 labels covering every key of the other catalogs (crates/ui-egui/src/i18n/ro.rs), ro-* system locales, the View-tab switcher and app.language.set; context keys show no prefix (File › Options test). English formulas and formats; AI-assisted draft pending native-speaker review
2026-10-20	minor	Japanese catalog (i18n/ja.rs) covers every key the Brazilian Portuguese catalog translates: the 398-label shared core moved verbatim plus 545 dialog, message, Backstage and menu strings — 943 keys, ~12% → ~43%. A test parses pt.rs's source, so the two catalogs can't drift apart again. Portuguese re-measured at 943 (was 923)
2026-10-15	minor	Italian catalog (i18n/it.rs, 971 entries, ~44%): every key the Brazilian Portuguese catalog translates plus the PivotTable Fields pane strings; it locale tags (it-IT, it-CH…) resolve to Italian. Labels follow Excel's Italian terminology; native-speaker review still pending
2026-10-20	minor	Dutch (nl) interface catalog (i18n/nl.rs, 518 labels, ~24%): the shared key set every language must cover (ribbon, context menus, File view, dialog titles, Options page), matching the German, French and Czech catalogs; nl-NL, nl-BE locale tags resolve to Dutch
2026-10-19	minor	Defined-name length counts characters, not bytes: Arabic names up to 255 letters are accepted, and Create from Selection keeps long Arabic headers
2026-10-19	minor	Table names are limited to 255 Unicode characters
2026-10-19	minor	Right-to-left sheets in legacy .xls files (common in older Arabic workbooks) open right-to-left
2026-10-19	trivial	Text boxes and shapes keep right-to-left paragraph direction (a:pPr rtl) on XLSX save, so Excel-authored Arabic and Hebrew text boxes reopen right to left
2026-10-19	minor	Save as Web Page and copied HTML mark right-to-left sheets dir="rtl", let General-aligned Arabic and Hebrew text align by its own direction (dir="auto"), and keep numbers on right-to-left sheets left to right and on the left
2026-10-19	minor	French and Serbian kept the context in three context|label translations ("Options|Général", "Opcije|Opšte" for Options|General; also Options|Save, Sheet Options|View). tr shows a found translation as it is, so File › Options headings and the Sheet Options "View" checkboxes showed the prefix. Fixed; a test checks that no catalog shows a |
2026-10-17	minor	Vietnamese catalog (i18n/vi.rs, every key in the master table); vi locale tags resolve to Vietnamese
2026-10-12	minor	Format Cells looks up its tabs, labels, options and note through Language::tr (Fill tab keyed Format Cells|Fill); dialog titles and OK/Cancel too. Labels already in a table (Number, Currency, Fill…) show translated; the rest fall back to English until the tables add them
2026-10-12	minor	Brazilian Portuguese catalog (i18n/pt.rs) grows from 377 to 923 entries: every key the other catalogs translate, including the dialog strings #669 starts looking up (~42%)
2026-10-11	minor	German ribbon catalog (i18n/de.rs, 266 labels, ~12%); de locale tags (de-DE, de-AT, de-CH…) resolve to German. PR #163 (localized German formulas/numbers) still open
2026-10-11	minor	Sheet Right-to-Left mirrors the grid (#146)
2026-10-11	minor	Czech (cs) ribbon table: 266 labels (~12%), menus only
2026-10-10	minor	Re-measured after #31, #104, #82, #38 merged: ribbon translated into ja, zh, ko, pt-BR and ru (266–268 labels, ~12%), system-language default, CJK/Thai/Hebrew font fallback; ~10% ready, 100–165 h
2026-10-10	major	Created: English only, no catalog, ~2,200 strings, script-support gaps, open language PRs