Church Slavonic Keyboard — Google Docs add-on

A click/tap on-screen keyboard that inserts Church Slavonic characters at the Docs cursor. Modeled loosely on the Ponomar cukeyb2 online keyboard, but with all modern-Russian letters removed — only the glyphs a standard Russian layout can't already produce.

Files

• appsscript.json — manifest (scopes: edit current doc + show sidebar)
• Code.gs — menu, sidebar launcher, insertAtCursor, deleteBackward
• Sidebar.html — the key grid (data-driven; edit the GROUPS array to change keys). Loads Ponomar from Google Fonts; a commented @font-face block offers a self-host / offline alternative.

Install (quickest path)

1. Open any Google Doc → Extensions ▸ Apps Script.
2. Paste Code.gs into the script file; add an HTML file named Sidebar and paste Sidebar.html into it.
3. Project Settings ▸ show the manifest, and paste appsscript.json.
4. Reload the doc → Extensions ▸ [project name] ▸ Open keyboard.

Or push the whole folder with clasp: clasp create --type docs, copy .clasp.json.example → .clasp.json (or let clasp create write it), then clasp push.

Extending

• Add/remove keys: edit the GROUPS array in Sidebar.html. Each key is a Unicode codepoint (\uXXXX); combining marks take combining: true.
• Capitals: a sticky Shift key toggles uppercase. Each cased letter is an explicit L(lower, upper) pair — uppercase codepoints aren't a fixed offset from lowercase (є U+0454 → Є U+0404, but ѣ U+0463 → Ѣ U+0462), so add new cased letters as pairs. To make Shift momentary (auto-release after one letter) instead of sticky, call toggleShift() at the end of send() when shift is on.

Known limits

• Cannot remap the physical keyboard inside the Docs body — palette insertion only.
• deleteBackward handles deletion within one text run (the common typing case).

License

The fonts are SIL OFL 1.1; the add-on is licensed under the MIT License.