hangul-off-on-search/plan.md

hangul-overview-latin — GNOME Shell Extension Plan

Goal

When the Activities Overview opens, ensure input is in Latin mode so overview search works immediately, even if ibus-hangul was in Hangul mode.

Environment

• Fedora Workstation, vanilla GNOME, Wayland
• ibus-hangul input engine (hangul IBus engine)
• GNOME 45+ extension format (ESM import, metadata.json with appropriate shell-version)
  • First step: check actual Shell version with gnome-shell --version and set shell-version accordingly.

Approach

Two candidate strategies, in order of preference:

Strategy A (primary): switch input source to English on overview open

• Use getInputSourceManager() from resource:///org/gnome/shell/ui/status/keyboard.js.
• On Main.overview showing signal, if current source is hangul, activate the xkb:us::eng (or first non-IBus) source.
• Pros: simple, engine-agnostic, reliable.
• Cons: changes the source, not the internal hangul/latin mode. User must switch source back (Super+Space) after leaving overview.
• Optional enhancement: remember previous source and restore it on hidden signal. Decide during implementation — restoring may be annoying if the user starts typing an app name and launches it (focus lands in new app with Hangul source restored). Ship without restore first; add behind a pref if wanted.

Strategy B (stretch): flip ibus-hangul's internal InputMode to latin

• ibus-hangul ≥ 1.5.15 exposes an InputMode property via the IBus property API.
• From a Shell extension, reach it through IBus.Bus → global engine property activation: ibus.set_global_engine() is not needed; instead use IBusManager (misc/ibusManager.js) and activateProperty('InputMode.Latin', ...) style calls — verify exact property key by running ibus engine hangul and inspecting with ibus introspection or reading ibus-hangul source (src/engine.c, property name is likely InputMode).
• Pros: user stays on hangul source; just the mode flips — closest to the stated desire.
• Cons: depends on ibus-hangul version/property names; more fragile.

Plan: implement A first, get it working, then attempt B as a follow-up. If B works, prefer it and drop the source-switching path.

File Structure

hangul-overview-latin@timothykim.net/
├── metadata.json
└── extension.js

No prefs UI in v1. If restore-on-hide becomes a toggle, add prefs.js + GSettings schema later.

metadata.json

{
  "uuid": "hangul-overview-latin@timothykim.net",
  "name": "Hangul Overview Latin",
  "description": "Switch to Latin input when the Activities Overview opens",
  "shell-version": ["48"],
  "url": ""
}

(Adjust shell-version to actual.)

extension.js sketch (Strategy A)

import * as Main from 'resource:///org/gnome/shell/ui/main.js';
import {getInputSourceManager} from 'resource:///org/gnome/shell/ui/status/keyboard.js';

export default class HangulOverviewLatin {
    enable() {
        this._ism = getInputSourceManager();
        this._showingId = Main.overview.connect('showing', () => {
            const current = this._ism.currentSource;
            if (current?.type === 'ibus' && current.id.startsWith('hangul')) {
                const sources = this._ism.inputSources;
                for (const i in sources) {
                    if (sources[i].type === 'xkb') { sources[i].activate(); break; }
                }
            }
        });
    }
    disable() {
        Main.overview.disconnect(this._showingId);
        this._showingId = null;
        this._ism = null;
    }
}

Verify against actual keyboard.js API for the installed Shell version — property names (currentSource, inputSources, activate()) drift between releases. Read /usr/share/gnome-shell/ resources or upstream source for the matching tag.

Implementation Steps

1. gnome-shell --version; note version.
2. Scaffold extension dir under ~/.local/share/gnome-shell/extensions/.
3. Confirm the extension class shape against GNOME 45+ docs (Extension base class from resource:///org/gnome/shell/extensions/extension.js is the current convention — use it, not a bare class).
4. Implement Strategy A.
5. Test (see below).
6. Investigate Strategy B: inspect ibus-hangul property names, try Main.panel.statusArea / IBusManager property activation from Looking Glass (lg) interactively before writing code.
7. If B works, gate A behind it or remove.

Testing (Wayland)

• No Alt+F2 r restart on Wayland. Options:
  • Nested session: dbus-run-session -- gnome-shell --nested --wayland (extension must be enabled inside it), or
  • Log out/in per iteration.
• Use Looking Glass (lg via run dialog... unavailable on Wayland restart-free flow; still usable for live inspection: Super, type lg won't work — use Alt+F2 is X11-only; on Wayland open Looking Glass via global.context from a nested session or use journalctl -f -o cat /usr/bin/gnome-shell for logs).
• Log with console.log(); watch journalctl --user -f | grep -i hangul.
• Test matrix:
  • Hangul source + hangul mode → Super → search types Latin.
  • Already on English source → Super → no-op.
  • Rapid open/close of overview → no signal leaks (check disable()/re-enable cycles).

Edge Cases / Open Questions

• Overview also opens via hot corner and Super in app grid state — showing signal covers all entry paths; confirm.
• disable() must disconnect signals (EGO review requirement if ever published).
• Interaction with Super+Space source cycling while overview is open.
• Does typing in overview search re-trigger IBus engine focus? (Search entry is a Clutter/St entry; IBus applies — that's why the problem exists at all.)