Files
amethyst/tools/ime-test/README.md
T
Claude 2415565ebf refactor: replace org.json with kotlinx.serialization in source files
Sweeps the last org.json usages out of the Kotlin sources and moves them
to kotlinx.serialization's JSON tree API (already the project standard):

- nappletHost: bridge/broker envelope handling in NappletHostActivity,
  NappletHostService, NappletBrowserActivity, NappletBrowserService and
  NappletFaviconSniffer now parses with Json.parseToJsonElement via new
  total helpers in JsonEnvelope.kt (absent/mistyped fields degrade to
  empty/false instead of throwing, matching the old opt* semantics).
  Adds the kotlinx-serialization-json runtime to the module (tree API
  only, so no serialization plugin needed).
- amethyst embed IME relay: EmbeddedImeBridge parses ime.* envelopes
  with JsonObject accessors; RemoteImeView and EmbeddedTabLayer build
  their outgoing envelopes with buildJsonObject.
- tools/ime-test: drops the now-stale "org.json is stubbed in JVM unit
  tests" rationale from the README and shim-events.mjs header.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AVcZwp65oybotmq5o66foW
2026-08-30 05:52:29 +00:00

123 lines
6.1 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
# IME / text-selection test harness
A single-file web page (`index.html`) for exercising and profiling the embedded
WebView IME + text-selection relay (see
`amethyst/plans/2026-06-25-embed-text-selection-native-parity.md`). It has a
plain `<input>` and a `<textarea>` plus an on-page green log that records, with
millisecond timestamps:
- focus/blur, `selectionchange`, `keydown`/`beforeinput`/`input`, composition
events, and the resulting `value`/selection — to catch erase, caret-jump, and
focus-transfer regressions;
- **paint latency** (`requestAnimationFrame` after each DOM change) — the metric
that exposed the first-letter freeze;
- **long-task** + **main-thread-block** detectors and a focus/selection
**heartbeat** — to catch anything stalling the WebView main thread or
spontaneously moving focus/selection.
The log lines are tagged `[ImeDiag]` and also go to `console.log`, so they show
up in `adb logcat` (the `:napplet` process owns the WebView console). Nothing
here ships in the app — it's a dev tool, which is why the `[ImeDiag]` strings
live only under `tools/`.
## Run it
1. Serve this directory over HTTP from your dev machine:
```bash
cd tools/ime-test && python3 -m http.server 8765
```
2. Reach it from the device/emulator:
- **Emulator:** the page is at `http://10.0.2.2:8765` (`10.0.2.2` is the
emulator's alias for the host loopback).
- **Physical device (USB):** `adb reverse tcp:8765 tcp:8765`, then the page is
at `http://localhost:8765`.
3. Open that URL as an **embedded** tab (this is the path that uses the relay —
*not* a full-screen activity):
- Open the in-app browser (`BrowserScreen`) and type the URL into its address
bar. The embedded browser handles `http`/`https`, so it loads into the
`:napplet` SurfaceControlViewHost surface.
To compare against native behavior, open the same URL in a full-screen
activity (where the WebView renders in-window with the native keyboard) — that
is also how you reproduce the **full-screen round-trip highlight bug** (open
full-screen, `back`, then selection highlight is dead across all embeds).
## Reading the log
- `INPUT … val=… sel=…` right after a keystroke with the right value = no erase.
- `PAINT-LATENCY Nms` spiking to ~1000ms = the first-letter freeze (should stay
low now that the surface no longer resizes on IME show).
- `MAINTHREAD BLOCKED` / `LONGTASK` = something is stalling the WebView thread.
- `HEARTBEAT` lines changing while idle = spontaneous focus/selection drift.
## `shim-events.mjs` — automated regression test for the IME protocol
`index.html` and `perf.html` are manual probes; this one is a real test. It loads
the shipped shim (`commons/.../napplet/shim.js`) into headless Chromium with the
embedded-surface flags set, drives genuine focus/tap/blur gestures, and asserts
the `ime.*` envelopes it emits — the doorbell fires on a tap in an
already-focused field, the doorbell stays payload-free, a host `ime.resync` is
answered with the field state and no geometry, `readonly` survives the round
trip, and a tap inside a `contenteditable` counts.
```bash
cd tools/ime-test
npm i playwright-core # once; the browser itself is already on the box
node shim-events.mjs # exits 0 on success, 1 with a per-case report
node shim-events.mjs /path/to/other/shim.js # diff a candidate against it
```
Set `CHROMIUM_PATH` if your Chromium lives somewhere other than
`/opt/pw-browsers/chromium-1194/chrome-linux/chrome`.
**Why this and not a JVM unit test.** The half worth protecting is the
page↔host contract — real browser focus/gesture behavior and the envelopes the
shim emits for it — and that only exists in a browser. A JVM test of the
host-side parser (`parseImeEvent`, kotlinx.serialization) would only re-parse
envelopes the test itself fabricated.
## `perf.html` — why does the embed feel slower than the full-screen browser?
`index.html` profiles the IME relay. `perf.html` answers a different question:
the embedded tab and the full-screen browser are the **same WebView in the same
`:napplet` process** with byte-identical `WebSettings`, so when a site's JS feels
slower in the embed, the cause is host-induced — and this page measures which
host effect it is.
Serve the directory (above) and open **the same URL in both hosts**, then compare
the summary line at the bottom of the page:
- **`vis=hidden`** — decisive. Chromium considers the embedded page hidden, so it
clamps timers to ~1Hz and suspends `requestAnimationFrame`. Everything the site
schedules lands late; it reads as "the JS got slow". Confirmed by
`timer50` (a 50ms interval firing at 500-1000ms) and `raf` (0 fps).
- **`vis=visible` but `cpu` is 2-4× the full-screen number** — the process is
running on the little cores. The site's JS runs in the WebView *renderer*
process, whose scheduling class is inherited from its host: `:napplet` is
`top-app` when it fronts the full-screen activity, but only a bound service
(`BIND_AUTO_CREATE`, no `BIND_IMPORTANT`) when it serves the embed. Cross-check
off-device with:
```bash
adb shell dumpsys activity processes | grep -E 'napplet|sandboxed'
adb shell "cat /proc/$(adb shell pidof com.vitorpamplona.amethyst:napplet)/cgroup"
```
Expect `/top-app` with the full-screen browser open and `/foreground` (or lower)
with an embed tab open.
- **`cpu` matches but `inputDelivery` is much higher** — the gap is input routing
into the embedded window, not compute. `inputDelivery` is the time between the
platform stamping the touch and JS receiving it.
- **`layout` much higher in the embed** — layout/paint is the bottleneck (check
logcat for WebView software-rendering warnings; a non-hardware-accelerated
`SurfaceControlViewHost` window would put Chromium on the software path).
- **`focus=false` in the embed is expected** and is not itself a throttle: the
host window owns the keyboard, which is the whole reason `RemoteImeView` exists.
`longtasks` counts main-thread blocks over 50ms while the page was measuring —
high counts in the embed with a matching `cpu` number point at something else in
the process competing (e.g. parked warm tabs that are never paused).