Tapping in the editor repositions the cursor, but it was never actually
verified (the old unit test only checked in-bounds/no-panic). On-device
verification found that on a large file scrolled deep, the cursor clamped to
the bottom of the viewport regardless of tap position.
Root cause: the tap handler computed the tap's text-local Y in content space
(pt.Y - region.Y + full ScrollOffset) and passed it to SetCursorFromPoint,
whose visualLine = y/lineHeight then produced a huge content-line number
(e.g. 91,640). But the GlyphLayout is window-relative (layout.Y==0 is the top
of the visible window), so the number far exceeded the window's line count and
clamped to the last group (bottom line). The Phase 3 windowing refactor
introduced the windowed layout without updating the tap handler.
Fix: tapLocalY() converts the tap Y to window-relative space by adding only the
sub-line remainder (ScrollOffset mod lineHeight), never the full scroll.
Extracted as a named helper so it is unit-testable. Added two regression tests
that fail on the pre-fix formula (cursor clamps to the bottom line) and pass on
the fix. Verified on-device: taps now map linearly across the viewport.
Also removed the per-tap/per-glyph log.Printf debug lines in SetCursorFromPoint.
internal/perf: single-goroutine profiler (no locks). When enabled by the
/storage/emulated/0/PadPerf/enable marker it records one CSV row per logic
frame (seq, ms, frame delta, page, scroll Dp, max-scroll Dp, total lines,
visible byte range), logs a rolling ~1/s summary, and on Stop reports
nearest-rank p50/p90/p99/max. Flushes per row-batch but never fsyncs per
flush (avoids periodic hitches in the logic path).
editor: PerfRecord package-level hook (nil when off) + ProbeRecord;
Logic.emitFrame() now centralizes every frame emission so the profiler sees
each logic frame exactly once, on the owner goroutine. State gains
VisibleStart/VisibleEnd so the probe can confirm shaping stays
viewport-bounded.
logic: optional debug cmd poller (off by default) watches <dir>/cmd as a
one-shot file (top/bottom/frac <0..1>/dp <int>) and the owner applies a
clamped [0,MaxScroll] jump + frame. Enables deterministic large-offset scroll
tests without pixel taps.
main: wires the profiler when the marker file exists; logs present-fps
every 2s; stops the profiler on Destroy.
docs: README package inventory (add internal/perf); architecture §11
profiler facility; spec §5 invariant 7 (scroll always clamped to
[0,maxScroll]) + §6 measured rows; development_plan v5 + Phase 6 results.
Verified: go build/vet + full -race green. On-device 10 MB file:
logic-frame cadence flat across offsets 0.02->1.0 (no large-offset
degradation), visible byte range <=4.3 KB at every offset, clamping exact
across 2->130,955-line files, PSS plateaus ~250 MB (bounded, no leak);
profiler overhead negligible.
- IME commit path validated on emulator (Gboard/API 35): single-char,
multi-char (human cadence), deletion (deleteSurroundingText->EditEvent),
and Unicode all commit correctly with cursor in sync; autosave persists.
- Build recipe scripted (gogio + apktool MANAGE_EXTERNAL_STORAGE + apksigner).
- Bugs: (1) open-file crash via Termux bridge -> fixed (c9c0d47); (2) viewport
opens at EOF because the opening tap leaks into the editor (open, Phase 3);
(3) rapid synthetic IME commits desync via per-frame snippet re-push (edge).
v1 (widget rebuild) was drafted against a stale snapshot. The live repo
already has the real filesystem, the Android APK, and a chunked buffer
(the 10 MB+ approach widget.Editor cannot do). The Android IME is
reachable from the op layer with only a small, precisely-defined gap:
missing key.SelectionCmd/SnippetCmd, an EditEvent handler that ignores
Range (corrupts swipe/autocorrect replacement commits), and a missing
InputHint. Completing those is now Phase 1; the emulator (now available
on the 16 GB VM) is the verification instrument.
NewLogic now takes (FileSystem, path, openfunc); update the e2e harness
and editor tests accordingly. The harness uses a no-op openfunc, matching
impl_other.go (the real app's OpenFile is a platform bridge, no-op off
Android).
Also adds doc/development_plan.md (draft, with corrections note re: the
live repo state).
