Two feature bodies accumulated in the working tree:
1. Pinch to change the app font size, continuously (no snapping):
- internal/ui/pinch_tracker.go: logic-free touch state machine.
Two-mover formation (the resting palm can land first or last;
movement is the only signal valid for both), pair = the mover
pair whose distance changed most, baseline = press distance
(formDist), lazy pending releases, survivor-scroll forwarding
after a pair break. Robust to ~1 fps frames: a whole pinch can
land in one drain (formDist/brokeFactor/lazy releases).
- render.go: pinch probe (raw pointer events) + grab lifecycle so
the pair is exclusive (scroll sees nothing of the pair) and the
survivor's finger keeps working as a scroll after the pinch.
- state.go/logic.go/session.go/frame.go: app-local float font
scale, content-point pin (buffer byte + offset from baseline,
not a layout point, so rewrap keeps the same character under
the center), restore/font pins, session persistence.
- pinch_test.go, pinch_font_test.go, tag_identity_test.go,
real_draw_probe_test.go: unit + real-Renderer/real-Router tests.
2. Soft keyboard must not shift content:
- Root cause: gioui.org/app calls Router.RevealFocus on any frame
the viewport shrinks (IME open under adjustResize) and
synthesizes a pointer.Scroll nudge aimed at the focused field's
stale pre-resize bounds; gesture.Scroll consumed it -> a 32 dp
content jump.
- Fix: main.go flags the shrink frame; render.go drains that one
synthetic scroll for the gesture's tag before Update (scroll-
range clamping cannot work: the router UNIONs ranges across
frames). Finger scroll (pointer.Drag) and the flinger are
untouched. reveal_focus_drain_test.go reproduces RevealFocus at
the router level and verifies the drain + zero delta.
Also: tools/touchinject (platform-signed emulator multi-touch
injection harness + e2e script, adb has no two-finger input),
docs (spec 2.2 + development_plan 18-20), .gitignore, gofmt.
Every scroll<->content mapping site (window start, sub-line shift, tap
mapping, max-scroll clamp, selection menu/handle positions) assumed
1 logical line = 1 visual line. When the viewport top crossed the
bottom of a wrapped line, the view jumped past the wrapped remainder
(jump magnitude (count-1)*lh) instead of moving pixel-by-pixel.
- WrapIndex (internal/editor/wrap_index.go): Fenwick tree of
per-logical-line visual-line counts, parallel to the LineIndex;
built at index-build time, bookkept by the same
UpdateLineIndexAfter{Insert,Delete} hooks (never under-stale: every
touched line resets to the estimate, the next shaping pass
re-corrects it).
- scrollVisualDecompose: the scroll offset lives in visual-line space:
k = LineForVisual(floor(s/lh)), r = s - V(k)*lh. All mapping sites
go through it, so the viewport top is always exactly s into the
document's visual space (V(k)*lh + r = s) — the jump invariant.
All-ones index reduces to the legacy 1:1 mapping (pre-shaping and
non-wrapped behavior unchanged by construction).
- Correction pipeline: the renderer's per-frame VisualLineStarts are
grouped per logical line and written back (applyWrapCounts). The
layout feedback now carries the exact window text the layout was
shaped for (carried in the frame) plus the window start line and the
content-edit counter; corrections apply only on edit-counter match,
and grouping over the current window text (wrong after a scroll moved
the window) is no longer possible.
- bytePosToScreenXY now applies the sub-line shift and the scaled line
pitch: the selection menu/handles were off by up to a full line.
- maxScroll uses TotalVisuals() with the effective (font-scaled) line
height; the bottom clamp lands exactly on the file end for wrapped
content.
- VisibleByteRange returns the real start line (was hardcoded 0).
- emitFrame: replace the unread handoff frame with the newer snapshot
instead of dropping it — a dropped final frame was never re-emitted
(emission is event-driven), leaving the consumer one state behind
forever; fixes the pre-existing TestRealFile_ShiftSelectionInsert
failure. Still non-blocking.
Tests (mutation-verified where practical): wrap_index_test.go (Fenwick
vs naive model, 3000 ops), wrap_bookkeeping_test.go (edit hooks vs
shadow-string oracle, 400 ops — caught a real m=0 under-marking),
wrap_mapping_test.go (the jump regression: V(k)*lh + r == s over sweeps
+ random offsets; legacy-identity pin; boundary sweep), wrap_apply_test.go
(VisualLineStarts grouping + guards — the first version exposed the
always-true WindowStartByte guard that blocked all post-scroll
corrections). go test -race ./... green.
On-device (emulator, 60 wrapped lines): dp sweep 0/17/50/67/134/340
lands on LINE000-vl0/1/3, LINE001-vl0, LINE002-vl0, LINE005-vl0 —
pixel-exact 1:1, no jump (dp 134 is where the old code jumped to
LINE008); bottom clamp exact.
Docs: architecture.md §6.2 (visual-line space invariant),
development_plan.md (Phase 13), spec.md (wrap + clamp lines).
- JNI: open_file_in_termux via ACTION_SEND intent (text/plain + file:// uri),
global context ref kept from registerFragment
- impl_android.go: OpenFile(path) attaches current thread if needed
- NewLogic takes openfunc; State.open + ui.OpenFile now func(string)
- ChunkedBuffer.VisibleByteRange: word-wrap path using
GlyphLayout.VisualLineStarts (+byteOffset, lineHeight, visual index param)
- GlyphLayout gains LineHeight; drawWrappedText records VisualLineStarts
- WordWrap default true; State.ByteOffset tracks first visible line
- types: VisualLineIndex
- scroll_fix_test.go (new)
- debug prints left in place (WIP; cleanup in later phase)
- Add ui.Dp and ui.Px as distinct named types
- Logic layer works exclusively in Dp (positions, sizes, regions)
- Renderer converts Dp→Px at Gio interop boundaries
- Capture gtx.Constraints once at start of Draw() for consistent positioning
- main.go converts app.ConfigEvent pixels to Dp before passing to logic layer
- Update documentation with new coordinate system architecture
