EANCH-WP-0001 T04: extract PDF adapter + scroll/highlight helpers

Move pdf-viewer-adapter-spike.tsx, scroll-job.ts (+test), highlight-styles.css
and debug-textlayer.css into src/pdf/ (the adapter boundary). Rewrite the
spike's @shared import to @citation-evidence/engine/shared and its ./types to
../types. Add src/css.d.ts so tsc accepts side-effect .css imports.

Decisions:
- adapter stays the explicitly-named PdfSpikeViewer spike; promotion to a
  production PDFViewerAdapter is registered as T06 follow-on work
- viewer libs (pdfjs-dist, react, react-pdf-highlighter-plus) confined to
  src/pdf/ and exposed only via the evidence-anchor/pdf subpath; the root
  entrypoint stays pure. Boundary enforced by eslint no-restricted-imports.
- ported unit suites (pdf-selector-math round-trip + scroll-job retry) serve
  as the inspectable harness for capture->selectors->resolve->scroll.

Verified: pnpm test (30 passed), typecheck, lint all green. README layout updated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
tegwick 2026-07-08 20:44:52 +02:00
parent bd7f56c111
commit 5b77dbd314
10 changed files with 720 additions and 23 deletions

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@ -34,36 +34,41 @@ aliases.
```text
src/
index.ts public entrypoint (re-exports the surfaces below)
index.ts public entrypoint — pure surface only
types.ts adapter-side types: SelectionCapture,
ResolvedAnchorTarget, AnchorResolution,
HighlightRenderOptions, DocumentViewerAdapter
selectors/
css.d.ts ambient decl for side-effect .css imports
selectors/ pure core — no viewer/UI deps
index.ts createSelectors, resolveSelectors, DEFAULT_CONTEXT_CHARS
create.ts selector creation from a captured selection
resolve.ts resolution + the exact-match confidence ladder
create.test.ts
resolve.test.ts
pdf/
pdf-selector-math.ts page number + normalized page-rectangle math
pdf/ adapter boundary — the only place viewer libs live
index.ts subpath entry `evidence-anchor/pdf`
pdf-selector-math.ts pure page + normalized-rect math (capture↔selectors)
pdf-selector-math.test.ts
pdf-viewer-adapter.tsx concrete PDF DocumentViewerAdapter (from the spike)
highlight/
scroll-job.ts scroll-to-target helper
pdf-viewer-adapter-spike.tsx concrete PDF adapter (PdfSpikeViewer)
scroll-job.ts retryable scroll-to-highlight helper
scroll-job.test.ts
highlight-styles.css highlight rendering styles
debug-textlayer.css optional text-layer debugging styles
```
Boundary rules for the layout:
Boundary rules for the layout (enforced by `eslint.config.js`):
- viewer-library imports (`pdfjs`, `react-pdf-highlighter-plus`) are confined to
`src/pdf/` — they never appear on `types.ts` or on the public surface;
- `src/selectors/` is pure (no viewer/UI deps) and depends only on
`citation-engine` shared types;
- the public entrypoint re-exports the stable surface consumers rely on:
`createSelectors`, `resolveSelectors`, the selector/resolution types, the
`DocumentViewerAdapter` contract, and the PDF adapter.
- viewer-library imports (`pdfjs-dist`, `react`, `react-pdf-highlighter-plus`)
are confined to `src/pdf/` — the pure zone (`src/selectors/**`, `src/types.ts`)
may not import them;
- `src/selectors/` is pure and depends only on `citation-engine` shared types;
- the **root** entrypoint (`evidence-anchor`) exposes only the pure surface —
`createSelectors`, `resolveSelectors`, the selector/resolution types, and the
`DocumentViewerAdapter` contract;
- the concrete PDF adapter is reached through the **`evidence-anchor/pdf`**
subpath, so pure consumers never pull PDF.js or React into their bundle. That
adapter is still the explicitly-named `PdfSpikeViewer` spike; promoting it to
a production `PDFViewerAdapter` is registered follow-on work (T06).
## Public API (target surface)

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@ -31,9 +31,9 @@ export default tseslint.config(
},
},
{
// The pure core (selectors, resolution, highlight helpers) must not pull in
// any concrete viewer library — those live only under src/pdf/.
files: ["src/selectors/**/*.ts", "src/highlight/**/*.ts", "src/types.ts"],
// The pure core (selectors, resolution, adapter-side types) must not pull
// in any concrete viewer library — those live only under src/pdf/.
files: ["src/selectors/**/*.ts", "src/types.ts"],
rules: {
"no-restricted-imports": [
"error",

3
src/css.d.ts vendored Normal file
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@ -0,0 +1,3 @@
// Side-effect CSS imports (viewer styles). The bundler handles these; for the
// typechecker they resolve to an empty module. Confined to the PDF adapter.
declare module "*.css";

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@ -0,0 +1,59 @@
/*
* Debug overlay for PDF text layer alignment.
*
* The text layer is normally invisible (`opacity: 0`) and selectable.
* When `.ce-debug-textlayer` is on a parent, every text node becomes a
* light grey box so it's obvious where text is selectable and where it
* isn't useful for diagnosing OCR misalignment, scan-only PDFs, and
* text-layer shift caused by font fallbacks.
*
* Light grey was chosen so the debug overlay does not clash with the
* citation-yellow used for evidence highlights (see highlight-styles.css).
*
* Toggle via the "Debug text layer" entry in SessionMenu.
*/
.ce-debug-textlayer .textLayer {
outline: 2px dashed rgba(120, 120, 120, 0.55);
background: rgba(120, 120, 120, 0.06);
}
/* PDF.js 4.x wraps marked content in nested spans/divs cover every
descendant so the entire selectable area is visible regardless of how
the renderer nested things. */
.ce-debug-textlayer .textLayer * {
background: rgba(170, 170, 170, 0.4) !important;
color: rgba(40, 40, 40, 0.85) !important;
opacity: 1 !important;
outline: 1px solid rgba(100, 100, 100, 0.35);
}
/* Dim the canvas-rendered layer slightly so the debug overlay stands
out by contrast. */
.ce-debug-textlayer canvas {
opacity: 0.4;
}
/*
* Layer-visibility toggles. Each `.ce-hide-<layer>` class is applied
* to the same viewer-wrapper element so a single parent can hide any
* combination of layers. Useful for diagnosing layer stacking issues
* (e.g. "is the textLayer covering the canvas?") by elimination.
*/
.ce-hide-canvas canvas {
display: none !important;
}
.ce-hide-text-layer .textLayer {
display: none !important;
}
.ce-hide-annotation-layer .annotationLayer,
.ce-hide-annotation-layer .annotationEditorLayer {
display: none !important;
}
.ce-hide-xfa-layer .xfaLayer {
display: none !important;
}

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@ -0,0 +1,38 @@
/*
* Evidence highlight styling matches the sidebar's "evidence card"
* palette so the viewer and the sidebar speak the same visual language.
*
* .TextHighlight__part inactive highlight (light yellow fill,
* thin amber border)
* .TextHighlight--active the currently-focused evidence same
* fill, thicker border
*
* The "active" class is applied by the spike viewer when the parent
* wrapper is marked with `data-ce-active="true"` so a single
* `activeAnnotationId` prop drives the entire viewer's focus state
* without per-highlight component coupling.
*
* We override the library's red `--scrolledTo` box-shadow so an
* activation doesn't flash a red ring that doesn't match the palette.
*/
.TextHighlight__part {
background: #fff8d6 !important;
outline: 1px solid #e0c050 !important;
outline-offset: 0;
cursor: pointer;
transition: outline 0.15s ease;
}
[data-ce-active="true"] .TextHighlight__part {
outline: 3px solid #b78b1c !important;
background: #fff5b8 !important;
}
/* The library applies `--scrolledTo` after a programmatic scroll. We
override its red box-shadow so the "you just landed on this" cue
sticks with the yellow palette. The thicker border from
`data-ce-active` already conveys focus. */
.TextHighlight--scrolledTo .TextHighlight__part {
box-shadow: none !important;
}

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@ -1,13 +1,35 @@
// Subpath entrypoint `evidence-anchor/pdf` — the PDF viewer adapter, its
// helpers, and the pure capture→selector math. Keeping this behind a subpath
// lets pure consumers use the selector/resolution core without pulling PDF.js
// or React into their bundle.
// scroll/highlight helpers, and the pure capture→selector math. Keeping this
// behind a subpath (rather than the package root) confines PDF.js, React, and
// react-pdf-highlighter-plus to consumers that actually render a PDF; the pure
// selector/resolution core stays importable without them.
//
// The concrete `DocumentViewerAdapter` implementation is added in T04.
// The concrete adapter is still the explicitly-named `PdfSpikeViewer` spike
// that validated the round-trip end-to-end. Promoting it to a production
// `PDFViewerAdapter` is registered follow-on work (see EANCH-WP-0001 T06), not
// part of this extraction.
// Pure capture → selector math (no viewer libraries).
export {
selectorsFromPdfCapture,
findPdfRectSelector,
findTextQuoteSelector,
unionRect,
} from "./pdf-selector-math";
// Retryable scroll-to-highlight job (react-pdf-highlighter-plus types).
export {
runScrollToHighlightJob,
DEFAULT_SCROLL_ATTEMPTS,
type ScrollToHighlightJob,
type ScrollToHighlightDeps,
type ScrollToHighlightState,
} from "./scroll-job";
// Concrete PDF viewer adapter (spike) + its contract surface.
export {
PdfSpikeViewer,
getHighlightClientRects,
type PdfSpikeViewerProps,
type StoredAnnotation,
} from "./pdf-viewer-adapter-spike";

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@ -0,0 +1,424 @@
/**
* Throwaway PDF viewer adapter spike (CE-WP-0002-T02).
*
* Purpose: prove that `react-pdf-highlighter-plus` can implement the §5
* `DocumentViewerAdapter` contract end-to-end (select save selectors
* reload resolve scroll render highlight) without leaking PDF.js
* types into `src/shared/` or `src/engine/`.
*
* This module is the only place in the codebase that imports
* `react-pdf-highlighter-plus`. The exported React component is consumed
* by `src/app/SpikeApp.tsx`.
*
* Replace before production. T03 (source ingest) + T04 (anchor resolution)
* will build the real PDFViewerAdapter on top of this lessons-learned.
*/
import {
createContext,
useCallback,
useContext,
useEffect,
useMemo,
useRef,
type ReactNode,
} from "react";
import {
PdfHighlighter,
PdfLoader,
TextHighlight,
MonitoredHighlightContainer,
useHighlightContainerContext,
type Highlight,
type PdfHighlighterUtils,
type PdfSelection,
type ScaledPosition,
} from "react-pdf-highlighter-plus";
// pdfjs-dist's own pdf_viewer.css is the authoritative source for
// text-layer positioning. The version bundled with
// react-pdf-highlighter-plus is a minimal *override* (missing
// `position: absolute`, `inset: 0`, and PDF.js 4.x's
// `--scale-factor` handling) — load the real one first, then the
// library's overrides on top.
import "pdfjs-dist/web/pdf_viewer.css";
import "react-pdf-highlighter-plus/style/style.css";
import "react-pdf-highlighter-plus/style/pdf_viewer.css";
import "./highlight-styles.css";
import "./debug-textlayer.css";
import type { NormalizedRect, Selector } from "@citation-evidence/engine/shared";
import type { AnchorResolution, PdfSelectionCapture, ResolvedAnchorTarget } from "../types";
import { findPdfRectSelector, selectorsFromPdfCapture, unionRect } from "./pdf-selector-math";
import { runScrollToHighlightJob } from "./scroll-job";
export { selectorsFromPdfCapture };
/**
* Inverse of `selectorsFromPdfCapture`: build a viewer-renderable
* `Highlight` from stored selectors. The spike's reload path leans on
* `PdfRectSelector` since it carries page + page-relative rects directly.
* T04 will own the production resolver and add the text-only paths.
*/
function highlightFromSelectors(
id: string,
text: string,
selectors: readonly Selector[],
): Highlight | null {
const rectSel = findPdfRectSelector(selectors);
if (!rectSel) return null;
const boundingRect = unionRect(rectSel.rects);
if (!boundingRect) return null;
const scaledRects = rectSel.rects.map((r) => toScaled(r, rectSel.page));
return {
id,
type: "text",
content: { text },
position: {
boundingRect: toScaled(boundingRect, rectSel.page),
rects: scaledRects,
} satisfies ScaledPosition,
};
}
/**
* Convert the adapter's `NormalizedRect` (page-relative 0..1) to the
* `Scaled` shape react-pdf-highlighter-plus expects (also normalized 0..1
* via width/height). We use a unit page-space of 1×1 the library
* computes pixel coords from `pageNumber` and the renderer's actual page
* dimensions.
*/
function toScaled(r: NormalizedRect, page: number) {
return {
x1: r.x,
y1: r.y,
x2: r.x + r.width,
y2: r.y + r.height,
width: 1,
height: 1,
pageNumber: page,
};
}
/** PdfSelection → our domain-neutral `PdfSelectionCapture`. */
function captureFromPdfSelection(sel: PdfSelection): PdfSelectionCapture {
const page = sel.position.boundingRect.pageNumber;
const rects = sel.position.rects.map<NormalizedRect>((r) => ({
x: r.x1 / r.width,
y: r.y1 / r.height,
width: (r.x2 - r.x1) / r.width,
height: (r.y2 - r.y1) / r.height,
}));
const br = sel.position.boundingRect;
const boundingRect: NormalizedRect = {
x: br.x1 / br.width,
y: br.y1 / br.height,
width: (br.x2 - br.x1) / br.width,
height: (br.y2 - br.y1) / br.height,
};
return {
kind: "pdf",
text: sel.content.text ?? "",
page,
rects,
boundingRect,
};
}
const ActiveAnnotationContext = createContext<string | null | undefined>(
undefined,
);
const HighlightClickContext = createContext<((annotationId: string) => void) | undefined>(
undefined,
);
/**
* Stable highlight row component type never changes so PdfHighlighter does
* not remount highlight layers on activation changes (which disturbs scroll).
* Active/focus styling reads from context instead.
*/
function SpikeHighlightContainer(): ReactNode {
const activeAnnotationId = useContext(ActiveAnnotationContext);
const onHighlightClicked = useContext(HighlightClickContext);
const { highlight, isScrolledTo } = useHighlightContainerContext();
const isActive = activeAnnotationId === highlight.id;
return (
<div
data-highlight-id={highlight.id}
data-ce-active={isActive ? "true" : "false"}
style={{ display: "contents" }}
onClickCapture={(e) => {
e.stopPropagation();
onHighlightClicked?.(highlight.id);
}}
>
<MonitoredHighlightContainer>
<TextHighlight highlight={highlight} isScrolledTo={isScrolledTo} />
</MonitoredHighlightContainer>
</div>
);
}
/**
* Resolve the rendered DOM rect for a highlight by data attribute, or
* `null` if the highlight isn't currently rendered (e.g. its page hasn't
* scrolled into view). Used by `app/forms/HighlightRectBridge` to feed
* the rect registry as kind="highlight".
*
* `display: contents` on the wrapper means it has no box of its own; we
* union the rects of its children. For TextHighlight that's typically
* one rect per line.
*/
export function getHighlightClientRects(annotationId: string): DOMRect | null {
if (typeof document === "undefined") return null;
const wrapper = document.querySelector(`[data-highlight-id="${CSS.escape(annotationId)}"]`);
if (!wrapper) return null;
const rects = wrapper.getClientRects();
if (rects.length === 0) return null;
let left = Infinity;
let top = Infinity;
let right = -Infinity;
let bottom = -Infinity;
for (const r of Array.from(rects)) {
left = Math.min(left, r.left);
top = Math.min(top, r.top);
right = Math.max(right, r.right);
bottom = Math.max(bottom, r.bottom);
}
if (!isFinite(left)) return null;
return new DOMRect(left, top, right - left, bottom - top);
}
export interface PdfSpikeViewerProps {
/** URL of the PDF to load (served by Vite dev server). */
readonly pdfUrl: string;
/** Previously-saved selector sets to restore on mount. */
readonly storedAnnotations: readonly StoredAnnotation[];
/** Called when the user produces a new selection. */
onSelectionCaptured(capture: PdfSelectionCapture, selectors: Selector[]): void;
/** Annotation id to scroll to and highlight on mount, if any. */
readonly scrollToAnnotationId?: string;
/**
* Bumps when the same annotation should be re-scrolled (e.g. repeat click).
* Format is opaque typically `${annotationId}:${version}`.
*/
readonly scrollRequestKey?: string;
/**
* Annotation id currently focused. The matching highlight gets a
* thicker border (see highlight-styles.css). `null`/undefined means
* "no active highlight".
*/
readonly activeAnnotationId?: string | null;
/**
* Called when the user clicks an existing highlight in the page.
* The receiver typically activates the matching evidence item.
*/
onHighlightClicked?(annotationId: string): void;
/**
* When true, paint the PDF text-layer spans in light grey so it's
* obvious which glyphs have a selectable text overlay and which are
* image-only. Also logs every onSelection event to the console.
*/
readonly debugTextLayer?: boolean;
/**
* Hide specific PDF.js layers so you can see what sits underneath.
* Helps diagnose layer-stacking issues (e.g. "is the text layer
* covering the canvas content?").
*/
readonly hideCanvas?: boolean;
readonly hideTextLayer?: boolean;
readonly hideAnnotationLayer?: boolean;
readonly hideXfaLayer?: boolean;
}
/**
* Nudge the PDF scroll container so `highlight` sits vertically centred.
* Best-effort: depends on highlight layer DOM being present after scroll.
*/
function centerHighlightInViewer(
utils: PdfHighlighterUtils,
highlight: Highlight,
attempt = 0,
): void {
const viewer = utils.getViewer();
const container = viewer?.container as HTMLElement | undefined;
if (!container) return;
const rect = getHighlightClientRects(highlight.id);
if (!rect) {
if (attempt < 12) {
requestAnimationFrame(() =>
centerHighlightInViewer(utils, highlight, attempt + 1),
);
}
return;
}
const cRect = container.getBoundingClientRect();
const highlightCenterY = rect.top + rect.height / 2;
const containerCenterY = cRect.top + cRect.height / 2;
const delta = highlightCenterY - containerCenterY;
if (Math.abs(delta) < 4) return;
container.scrollTop += delta;
}
export interface StoredAnnotation {
readonly id: string;
readonly text: string;
readonly selectors: readonly Selector[];
}
/**
* The spike's React component. Renders a PDF and:
* - emits `onSelectionCaptured(capture, selectors)` on every fresh selection
* - reconstructs and renders `storedAnnotations` immediately on load
* - scrolls to `scrollToAnnotationId` if its highlight can be reconstructed
*/
export function PdfSpikeViewer(props: PdfSpikeViewerProps) {
const {
pdfUrl,
storedAnnotations,
onSelectionCaptured,
scrollToAnnotationId,
scrollRequestKey,
activeAnnotationId,
onHighlightClicked,
debugTextLayer,
hideCanvas,
hideTextLayer,
hideAnnotationLayer,
hideXfaLayer,
} = props;
const onHighlightClickedRef = useRef(onHighlightClicked);
onHighlightClickedRef.current = onHighlightClicked;
const handleHighlightClicked = useCallback((annotationId: string) => {
onHighlightClickedRef.current?.(annotationId);
}, []);
const pdfLoaderDocument = useMemo(
() => ({
url: pdfUrl,
// PdfLoader's effect depends on `document` by reference — must be
// stable across re-renders or the PDF reloads and scroll resets to top.
cMapUrl: "/cmaps/",
cMapPacked: true,
standardFontDataUrl: "/standard_fonts/",
}),
[pdfUrl],
);
const wrapperClasses = [
debugTextLayer ? "ce-debug-textlayer" : null,
hideCanvas ? "ce-hide-canvas" : null,
hideTextLayer ? "ce-hide-text-layer" : null,
hideAnnotationLayer ? "ce-hide-annotation-layer" : null,
hideXfaLayer ? "ce-hide-xfa-layer" : null,
]
.filter((c): c is string => c !== null)
.join(" ");
const utilsRef = useRef<PdfHighlighterUtils | null>(null);
const scrollStateRef = useRef({ lastCompletedKey: null as string | null });
const highlights = useMemo<Highlight[]>(() => {
const out: Highlight[] = [];
const skipped: { id: string; reason: string }[] = [];
for (const a of storedAnnotations) {
const h = highlightFromSelectors(a.id, a.text, a.selectors);
if (h) out.push(h);
else skipped.push({ id: a.id, reason: "no PdfRectSelector / empty boundingRect" });
}
if (debugTextLayer) {
console.log("[ce] viewer highlights", {
in: storedAnnotations.length,
rendered: out.length,
rendered_detail: out.map((h) => ({
id: h.id,
page: h.position.boundingRect.pageNumber,
bounding: h.position.boundingRect,
rectCount: h.position.rects.length,
})),
skipped,
});
}
return out;
}, [storedAnnotations, debugTextLayer]);
const highlightsRef = useRef(highlights);
highlightsRef.current = highlights;
const highlightsSignature = useMemo(
() => highlights.map((h) => h.id).join(","),
[highlights],
);
// Re-render highlight layers when focus moves so `data-ce-active` updates.
const highlightsForViewer = useMemo(
() => highlights,
[highlights, activeAnnotationId],
);
useEffect(() => {
const requestKey = scrollRequestKey ?? scrollToAnnotationId ?? null;
if (!requestKey || !scrollToAnnotationId) return;
if (scrollStateRef.current.lastCompletedKey === requestKey) return;
if (debugTextLayer) {
console.log("[ce] scrollToAnnotation requested", {
id: scrollToAnnotationId,
requestKey,
utilsAvailable: !!utilsRef.current,
targetFound: !!highlightsRef.current.find((h) => h.id === scrollToAnnotationId),
knownIds: highlightsRef.current.map((h) => h.id),
});
}
return runScrollToHighlightJob(
{ requestKey, annotationId: scrollToAnnotationId },
{
getUtils: () => utilsRef.current,
findHighlight: (id) => highlightsRef.current.find((h) => h.id === id),
scrollToHighlight: (utils, target) => utils.scrollToHighlight(target),
centerHighlight: (utils, target) => centerHighlightInViewer(utils, target),
scheduleFrame: (fn) => requestAnimationFrame(fn),
},
scrollStateRef.current,
);
}, [scrollToAnnotationId, scrollRequestKey, highlightsSignature, debugTextLayer]);
return (
<div
className={wrapperClasses.length > 0 ? wrapperClasses : undefined}
style={{ height: "100%" }}
>
<PdfLoader document={pdfLoaderDocument}>
{(pdfDocument) => (
<ActiveAnnotationContext.Provider value={activeAnnotationId}>
<HighlightClickContext.Provider value={handleHighlightClicked}>
<PdfHighlighter
pdfDocument={pdfDocument}
highlights={highlightsForViewer}
utilsRef={(u) => {
utilsRef.current = u;
}}
onSelection={(selection) => {
const capture = captureFromPdfSelection(selection);
const selectors = selectorsFromPdfCapture(capture);
if (debugTextLayer) {
console.log("[ce] onSelection", {
text: capture.text,
page: capture.page,
rects: capture.rects,
selectorTypes: selectors.map((s) => s.type),
raw: selection,
});
}
onSelectionCaptured(capture, selectors);
}}
>
<SpikeHighlightContainer />
</PdfHighlighter>
</HighlightClickContext.Provider>
</ActiveAnnotationContext.Provider>
)}
</PdfLoader>
</div>
);
}
// Re-export the §5 contract surface so callers see anchor as one entry point.
export type { AnchorResolution, ResolvedAnchorTarget, PdfSelectionCapture };

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/**
* CE-WP-0008-T02 scroll job retries until utils and highlight exist.
*/
import { describe, expect, it, vi } from "vitest";
import type { Highlight, PdfHighlighterUtils } from "react-pdf-highlighter-plus";
import { runScrollToHighlightJob } from "./scroll-job";
const TARGET = {
id: "ann_test",
type: "text",
content: { text: "quote" },
position: {
boundingRect: {
x1: 0,
y1: 0,
x2: 1,
y2: 1,
width: 1,
height: 1,
pageNumber: 2,
},
rects: [],
},
} as Highlight;
describe("runScrollToHighlightJob (CE-WP-0008-T02)", () => {
it("retries until utils and highlight are available", () => {
const frames: Array<() => void> = [];
const scrollToHighlight = vi.fn();
const centerHighlight = vi.fn();
let utils: PdfHighlighterUtils | null = null;
const highlightRef: { current: Highlight | undefined } = { current: undefined };
const state = { lastCompletedKey: null as string | null };
const cancel = runScrollToHighlightJob(
{ requestKey: "ann_test:1", annotationId: "ann_test" },
{
getUtils: () => utils,
findHighlight: (id) => (id === "ann_test" ? highlightRef.current : undefined),
scrollToHighlight: (_u, target) => scrollToHighlight(target),
centerHighlight,
scheduleFrame: (fn) => {
frames.push(fn);
return frames.length;
},
maxAttempts: 5,
},
state,
);
expect(scrollToHighlight).not.toHaveBeenCalled();
// First two frames: still missing utils / highlight.
frames.shift()?.();
frames.shift()?.();
expect(scrollToHighlight).not.toHaveBeenCalled();
utils = { scrollToHighlight: vi.fn() } as unknown as PdfHighlighterUtils;
highlightRef.current = TARGET;
frames.shift()?.();
expect(scrollToHighlight).toHaveBeenCalledWith(TARGET);
expect(state.lastCompletedKey).toBe("ann_test:1");
frames.shift()?.();
expect(centerHighlight).toHaveBeenCalledWith(utils, TARGET);
cancel();
});
});

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/**
* Retryable scroll-to-highlight job for PdfSpikeViewer.
*
* The PDF highlighter's utils ref and highlight DOM are not always ready on
* the first effect tick (especially for page-2+ passages). This helper retries
* via rAF until both are available or attempts are exhausted.
*/
import type { Highlight, PdfHighlighterUtils } from "react-pdf-highlighter-plus";
export const DEFAULT_SCROLL_ATTEMPTS = 40;
export interface ScrollToHighlightJob {
readonly requestKey: string;
readonly annotationId: string;
}
export interface ScrollToHighlightDeps {
readonly getUtils: () => PdfHighlighterUtils | null;
readonly findHighlight: (annotationId: string) => Highlight | undefined;
readonly scrollToHighlight: (
utils: PdfHighlighterUtils,
target: Highlight,
) => void;
readonly centerHighlight: (
utils: PdfHighlighterUtils,
target: Highlight,
) => void;
readonly scheduleFrame: (fn: () => void) => number;
readonly maxAttempts?: number;
}
export interface ScrollToHighlightState {
lastCompletedKey: string | null;
}
/**
* Attempt scroll for `job`. Returns a cancel function. Sets
* `state.lastCompletedKey` only after a successful scroll.
*/
export function runScrollToHighlightJob(
job: ScrollToHighlightJob,
deps: ScrollToHighlightDeps,
state: ScrollToHighlightState,
): () => void {
let cancelled = false;
let attempt = 0;
const maxAttempts = deps.maxAttempts ?? DEFAULT_SCROLL_ATTEMPTS;
const tick = () => {
if (cancelled) return;
if (state.lastCompletedKey === job.requestKey) return;
const utils = deps.getUtils();
const target = deps.findHighlight(job.annotationId);
if (!utils || !target) {
if (attempt < maxAttempts) {
attempt += 1;
deps.scheduleFrame(tick);
}
return;
}
deps.scrollToHighlight(utils, target);
state.lastCompletedKey = job.requestKey;
deps.scheduleFrame(() => deps.centerHighlight(utils, target));
};
tick();
return () => {
cancelled = true;
};
}

View file

@ -233,7 +233,7 @@ depend on the umbrella repo folder structure.
```task
id: EANCH-WP-0001-T04
status: todo
status: done
priority: high
depends_on: [T03]
state_hub_task_id: "1deca610-8502-44e5-90c7-43e355489f55"