New architecture

This commit is contained in:
2026-04-03 18:45:08 +02:00
parent 4613b8e5dd
commit 0d0e9fe043
24 changed files with 2747 additions and 908 deletions

View File

@@ -0,0 +1,567 @@
"use strict";
(() => {
// src/types.ts
var PageState = {
PLACEHOLDER: 0,
RENDERING: 1,
RENDERED: 2
};
// src/page-manager.ts
var MAX_CANVAS_PIXELS = 16777216;
function clampedRenderScale(vpWidth, vpHeight, desiredScale, dpr) {
const w = vpWidth * desiredScale * dpr;
const h = vpHeight * desiredScale * dpr;
const pixels = w * h;
if (pixels <= MAX_CANVAS_PIXELS) return desiredScale * dpr;
return desiredScale * dpr * Math.sqrt(MAX_CANVAS_PIXELS / pixels);
}
var PageManager = class {
constructor(wrapper, dims, initialScale, dpr, dispatchRender2) {
this._wrappers = [];
this._renderGen = 0;
this._inFlight = 0;
this._zooming = false;
this._wrapper = wrapper;
this._dims = dims;
this._scale = initialScale;
this._dpr = dpr;
this._dispatchRender = dispatchRender2;
this._states = new Array(dims.length).fill(PageState.PLACEHOLDER);
this._canvases = new Array(dims.length).fill(null);
this._buildPlaceholders();
}
get pageWrappers() {
return this._wrappers;
}
get numPages() {
return this._dims.length;
}
get renderGen() {
return this._renderGen;
}
/** True when no renders are currently in flight (all visible pages are sharp). */
get allRendered() {
return this._inFlight === 0;
}
/** Called by ZoomController to suppress canvas teardown during Phase 1 CSS zoom. */
setZooming(z) {
this._zooming = z;
}
_buildPlaceholders() {
for (let i = 0; i < this._dims.length; i++) {
const dim = this._dims[i];
const wrap = document.createElement("div");
wrap.className = "page-wrapper";
wrap.dataset["page"] = String(i + 1);
wrap.style.width = dim.width * this._scale + "px";
wrap.style.height = dim.height * this._scale + "px";
this._wrapper.appendChild(wrap);
this._wrappers.push(wrap);
}
}
/**
* Called on each IntersectionObserver tick.
* Dispatches renders for pages entering the buffer (visible pages first).
* Cleans up pages that have left the buffer (unless zooming).
*/
reconcile(bufferSet, visibleSet) {
const gen = this._renderGen;
const toRender = [
...[...visibleSet].sort((a, b) => a - b),
...[...bufferSet].filter((p) => !visibleSet.has(p)).sort((a, b) => a - b)
];
for (const pageNum of toRender) {
const i = pageNum - 1;
if (i < 0 || i >= this._dims.length) continue;
if (this._states[i] === PageState.PLACEHOLDER) {
this._startRender(i, gen);
}
}
for (let i = 0; i < this._dims.length; i++) {
const pageNum = i + 1;
if (!this._zooming && !bufferSet.has(pageNum) && this._states[i] === PageState.RENDERED) {
this._cleanup(i);
}
if (!bufferSet.has(pageNum) && this._states[i] === PageState.RENDERING) {
this._inFlight--;
this._states[i] = PageState.PLACEHOLDER;
}
}
}
_startRender(i, gen) {
const dim = this._dims[i];
const scale = clampedRenderScale(dim.width, dim.height, this._scale, this._dpr);
this._states[i] = PageState.RENDERING;
this._inFlight++;
this._dispatchRender(i + 1, scale, gen);
}
_cleanup(i) {
if (this._states[i] === PageState.RENDERING) this._inFlight--;
this._states[i] = PageState.PLACEHOLDER;
const canvas = this._canvases[i];
if (canvas) {
canvas.remove();
this._canvases[i] = null;
}
}
/**
* Called when the render worker returns a finished bitmap.
*
* Double-buffer swap: the old canvas stays in the DOM until the new one is
* ready, then both mutations happen in the same synchronous JS turn so the
* browser produces exactly one paint frame for the transition.
*/
onRendered(pageNum, gen, bitmap) {
if (gen !== this._renderGen) {
bitmap.close();
return;
}
const i = pageNum - 1;
if (i < 0 || i >= this._dims.length || this._states[i] !== PageState.RENDERING) {
bitmap.close();
return;
}
this._inFlight--;
const dim = this._dims[i];
const wrap = this._wrappers[i];
const cssW = dim.width * this._scale;
const cssH = dim.height * this._scale;
const canvas = document.createElement("canvas");
canvas.width = bitmap.width;
canvas.height = bitmap.height;
canvas.style.width = cssW + "px";
canvas.style.height = cssH + "px";
canvas.style.display = "block";
const bitmapCtx = canvas.getContext("bitmaprenderer");
if (bitmapCtx) {
bitmapCtx.transferFromImageBitmap(bitmap);
} else {
canvas.getContext("2d").drawImage(bitmap, 0, 0);
bitmap.close();
}
wrap.style.width = cssW + "px";
wrap.style.height = cssH + "px";
const old = this._canvases[i];
if (old) old.remove();
wrap.appendChild(canvas);
this._canvases[i] = canvas;
this._states[i] = PageState.RENDERED;
}
/**
* Called after the zoom debounce fires (Phase 2).
* Increments renderGen to cancel all stale in-flight renders, resizes
* placeholders, then re-dispatches renders for the buffer zone.
*/
onScaleChange(newScale, bufferSet, visibleSet) {
this._scale = newScale;
this._renderGen++;
for (let i = 0; i < this._dims.length; i++) {
const pageNum = i + 1;
const dim = this._dims[i];
const wrap = this._wrappers[i];
const cssW = dim.width * newScale;
const cssH = dim.height * newScale;
wrap.style.width = cssW + "px";
wrap.style.height = cssH + "px";
wrap.style.setProperty("zoom", "1");
if (bufferSet.has(pageNum)) {
const canvas = this._canvases[i];
if (canvas) {
canvas.style.width = cssW + "px";
canvas.style.height = cssH + "px";
}
if (this._states[i] === PageState.RENDERING) this._inFlight--;
this._states[i] = PageState.PLACEHOLDER;
} else {
const canvas = this._canvases[i];
if (canvas) {
canvas.remove();
this._canvases[i] = null;
}
this._states[i] = PageState.PLACEHOLDER;
}
}
this.reconcile(bufferSet, visibleSet);
}
/** Returns the 1-based page number of the topmost visible page. */
getCurrentPage(visibleSet) {
if (visibleSet.size > 0) return Math.min(...visibleSet);
const top = this._wrapper.parentElement?.getBoundingClientRect().top ?? 0;
for (const wrap of this._wrappers) {
if (wrap.getBoundingClientRect().bottom > top + 4) {
return parseInt(wrap.dataset["page"], 10);
}
}
return 1;
}
};
// src/viewport-tracker.ts
var ViewportTracker = class {
constructor(root, pageWrappers, onChange) {
this._visibleSet = /* @__PURE__ */ new Set();
this._bufferSet = /* @__PURE__ */ new Set();
this._visibleObserver = null;
this._bufferObserver = null;
this._rafPending = null;
this._onChange = onChange;
this._observe(root, pageWrappers);
}
_observe(root, pageWrappers) {
const scheduleNotify = () => {
if (this._rafPending !== null) return;
this._rafPending = requestAnimationFrame(() => {
this._rafPending = null;
for (const p of this._visibleSet) this._bufferSet.add(p);
this._onChange(new Set(this._bufferSet), new Set(this._visibleSet));
});
};
this._visibleObserver = new IntersectionObserver((entries) => {
for (const e of entries) {
const page = parseInt(e.target.dataset["page"], 10);
if (e.isIntersecting) this._visibleSet.add(page);
else this._visibleSet.delete(page);
}
scheduleNotify();
}, { root, rootMargin: "0px", threshold: 0 });
this._bufferObserver = new IntersectionObserver((entries) => {
for (const e of entries) {
const page = parseInt(e.target.dataset["page"], 10);
if (e.isIntersecting) this._bufferSet.add(page);
else this._bufferSet.delete(page);
}
scheduleNotify();
}, { root, rootMargin: "200% 0px", threshold: 0 });
for (const wrap of pageWrappers) {
this._visibleObserver.observe(wrap);
this._bufferObserver.observe(wrap);
}
}
/** Observe a newly-added page wrapper (unused currently, kept for extensibility). */
observe(wrap) {
this._visibleObserver?.observe(wrap);
this._bufferObserver?.observe(wrap);
}
disconnect() {
this._visibleObserver?.disconnect();
this._bufferObserver?.disconnect();
this._visibleSet.clear();
this._bufferSet.clear();
if (this._rafPending !== null) {
cancelAnimationFrame(this._rafPending);
this._rafPending = null;
}
}
};
// src/zoom-controller.ts
var CONTENT_PADDING_TOP = 20;
var PAGE_GAP = 12;
var _ZoomController = class _ZoomController {
constructor(container2, pageManager2, onReRender, getBuffer, zoomLabel2, initialScale) {
this._debounce = null;
this._rafPending = null;
this._container = container2;
this._pm = pageManager2;
this._onReRender = onReRender;
this._getBuffer = getBuffer;
this._zoomLabel = zoomLabel2;
this._scale = initialScale;
this._renderScale = initialScale;
this._updateLabel();
this._bindScrollZoom();
}
get scale() {
return this._scale;
}
clamp(s) {
return Math.max(_ZoomController.ZOOM_MIN, Math.min(_ZoomController.ZOOM_MAX, s));
}
_updateLabel() {
this._zoomLabel.textContent = Math.round(this._scale * 100) + "%";
}
/**
* Apply a new zoom level.
*
* @param newScale - Target zoom scale.
* @param anchorY - Pixel offset within container to hold fixed (default: center).
* @param anchorX - Pixel offset within container to hold fixed (default: center).
*/
applyScale(newScale, anchorY, anchorX) {
const container2 = this._container;
const oldScale = this._scale;
this._scale = this.clamp(newScale);
this._updateLabel();
this._pm.setZooming(true);
if (anchorY === void 0) anchorY = container2.clientHeight / 2;
if (anchorX === void 0) anchorX = container2.clientWidth / 2;
const anchorContentY = container2.scrollTop + anchorY;
let fixedAbove = CONTENT_PADDING_TOP;
let cumY = CONTENT_PADDING_TOP;
for (const wrap of this._pm.pageWrappers) {
const zoom = parseFloat(wrap.style.getPropertyValue("zoom") || "1") || 1;
const h = parseFloat(wrap.style.height) * zoom;
if (cumY + h > anchorContentY) break;
cumY += h + PAGE_GAP;
fixedAbove += PAGE_GAP;
}
const cssZoom = this._scale / this._renderScale;
for (const wrap of this._pm.pageWrappers) {
wrap.style.setProperty("zoom", String(cssZoom));
}
const ratio = this._scale / oldScale;
const scalable = container2.scrollTop + anchorY - fixedAbove;
container2.scrollTop = Math.max(0, fixedAbove + scalable * ratio - anchorY);
container2.scrollLeft = Math.max(0, (container2.scrollLeft + anchorX) * ratio - anchorX);
this._scheduleReRender();
}
_scheduleReRender() {
if (this._rafPending !== null) cancelAnimationFrame(this._rafPending);
this._rafPending = requestAnimationFrame(() => {
this._rafPending = null;
if (this._debounce !== null) clearTimeout(this._debounce);
this._debounce = setTimeout(() => this._triggerReRender(), 250);
});
}
_triggerReRender() {
this._pm.setZooming(false);
this._renderScale = this._scale;
const { bufferSet, visibleSet } = this._getBuffer();
this._onReRender(this._scale, bufferSet, visibleSet);
}
_bindScrollZoom() {
this._container.addEventListener("wheel", (ev) => {
if (!ev.ctrlKey) return;
ev.preventDefault();
const rect = this._container.getBoundingClientRect();
const anchorY = ev.clientY - rect.top;
const anchorX = ev.clientX - rect.left;
this.applyScale(
this._scale * (ev.deltaY < 0 ? 1.1 : 1 / 1.1),
anchorY,
anchorX
);
}, { passive: false });
}
};
_ZoomController.ZOOM_MIN = 0.1;
_ZoomController.ZOOM_MAX = 5;
var ZoomController = _ZoomController;
// src/viewer.ts
if (typeof requestIdleCallback === "undefined") {
self["requestIdleCallback"] = (cb) => setTimeout(() => cb({ timeRemaining: () => 50, didTimeout: false }), 1);
}
var container = document.getElementById("canvas-container");
var pagesWrapper = document.getElementById("pages-wrapper");
var statusEl = document.getElementById("status");
var zoomLabel = document.getElementById("zoom-label");
var pageIndicator = document.getElementById("page-indicator");
var params = new URLSearchParams(location.search);
var refId = params.get("ref_id") ?? "";
var savedZoom = parseFloat(params.get("zoom") ?? "");
var savedScrollTop = parseFloat(params.get("scroll_top") ?? "");
var DPR = window.devicePixelRatio || 1;
var pageManager = null;
var viewportTracker = null;
var zoomController = null;
var renderWorker = null;
var currentBufferSet = /* @__PURE__ */ new Set();
var currentVisibleSet = /* @__PURE__ */ new Set();
function setStatus(msg) {
statusEl.textContent = msg;
}
function showError(msg) {
const b = document.getElementById("error-banner");
b.textContent = msg;
b.style.display = "block";
setStatus("Error");
}
function refreshPageIndicator() {
if (!pageManager) return;
const cur = pageManager.getCurrentPage(currentVisibleSet);
pageIndicator.textContent = `${cur} / ${pageManager.numPages}`;
}
function scrollToPage(pageNum) {
if (!pageManager) return;
const wrap = pageManager.pageWrappers[pageNum - 1];
if (!wrap) return;
container.scrollTop += wrap.getBoundingClientRect().top - container.getBoundingClientRect().top;
}
function sendViewerState() {
if (!zoomController || window.parent === window) return;
const msg = {
type: "brittle:viewer-state",
refId,
zoom: zoomController.scale,
scrollTop: container.scrollTop
};
window.parent.postMessage(msg, "*");
}
function dispatchRender(pageNum, scale, gen) {
const msg = { type: "render", pageNum, scale, gen };
renderWorker?.postMessage(msg);
}
function onVisibilityChange(bufferSet, visibleSet) {
currentBufferSet = bufferSet;
currentVisibleSet = visibleSet;
pageManager?.reconcile(bufferSet, visibleSet);
refreshPageIndicator();
}
function fitScale(dims) {
const dim = dims[0] ?? { width: 595, height: 842 };
return Math.max(0.1, Math.min(5, Math.min(
(container.clientWidth - 40) / dim.width,
(container.clientHeight - 40) / dim.height
)));
}
async function load() {
if (!refId) {
showError("No ref_id in URL.");
return;
}
setStatus("Loading\u2026");
try {
const [workerBlob, pdfBuf] = await Promise.all([
fetch("brittle://app/viewer/render-worker.bundle.js").then((r) => r.blob()),
fetch(`brittle://app/pdf?ref_id=${encodeURIComponent(refId)}`).then((r) => r.arrayBuffer())
]);
renderWorker = new Worker(URL.createObjectURL(workerBlob));
const { numPages, dims } = await new Promise((resolve, reject) => {
renderWorker.onmessage = (ev) => {
const msg = ev.data;
if (msg.type === "ready") resolve({ numPages: msg.numPages, dims: msg.dims });
if (msg.type === "error") reject(new Error(msg.message));
};
renderWorker.onerror = (e) => reject(new Error(e.message));
const initMsg = { type: "init", pdfData: pdfBuf };
renderWorker.postMessage(initMsg, [pdfBuf]);
});
const fitted = fitScale(dims);
const initialScale = savedZoom > 0 ? Math.max(0.1, Math.min(5, savedZoom)) : fitted;
pageManager = new PageManager(
pagesWrapper,
dims,
initialScale,
DPR,
dispatchRender
);
renderWorker.onmessage = (ev) => {
const msg = ev.data;
if (msg.type === "rendered") {
pageManager?.onRendered(msg.pageNum, msg.gen, msg.bitmap);
refreshPageIndicator();
if (pageManager?.allRendered) setStatus("Ready");
} else if (msg.type === "error") {
console.warn("[viewer] worker error:", msg.message);
}
};
viewportTracker = new ViewportTracker(
container,
[...pageManager.pageWrappers],
onVisibilityChange
);
zoomController = new ZoomController(
container,
pageManager,
(newScale, bufferSet, visibleSet) => {
pageManager.onScaleChange(newScale, bufferSet, visibleSet);
sendViewerState();
},
() => ({ bufferSet: currentBufferSet, visibleSet: currentVisibleSet }),
zoomLabel,
initialScale
);
document.getElementById("btn-zoom-out").addEventListener(
"click",
() => zoomController.applyScale(zoomController.scale / 1.25)
);
document.getElementById("btn-zoom-in").addEventListener(
"click",
() => zoomController.applyScale(zoomController.scale * 1.25)
);
document.getElementById("btn-zoom-fit").addEventListener(
"click",
() => zoomController.applyScale(fitScale(dims))
);
document.addEventListener("keydown", (ev) => {
if (ev.target.tagName === "INPUT") return;
if (ev.key === "+" || ev.key === "=") {
ev.preventDefault();
zoomController.applyScale(zoomController.scale * 1.25);
}
if (ev.key === "-") {
ev.preventDefault();
zoomController.applyScale(zoomController.scale / 1.25);
}
if (ev.key === "0") {
ev.preventDefault();
zoomController.applyScale(fitScale(dims));
}
if (window.parent !== window) {
const msg = {
type: "brittle:keydown",
key: ev.key,
ctrlKey: ev.ctrlKey,
shiftKey: ev.shiftKey,
altKey: ev.altKey,
metaKey: ev.metaKey
};
window.parent.postMessage(msg, "*");
}
});
let scrollSaveTimer = null;
container.addEventListener("scroll", () => {
refreshPageIndicator();
if (scrollSaveTimer !== null) clearTimeout(scrollSaveTimer);
scrollSaveTimer = setTimeout(sendViewerState, 500);
}, { passive: true });
if (savedScrollTop > 0) {
requestAnimationFrame(() => {
container.scrollTop = savedScrollTop;
});
}
window.addEventListener("message", (ev) => {
if (ev.data === "pdf.page.next") {
scrollToPage(Math.min(
pageManager.getCurrentPage(currentVisibleSet) + 1,
numPages
));
}
if (ev.data === "pdf.page.prev") {
scrollToPage(Math.max(
pageManager.getCurrentPage(currentVisibleSet) - 1,
1
));
}
});
document.addEventListener("visibilitychange", () => {
if (document.hidden) {
renderWorker?.postMessage({ type: "cleanup" });
} else {
pageManager?.reconcile(currentBufferSet, currentVisibleSet);
}
});
matchMedia(`(resolution: ${DPR}dppx)`).addEventListener("change", () => {
if (pageManager && zoomController) {
pageManager.onScaleChange(
zoomController.scale,
currentBufferSet,
currentVisibleSet
);
}
});
window.addEventListener("beforeunload", () => {
viewportTracker?.disconnect();
renderWorker?.postMessage({ type: "destroy" });
renderWorker = null;
});
pageIndicator.textContent = `1 / ${numPages}`;
setStatus("Rendering\u2026");
} catch (e) {
showError("Could not load PDF: " + (e.message ?? String(e)));
}
}
load();
})();