feat(转换能力): 新增批量转换功能

assets/webui/index.html

@@ -20,6 +20,7 @@
 				<button id="newButton" class="icon-button" type="button" title="新建" aria-label="新建"><span class="new-icon" aria-hidden="true"></span></button>
 				<button id="saveButton" class="icon-button" type="button" title="保存" aria-label="保存" aria-keyshortcuts="Control+S Meta+S" disabled><span class="save-icon" aria-hidden="true"></span></button>
 				<button id="editButton" class="icon-button" type="button" title="编辑" aria-label="编辑" aria-pressed="false" disabled><span class="edit-icon" aria-hidden="true"></span></button>
+				<button id="convertButton" class="icon-button" type="button" title="转换" aria-label="转换" aria-haspopup="dialog" aria-controls="convertPanel"><span aria-hidden="true">&#8644;</span></button>
 				<button id="togglePagesButton" class="icon-button" type="button" title="页面栏" aria-label="页面栏" aria-pressed="true">&#9776;</button>
 				<button id="toggleMetaButton" class="icon-button" type="button" title="信息栏" aria-label="信息栏" aria-pressed="true">&#9432;</button>
 			</div>
@@ -171,6 +172,23 @@
 				<button id="batchPagesButton" class="editor-group-action" type="button" title="批量页面" aria-label="批量页面" aria-haspopup="dialog" aria-controls="batchPagesPanel">页面</button>
 			</div>
 		</div>
+		<dialog id="convertPanel" class="form-dialog convert-dialog" aria-labelledby="convertTitle">
+			<form id="convertForm">
+				<h2 id="convertTitle" class="form-title">批量转换<span id="convertCount"></span></h2>
+				<input id="convertInput" class="file-input" type="file" accept=".pdf,.ofd" multiple>
+				<div class="convert-table"><table><thead><tr><th scope="col">文件</th><th scope="col">页码</th><th scope="col">格式</th><th scope="col">状态</th><th scope="col">操作</th></tr></thead><tbody id="convertList"></tbody></table><div id="convertEmpty" class="convert-empty">暂无文件</div></div>
+				<div class="convert-progress"><progress id="convertProgress" max="1" value="0" aria-label="转换进度"></progress><div id="convertStatus" role="status" aria-live="polite"></div></div>
+				<div class="form-actions">
+					<button id="convertAdd" class="button" type="button">添加</button><button id="convertClear" class="button" type="button">清空</button>
+					<div class="convert-options">
+						<div class="form-row"><label for="convertFormat">格式</label><select id="convertFormat" required></select></div>
+						<div id="convertDPIRow" class="form-row" hidden><label for="convertDPI">精度</label><select id="convertDPI"><option value="96">96 dpi</option><option value="150">150 dpi</option><option value="300" selected>300 dpi</option><option value="600">600 dpi</option></select></div>
+						<div class="form-row"><label for="convertDestination">保存</label><select id="convertDestination"><option value="directory">目录</option><option value="archive">打包</option></select></div>
+					</div>
+					<button id="convertClose" class="button" type="button">关闭</button><button id="convertCancel" class="button" type="button" hidden>取消</button><button id="convertStart" class="button" type="submit" disabled>转换</button>
+				</div>
+			</form>
+		</dialog>
 		<dialog id="batchPagesPanel" class="form-dialog" aria-label="批量页面">
 			<form id="batchPagesForm">
 				<div class="form-row"><label for="batchPageAction">操作</label><select id="batchPageAction"><option value="copy">复制</option><option value="move">移动</option><option value="delete">删除</option><option value="save">另存</option></select></div>

assets/webui/ofdgo.css

@@ -690,6 +690,237 @@ button:not(:disabled):hover {
 	line-height: 1.5;
 }
 
+.convert-dialog {
+	--convert-format-width: 64px;
+	width: 720px;
+}
+
+.convert-dialog .form-title {
+	display: flex;
+	align-items: center;
+	gap: 12px;
+}
+
+.convert-options {
+	flex: none;
+	display: grid;
+	grid-template-columns: calc(2em + 8px + var(--convert-format-width)) 132px calc(2em + 8px + var(--convert-format-width));
+	gap: 12px;
+	margin: 0 auto;
+}
+
+.convert-options:has(#convertDPIRow[hidden]) {
+	grid-template-columns: repeat(2, calc(2em + 8px + var(--convert-format-width)));
+}
+
+.convert-options .form-row {
+	gap: 8px;
+	margin-bottom: 0;
+}
+
+#convertCount {
+	margin-left: auto;
+	color: var(--text-muted);
+	font-size: 12px;
+	font-weight: 400;
+}
+
+.convert-table {
+	max-height: 40dvh;
+	min-height: 120px;
+	overflow: auto;
+	border: 1px solid var(--line);
+	background: #fff;
+}
+
+.convert-table table {
+	width: 100%;
+	border-collapse: collapse;
+	table-layout: fixed;
+}
+
+.convert-table th,
+.convert-table td {
+	padding: 8px;
+	border-bottom: 1px solid var(--line);
+	text-align: left;
+	vertical-align: middle;
+}
+
+.convert-table th {
+	position: sticky;
+	top: 0;
+	z-index: 1;
+	background: #eef1f4;
+	font-weight: 500;
+}
+
+.convert-table th:nth-child(2) {
+	width: 112px;
+}
+
+.convert-table th:nth-child(3),
+.convert-table th:nth-child(4) {
+	width: calc(var(--convert-format-width) + 16px);
+}
+
+.convert-table select,
+.convert-table input {
+	width: 100%;
+	min-width: 0;
+	height: var(--control-height);
+	padding: 0 6px;
+	border: 1px solid var(--line);
+	border-radius: 0;
+	background: #fff;
+	color: inherit;
+}
+
+.convert-table input {
+	font-variant-numeric: tabular-nums;
+}
+
+.convert-table th:last-child,
+.convert-table td:last-child {
+	width: 48px;
+	text-align: center;
+}
+
+.convert-table tbody tr:last-child td {
+	border-bottom: 0;
+}
+
+.convert-name {
+	display: block;
+	overflow: hidden;
+	text-overflow: ellipsis;
+	white-space: nowrap;
+}
+
+.convert-table tr:has(+ .convert-details) > td {
+	border-bottom: 0;
+}
+
+.convert-table .convert-details > td {
+	width: auto;
+	padding-top: 0;
+	text-align: left;
+}
+
+.convert-table .convert-details details {
+	margin: 0;
+	color: var(--text-muted);
+	overflow-wrap: anywhere;
+	font-size: 12px;
+}
+
+.convert-table .convert-details details[open] > summary {
+	margin-bottom: 8px;
+}
+
+.convert-messages {
+	max-height: min(180px, 24dvh);
+	margin: 0;
+	padding: 0;
+	overflow: auto;
+	list-style: none;
+	line-height: 1.5;
+	white-space: pre-wrap;
+}
+
+.convert-messages > li + li {
+	margin-top: 6px;
+}
+
+.convert-table td[data-status="failed"] {
+	color: #b42318;
+}
+
+.convert-table td[data-status="done"] {
+	color: var(--accent-strong);
+}
+
+.convert-empty {
+	padding: 28px 12px;
+	text-align: center;
+	color: var(--text-muted);
+}
+
+.convert-progress {
+	margin-top: 12px;
+}
+
+.convert-dialog .form-actions {
+	display: flex;
+	align-items: center;
+	justify-content: flex-end;
+	margin-top: 12px;
+}
+
+.convert-dialog .form-actions .button {
+	min-width: 3.5em;
+}
+
+.convert-progress progress {
+	display: block;
+	width: 100%;
+	height: 6px;
+	accent-color: var(--accent);
+}
+
+#convertStatus {
+	min-height: 1.5em;
+	margin-top: 12px;
+	line-height: 1.5;
+	overflow-wrap: anywhere;
+	color: var(--text-muted);
+}
+
+#convertButton[data-running] {
+	color: var(--accent-strong);
+	background: var(--accent-soft);
+}
+
+@media (max-width: 700px) {
+	.convert-dialog .form-actions { flex-wrap: wrap; }
+	.convert-options { order: -1; flex-basis: 100%; justify-content: center; margin: 0 0 4px; }
+	#convertClose { margin-left: auto; }
+}
+
+@media (max-width: 620px) {
+	.convert-options {
+		grid-template-columns: calc(2em + 8px + var(--convert-format-width)) 132px;
+	}
+	.convert-table table,
+	.convert-table tbody { display: block; }
+	.convert-table thead { display: none; }
+	.convert-table tr {
+		display: flex;
+		flex-wrap: wrap;
+		align-items: center;
+		gap: 8px;
+		padding: 8px;
+		border-bottom: 1px solid var(--line);
+	}
+	.convert-table tr:last-child { border-bottom: 0; }
+	.convert-table tr:has(+ .convert-details) { padding-bottom: 0; border-bottom: 0; }
+	.convert-table td { min-width: 0; padding: 0; border: 0; }
+	.convert-table td:first-child { flex: 0 0 calc(100% - var(--convert-format-width) - var(--control-height) - 16px); }
+	.convert-table td:nth-child(4) { order: 1; flex: 0 0 var(--convert-format-width); text-align: right; }
+	.convert-table td:last-child { order: 2; flex: 0 0 var(--control-height); }
+	.convert-table td[data-label] {
+		order: 3;
+		display: grid;
+		grid-template-columns: 2em minmax(0, 1fr);
+		align-items: center;
+		gap: 8px;
+	}
+	.convert-table td:nth-child(2) { flex: 1 1 0; }
+	.convert-table td:nth-child(3) { flex: 0 0 calc(2em + 8px + var(--convert-format-width)); }
+	.convert-table td[data-label]::before { content: attr(data-label); color: var(--text-muted); }
+	.convert-table .convert-details > td { flex: 0 0 100%; }
+}
+
 #sourceTextPanel {
 	width: 440px;
 }

assets/webui/ofdgo.js

@@ -19,6 +19,8 @@ const STATUS = {
 };
 const wasmRequests = new Map();
 const metaContents = new WeakMap();
+const batch = { items: [], formats: [], running: false, canceled: false, worker: null, requests: new Map(), sequence: 0, activeID: 0, progressTime: 0 };
+const batchElements = Object.fromEntries(["Button", "Panel", "Form", "Input", "Add", "Clear", "Count", "Format", "Destination", "DPIRow", "DPI", "List", "Empty", "Progress", "Status", "Close", "Cancel", "Start"].map(name => [name, document.querySelector(`#convert${name}`)]));
 
 let wasmPromise = null;
 let wasmWorker = null;
@@ -1086,6 +1088,18 @@ el.pageForm.addEventListener("submit", async (event) => {
 	}
 });
 el.ofdButton.addEventListener("click", openOFDFile);
+batchElements.Button.addEventListener("click", () => { updateBatchControls(); batchElements.Panel.showModal(); });
+batchElements.Add.addEventListener("click", () => batchElements.Input.click());
+batchElements.Input.addEventListener("change", () => { addBatchFiles(batchElements.Input.files); batchElements.Input.value = ""; });
+batchElements.Clear.addEventListener("click", () => { batch.items = []; renderBatchList(); batchElements.Status.textContent = ""; batchElements.Progress.value = 0; });
+batchElements.Format.addEventListener("change", updateBatchControls);
+batchElements.Close.addEventListener("click", () => batchElements.Panel.close());
+batchElements.Cancel.addEventListener("click", cancelBatch);
+batchElements.Form.addEventListener("submit", event => { event.preventDefault(); runBatch(); });
+batchElements.Panel.addEventListener("dragover", event => { event.preventDefault(); event.stopPropagation(); event.dataTransfer.dropEffect = batch.running ? "none" : "copy"; });
+batchElements.Panel.addEventListener("drop", event => { event.preventDefault(); event.stopPropagation(); if (!batch.running) addBatchFiles(event.dataTransfer.files); });
+batchElements.Destination.querySelector('[value="directory"]').disabled = !window.showDirectoryPicker;
+batchElements.Destination.value = window.showDirectoryPicker ? "directory" : "archive";
 el.newButton.addEventListener("click", openCreatePanel);
 el.editButton.addEventListener("click", toggleEditor);
 el.editButton.addEventListener("pointerdown", (event) => {
@@ -1443,7 +1457,7 @@ function handleKeyDown(event) {
 }
 
 function formDialogOpen() {
-	return el.exportPanel.open || el.createPanel.open || el.insertPanel.open || el.pagePanel.open || el.paragraphPanel.open || el.importPanel.open || el.infoPanel.open
+	return batchElements.Panel.open || el.exportPanel.open || el.createPanel.open || el.insertPanel.open || el.pagePanel.open || el.paragraphPanel.open || el.importPanel.open || el.infoPanel.open
 		|| el.batchPagesPanel.open || el.objectStylePanel.open || el.sourceTextPanel.open || el.outlinePanel.open || el.objectBoundsPanel.open || el.annotationNote.open || el.annotationCreate.open || el.objectPicker.open;
 }
 
@@ -3173,6 +3187,9 @@ async function refreshApplication() {
 }
 
 async function loadExportFormats() {
+	batch.formats = await callWASM("ofdgoOutputFormats");
+	batchElements.Format.replaceChildren(...batch.formats.map(format => new Option(format.label, format.value)));
+	updateBatchControls();
 	const formats = await callWASM("ofdgoExportFormats") || [];
 	state.exportFormats = formats;
 	el.exportFormat.replaceChildren();
@@ -4382,6 +4399,307 @@ async function updateExportRange() {
 	}
 }
 
+function addBatchFiles(files) {
+	let rejected = false;
+	for (const file of files) {
+		if (!/\.(ofd|pdf)$/i.test(file.name)) { rejected = true; continue; }
+		batch.items.push({ file, format: "", pages: "", status: "pending", text: "待转", details: [] });
+	}
+	if (rejected) batchElements.Status.textContent = "仅支持PDF、OFD";
+	renderBatchList();
+}
+
+function renderBatchList() {
+	const fragment = document.createDocumentFragment();
+	for (const item of batch.items) {
+		const row = document.createElement("tr");
+		const name = row.insertCell();
+		const label = document.createElement("span");
+		label.className = "convert-name";
+		label.textContent = item.file.name;
+		label.title = item.file.name;
+		name.append(label);
+		let detailRow;
+		if (item.details.length) {
+			detailRow = document.createElement("tr");
+			detailRow.className = "convert-details";
+			const cell = detailRow.insertCell();
+			cell.colSpan = 5;
+			const details = document.createElement("details");
+			const summary = document.createElement("summary");
+			summary.textContent = "提示";
+			const messages = document.createElement("ul");
+			messages.className = "convert-messages";
+			messages.tabIndex = 0;
+			messages.setAttribute("aria-label", `${item.file.name}的转换提示`);
+			for (const message of item.details) {
+				const entry = document.createElement("li");
+				entry.textContent = message;
+				messages.append(entry);
+			}
+			details.append(summary, messages);
+			cell.append(details);
+		}
+		const reset = () => {
+			item.details = [];
+			detailRow?.remove();
+			batchStatus(item, "pending", "待转");
+			batchElements.Status.textContent = "";
+			batchElements.Progress.value = 0;
+			updateBatchControls();
+		};
+		const pagesCell = row.insertCell();
+		pagesCell.dataset.label = "页码";
+		const pages = document.createElement("input");
+		pages.type = "text";
+		pages.placeholder = "全部";
+		pages.title = "如1-3,5；留空为全部";
+		pages.setAttribute("aria-label", `${item.file.name}的输出页码`);
+		pages.value = item.pages;
+		pages.disabled = batch.running;
+		pages.addEventListener("change", () => { item.pages = pages.value; reset(); });
+		pagesCell.append(pages);
+		const formatCell = row.insertCell();
+		formatCell.dataset.label = "格式";
+		const format = document.createElement("select");
+		format.setAttribute("aria-label", `${item.file.name}的输出格式`);
+		format.append(new Option("默认", ""), ...batch.formats.map(value => new Option(value.label, value.value)));
+		format.value = item.format;
+		format.disabled = batch.running;
+		format.addEventListener("change", () => { item.format = format.value; reset(); });
+		formatCell.append(format);
+		item.cell = row.insertCell();
+		item.cell.textContent = item.text;
+		item.cell.dataset.status = item.status;
+		const action = row.insertCell();
+		const remove = document.createElement("button");
+		remove.type = "button";
+		remove.className = "icon-button";
+		remove.textContent = "×";
+		remove.title = "移除";
+		remove.setAttribute("aria-label", `移除${item.file.name}`);
+		remove.disabled = batch.running;
+		remove.addEventListener("click", () => { batch.items.splice(batch.items.indexOf(item), 1); renderBatchList(); });
+		action.append(remove);
+		fragment.append(row);
+		if (detailRow) fragment.append(detailRow);
+	}
+	batchElements.List.replaceChildren(fragment);
+	batchElements.Empty.hidden = batch.items.length > 0;
+	updateBatchControls();
+}
+
+function updateBatchControls() {
+	for (const name of ["Add", "Clear", "Format", "Destination", "DPI"]) batchElements[name].disabled = batch.running;
+	batchElements.Clear.disabled ||= !batch.items.length;
+	batchElements.Start.disabled = batch.running || !batch.items.length || !batch.formats.length;
+	batchElements.Start.hidden = batch.running;
+	batchElements.Cancel.hidden = !batch.running;
+	batchElements.Cancel.disabled = batch.canceled;
+	batchElements.Close.textContent = batch.running ? "收起" : "关闭";
+	batchElements.Count.textContent = batch.items.length ? `${batch.items.length}个文件` : "";
+	const formats = batch.items.length ? batch.items.map(item => item.format || batchElements.Format.value) : [batchElements.Format.value];
+	batchElements.DPIRow.hidden = !formats.some(value => batch.formats.find(format => format.value === value)?.raster);
+	batchElements.Button.toggleAttribute("data-running", batch.running);
+}
+
+function batchStatus(item, status, text) {
+	item.status = status;
+	item.text = text;
+	item.cell.textContent = text;
+	item.cell.dataset.status = status;
+}
+
+function batchProgress(item, position, count, progress) {
+	const now = performance.now();
+	if (now - batch.progressTime < 80 && progress.completed !== progress.total) return;
+	batch.progressTime = now;
+	const stage = progress.phase?.startsWith("write.") ? "写入" : { open: "读取", pages: "解析", convert: "转换", prepare: "准备", fonts: "字体", resources: "资源", references: "检查", write: "写入", export: "导出", pack: "打包", commit: "保存" }[progress.phase] || "处理";
+	const detail = progress.total > 0 ? `${progress.completed}/${progress.total}` : "";
+	if (item) batchStatus(item, "running", stage);
+	batchElements.Status.textContent = progress.phase === "pack" ? `打包 ${detail}` : `文件 ${position + 1}/${count} · ${stage}${detail ? ` ${detail}` : ""}`;
+	batchElements.Progress.max = count;
+	batchElements.Progress.value = progress.phase === "pack" && progress.total > 0 ? progress.completed / progress.total : position;
+}
+
+function batchCall(name, args, onProgress) {
+	return new Promise((resolve, reject) => {
+		if (batch.workerError) { reject(batch.workerError); return; }
+		const id = ++batch.sequence;
+		batch.activeID = id;
+		batch.requests.set(id, { resolve, reject, onProgress, destination: name === "ofdgoConvertFile" ? args[3] : null });
+		try { batch.worker.postMessage({ id, name, args }); }
+		catch (err) { batch.requests.delete(id); batch.activeID = 0; reject(err); }
+	});
+}
+
+function startBatchWorker() {
+	batch.workerError = null;
+	return new Promise((resolve, reject) => {
+		const worker = new Worker("./ofdgo_wasm.js");
+		batch.worker = worker;
+		const fail = async error => {
+			batch.workerError = error;
+			worker.terminate();
+			reject(error);
+			const requests = [...batch.requests.values()];
+			batch.requests.clear();
+			for (const request of requests) {
+				if (request.destination && request.outputName) {
+					try { await request.destination.removeEntry(request.outputName, { recursive: true }); }
+					catch (err) { error = new Error(`${error.message}；清理失败：${err.message}`); }
+				}
+				request.reject(error);
+			}
+		};
+		worker.onerror = event => fail(new Error(event.message || "转换引擎异常"));
+		worker.onmessageerror = () => fail(new Error("转换数据传递失败"));
+		worker.onmessage = ({ data }) => {
+			if (data.type === "ready") { resolve(); return; }
+			if (data.type === "exit") { fail(new Error(data.error)); return; }
+			if (data.type === "progress") { batchElements.Status.textContent = data.text; return; }
+			const request = batch.requests.get(data.id);
+			if (!request) return;
+			if (data.type === "output") { request.outputName = data.name; return; }
+			if (data.type === "conversion") { request.onProgress?.(data); return; }
+			batch.requests.delete(data.id);
+			if (batch.activeID === data.id) batch.activeID = 0;
+			if (data.ok) request.resolve(data.data);
+			else request.reject(Object.assign(new Error(data.error), { code: data.code, name: data.canceled ? "AbortError" : "Error" }));
+		};
+	});
+}
+
+function cancelBatch() {
+	batch.canceled = true;
+	batchElements.Cancel.disabled = true;
+	batchElements.Status.textContent = "正在取消";
+	if (batch.activeID) batch.worker.postMessage({ type: "cancel", id: batch.activeID });
+}
+
+function warnBatch(event) {
+	if (batch.running) { event.preventDefault(); event.returnValue = ""; }
+}
+
+async function runBatch() {
+	if (batch.running || !batch.items.length) return;
+	const defaultFormat = batch.formats.find(format => format.value === batchElements.Format.value);
+	if (!defaultFormat) return;
+	const pageRange = item => item.pages.trim() === "全部" ? "" : item.pages.trim();
+	const dpi = Number(batchElements.DPI.value);
+	const archive = batchElements.Destination.value === "archive";
+	const backend = state.renderBackend;
+	for (const item of batch.items) {
+		const format = batch.formats.find(format => format.value === (item.format || defaultFormat.value));
+		const key = JSON.stringify([format.value, pageRange(item), format.raster ? dpi : 0, archive, backend]);
+		if (item.settingsKey !== key) {
+			item.status = "pending";
+			item.text = "待转";
+			item.details = [];
+			item.settingsKey = key;
+		}
+	}
+	renderBatchList();
+	let jobs = batch.items.filter(item => item.status !== "done" && item.status !== "unchanged");
+	if (!jobs.length) {
+		jobs = [...batch.items];
+		for (const item of jobs) { item.status = "pending"; item.text = "待转"; item.details = []; }
+	}
+	batch.running = true;
+	batch.canceled = false;
+	renderBatchList();
+	window.addEventListener("beforeunload", warnBatch);
+	let destination = null;
+	let zipFile = null;
+	let storage = null;
+	let stagingName = "";
+	let packed = false;
+	const entries = [];
+	try {
+		if (archive) {
+			if (window.showSaveFilePicker) zipFile = await window.showSaveFilePicker({ suggestedName: "转换结果.zip", types: [{ description: "ZIP", accept: { "application/zip": [".zip"] } }] });
+			if (navigator.storage?.getDirectory) {
+				storage = await navigator.storage.getDirectory();
+				stagingName = `ofdgo-convert-${crypto.randomUUID()}`;
+				destination = await storage.getDirectoryHandle(stagingName, { create: true });
+			}
+		} else destination = await window.showDirectoryPicker({ mode: "readwrite" });
+		if (batch.canceled) return;
+		batchElements.Status.textContent = "正在准备引擎";
+		await startBatchWorker();
+		const fonts = await fontManager.files(fontManager.records());
+		const names = new Set();
+		for (const [position, item] of jobs.entries()) {
+			if (batch.canceled) break;
+			item.details = [];
+			const format = batch.formats.find(format => format.value === (item.format || defaultFormat.value));
+			const base = item.file.name.replace(/\.[^.]+$/, "").replace(/[<>:"/\\|?*\x00-\x1f]/g, "_").replace(/[. ]+$/g, "") || "document";
+			let unique = base;
+			const outputName = () => (format.paged ? unique : `${unique}.${format.extension}`).toLowerCase();
+			for (let suffix = 2; archive && names.has(outputName()); suffix++) unique = `${base} (${suffix})`;
+			names.add(outputName());
+			const options = { format: format.value, pages: pageRange(item), dpi, backend, archive, base: unique, credentials: null };
+			try {
+				for (;;) {
+					try {
+						const result = await batchCall("ofdgoConvertFile", [item.file, options, fonts, destination], progress => batchProgress(item, position, jobs.length, progress));
+						for (const file of result.files) entries.push(file);
+						item.details = (result.pdf?.Warnings || []).map(warning => `${warning.Page ? `第${warning.Page}页：` : ""}${warning.Message}`);
+						if (result.unchanged) {
+							batchStatus(item, "unchanged", "原样");
+							item.details = ["无需转换，源文件未改动"];
+						} else batchStatus(item, archive ? "ready" : "done", archive ? "待存" : "完成");
+						break;
+					} catch (err) {
+						if (batch.canceled || !["credentialsRequired", "invalidCredentials"].includes(err.code)) throw err;
+						options.credentials?.password?.fill(0);
+						options.credentials?.key?.fill(0);
+						options.credentials?.keyPassword?.fill(0);
+						options.credentials = await requestCredentials(err.code, state.openSeq);
+						if (!options.credentials) throw new DOMException("已取消解锁", "AbortError");
+						if (!window.confirm("转换结果将不保留原加密，是否继续？")) throw new DOMException("已取消转换", "AbortError");
+					}
+				}
+			} catch (err) {
+				batchStatus(item, err.name === "AbortError" ? "canceled" : "failed", err.name === "AbortError" ? "取消" : "失败");
+				item.details = [err.message];
+				if (batch.workerError) throw err;
+			} finally {
+				options.credentials?.password?.fill(0);
+				options.credentials?.key?.fill(0);
+				options.credentials?.keyPassword?.fill(0);
+			}
+			batchElements.Progress.max = jobs.length;
+			batchElements.Progress.value = position + 1;
+		}
+		if (archive && entries.length && !batch.canceled) {
+			const result = await batchCall("ofdgoPackFiles", [entries, zipFile], progress => batchProgress(null, 0, 1, progress));
+			if (result.blob) downloadBytes(result.blob, "application/zip", "转换结果.zip");
+			packed = true;
+			for (const item of jobs) if (item.status === "ready") batchStatus(item, "done", "完成");
+		}
+		const done = jobs.filter(item => item.status === "done").length;
+		const failed = jobs.filter(item => item.status === "failed").length;
+		const unchanged = batch.items.filter(item => item.status === "unchanged").length;
+		batchElements.Status.textContent = `${batch.canceled ? "已取消 · " : ""}完成 ${done}${failed ? ` · 失败 ${failed}` : ""}${unchanged ? ` · 原样 ${unchanged}` : ""}`;
+	} catch (err) {
+		batchElements.Status.textContent = err.name === "AbortError" ? "转换已取消" : err.message;
+	} finally {
+		if (archive && !packed) for (const item of jobs) if (item.status === "ready") { item.status = "pending"; item.text = "待转"; }
+		batch.worker?.terminate();
+		batch.worker = null;
+		batch.requests.clear();
+		batch.activeID = 0;
+		if (storage && stagingName) {
+			try { await storage.removeEntry(stagingName, { recursive: true }); }
+			catch { batchElements.Status.textContent += " · 临时文件清理失败"; }
+		}
+		batch.running = false;
+		window.removeEventListener("beforeunload", warnBatch);
+		renderBatchList();
+	}
+}
+
 async function exportFile(whole, indices = null, value = el.exportFormat.value, encryption = null) {
 	if (!state.doc || document.body.hasAttribute("aria-busy")) {
 		return;

assets/webui/ofdgo_wasm.js

@@ -7,11 +7,138 @@ self.onmessage = ({ data }) => {
 		operations.get(data.id)?.abort();
 		return;
 	}
-	if (data.name === "ofdgoConvertPDF" || data.name === "ofdgoExportPage" || data.name === "ofdgoExportDocument" || data.name === "ofdgoExportAttachment" || data.name === "ofdgoSaveDocument" || data.name === "ofdgoSaveEncrypted" || data.name === "ofdgoSaveSigned" || data.name === "ofdgoImportPages") {
+	if (data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles" || data.name === "ofdgoConvertPDF" || data.name === "ofdgoExportPage" || data.name === "ofdgoExportDocument" || data.name === "ofdgoExportAttachment" || data.name === "ofdgoSaveDocument" || data.name === "ofdgoSaveEncrypted" || data.name === "ofdgoSaveSigned" || data.name === "ofdgoImportPages") {
 		operations.set(data.id, new AbortController());
 	}
-	pending = pending.then(() => handleMessage(data));
+	pending = pending.then(() => data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles" ? handleBatchMessage(data) : handleMessage(data));
 };
+
+async function availableOutput(directory, base, format) {
+	for (let suffix = 0; ; suffix++) {
+		const stem = suffix ? `${base} (${suffix + 1})` : base;
+		const name = format.paged ? stem : `${stem}.${format.extension}`;
+		try {
+			await directory.getFileHandle(name);
+		} catch (err) {
+			if (err.name === "NotFoundError") return { stem, name };
+			if (err.name !== "TypeMismatchError") throw err;
+		}
+	}
+}
+
+async function handleBatchMessage({ id, name, args }) {
+	const signal = operations.get(id).signal;
+	const channel = new MessageChannel();
+	const finish = (done, err) => {
+		channel.port1.onmessage = () => done(err?.message || "", signal.aborted);
+		channel.port2.postMessage(null);
+	};
+	const reader = new FileReaderSync();
+	const read = file => (offset, size) => new Uint8Array(reader.readAsArrayBuffer(file.slice(offset, offset + size)));
+	let output = null;
+	let chunks = [];
+	let files = [];
+	let directory = null;
+	let created = null;
+	let root = null;
+	let current = null;
+	let size = 0;
+	let credentials = null;
+	const write = (bytes, done) => {
+		if (signal.aborted) return finish(done);
+		size += bytes.byteLength;
+		if (output) output.write(bytes).then(() => finish(done), err => finish(done, err));
+		else { chunks.push(new Blob([bytes])); finish(done); }
+	};
+	try {
+		signal.throwIfAborted();
+		let payload;
+		if (name === "ofdgoConvertFile") {
+			const [file, options, fonts, destination] = args;
+			credentials = options.credentials;
+			const formats = JSON.parse(globalThis.ofdgoOutputFormats()).data;
+			const format = formats.find(item => item.value === options.format);
+			if (!format) throw new Error("不支持此格式");
+			root = destination;
+			const base = options.base.replace(/[<>:"/\\|?*\x00-\x1f]/g, "_").replace(/[. ]+$/g, "") || "document";
+			const target = root ? await availableOutput(root, base, format) : { stem: base, name: format.paged ? base : `${base}.${format.extension}` };
+			if (root && format.paged) {
+				directory = await root.getDirectoryHandle(target.name, { create: true });
+				created = target.name;
+				self.postMessage({ id, type: "output", name: created });
+			} else directory = root;
+			const boundary = async (action, pageName) => {
+				signal.throwIfAborted();
+				if (action === "open") {
+					const fileName = format.paged ? pageName : target.name;
+					current = { name: format.paged ? `${target.stem}/${pageName}` : fileName, mime: format.mime };
+					chunks = [];
+					if (directory) {
+						const handle = await directory.getFileHandle(fileName, { create: true });
+						if (!format.paged) {
+							created = fileName;
+							self.postMessage({ id, type: "output", name: created });
+						}
+						current.handle = handle;
+						output = await handle.createWritable();
+					}
+				} else {
+					if (output) { await output.close(); output = null; }
+					if (options.archive) current.file = current.handle ? await current.handle.getFile() : new File(chunks, pageName, { type: format.mime });
+					delete current.handle;
+					files.push(current);
+					chunks = [];
+				}
+			};
+			payload = await globalThis.ofdgoConvertFile(read(file), file.size, options, write,
+				(phase, completed, total, done) => {
+					self.postMessage({ id, type: "conversion", phase, completed, total });
+					finish(done);
+				},
+				(action, pageName, done) => boundary(action, pageName).then(() => finish(done), err => finish(done, err)),
+				done => finish(done), fonts);
+		} else {
+			const [entries, handle] = args;
+			if (handle) output = await handle.createWritable();
+			payload = await globalThis.ofdgoPackFiles(entries.map(entry => ({ name: entry.name, size: entry.file.size })),
+				index => read(entries[index].file), write,
+				(completed, total, done) => { self.postMessage({ id, type: "conversion", phase: "pack", completed, total }); finish(done); },
+				done => finish(done));
+		}
+		signal.throwIfAborted();
+		const result = typeof payload === "string" ? JSON.parse(payload) : payload;
+		if (!result.ok) throw Object.assign(new Error(result.error), { code: result.code });
+		if (name === "ofdgoPackFiles") {
+			if (output) { await output.close(); output = null; }
+			else result.data.blob = new Blob(chunks, { type: "application/zip" });
+		} else {
+			if (result.data.unchanged) {
+				if (output) { await output.abort(); output = null; }
+				if (root && created) { await root.removeEntry(created, { recursive: true }); created = null; }
+				files = [];
+			}
+			result.data.files = files;
+		}
+		result.data.size = size;
+		operations.delete(id);
+		self.postMessage({ id, ...result });
+	} catch (err) {
+		await output?.abort().catch(() => {});
+		let message = signal.aborted ? "转换已取消" : err.message;
+		if (root && created) {
+			try { await root.removeEntry(created, { recursive: true }); }
+			catch (cleanupError) { message += `；清理失败：${cleanupError.message}`; }
+		}
+		self.postMessage({ id, ok: false, error: message, code: err.code, canceled: signal.aborted });
+	} finally {
+		credentials?.password?.fill(0);
+		credentials?.key?.fill(0);
+		credentials?.keyPassword?.fill(0);
+		channel.port1.close();
+		channel.port2.close();
+		operations.delete(id);
+	}
+}
 async function handleMessage({ id, name, args }) {
 	let output;
 	let channel;

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c
 	github.com/tdewolff/font v0.0.0-20260913163313-54f98bb59ee6
 	github.com/xiaoqidun/jbig2 v1.1.1
-	github.com/xiaoqidun/pdfgo v0.0.0-20260926024032-ab5bec77f380
+	github.com/xiaoqidun/pdfgo v0.0.0-20260926052151-12ff0e0004de
 	golang.org/x/crypto v0.57.0
 	golang.org/x/image v0.46.0
 	golang.org/x/text v0.42.0

go.sum

@@ -62,8 +62,8 @@ github.com/tdewolff/test v1.0.12 h1:7F21DqIajswxuche0geHdrUZRCWE4oko4b7bcmkkrxk=
 github.com/tdewolff/test v1.0.12/go.mod h1:XPuWBzvdUzhCuxWO1ojpXsyzsA5bFoS3tO/Q3kFuTG8=
 github.com/xiaoqidun/jbig2 v1.1.1 h1:SjliS9ZO0e9HX5oYUfBuXrfFsXhWricrSz+XY4zORDI=
 github.com/xiaoqidun/jbig2 v1.1.1/go.mod h1:8QonVWtENmh2kc6l+leqeGl7psb79DWlHDkCpdChjfQ=
-github.com/xiaoqidun/pdfgo v0.0.0-20260926024032-ab5bec77f380 h1:NIKpfWSCzRi0ytSS43KFwfV0lxItrepU+QEeab1Yt1w=
-github.com/xiaoqidun/pdfgo v0.0.0-20260926024032-ab5bec77f380/go.mod h1:4Pf0JO0BEf1uzRY+uZjlMjN/OPn3PYa0YMi6cqPPTLQ=
+github.com/xiaoqidun/pdfgo v0.0.0-20260926052151-12ff0e0004de h1:Aiyem3mCMV7+EAAGLYaI2XQGwEK1bZ1Bz+xTF5f0xiY=
+github.com/xiaoqidun/pdfgo v0.0.0-20260926052151-12ff0e0004de/go.mod h1:4Pf0JO0BEf1uzRY+uZjlMjN/OPn3PYa0YMi6cqPPTLQ=
 github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
 github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
 github.com/yuin/goldmark v1.8.5 h1:r6N5afV5qj/5S4UTch8agZHJ8UxNCMwX7WjkkJam2NA=

internal/webui/wasm.go

@@ -17,6 +17,7 @@
 package webui
 
 import (
+	"archive/zip"
 	"bufio"
 	"bytes"
 	"context"
@@ -28,6 +29,7 @@ import (
 	"image"
 	"image/color"
 	"io"
+	"io/fs"
 	"math"
 	"path"
 	"reflect"
@@ -45,6 +47,16 @@ type exportWriter struct {
 	write js.Value
 }
 
+// browserReaderAt 分块读取浏览器文件，只缓存最近的一个数据块
+type browserReaderAt struct {
+	read       js.Value
+	checkpoint js.Value
+	size       int64
+	offset     int64
+	data       []byte
+	checked    time.Time
+}
+
 // apiResult 浏览器接口返回结果
 type apiResult struct {
 	OK            bool                     `json:"ok"`
@@ -133,6 +145,45 @@ func (w exportWriter) Write(data []byte) (int, error) {
 	return size, nil
 }
 
+// ReadAt 按需读取文件片段并定期交付取消检查点
+// 入参: data 目标缓冲, offset 文件偏移
+// 返回: int 读取字节数, error 读取错误
+func (r *browserReaderAt) ReadAt(data []byte, offset int64) (int, error) {
+	if offset < 0 {
+		return 0, fmt.Errorf("negative file offset")
+	}
+	n := 0
+	for len(data) > 0 {
+		if offset >= r.size {
+			return n, io.EOF
+		}
+		if time.Since(r.checked) >= 50*time.Millisecond {
+			if err := awaitExport(r.checkpoint); err != nil {
+				return n, err
+			}
+			r.checked = time.Now()
+		}
+		if len(r.data) == 0 || offset < r.offset || offset-r.offset >= int64(len(r.data)) {
+			r.offset = offset / (256 << 10) * (256 << 10)
+			size := int(min(int64(256<<10), r.size-r.offset))
+			if cap(r.data) < size {
+				r.data = make([]byte, size)
+			} else {
+				r.data = r.data[:size]
+			}
+			value := r.read.Invoke(float64(r.offset), size)
+			if js.CopyBytesToGo(r.data, value) != size {
+				return n, io.ErrUnexpectedEOF
+			}
+		}
+		copied := copy(data, r.data[offset-r.offset:])
+		n += copied
+		offset += int64(copied)
+		data = data[copied:]
+	}
+	return n, nil
+}
+
 // awaitExport 等待浏览器处理导出检查点
 // 入参: fn 浏览器回调, args 回调参数
 // 返回: error 写入错误或取消原因
@@ -157,6 +208,9 @@ func awaitExport(fn js.Value, args ...any) error {
 func RunWASM() {
 	registerCallback("ofdgoOpen", openDocument)
 	registerAsyncCallback("ofdgoConvertPDF", convertPDFDocument)
+	registerAsyncCallback("ofdgoConvertFile", convertFile)
+	registerAsyncCallback("ofdgoPackFiles", packFiles)
+	registerCallback("ofdgoOutputFormats", func([]js.Value) (any, error) { return ofdgo.OutputFormats(), nil })
 	registerCallback("ofdgoConfigure", configureDocument)
 	registerCallback("ofdgoDocumentInfo", documentInfo)
 	registerCallback("ofdgoVerifySignatures", verifySignatures)
@@ -336,6 +390,131 @@ func convertPDFDocument(args []js.Value) (any, error) {
 	return successResult(map[string]any{"bytes": bytesToJS(output.Bytes()), "warnings": string(warnings)}), nil
 }
 
+// convertFile 使用库转换独立文件，不读取或修改当前阅读和编辑会话
+// 入参: args 随机读取、文件大小、转换选项、写出、进度、文件边界、取消检查及字体
+// 返回: any 转换报告, error 转换错误
+func convertFile(args []js.Value) (any, error) {
+	if len(args) != 8 {
+		return nil, fmt.Errorf("missing conversion arguments")
+	}
+	settings := args[2]
+	backends, err := ofdgo.NewRenderBackends(settings.Get("backend").String())
+	if err != nil {
+		return nil, err
+	}
+	fonts, err := fontsFromJS(args[7])
+	if err != nil {
+		return nil, err
+	}
+	options := ofdgo.ConvertOptions{
+		Format: settings.Get("format").String(), PageRange: settings.Get("pages").String(),
+		SkipUnchanged:   true,
+		Backends:        &backends,
+		RendererOptions: []ofdgo.RendererOption{ofdgo.WithDPI(settings.Get("dpi").Float())},
+		OnProgress: func(progress ofdgo.ConvertProgress) error {
+			return awaitExport(args[4], progress.Stage, progress.Completed, progress.Total)
+		},
+	}
+	if len(fonts) > 0 {
+		options.RendererOptions = append(options.RendererOptions, ofdgo.WithFontFS(ofdgo.NewFontFS(fonts)))
+	}
+	if value := settings.Get("credentials"); !value.IsNull() && !value.IsUndefined() {
+		credentials, err := credentialsFromJS(value)
+		if err != nil {
+			return nil, err
+		}
+		defer clear(credentials.Password)
+		options.ReaderOptions = append(options.ReaderOptions, ofdgo.WithCredentials(credentials))
+	}
+	var format ofdgo.OutputFormat
+	for _, item := range ofdgo.OutputFormats() {
+		if item.Value == options.Format {
+			format = item
+		}
+	}
+	writer := bufio.NewWriterSize(exportWriter{write: args[3]}, 1<<20)
+	if format.Paged {
+		options.PageOutput = func(index int, export func(io.Writer) error) error {
+			name := fmt.Sprintf("%06d.%s", index+1, format.Extension)
+			if err := awaitExport(args[5], "open", name); err != nil {
+				return err
+			}
+			if err := export(writer); err != nil {
+				return err
+			}
+			if err := writer.Flush(); err != nil {
+				return err
+			}
+			return awaitExport(args[5], "close", name)
+		}
+	} else if err := awaitExport(args[5], "open", "document."+format.Extension); err != nil {
+		return nil, err
+	}
+	source := &browserReaderAt{read: args[0], checkpoint: args[6], size: int64(args[1].Float())}
+	report, err := ofdgo.Convert(context.Background(), source, source.size, writer, options)
+	if err != nil {
+		return nil, err
+	}
+	if report.Unchanged {
+		return report, nil
+	}
+	if err := writer.Flush(); err != nil {
+		return nil, err
+	}
+	if !format.Paged {
+		if err := awaitExport(args[5], "close", "document."+format.Extension); err != nil {
+			return nil, err
+		}
+	}
+	return report, nil
+}
+
+// packFiles 将已经成功转换的文件逐个打包，不重复转换或读取整个文件
+// 入参: args 文件列表、分块读取、分块写出、进度及取消检查
+// 返回: any 输出格式, error 打包错误
+func packFiles(args []js.Value) (any, error) {
+	if len(args) != 5 {
+		return nil, fmt.Errorf("missing archive arguments")
+	}
+	writer := bufio.NewWriterSize(exportWriter{write: args[2]}, 1<<20)
+	archive := zip.NewWriter(writer)
+	files := args[0]
+	for i := 0; i < files.Length(); i++ {
+		if err := awaitExport(args[3], i, files.Length()); err != nil {
+			return nil, err
+		}
+		file := files.Index(i)
+		name := file.Get("name").String()
+		if !fs.ValidPath(name) || strings.Contains(name, "\\") {
+			return nil, fmt.Errorf("invalid archive path %q", name)
+		}
+		method := uint16(zip.Deflate)
+		switch strings.ToLower(path.Ext(name)) {
+		case ".ofd", ".pdf", ".png", ".jpg", ".jpeg":
+			method = zip.Store
+		}
+		entry, err := archive.CreateHeader(&zip.FileHeader{Name: name, Method: method})
+		if err != nil {
+			return nil, err
+		}
+		read := args[1].Invoke(i)
+		source := &browserReaderAt{read: read, checkpoint: args[4], size: int64(file.Get("size").Float())}
+		if _, err := io.Copy(entry, io.NewSectionReader(source, 0, source.size)); err != nil {
+			return nil, err
+		}
+	}
+	if err := archive.Close(); err != nil {
+		return nil, err
+	}
+	if err := writer.Flush(); err != nil {
+		return nil, err
+	}
+	if err := awaitExport(args[3], files.Length(), files.Length()); err != nil {
+		return nil, err
+	}
+	return map[string]any{"mime": "application/zip"}, nil
+}
+
 // openDocument 打开OFD文档
 // 入参: args 浏览器参数
 // 返回: any 文档信息, error 错误信息

internal/webui/webui.go

@@ -137,12 +137,7 @@ type PageSVG struct {
 }
 
 // ExportFormat 导出格式
-type ExportFormat struct {
-	Value     string `json:"value"`
-	Label     string `json:"label"`
-	Extension string `json:"extension"`
-	MIME      string `json:"mime"`
-}
+type ExportFormat = ofdgo.OutputFormat
 
 // SignatureInfo 签名验证信息
 type SignatureInfo struct {
@@ -257,16 +252,6 @@ type EncryptionInfo struct {
 	Layers    int      `json:"layers,omitempty"`
 }
 
-// supportedExportFormats 导出格式列表
-var supportedExportFormats = []ExportFormat{
-	{Value: "pdf", Label: "PDF", Extension: "pdf", MIME: "application/pdf"},
-	{Value: "svg", Label: "SVG", Extension: "svg", MIME: "image/svg+xml"},
-	{Value: "eps", Label: "EPS", Extension: "eps", MIME: "application/postscript"},
-	{Value: "png", Label: "PNG", Extension: "png", MIME: "image/png"},
-	{Value: "jpg", Label: "JPG", Extension: "jpg", MIME: "image/jpeg"},
-	{Value: "txt", Label: "TXT", Extension: "txt", MIME: "text/plain"},
-}
-
 // Open 打开浏览器内存中的OFD文档
 // 入参: data OFD文件数据, opts 打开选项
 // 返回: *Session 文档会话, error 错误信息
@@ -676,9 +661,7 @@ func (s *Session) pageBox(index int, page *ofdgo.PageContent) (ofdgo.Box, error)
 // ExportFormats 获取导出格式
 // 返回: []ExportFormat 导出格式列表
 func ExportFormats() []ExportFormat {
-	formats := make([]ExportFormat, len(supportedExportFormats))
-	copy(formats, supportedExportFormats)
-	return formats
+	return ofdgo.OutputFormats()[1:]
 }
 
 // exportFormat 获取导出格式
@@ -689,7 +672,7 @@ func exportFormat(value string) (ExportFormat, bool) {
 	if value == "jpeg" {
 		value = "jpg"
 	}
-	for _, format := range supportedExportFormats {
+	for _, format := range ExportFormats() {
 		if format.Value == value {
 			return format, true
 		}

ofdgo_convert.go

@@ -0,0 +1,316 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// OutputFormat 描述文档输出格式，Paged表示逐页文件，Raster表示受DPI控制的位图
+type OutputFormat struct {
+	Value     string `json:"value"`
+	Label     string `json:"label"`
+	Extension string `json:"extension"`
+	MIME      string `json:"mime"`
+	Paged     bool   `json:"paged,omitempty"`
+	Raster    bool   `json:"raster,omitempty"`
+}
+
+// ConvertProgress 回报open、pages、convert、prepare、write、write.*及export阶段，Total为0表示总量未知
+type ConvertProgress struct {
+	Stage     string `json:"stage"`
+	Completed int    `json:"completed"`
+	Total     int    `json:"total"`
+}
+
+// ConvertOptions 设置文档转换格式、页码、阅读和渲染选项
+// Input为空时识别源格式，Format为输出格式，Pages使用零基索引，nil表示全部页面
+// PageRange使用一基页码表达式，与Pages互斥，空字符串表示全部页面
+// SkipUnchanged在源格式与目标相同且未选页时不写出数据，不校验或重新生成源文档
+// PDF先转换为OFD对象再输出，PDF选项中的进度回调仍会调用
+// Backends统一配置转换与输出，优先于PDF和RendererOptions中的后端设置
+// PageOutput仅用于逐页格式，同步调用export写出一页并自行处理提交或回滚；此时output可为nil
+// 未提供PageOutput时，逐页格式打包ZIP；所有回调返回错误均会停止转换
+type ConvertOptions struct {
+	Input           string
+	Format          string
+	Pages           []int
+	PageRange       string
+	SkipUnchanged   bool
+	Backends        *RenderBackends
+	ReaderOptions   []ReaderOption
+	RendererOptions []RendererOption
+	PDF             PDFImportOptions
+	OnProgress      func(ConvertProgress) error
+	PageOutput      func(index int, export func(io.Writer) error) error
+}
+
+// ConvertReport 汇总源格式、输出格式、页数、字节数及PDF转换诊断
+// Unchanged表示无需转换或完整OFD原样复制，Bytes仅统计实际输出，不包含调用方额外封装
+type ConvertReport struct {
+	Input     string          `json:"input"`
+	Format    OutputFormat    `json:"format"`
+	Pages     int             `json:"pages"`
+	Bytes     int64           `json:"bytes"`
+	Unchanged bool            `json:"unchanged,omitempty"`
+	PDF       PDFImportReport `json:"pdf"`
+}
+
+// convertReader 将取消上下文传递到随机读取
+type convertReader struct {
+	context context.Context
+	source  io.ReaderAt
+}
+
+// convertWriter 将取消上下文传递到写入并统计实际字节数
+type convertWriter struct {
+	context context.Context
+	writer  io.Writer
+	count   *int64
+}
+
+// OutputFormats 返回独立的输出格式列表，不依赖WebUI或具体渲染后端
+// 返回: []OutputFormat 输出格式列表
+func OutputFormats() []OutputFormat {
+	return []OutputFormat{
+		{Value: "ofd", Label: "OFD", Extension: "ofd", MIME: "application/ofd"},
+		{Value: "pdf", Label: "PDF", Extension: "pdf", MIME: "application/pdf"},
+		{Value: "svg", Label: "SVG", Extension: "svg", MIME: "image/svg+xml", Paged: true},
+		{Value: "eps", Label: "EPS", Extension: "eps", MIME: "application/postscript", Paged: true},
+		{Value: "png", Label: "PNG", Extension: "png", MIME: "image/png", Paged: true, Raster: true},
+		{Value: "jpg", Label: "JPG", Extension: "jpg", MIME: "image/jpeg", Paged: true, Raster: true},
+		{Value: "txt", Label: "TXT", Extension: "txt", MIME: "text/plain"},
+	}
+}
+
+// Convert 将PDF或OFD转换为指定格式，不关闭调用方的输入和输出
+// 完整OFD另存保持源字节，包括制作软件、签名及加密；选页和跨格式输出重新生成文档
+// 输入按需随机读取，输出分块写出；解析对象及后端可能缓存资源，不保证恒定内存
+// 出错时报告保留已有诊断，调用方应丢弃未完成输出；只有返回nil才表示转换成功
+// 入参: ctx 取消上下文, source 源数据, size 源字节数, output 输出流, options 转换选项
+// 返回: ConvertReport 转换报告, error 错误信息
+func Convert(ctx context.Context, source io.ReaderAt, size int64, output io.Writer, options ConvertOptions) (report ConvertReport, err error) {
+	if err = ctx.Err(); err != nil {
+		return report, err
+	}
+	format := strings.ToLower(strings.TrimSpace(options.Format))
+	if format == "jpeg" {
+		format = "jpg"
+	}
+	for _, candidate := range OutputFormats() {
+		if candidate.Value == format {
+			report.Format = candidate
+			break
+		}
+	}
+	if report.Format.Value == "" {
+		return report, fmt.Errorf("unsupported output format %s", options.Format)
+	}
+	if options.PageOutput != nil && !report.Format.Paged {
+		return report, fmt.Errorf("page output requires a paged format")
+	}
+	if options.Pages != nil && len(options.Pages) == 0 {
+		return report, fmt.Errorf("no pages selected")
+	}
+	if options.Pages != nil && strings.TrimSpace(options.PageRange) != "" {
+		return report, fmt.Errorf("conflicting page selections")
+	}
+	progress := func(stage string, completed, total int) error {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		if options.OnProgress != nil {
+			return options.OnProgress(ConvertProgress{Stage: stage, Completed: completed, Total: total})
+		}
+		return nil
+	}
+	writeProgress := func(stage string, completed, total int) error {
+		if stage == "write" {
+			return progress(stage, completed, total)
+		}
+		return progress("write."+stage, completed, total)
+	}
+	if err = progress("open", 0, 0); err != nil {
+		return report, err
+	}
+	source = convertReader{context: ctx, source: source}
+	report.Input = strings.ToLower(strings.TrimSpace(options.Input))
+	if report.Input == "" {
+		var header [1024]byte
+		n, readErr := source.ReadAt(header[:], 0)
+		if readErr != nil && readErr != io.EOF {
+			return report, readErr
+		}
+		switch {
+		case bytes.HasPrefix(header[:n], []byte("PK\x03\x04")):
+			report.Input = "ofd"
+		case bytes.Contains(header[:n], []byte("%PDF-")):
+			report.Input = "pdf"
+		}
+	}
+	var reader *Reader
+	var editor *Editor
+	var count int
+	if report.Input != "pdf" && report.Input != "ofd" {
+		return report, fmt.Errorf("unsupported input format")
+	}
+	if options.SkipUnchanged && report.Input == format && options.Pages == nil && strings.TrimSpace(options.PageRange) == "" {
+		report.Unchanged = true
+		return report, nil
+	}
+	if output == nil && options.PageOutput == nil {
+		return report, fmt.Errorf("missing output writer")
+	}
+	switch report.Input {
+	case "pdf":
+		pdfOptions := options.PDF
+		if options.Backends != nil {
+			pdfOptions.Backends = options.Backends
+		}
+		pdfOptions.OnProgress = func(stage string, completed, total int) error {
+			if err := progress(stage, completed, total); err != nil {
+				return err
+			}
+			if options.PDF.OnProgress != nil {
+				return options.PDF.OnProgress(stage, completed, total)
+			}
+			return nil
+		}
+		editor, report.PDF, err = ImportPDF(ctx, source, size, pdfOptions)
+		if err != nil {
+			return report, err
+		}
+		count = editor.PageCount()
+	case "ofd":
+		reader, err = NewReader(source, size, options.ReaderOptions...)
+		if err != nil {
+			return report, err
+		}
+		defer reader.Close()
+		count, err = reader.PageCount()
+		if err != nil {
+			return report, err
+		}
+	}
+	if strings.TrimSpace(options.PageRange) != "" {
+		options.Pages, err = ParsePageRange(options.PageRange, count)
+		if err != nil {
+			return report, err
+		}
+	}
+	indices, err := exportPageIndices(count, options.Pages)
+	if err != nil {
+		return report, err
+	}
+	report.Pages = len(indices)
+	writer := convertWriter{context: ctx, writer: output, count: &report.Bytes}
+	if format == "ofd" {
+		if options.Pages == nil && editor == nil {
+			if err = progress("write", 0, 0); err != nil {
+				return report, err
+			}
+			_, err = io.Copy(writer, io.NewSectionReader(source, 0, size))
+			report.Unchanged = err == nil
+			return report, err
+		}
+		if editor == nil {
+			editor, err = reader.Editor()
+			if err != nil {
+				return report, err
+			}
+		}
+		editor.OnWriteProgress = writeProgress
+		if options.Pages == nil {
+			_, err = editor.WriteTo(writer)
+		} else {
+			_, err = editor.WritePagesTo(writer, indices)
+		}
+		return report, err
+	}
+	if reader == nil {
+		if err = progress("prepare", 0, count); err != nil {
+			return report, err
+		}
+		reader, err = editor.reader(progress)
+		if err != nil {
+			return report, err
+		}
+		defer reader.Close()
+	}
+	renderer := NewRenderer(reader, options.RendererOptions...)
+	if options.Backends != nil {
+		WithRenderBackends(*options.Backends)(renderer)
+	}
+	renderer.OnExportProgress = func(completed, total int) error {
+		return progress("export", completed, total)
+	}
+	switch format {
+	case "pdf":
+		err = renderer.RenderToMultiPagePDF(writer, indices...)
+	case "txt":
+		err = renderer.RenderToMultiPageText(writer, indices...)
+	default:
+		if options.PageOutput == nil {
+			err = renderer.RenderToZIP(writer, format, indices...)
+			report.Format = OutputFormat{Value: "zip", Label: "ZIP", Extension: "zip", MIME: "application/zip"}
+			break
+		}
+		for i, index := range indices {
+			if err = progress("export", i, len(indices)); err != nil {
+				return report, err
+			}
+			page, readErr := reader.PageContentByIndex(index)
+			if readErr != nil {
+				return report, readErr
+			}
+			if err = options.PageOutput(index, func(output io.Writer) error {
+				return renderer.RenderTo(page, convertWriter{context: ctx, writer: output, count: &report.Bytes}, format)
+			}); err != nil {
+				return report, fmt.Errorf("export page %d: %w", index+1, err)
+			}
+		}
+		err = progress("export", len(indices), len(indices))
+	}
+	return report, err
+}
+
+// ReadAt 读取指定位置的数据并响应取消
+// 入参: data 目标缓冲, offset 源偏移
+// 返回: int 读取字节数, error 读取错误
+func (r convertReader) ReadAt(data []byte, offset int64) (int, error) {
+	if err := r.context.Err(); err != nil {
+		return 0, err
+	}
+	return r.source.ReadAt(data, offset)
+}
+
+// Write 写出数据并响应取消及短写
+// 入参: data 待写数据
+// 返回: int 写入字节数, error 写入错误
+func (w convertWriter) Write(data []byte) (int, error) {
+	if err := w.context.Err(); err != nil {
+		return 0, err
+	}
+	n, err := w.writer.Write(data)
+	*w.count += int64(n)
+	if err == nil && n != len(data) {
+		err = io.ErrShortWrite
+	}
+	return n, err
+}

ofdgo_pdf.go

@@ -197,11 +197,18 @@ func ConvertPDF(ctx context.Context, source io.ReaderAt, size int64, output io.W
 		if err := options.OnProgress("write", 0, 0); err != nil {
 			return PDFImportReport{}, err
 		}
-		editor.OnWriteProgress = func(stage string, completed, total int) error {
+	}
+	editor.OnWriteProgress = func(stage string, completed, total int) error {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		if options.OnProgress != nil {
 			return options.OnProgress("write."+stage, completed, total)
 		}
+		return nil
 	}
-	_, err = editor.WriteTo(output)
+	var written int64
+	_, err = editor.WriteTo(convertWriter{context: ctx, writer: output, count: &written})
 	return report, err
 }
 

ofdgo_renderer_font_loader_canvas.go

@@ -14,7 +14,11 @@
 
 package ofdgo
 
-import "github.com/tdewolff/canvas"
+import (
+	"fmt"
+
+	"github.com/tdewolff/canvas"
+)
 
 // loadFont 加载字体
 // 入参: fontID 字体ID
@@ -30,6 +34,13 @@ func (r *Renderer) loadFont(fontID string) *canvas.FontFamily {
 	}
 	of := r.Reader.fontCache[fontID]
 	if len(resolved.Data) == 0 {
+		if !r.textOnly {
+			name := fontID
+			if of != nil && of.FontName != "" {
+				name = of.FontName
+			}
+			r.renderError = fmt.Errorf("font %q is unavailable", name)
+		}
 		return nil
 	}
 	if of == nil {

ofdgo_writer.go

@@ -501,7 +501,9 @@ func (x *ofdXML) resources(fonts, images []editorResource, spaces []ColorSpace)
 				attrs.add("FixedWidth", "true")
 			}
 			x.start("Font", attrs)
-			x.text("FontFile", font.FontFile)
+			if font.FontFile != "" {
+				x.text("FontFile", font.FontFile)
+			}
 			x.end("Font")
 		}
 		x.end("Fonts")