feat(加强兼容): 支持多文档

assets/webui/index.html

@@ -597,6 +597,7 @@
 					<button id="infoButton" class="small-button" type="button" aria-label="修改文档信息" aria-haspopup="dialog" aria-controls="infoPanel" hidden>修改</button>
 				</div>
 				<div id="editNotice" class="font-permission-hint" role="status" hidden></div>
+				<select id="documentSelect" class="document-select" aria-label="选择文档" title="切换文档" hidden></select>
 				<dl class="meta-list">
 					<div>
 						<dt>文件</dt>

assets/webui/ofdgo.css

@@ -1516,6 +1516,15 @@ body[data-hide-meta] .meta-panel {
 	white-space: nowrap;
 }
 
+.document-select {
+	width: 100%;
+	min-width: 0;
+	height: 28px;
+	margin-bottom: 10px;
+	padding: 0 6px;
+	font-size: 12px;
+}
+
 .app-panel {
 	margin-bottom: 12px;
 	padding-bottom: 12px;

assets/webui/ofdgo.js

@@ -51,6 +51,7 @@ const state = {
 	editorInfo: null,
 	editorViews: new Map(),
 	savedRevision: null,
+	packageDirty: false,
 	encryptionDirty: false,
 	insertObject: null,
 	importPageCount: 0,
@@ -231,6 +232,7 @@ const el = {
 	textFontAdd: document.querySelector("#textFontAdd"),
 	paragraphButton: document.querySelector("#paragraphButton"),
 	infoButton: document.querySelector("#infoButton"),
+	documentSelect: document.querySelector("#documentSelect"),
 	infoPanel: document.querySelector("#infoPanel"),
 	infoForm: document.querySelector("#infoForm"),
 	infoTitle: document.querySelector("#infoTitle"),
@@ -611,10 +613,12 @@ const canvasEditor = new CanvasEditor(el.viewerPanel, {
 });
 
 function updatePendingChanges() {
-	setDirty(state.encryptionDirty || Boolean(state.editorInfo) && (state.editorInfo.revision !== state.savedRevision
+	setDirty(state.packageDirty || state.encryptionDirty || Boolean(state.editorInfo) && (state.editorInfo.revision !== state.savedRevision
 		|| canvasEditor.textChanged() || canvasEditor.cropChanged() || canvasEditor.nudgeChanged()));
 }
 
+el.documentSelect.addEventListener("change", () => switchDocument(Number(el.documentSelect.value)));
+
 el.editorTools.addEventListener("pointerdown", (event) => {
 	if ((canvasEditor.input || canvasEditor.nudge) && event.target.closest("button")) event.preventDefault();
 });
@@ -1929,7 +1933,40 @@ function discardChanges() {
 function setEditorInfo(doc) {
 	state.editorInfo = { revision: doc.revision, canUndo: doc.canUndo, canRedo: doc.canRedo,
 		pageCapabilities: doc.pageCapabilities, editWarnings: doc.editWarnings || [] };
-	setDirty(state.encryptionDirty || doc.revision !== state.savedRevision);
+	setDirty(state.packageDirty || state.encryptionDirty || doc.revision !== state.savedRevision);
+}
+
+async function switchDocument(index) {
+	if (!state.doc || document.body.hasAttribute("aria-busy") || state.exporting || formDialogOpen()) return;
+	const previous = state.doc.documentIndex || 0;
+	if (index === previous) return;
+	if (!await canvasEditor.commitNudge() || !await canvasEditor.commitText() || !await canvasEditor.commitCrop()) {
+		el.documentSelect.value = String(previous);
+		return;
+	}
+	const openSeq = ++state.openSeq;
+	setBusy(true, "正在切换文档");
+	try {
+		const doc = await callWASM("ofdgoSelectDocument", index);
+		if (openSeq !== state.openSeq) return;
+		state.packageDirty ||= state.dirty;
+		state.savedRevision = doc.revision;
+		state.editorViews.clear();
+		state.objectClipboard = state.styleClipboard = null;
+		resetCompositeScope();
+		canvasEditor.clear();
+		canvasEditor.setTool("");
+		state.ofdBytes = null;
+		setEditorInfo(doc);
+		await openDocument({ doc, openSeq, skipAutoFonts: true, resetScroll: true, clearSelection: true, fitMode: state.fitMode, scale: state.scale });
+	} catch (error) {
+		if (openSeq === state.openSeq) {
+			el.documentSelect.value = String(previous);
+			showError(error, false);
+		}
+	} finally {
+		if (openSeq === state.openSeq) setBusy(false);
+	}
 }
 
 function editorLocation() {
@@ -2110,6 +2147,7 @@ async function createDocument(event) {
 		state.fileName = `${title.replace(/[\\/:*?"<>|]+/g, "_").replace(/\.ofd$/i, "")}.ofd`;
 		state.conversionWarnings = [];
 		state.savedRevision = null;
+		state.packageDirty = false;
 		state.encryptionDirty = false;
 		setEditorInfo(doc);
 		el.createPanel.close();
@@ -3616,6 +3654,7 @@ async function openOFD(file, remote = null) {
 		state.editorViews.clear();
 		state.fontRenderPending = false;
 		state.savedRevision = null;
+		state.packageDirty = false;
 		state.encryptionDirty = false;
 		canvasEditor.clear();
 		setDirty(false);
@@ -5299,6 +5338,7 @@ async function exportFile(whole, indices = null, value = el.exportFormat.value)
 		}
 		if (saving && indices === null && state.editorInfo) {
 			state.savedRevision = state.editorInfo.revision;
+			state.packageDirty = false;
 			state.encryptionDirty = false;
 			setDirty(false);
 		}
@@ -7383,6 +7423,16 @@ function renderMeta(keepDetails = false) {
 		}));
 	});
 	const doc = state.doc || {};
+	el.documentSelect.hidden = (doc.documents?.length || 0) < 2;
+	renderMetaContent(el.documentSelect, doc.documents || [], () => {
+		el.documentSelect.replaceChildren(...(doc.documents || []).map(entry => {
+			const option = document.createElement("option");
+			option.value = String(entry.index);
+			option.textContent = `${entry.index + 1} · ${entry.title || "未命名"}`;
+			return option;
+		}));
+	});
+	el.documentSelect.value = String(doc.documentIndex || 0);
 	el.metaPanel.setAttribute("aria-busy", String(!!doc.detailsPending));
 	document.title = `OFDGo WebUI - ${state.fileName}`;
 	el.metaFile.textContent = state.fileName;
@@ -8200,6 +8250,7 @@ function updateControls() {
 	el.attachmentAdd.disabled = !state.editing || !state.ready || state.exporting;
 	renderMetaContent(el.attachmentList, [state.doc?.attachments, state.doc?.attachmentError, state.editing], renderAttachments);
 	const hasDoc = Boolean(state.doc);
+	el.documentSelect.disabled = !hasDoc || !state.ready || state.exporting || document.body.hasAttribute("aria-busy");
 	updateDisplayControls();
 	updateEditorTools();
 	const pageCount = state.doc ? state.doc.pageCount : 0;
@@ -8403,6 +8454,7 @@ function showError(err, empty = !state.doc) {
 
 function setBusy(busy, text = "", percent = 0, status = "") {
 	document.body.toggleAttribute("aria-busy", busy);
+	el.documentSelect.disabled = busy || !state.doc || !state.ready || state.exporting;
 	renderSecurity();
 	updateDisplayControls();
 	el.editButton.disabled = busy || Boolean(sealPreview) || !state.doc || !state.ready || state.exporting;

assets/webui/ofdgo_edit.js

@@ -536,6 +536,12 @@ export class CanvasEditor {
 	}
 
 	start(event) {
+		if (event.target === this.viewer) {
+			const rect = this.viewer.getBoundingClientRect();
+			const left = rect.left + (this.viewer.clientLeft || 0), top = rect.top + (this.viewer.clientTop || 0);
+			if (event.clientX < left || event.clientX >= left + this.viewer.clientWidth
+				|| event.clientY < top || event.clientY >= top + this.viewer.clientHeight) return;
+		}
 		if (this.nudge) {
 			this.commitNudge();
 			return;

internal/webui/wasm.go

@@ -184,6 +184,7 @@ func (r *browserReaderAt) ReadAt(data []byte, offset int64) (int, error) {
 // RunWASM 注册浏览器WASM接口并阻塞运行
 func RunWASM() {
 	registerCallback("ofdgoOpen", openDocument)
+	registerCallback("ofdgoSelectDocument", selectDocument)
 	registerAsyncCallback("ofdgoConvertPDF", convertPDFDocument)
 	registerAsyncCallback("ofdgoConvertFile", convertFile)
 	registerAsyncCallback("ofdgoPackFiles", packFiles)
@@ -3359,6 +3360,27 @@ func changeAttachment(args []js.Value) (any, error) {
 	})
 }
 
+// selectDocument 切换包内文档，保留编辑快照并清除跨文档剪贴板
+// 入参: args 文档索引
+// 返回: any 文档信息, error 错误信息
+func selectDocument(args []js.Value) (any, error) {
+	if currentSession == nil || len(args) == 0 {
+		return nil, fmt.Errorf("ofd document is not opened")
+	}
+	session, err := currentSession.Document(args[0].Int())
+	if err != nil {
+		return nil, err
+	}
+	_ = currentSession.Close()
+	currentSession, currentEditor = session, session.editor
+	if pendingImport != nil {
+		_ = pendingImport.Close()
+		pendingImport = nil
+	}
+	copiedObjects, copiedStyle = nil, nil
+	return editorSummary(), nil
+}
+
 // editDocument 将已打开文档接入编辑器，沿用页面、资源及字体配置
 // 入参: args 当前页索引，省略时使用首页
 // 返回: any 编辑状态, error 错误信息
@@ -3367,6 +3389,7 @@ func editDocument(args []js.Value) (any, error) {
 		return nil, fmt.Errorf("ofd document is not opened")
 	}
 	if currentEditor != nil {
+		currentSession.editing = true
 		return editorSummary(), nil
 	}
 	editor, err := currentSession.Reader.Editor()
@@ -3952,7 +3975,7 @@ func verifySignatures(args []js.Value) (any, error) {
 			Certificates:                append(files["certificates"], files["roots"]...), Required: policy.RequireRevocation, VerifyTime: &now,
 		}))
 	}
-	reports, err := currentSession.Reader.VerifySignatures(options...)
+	reports, err := currentSession.Reader.VerifyDocumentSignatures(currentSession.Reader.DocumentIndex(), options...)
 	if err != nil {
 		return nil, err
 	}

internal/webui/webui.go

@@ -72,6 +72,8 @@ type pageBoxInfo struct {
 
 // DocumentInfo 文档信息
 type DocumentInfo struct {
+	DocumentIndex   int                `json:"documentIndex"`
+	Documents       []DocumentEntry    `json:"documents,omitempty"`
 	Encryption      EncryptionInfo     `json:"encryption"`
 	Version         string             `json:"version"`
 	DocType         string             `json:"docType"`
@@ -96,6 +98,12 @@ type DocumentInfo struct {
 	DetailsPending  bool               `json:"detailsPending,omitempty"`
 }
 
+// DocumentEntry 包内文档入口，不预先解析其他文档的页面和资源
+type DocumentEntry struct {
+	Index int    `json:"index"`
+	Title string `json:"title"`
+}
+
 // DocumentDetails 不含页面数组的文档补充信息
 type DocumentDetails struct {
 	FontCount       int              `json:"fontCount"`
@@ -287,6 +295,45 @@ func (s *Session) Close() error {
 	return nil
 }
 
+// Document 创建指定文档的会话，保留编辑内容和字体配置，不复用页面缓存
+// 不关闭原会话，输入文件的生命周期由原会话管理
+// 入参: index 文档索引，从0开始
+// 返回: *Session 文档会话, error 错误信息
+func (s *Session) Document(index int) (*Session, error) {
+	reader := s.Reader
+	if s.editor != nil {
+		var err error
+		reader, err = s.editor.Reader()
+		if err != nil {
+			return nil, err
+		}
+	}
+	reader, err := reader.Document(index)
+	if err != nil {
+		return nil, err
+	}
+	next, err := newSession(reader, OpenOptions{RenderAnnotations: s.Renderer.RenderAnnotations})
+	if err != nil {
+		return nil, err
+	}
+	ofdgo.WithRenderBackends(s.Renderer.Backends())(next.Renderer)
+	next.fontFS = s.fontFS
+	if next.fontFS != nil {
+		next.Renderer.SetFontFS(next.fontFS)
+	}
+	next.editor, err = reader.Editor()
+	if err != nil {
+		return nil, err
+	}
+	next.editor.SetHistoryLimit(100)
+	if next.fontFS != nil {
+		next.editor.SetFontFS(next.fontFS)
+	}
+	next.editor.SetRenderBackends(next.Renderer.Backends())
+	next.editing = true
+	return next, nil
+}
+
 // SetFonts 更新字体配置并保留文档、页面和验签结果
 // 入参: fonts 字体文件列表
 // 返回: error 错误信息
@@ -376,6 +423,7 @@ func (s *Session) SearchPage(index int, query string) ([]ofdgo.TextMatch, error)
 // 返回: DocumentInfo 文档信息
 func (s *Session) Summary() DocumentInfo {
 	info := DocumentInfo{
+		DocumentIndex:  s.Reader.DocumentIndex(),
 		Encryption:     s.encryptionInfo(),
 		Version:        s.Reader.Version(),
 		DocType:        s.Reader.DocType(),
@@ -384,6 +432,9 @@ func (s *Session) Summary() DocumentInfo {
 		Outlines:       s.doc.OutlineInfos(),
 		DetailsPending: true,
 	}
+	for index, body := range s.Reader.OFD.DocBody {
+		info.Documents = append(info.Documents, DocumentEntry{Index: index, Title: body.DocInfo.Title})
+	}
 	if docInfo, err := s.Reader.DocInfo(); err == nil && docInfo != nil {
 		info.Title = docInfo.Title
 		info.Author = docInfo.Author
@@ -788,7 +839,7 @@ func (s *Session) signatureInfos() ([]SignatureInfo, error) {
 		return s.signatures, s.signatureError
 	}
 	s.signaturesRead = true
-	reports, err := s.Reader.VerifySignatures()
+	reports, err := s.Reader.VerifyDocumentSignatures(s.Reader.DocumentIndex())
 	if err != nil {
 		s.signatureError = err
 		return nil, err

ofdgo_editor_annot.go

@@ -265,7 +265,7 @@ func (e *Editor) editAnnotations(index int, ids []string, edit func([]byte, *edi
 	if len(patches) != 0 {
 		parts[name] = editorPatchXML(data, patches)
 		if remaining == 0 {
-			docName, err := editorPageLocation(reader, nil, "", "/"+cleanPackagePath(reader.OFD.DocBody[0].DocRoot))
+			docName, err := editorPageLocation(reader, nil, "", "/"+cleanPackagePath(reader.OFD.DocBody[reader.documentIndex].DocRoot))
 			if err != nil {
 				return err
 			}

ofdgo_editor_annot_content.go

@@ -313,7 +313,7 @@ func (e *Editor) appendAnnotations(index int, annotations []byte) error {
 	}
 	parts := map[string][]byte{name: data, file: content}
 	if base.document.Annotations == "" {
-		docName := cleanPackagePath(reader.OFD.DocBody[0].DocRoot)
+		docName := cleanPackagePath(reader.OFD.DocBody[reader.documentIndex].DocRoot)
 		docData, err := reader.readFile(docName)
 		if err != nil {
 			return err
@@ -391,7 +391,7 @@ func (e *Editor) commitAnnotationParts(base *editorSource, parts map[string][]by
 		}
 		files[name] = data
 	}
-	reader := &Reader{Zip: base.reader.Zip, files: files}
+	reader := &Reader{Zip: base.reader.Zip, files: files, encryption: base.reader.encryption, documentIndex: base.reader.documentIndex}
 	if err := reader.initRoot(); err != nil {
 		return err
 	}

ofdgo_editor_annot_ops.go

@@ -140,7 +140,7 @@ func (e *Editor) PasteAnnotations(page int, selection *AnnotationSelection, dx,
 		edit.source.annotationStates = states
 		if len(selection.resources) != 0 {
 			reader := edit.source.reader
-			name := cleanPackagePath(reader.OFD.DocBody[0].DocRoot)
+			name := cleanPackagePath(reader.OFD.DocBody[reader.documentIndex].DocRoot)
 			data, err := reader.readFile(name)
 			if err != nil {
 				return err

ofdgo_editor_attachment.go

@@ -65,7 +65,7 @@ func (e *Editor) AddAttachment(name string, data []byte) (string, error) {
 		return "", err
 	}
 	entry = bytes.TrimPrefix(entry, []byte(xml.Header))
-	docName := cleanPackagePath(base.reader.OFD.DocBody[0].DocRoot)
+	docName := cleanPackagePath(base.reader.OFD.DocBody[base.reader.documentIndex].DocRoot)
 	docData, err := base.reader.readFile(docName)
 	if err != nil {
 		return "", err
@@ -190,7 +190,7 @@ func (e *Editor) editAttachment(id string, change func([]byte, *editorXML, map[s
 	if base == nil {
 		return fmt.Errorf("attachment not found: %s", id)
 	}
-	name := cleanPackagePath(base.reader.OFD.DocBody[0].DocRoot)
+	name := cleanPackagePath(base.reader.OFD.DocBody[base.reader.documentIndex].DocRoot)
 	external := strings.TrimSpace(base.document.Attachments.Path) != ""
 	if external {
 		name = base.reader.ResPath(base.document.Attachments.Path)

ofdgo_editor_import.go

@@ -224,7 +224,7 @@ func (e *Editor) ImportObjects(source *Editor, sourcePage int, ids []string, pag
 	return copied, err
 }
 
-// ImportPages 将来源主文档中的指定页面插入目标位置，保持输入顺序并作为一次撤销操作
+// ImportPages 将来源当前文档中的指定页面插入目标位置，保持输入顺序并作为一次撤销操作
 // 页面索引从0开始，at可等于当前页数；复制关联模板、注释、签章外观和实际引用的资源
 // 不导入来源元数据和目录，指向未选页面的跳转被移除；签名数据仅保留原始凭据，不代表合并后文档有效
 // 返回后可关闭来源Reader，目标原Reader的生命周期要求不变
@@ -450,7 +450,7 @@ func (e *Editor) prepareImport(source *Reader, doc *Document, selected map[strin
 	for _, resource := range e.resources {
 		m.files[resource.name] = nil
 	}
-	m.documentXML, err = m.readFile(source.ResPath(source.OFD.DocBody[0].DocRoot))
+	m.documentXML, err = m.readFile(source.ResPath(source.OFD.DocBody[source.documentIndex].DocRoot))
 	if err != nil {
 		return nil, nil, err
 	}
@@ -530,7 +530,7 @@ func (m *editorPageImport) readFile(name string) ([]byte, error) {
 // outlines 筛选指向导入页面的目录树并复用标准动作迁移
 // 返回: []byte 目录片段, error 错误信息
 func (m *editorPageImport) outlines() ([]byte, error) {
-	name := m.reader.ResPath(m.reader.OFD.DocBody[0].DocRoot)
+	name := m.reader.ResPath(m.reader.OFD.DocBody[m.reader.documentIndex].DocRoot)
 	data, err := m.readFile(name)
 	if err != nil {
 		return nil, err
@@ -1132,7 +1132,7 @@ func (m *editorPageImport) attachment(id string) (string, error) {
 	if _, exists := m.attachments[id]; exists {
 		return m.id(id), nil
 	}
-	name := m.reader.ResPath(m.reader.OFD.DocBody[0].DocRoot)
+	name := m.reader.ResPath(m.reader.OFD.DocBody[m.reader.documentIndex].DocRoot)
 	if m.doc.Attachments.Path != "" {
 		name = m.reader.ResPath(m.doc.Attachments.Path)
 	}
@@ -1215,7 +1215,7 @@ func (m *editorPageImport) merge(base *editorSource, refs []Page, annotations, s
 		files = make(map[string][]byte)
 	}
 	maps.Copy(files, m.files)
-	name := base.reader.ResPath(base.reader.OFD.DocBody[0].DocRoot)
+	name := base.reader.ResPath(base.reader.OFD.DocBody[base.reader.documentIndex].DocRoot)
 	if file, ok := base.reader.packageFile(name); ok {
 		name = cleanPackagePath(file.Name)
 	}
@@ -1318,10 +1318,10 @@ func (m *editorPageImport) merge(base *editorSource, refs []Page, annotations, s
 			if file, ok := base.reader.packageFile(name); ok {
 				name = cleanPackagePath(file.Name)
 			}
-			files[name] = editorXMLSetText(ofd, root.child("DocBody"), [][2]string{{"Signatures", loc}})
+			files[name] = editorXMLSetText(ofd, root.childAt("DocBody", base.reader.documentIndex), [][2]string{{"Signatures", loc}})
 		}
 	}
-	reader := &Reader{Zip: base.reader.Zip, files: files}
+	reader := &Reader{Zip: base.reader.Zip, files: files, encryption: base.reader.encryption, documentIndex: base.reader.documentIndex}
 	if err := reader.initRoot(); err != nil {
 		return nil, err
 	}

ofdgo_editor_metadata.go

@@ -29,7 +29,7 @@ func (e *Editor) sourceInfoXML() ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	data, info, err := editorDocInfoXML(data, e.source.fallbackDocID)
+	data, info, err := editorDocInfoXML(data, e.source.fallbackDocID, e.source.reader.documentIndex)
 	if err != nil {
 		return nil, err
 	}
@@ -50,16 +50,16 @@ func (e *Editor) sourceInfoXML() ([]byte, error) {
 		if err != nil {
 			return nil, err
 		}
-		return editorCustomDatas(data, root.child("DocBody").child("DocInfo"), after.CustomDatas)
+		return editorCustomDatas(data, root.childAt("DocBody", e.source.reader.documentIndex).child("DocInfo"), after.CustomDatas)
 	}
 	return data, nil
 }
 
-// editorCreatorXML 更新首份文档的制作软件，移除原软件版本，保留其余根索引内容
+// editorCreatorXML 更新指定文档的制作软件，移除原软件版本，保留其余根索引内容
-// 入参: data 当前根索引XML, docID 缺少文档描述时使用的标识
+// 入参: data 当前根索引XML, docID 缺少文档描述时使用的标识, index 文档索引
 // 返回: []byte 修改后的XML, error 解析错误
-func editorCreatorXML(data []byte, docID string) ([]byte, error) {
+func editorCreatorXML(data []byte, docID string, index int) ([]byte, error) {
-	data, info, err := editorDocInfoXML(data, docID)
+	data, info, err := editorDocInfoXML(data, docID, index)
 	if err != nil {
 		return nil, err
 	}
@@ -67,14 +67,14 @@ func editorCreatorXML(data []byte, docID string) ([]byte, error) {
 }
 
 // editorDocInfoXML 获取文档描述，修改缺少描述的源文件时补建标准容器及标识
-// 入参: data 根索引XML, docID 缺少文档描述时使用的标识
+// 入参: data 根索引XML, docID 缺少文档描述时使用的标识, index 文档索引
 // 返回: []byte 根索引XML, *editorXML 描述节点, error 解析错误
-func editorDocInfoXML(data []byte, docID string) ([]byte, *editorXML, error) {
+func editorDocInfoXML(data []byte, docID string, index int) ([]byte, *editorXML, error) {
 	root, err := parseEditorXML(data)
 	if err != nil {
 		return nil, nil, err
 	}
-	body := root.child("DocBody")
+	body := root.childAt("DocBody", index)
 	if body == nil {
 		return nil, nil, fmt.Errorf("document has no DocBody")
 	}
@@ -90,7 +90,7 @@ func editorDocInfoXML(data []byte, docID string) ([]byte, *editorXML, error) {
 	if err != nil {
 		return nil, nil, err
 	}
-	return data, root.child("DocBody").child("DocInfo"), nil
+	return data, root.childAt("DocBody", index).child("DocInfo"), nil
 }
 
 // editorCustomDatas 更新自定义字段，保留原字段及容器的扩展内容

ofdgo_editor_open.go

@@ -108,7 +108,7 @@ type PageCapabilities struct {
 	Resize bool
 }
 
-// Editor 打开主文档进行保真编辑，不修改输入包，不以权限声明或签名限制编辑
+// Editor 打开当前文档进行保真编辑，不修改输入包，不以权限声明或签名限制编辑
 // 原权限和签名数据保留，修改受保护内容会使原签名失效，不重新签名
 // 页面按需解析，未修改条目直接保留；编辑器及其Reader快照使用期间不得关闭输入Reader
 // 返回: *Editor 编辑器, error 错误信息
@@ -205,7 +205,7 @@ func (c ObjectCapabilities) editError() error {
 }
 
 // cloneEditorReader 复用已验证的只读包索引，独立保存可变文档与读取缓存
-// 入参: reader 已加载主文档的阅读器
+// 入参: reader 已加载当前文档的阅读器
 // 返回: *Reader 不拥有输入文件的独立阅读器
 func cloneEditorReader(reader *Reader) *Reader {
 	next := *reader

ofdgo_editor_outline.go

@@ -264,7 +264,7 @@ func (e *Editor) outlineXML() ([]byte, error) {
 	}
 	if e.source != nil {
 		reader := e.source.reader
-		data, err := reader.readFile(reader.ResPath(reader.OFD.DocBody[0].DocRoot))
+		data, err := reader.readFile(reader.ResPath(reader.OFD.DocBody[reader.documentIndex].DocRoot))
 		if err != nil {
 			return nil, err
 		}

ofdgo_editor_package.go

@@ -99,7 +99,7 @@ func (e *Editor) sourceParts(progress editorProgress) (map[string][]byte, error)
 	}
 	pagesChanged := !slices.Equal(pageRefs, source.document.Pages.Page)
 	if pagesChanged || len(resourceFiles) != 0 || len(parts) != 0 && e.maxID != source.document.CommonData.MaxUnitID {
-		name := reader.ResPath(reader.OFD.DocBody[0].DocRoot)
+		name := reader.ResPath(reader.OFD.DocBody[reader.documentIndex].DocRoot)
 		data, err := reader.readFile(name)
 		if err != nil {
 			return nil, err
@@ -199,7 +199,7 @@ func (e *Editor) sourceParts(progress editorProgress) (map[string][]byte, error)
 		parts["OFD.xml"] = data
 	}
 	if e.outlines != nil {
-		name := reader.ResPath(reader.OFD.DocBody[0].DocRoot)
+		name := reader.ResPath(reader.OFD.DocBody[reader.documentIndex].DocRoot)
 		data, ok := parts[name]
 		if !ok {
 			var err error
@@ -468,7 +468,7 @@ func (e *Editor) writeSource(writer io.Writer, fonts map[string][]byte, progress
 				return 0, err
 			}
 		}
-		data, err = editorCreatorXML(data, e.source.fallbackDocID)
+		data, err = editorCreatorXML(data, e.source.fallbackDocID, reader.documentIndex)
 		if err != nil {
 			return 0, err
 		}
@@ -592,7 +592,7 @@ func (e *Editor) sourceReader(progress editorProgress) (*Reader, error) {
 		files = make(map[string][]byte)
 	}
 	maps.Copy(files, parts)
-	reader := &Reader{Zip: e.source.reader.Zip, files: files, encryption: e.encryption}
+	reader := &Reader{Zip: e.source.reader.Zip, files: files, encryption: e.encryption, documentIndex: e.source.reader.documentIndex}
 	if err := reader.initRoot(); err != nil {
 		return nil, err
 	}

ofdgo_editor_pages.go

@@ -21,7 +21,7 @@ import (
 )
 
 // prunePageReferences 在输出快照中删除已移除页面的标准引用，不修改历史快照或其他文档
-// 沿主文档、页面、模板、资源、注释和签名索引检查，不进入附件、私有扩展和签名原始凭据
+// 沿当前文档、页面、模板、资源、注释和签名索引检查，不进入附件、私有扩展和签名原始凭据
 // 入参: parts 输出覆盖条目
 // 返回: error 读取或解析错误
 func (e *Editor) prunePageReferences(parts map[string][]byte) error {
@@ -48,7 +48,7 @@ func (e *Editor) prunePageReferences(parts map[string][]byte) error {
 			bookmarks[bookmark.Name] = true
 		}
 	}
-	queue := []string{reader.ResPath(reader.OFD.DocBody[0].DocRoot)}
+	queue := []string{reader.ResPath(reader.OFD.DocBody[reader.documentIndex].DocRoot)}
 	if name := e.source.document.Signatures; name != "" {
 		queue = append(queue, reader.ResPath(name))
 	}

ofdgo_editor_resources.go

@@ -37,10 +37,11 @@ type editorResourceRefs struct {
 // compactSourceResources 在保存副本中清理无引用字体、图片和已删除附件，并裁剪可完整确认用字的原有字体
 // 按GB/T33190-2016附录A检查标识和路径引用，包括模板、注释、底纹、裁剪、版本和其他文档
 // 全包检查保留孤立XML中的引用；未知命名空间、扩展数据或无法解析的XML使本次清理跳过
+// 多文档包保留原资源，避免独立文档的同号资源和共享文件被误删或裁剪
 // 入参: parts 已修改和新增的包内条目, progress 保存进度回调
 // 返回: map[string]bool 可移除的二进制条目, error 读取错误
 func (e *Editor) compactSourceResources(parts map[string][]byte, progress editorProgress) (map[string]bool, error) {
-	if e.output != nil && e.output.protected {
+	if e.source.reader.DocumentCount() > 1 || e.output != nil && e.output.protected {
 		return nil, nil
 	}
 	if len(parts) == 0 && e.revision == 0 && (e.output == nil || e.output.options.Mode == CompressionUnchanged) {

ofdgo_editor_xml.go

@@ -84,9 +84,19 @@ func parseEditorXML(data []byte) (*editorXML, error) {
 // 入参: name 节点名称
 // 返回: *editorXML 节点，不存在时为nil
 func (n *editorXML) child(name string) *editorXML {
+	return n.childAt(name, 0)
+}
+
+// childAt 查找指定序号的OFD直接子节点
+// 入参: name 节点名称, index 从0开始的节点序号
+// 返回: *editorXML 节点，不存在时为nil
+func (n *editorXML) childAt(name string, index int) *editorXML {
 	for _, child := range n.children {
 		if child.name.Local == name && (child.name.Space == n.name.Space || child.name.Space == ofdNamespace || child.name.Space == "") {
-			return child
+			if index == 0 {
+				return child
+			}
+			index--
 		}
 	}
 	return nil

ofdgo_reader.go

@@ -46,6 +46,7 @@ type Reader struct {
 	compositeGraphicUnitCache map[string]*CompositeGraphicUnit
 	pageHeaderCache           map[string]PageContent
 	doc                       *Document
+	documentIndex             int
 	Stamps                    map[string][]Stamp
 	Annots                    map[string][]Annotation
 	annotationFiles           map[string][]string
@@ -67,16 +68,49 @@ func (r *Reader) Close() error {
 	return nil
 }
 
-// Doc 获取主文档结构
+// DocumentCount 获取包内文档数量
+// 返回: int 文档数量
+func (r *Reader) DocumentCount() int {
+	if r.OFD == nil {
+		return 0
+	}
+	return len(r.OFD.DocBody)
+}
+
+// DocumentIndex 获取当前文档索引，从0开始
+// 返回: int 文档索引
+func (r *Reader) DocumentIndex() int {
+	return r.documentIndex
+}
+
+// Document 创建指定文档的独立阅读器，不改变当前文档或混用资源缓存
+// 返回的阅读器不关闭输入文件，使用期间不得关闭持有输入文件的原阅读器
+// 入参: index 文档索引，从0开始
+// 返回: *Reader 文档阅读器, error 错误信息
+func (r *Reader) Document(index int) (*Reader, error) {
+	if index < 0 || index >= r.DocumentCount() {
+		return nil, fmt.Errorf("document index %d out of range", index)
+	}
+	next := &Reader{Path: r.Path, Zip: r.Zip, files: r.files, encryption: r.encryption, documentIndex: index}
+	if err := next.initRoot(); err != nil {
+		return nil, err
+	}
+	if _, err := next.Doc(); err != nil {
+		return nil, err
+	}
+	return next, nil
+}
+
+// Doc 获取当前文档结构
 // 返回: *Document 文档结构, error 错误信息
 func (r *Reader) Doc() (*Document, error) {
 	if r.doc != nil {
 		return r.doc, nil
 	}
-	if r.OFD == nil || len(r.OFD.DocBody) == 0 {
+	if r.OFD == nil || r.documentIndex < 0 || r.documentIndex >= len(r.OFD.DocBody) {
 		return nil, fmt.Errorf("no docbody found")
 	}
-	docAttr := r.OFD.DocBody[0]
+	docAttr := r.OFD.DocBody[r.documentIndex]
 	docRootPath := docAttr.DocRoot
 	r.RootDir = path.Dir(docRootPath)
 	data, err := r.readFile(docRootPath)
@@ -197,10 +231,10 @@ func (r *Reader) DocType() string {
 // DocInfo 获取文档元数据
 // 返回: *DocInfo 元数据, error 错误信息
 func (r *Reader) DocInfo() (*DocInfo, error) {
-	if r.OFD == nil || len(r.OFD.DocBody) == 0 {
+	if r.OFD == nil || r.documentIndex < 0 || r.documentIndex >= len(r.OFD.DocBody) {
 		return nil, fmt.Errorf("no docbody found")
 	}
-	return &r.OFD.DocBody[0].DocInfo, nil
+	return &r.OFD.DocBody[r.documentIndex].DocInfo, nil
 }
 
 // Permissions 获取文档权限信息

ofdgo_sign_verify.go

@@ -299,7 +299,7 @@ func (r *Reader) VerifyDocumentSignatures(index int, opts ...SignatureVerifyOpti
 	}
 	body := r.OFD.DocBody[index]
 	options.DocIndex, options.DocRoot = index, r.signatureCoveragePath(body.DocRoot)
-	if index == 0 && r.doc != nil && r.doc.Signatures == "" {
+	if index == r.documentIndex && r.doc != nil && r.doc.Signatures == "" {
 		return nil, nil
 	}
 	data, err := r.readFile(body.DocRoot)
@@ -316,7 +316,10 @@ func (r *Reader) VerifyDocumentSignatures(index int, opts ...SignatureVerifyOpti
 	if doc.Signatures == "" {
 		return nil, nil
 	}
-	view := *r
+	view := &Reader{Zip: r.Zip, files: r.files, encryption: r.encryption, documentIndex: index}
+	if err := view.initRoot(); err != nil {
+		return nil, err
+	}
 	view.doc, view.RootDir = &doc, path.Dir(body.DocRoot)
 	sigListPath := view.ResPath(doc.Signatures)
 	data, err = view.readFile(sigListPath)

ofdgo_sign_write.go

@@ -109,6 +109,12 @@ func SignEditorTo(writer io.Writer, editor *Editor, options SignatureWriteOption
 	if err != nil {
 		return 0, err
 	}
+	if editor.source != nil {
+		r, err = r.Document(editor.source.reader.DocumentIndex())
+		if err != nil {
+			return 0, err
+		}
+	}
 	r.encryption = editor.encryption
 	options.progress = editorProgress(editor.OnWriteProgress)
 	return r.SignTo(writer, options)
@@ -167,7 +173,7 @@ func signatureWriteOutput(r *Reader, options SignatureWriteOptions) ([]byte, err
 	if err := options.progress.report("sign", 0, 1); err != nil {
 		return nil, err
 	}
-	data, err := signatureWritePackage(parts, options)
+	data, err := signatureWritePackage(parts, options, r.DocumentIndex())
 	if err != nil {
 		return nil, err
 	}
@@ -213,27 +219,49 @@ func signatureWriteParts(r *Reader) (map[string][]byte, error) {
 
 // signatureWritePackage 完成输出优化后计算签名，不改写已有签名保护的资源
 // 签名目录采用Sign_N兼容OFDRW容器，标识使用独立的sN签章域
-// 入参: parts 独立包文件, options 签署选项
+// 入参: parts 独立包文件, options 签署选项, index 文档索引
 // 返回: []byte 完整包, error 错误信息
-func signatureWritePackage(parts map[string][]byte, options SignatureWriteOptions) ([]byte, error) {
+func signatureWritePackage(parts map[string][]byte, options SignatureWriteOptions, index int) ([]byte, error) {
 	if err := options.Compression.Validate(); err != nil {
 		return nil, err
 	}
 	if options.Mode != SignatureAppend && options.Mode != SignatureReplace {
 		return nil, fmt.Errorf("unsupported signature write mode")
 	}
-	r := &Reader{files: parts}
+	r := &Reader{files: parts, documentIndex: index}
 	if err := r.initRoot(); err != nil {
 		return nil, err
 	}
-	if len(r.OFD.DocBody) != 1 {
-		return nil, fmt.Errorf("signature writing requires exactly one document")
-	}
 	doc, err := r.Doc()
 	if err != nil {
 		return nil, err
 	}
-	if options.Compression.Mode != CompressionUnchanged && doc.Signatures == "" {
+	protected := make(map[string][]byte)
+	for other := range r.OFD.DocBody {
+		if other == index {
+			continue
+		}
+		view, err := r.Document(other)
+		if err != nil {
+			return nil, err
+		}
+		if view.doc.Signatures == "" {
+			continue
+		}
+		reports, err := r.VerifyDocumentSignatures(other)
+		if err != nil {
+			return nil, err
+		}
+		for _, report := range reports {
+			if report.Error != "" {
+				return nil, fmt.Errorf("cannot preserve document %d signature: %s", other, report.Error)
+			}
+			for _, ref := range report.References {
+				protected[ref.Path] = bytes.Clone(parts[ref.Path])
+			}
+		}
+	}
+	if options.Compression.Mode != CompressionUnchanged && doc.Signatures == "" && len(protected) == 0 {
 		images, err := r.Images(context.Background())
 		if err != nil {
 			return nil, err
@@ -271,7 +299,7 @@ func signatureWritePackage(parts map[string][]byte, options SignatureWriteOption
 				delete(parts, name)
 			}
 		}
-		r = &Reader{files: parts}
+		r = &Reader{files: parts, documentIndex: index}
 		if err := r.initRoot(); err != nil {
 			return nil, err
 		}
@@ -307,7 +335,7 @@ func signatureWritePackage(parts map[string][]byte, options SignatureWriteOption
 	verifyOptions := append([]SignatureVerifyOption(nil), options.ExistingVerifyOptions...)
 	verifyOptions = append(verifyOptions, WithSignatureCert(identity.cert.Raw))
 	if options.Mode == SignatureAppend && oldCount > 0 {
-		reports, err := r.VerifySignatures(verifyOptions...)
+		reports, err := r.VerifyDocumentSignatures(index, verifyOptions...)
 		if err != nil {
 			return nil, err
 		}
@@ -330,7 +358,7 @@ func signatureWritePackage(parts map[string][]byte, options SignatureWriteOption
 		if err != nil {
 			return nil, err
 		}
-		body := root.child("DocBody")
+		body := root.childAt("DocBody", index)
 		if body == nil {
 			return nil, fmt.Errorf("missing document body")
 		}
@@ -411,6 +439,11 @@ func signatureWritePackage(parts map[string][]byte, options SignatureWriteOption
 	if err != nil {
 		return nil, err
 	}
+	for name, before := range protected {
+		if !bytes.Equal(before, parts[name]) {
+			return nil, fmt.Errorf("another document signature protects %s", name)
+		}
+	}
 	output, err := signatureWriteZIP(parts, options.Compression)
 	if err != nil {
 		return nil, err
@@ -419,7 +452,7 @@ func signatureWritePackage(parts map[string][]byte, options SignatureWriteOption
 	if err != nil {
 		return nil, err
 	}
-	reports, err := check.VerifySignatures(verifyOptions...)
+	reports, err := check.VerifyDocumentSignatures(index, verifyOptions...)
 	if err != nil {
 		return nil, err
 	}