feat(转换能力): 补齐目录导入，规范导航转换

ofdgo_pdf.go

@@ -215,6 +215,9 @@ func ImportPDF(ctx context.Context, source io.ReaderAt, size int64, options PDFI
 	}
 	if len(editor.pages) != 0 {
 		importer.page = -1
+		if err := importer.outlines(ctx); err != nil {
+			return nil, PDFImportReport{}, fmt.Errorf("import PDF outlines: %w", err)
+		}
 		if err := importer.documentOpenActions(ctx); err != nil {
 			return nil, PDFImportReport{}, fmt.Errorf("import PDF document actions: %w", err)
 		}

ofdgo_pdf_link.go

@@ -406,8 +406,14 @@ func (p *pdfImporter) linkAction(annotation pdfgo.Annotation, strict bool, curre
 			case pdfgo.Name("LastPage"):
 				index = len(p.editor.pages) - 1
 			case pdfgo.Name("NextPage"):
+				if index < 0 {
+					return nil, &pdfgo.UnsupportedError{Feature: "relative page action without a fixed current page"}
+				}
 				index = min(index+1, len(p.editor.pages)-1)
 			case pdfgo.Name("PrevPage"):
+				if index < 0 {
+					return nil, &pdfgo.UnsupportedError{Feature: "relative page action without a fixed current page"}
+				}
 				index = max(index-1, 0)
 			default:
 				return nil, nil

ofdgo_pdf_outline.go

@@ -0,0 +1,122 @@
+// 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"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"strconv"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// outlines 按先序批量转换目录，保留层级、展开状态和动作顺序
+// 入参: ctx 取消上下文
+// 返回: error 严格模式转换错误或取消错误
+func (p *pdfImporter) outlines(ctx context.Context) error {
+	count := 0
+	data, err := encodeOFDXMLContext(ctx, func(x *ofdXML) {
+		x.root("Outlines", nil)
+		depth := 0
+		err := p.reader.WalkOutlines(ctx, func(level int, item pdfgo.OutlineItem) error {
+			actions, err := p.outlineActions(ctx, item)
+			if err != nil {
+				if p.warning == nil || ctx.Err() != nil || errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+					return err
+				}
+				p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF outline %q actions not transferred to OFD: %v", item.Title, err)})
+				actions = nil
+			}
+			for depth > level {
+				x.end("OutlineElem")
+				depth--
+			}
+			attrs := ofdAttrs{{Name: xml.Name{Local: "Title"}, Value: item.Title}}
+			attrs.add("Expanded", strconv.FormatBool(item.Expanded))
+			x.start("OutlineElem", attrs)
+			x.actions(actions)
+			depth++
+			count++
+			return x.err
+		})
+		if err != nil {
+			x.err = err
+			return
+		}
+		for depth > 0 {
+			x.end("OutlineElem")
+			depth--
+		}
+		x.end("Outlines")
+	})
+	if err != nil {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		if p.warning == nil || errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+			return err
+		}
+		p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF outlines not transferred to OFD: %v", err)})
+		return nil
+	}
+	if count > 0 {
+		p.editor.outlines = bytes.TrimPrefix(data, []byte(xml.Header))
+	}
+	return nil
+}
+
+// outlineActions 转换目录目标及动作链，不为无目标节点补充跳转
+// 入参: ctx 取消上下文, item PDF目录节点
+// 返回: []Action OFD动作序列, error 动作或取消错误
+func (p *pdfImporter) outlineActions(ctx context.Context, item pdfgo.OutlineItem) ([]Action, error) {
+	object, err := p.reader.Resolve(item.Action)
+	if err != nil {
+		return nil, err
+	}
+	dest, err := p.reader.Resolve(item.Destination)
+	if err != nil {
+		return nil, err
+	}
+	if dest != nil {
+		if object != nil {
+			return nil, fmt.Errorf("PDF outline has both destination and action")
+		}
+		object = pdfgo.Dictionary{"S": pdfgo.Name("GoTo"), "D": dest}
+	}
+	currentPage := -1
+	var actions []Action
+	err = p.reader.WalkActions(ctx, object, func(info pdfgo.ActionInfo) error {
+		action, err := p.linkAction(pdfgo.Annotation{Dictionary: pdfgo.Dictionary{"A": info.Dictionary}}, p.warning == nil, &currentPage)
+		if err != nil {
+			var unsupported *pdfgo.UnsupportedError
+			if p.warning != nil && (errors.As(err, &unsupported) || errors.Is(err, pdfgo.ErrInvalidDestination) || errors.Is(err, pdfgo.ErrInvalidAction)) {
+				p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF outline action not transferred to OFD: %v", err)})
+				currentPage = -1
+				return nil
+			}
+			return err
+		}
+		if action != nil {
+			actions = append(actions, *action)
+		} else {
+			currentPage = -1
+		}
+		return nil
+	})
+	return actions, err
+}