feat(编辑能力): 修复复制页面后删除原页可能导致的字体、图片丢失问题

ofdgo_editor_pages.go

@@ -0,0 +1,167 @@
+// 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 (
+	"fmt"
+	"strings"
+)
+
+// 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
+// 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 {
+	removed := make(map[string]bool)
+	for id := range e.source.pages {
+		removed[id] = true
+	}
+	for _, page := range e.pages {
+		delete(removed, page.ID)
+	}
+	if len(removed) == 0 {
+		return nil
+	}
+	reader := e.source.reader
+	bookmarks := make(map[string]bool)
+	for _, bookmark := range e.source.document.Bookmarks.Bookmark {
+		if removed[bookmark.Dest.PageID] {
+			bookmarks[bookmark.Name] = true
+		}
+	}
+	queue := []string{reader.ResPath(reader.OFD.DocBody[0].DocRoot)}
+	if name := e.source.document.Signatures; name != "" {
+		queue = append(queue, reader.ResPath(name))
+	}
+	seen := make(map[string]bool)
+	for len(queue) > 0 {
+		name := queue[0]
+		queue = queue[1:]
+		if seen[strings.ToLower(name)] {
+			continue
+		}
+		seen[strings.ToLower(name)] = true
+		data, ok := parts[name]
+		if !ok {
+			var err error
+			data, err = reader.readFile(name)
+			if err != nil {
+				return err
+			}
+		}
+		root, err := parseEditorXML(data)
+		if err != nil {
+			return err
+		}
+		var patches []editorXMLPatch
+		var walk func(*editorXML) error
+		walk = func(node *editorXML) error {
+			if node.name.Space != "" && node.name.Space != ofdNamespace && node.name.Space != "http://www.ofdspec.org" {
+				return nil
+			}
+			remove := false
+			switch node.name.Local {
+			case "Action":
+				if target := node.child("Goto"); target != nil {
+					if dest := target.child("Dest"); dest != nil {
+						remove = removed[dest.attr("PageID")]
+					} else if bookmark := target.child("Bookmark"); bookmark != nil {
+						remove = bookmarks[bookmark.attr("Name")]
+					}
+				}
+			case "Bookmark":
+				if node.parent != nil && node.parent.name.Local == "Bookmarks" {
+					remove = bookmarks[node.attr("Name")]
+				}
+			case "Page":
+				if root.name.Local == "Annotations" {
+					remove = removed[node.attr("PageID")]
+				}
+			case "Dest":
+				remove = removed[node.attr("PageID")]
+			case "StampAnnot":
+				remove = removed[node.attr("PageRef")]
+			case "Extension":
+				remove = removed[node.attr("RefId")]
+			}
+			if remove {
+				patches = append(patches, editorXMLPatch{start: node.start, end: node.end})
+				return nil
+			}
+			var location string
+			switch node.name.Local {
+			case "Page", "TemplatePage", "Signature":
+				if node.parent != nil && (node.parent.name.Local == "Pages" || node.parent.name.Local == "CommonData" || node.parent.name.Local == "Signatures") {
+					location = node.attr("BaseLoc")
+				}
+			case "PublicRes", "DocumentRes", "PageRes", "Annotations", "Extensions":
+				if len(node.children) == 0 {
+					location = strings.TrimSpace(editorImportText(data, node))
+				}
+			case "FileLoc":
+				if root.name.Local == "Annotations" {
+					location = strings.TrimSpace(editorImportText(data, node))
+				}
+			case "CustomTags", "ExtendData", "Data":
+				return nil
+			}
+			if location != "" {
+				resolved, err := editorPageLocation(reader, parts, name, location)
+				if err != nil {
+					return err
+				}
+				queue = append(queue, resolved)
+			}
+			start := len(patches)
+			for _, child := range node.children {
+				if err := walk(child); err != nil {
+					return err
+				}
+			}
+			if (node.name.Local == "Actions" || node.name.Local == "Bookmarks") && len(node.children) > 0 && len(patches)-start == len(node.children) {
+				empty := true
+				for i, child := range node.children {
+					empty = empty && patches[start+i].start == child.start && patches[start+i].end == child.end
+				}
+				if empty {
+					patches = append(patches[:start], editorXMLPatch{start: node.start, end: node.end})
+				}
+			}
+			return nil
+		}
+		if err := walk(root); err != nil {
+			return err
+		}
+		if len(patches) != 0 {
+			parts[name] = editorPatchXML(data, patches)
+		}
+	}
+	return nil
+}
+
+// editorPageLocation 解析标准XML引用，优先使用所在文件的相对路径
+// 入参: reader 原包, parts 覆盖条目, name 所在XML, value 路径
+// 返回: string 包内路径, error 路径不存在
+func editorPageLocation(reader *Reader, parts map[string][]byte, name, value string) (string, error) {
+	for _, candidate := range []string{resolveResourcePath(name, "", value), reader.ResPath(value)} {
+		if _, ok := parts[candidate]; ok || reader.files[candidate] != nil {
+			return candidate, nil
+		}
+		if file, ok := reader.packageFile(candidate); ok {
+			return cleanPackagePath(file.Name), nil
+		}
+	}
+	return "", fmt.Errorf("page reference %q in %s not found", value, name)
+}