feat(阅读编辑): 完善组合编辑与正文注解交互，修复页面定位和侧栏闪烁

ofdgo_editor_composite_group.go

@@ -0,0 +1,236 @@
+// 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"
+	"encoding/xml"
+	"fmt"
+	"maps"
+	"slices"
+)
+
+// GroupCompositeObjects 组合内部同一容器的连续成员，保留标识、绘制顺序及共享资源
+// 入参: page 页面索引, path 父路径, indexes 至少两个成员序号
+// 返回: int 新组合序号, error 错误信息
+func (e *Editor) GroupCompositeObjects(page int, path ObjectPath, indexes []int) (int, error) {
+	if len(indexes) < 2 {
+		return 0, fmt.Errorf("grouping requires at least two objects")
+	}
+	var result int
+	err := e.editCompositeObjects(page, path, indexes, func(_ *Renderer, nodes []*editorCompositeNode, members []CompositeMember) error {
+		for _, member := range members {
+			if !member.Capabilities.Copy || !member.Capabilities.Order {
+				return fmt.Errorf("composite member cannot be grouped")
+			}
+		}
+		slices.SortFunc(nodes, func(a, b *editorCompositeNode) int { return a.index - b.index })
+		siblings := nodes[0].siblings()
+		first := slices.Index(siblings, nodes[0])
+		var content []byte
+		for i, node := range nodes {
+			if first+i >= len(siblings) || siblings[first+i] != node {
+				return fmt.Errorf("grouping requires consecutive members in the same container")
+			}
+			content = append(content, bytes.TrimPrefix(node.data, []byte(xml.Header))...)
+		}
+		content, err := editorXMLContainer("Content", nil, content)
+		if err != nil {
+			return err
+		}
+		content, err = editorXMLContainer("CompositeObject", ofdAttrs{{Name: xml.Name{Local: "ID"}, Value: e.nextID()}, {Name: xml.Name{Local: "Boundary"}, Value: "0 0 1 1"}}, bytes.TrimPrefix(content, []byte(xml.Header)))
+		if err != nil {
+			return err
+		}
+		for i, node := range nodes {
+			var replacement []byte
+			if i == 0 {
+				replacement = bytes.TrimPrefix(content, []byte(xml.Header))
+			}
+			node.owner.patches = append(node.owner.patches, editorXMLPatch{node.span.start, node.span.end, replacement})
+		}
+		result = nodes[0].index
+		return nil
+	})
+	return result, err
+}
+
+// UngroupCompositeObject 展开内部组合，隔离引用资源并保留父容器的样式和裁剪
+// 入参: page 页面索引, path 父路径, index 组合序号
+// 返回: []int 展开后的成员序号, error 错误信息
+func (e *Editor) UngroupCompositeObject(page int, path ObjectPath, index int) ([]int, error) {
+	var result []int
+	err := e.editCompositeObjects(page, path, []int{index}, func(renderer *Renderer, nodes []*editorCompositeNode, members []CompositeMember) error {
+		node := nodes[0]
+		if !members[0].Capabilities.Order {
+			return fmt.Errorf("composite container cannot be reordered")
+		}
+		return e.ungroupCompositeNode(renderer, node, func(objects []GraphicObject) error {
+			var content []byte
+			for i, object := range objects {
+				content = append(content, object.origin.data...)
+				maps.Copy(node.owner.states, object.CompositeGraphicUnit.states)
+				node.owner.states[editorObjectID(object)] = object.state
+				result = append(result, index+i)
+			}
+			delete(node.owner.states, editorObjectID(node.object))
+			node.owner.patches = append(node.owner.patches, editorXMLPatch{node.span.start, node.span.end, content})
+			return nil
+		})
+	})
+	return result, err
+}
+
+// ungroupCompositeNode 将组合展开至所在坐标系，祖先透明度和裁剪仅由原父级应用一次
+// 入参: renderer 当前读取器, node 待展开组合, replace 原子替换回调
+// 返回: error 错误信息
+func (e *Editor) ungroupCompositeNode(renderer *Renderer, node *editorCompositeNode, replace func([]GraphicObject) error) error {
+	if !e.compositeUngroupable(node.node) {
+		return fmt.Errorf("group container cannot be removed without losing attributes")
+	}
+	copy, err := newEditorCompositeNode(node.data)
+	if err != nil {
+		return err
+	}
+	copy.setStates(node.states)
+	if !node.boundaryInCTM {
+		if err := copy.convertCoordinates(node.parent, true); err != nil {
+			return err
+		}
+	}
+	copy.parent, copy.boundaryInCTM, copy.visible = IdentityMatrix, true, true
+	copy.defaults, copy.drawParams = node.defaults, node.drawParams
+	members, err := e.compositeMembers(copy, renderer.Reader, renderer, make(map[string]bool))
+	if err != nil {
+		return err
+	}
+	if len(members) == 0 {
+		return fmt.Errorf("group has no objects")
+	}
+	for _, member := range members {
+		if !member.transformable() || !editorXMLCopyable(member.node) {
+			return fmt.Errorf("group member cannot be expanded")
+		}
+	}
+	return e.pasteCompositeSelection(&CompositeSelection{editor: e, nodes: members}, func(objects []GraphicObject) error {
+		ids := make(map[string]string)
+		if copy.ref != nil {
+			for _, object := range objects {
+				if err := e.collectCompositeIDs(object.origin.node, ids); err != nil {
+					return err
+				}
+			}
+		}
+		for i, object := range objects {
+			data := object.origin.data
+			if len(ids) != 0 {
+				data, err = editorXMLRemapIDs(data, object.origin.node, ids)
+				if err != nil {
+					return err
+				}
+			}
+			member, err := newEditorCompositeNode(data)
+			if err != nil {
+				return err
+			}
+			states := maps.Clone(object.CompositeGraphicUnit.states)
+			if states == nil {
+				states = make(map[string]editorCompositeState)
+			}
+			states[editorObjectID(object)] = object.state
+			if len(ids) != 0 {
+				states = remapCompositeStates(states, ids)
+			}
+			if object.Type == "CompositeObject" || object.Type == "CompositeGraphicUnit" {
+				if err := member.convertCoordinates(IdentityMatrix, true); err != nil {
+					return err
+				}
+			}
+			if !node.boundaryInCTM {
+				if err := member.convertCoordinates(node.parent, false); err != nil {
+					return err
+				}
+			}
+			member.node.parent = &editorXML{name: xml.Name{Local: "Layer"}, parent: &editorXML{name: xml.Name{Local: "Content"}}}
+			member.object.state = states[editorObjectID(member.object)]
+			member.object.TextObject.layout = member.object.state.layout
+			member.object.CompositeGraphicUnit.states = states
+			member.object.origin = &editorObjectOrigin{editor: e, data: member.data, node: member.node, object: member.object}
+			objects[i] = member.object
+		}
+		return replace(objects)
+	})
+}
+
+// compositeUngroupable 检查待移除的容器及引用链，子对象原文不展开重写
+// 入参: node 组合节点
+// 返回: bool 是否可解组
+func (e *Editor) compositeUngroupable(node *editorXML) bool {
+	seen := make(map[string]bool)
+	for {
+		if !editorUngroupable(node) {
+			return false
+		}
+		id := node.attr("ResourceID")
+		if id == "" {
+			return true
+		}
+		if seen[id] {
+			return false
+		}
+		seen[id] = true
+		resource, err := e.compositeDefinition(id)
+		if err != nil {
+			return false
+		}
+		node = resource.node
+	}
+}
+
+// compositeDefinition 读取复合资源原文，不加载图片或字体数据
+// 入参: id 资源标识
+// 返回: *editorCompositeNode 定义节点, error 错误信息
+func (e *Editor) compositeDefinition(id string) (*editorCompositeNode, error) {
+	var data []byte
+	for _, resource := range e.resources {
+		if resource.composite == id {
+			data = resource.data
+			break
+		}
+	}
+	if data == nil && e.source != nil {
+		var err error
+		data, err = e.source.reader.readFile(e.source.reader.resourceFiles[id])
+		if err != nil {
+			return nil, err
+		}
+	}
+	root, err := parseEditorXML(data)
+	if err != nil {
+		return nil, err
+	}
+	if units := root.child("CompositeGraphicUnits"); units != nil {
+		for _, unit := range units.children {
+			if unit.name.Local == "CompositeGraphicUnit" && unit.attr("ID") == id {
+				fragment, err := editorXMLStandalone(data[unit.start:unit.end], unit)
+				if err != nil {
+					return nil, err
+				}
+				return newEditorCompositeNode(fragment)
+			}
+		}
+	}
+	return nil, fmt.Errorf("composite resource %q not found", id)
+}